Application of Robotics in Orthodontics: A Systematic Review.

Robotics has various applications in dentistry, particularly in orthodontics, although the potential use of these technologies is not yet clear. This review aims to summarize the application of robotics in orthodontics and clarify its function and scope in clinical practice. Original articles addressing the application of robotics in any area of orthodontic practice were included, and review articles were excluded. PubMed, Google Scholar, Scopus, and DOAJ were searched from June to August 2023. The risk of bias was established using the risk of bias in non-randomized studies (ROBINS) and certainty assessment tools following the grading of recommendations, assessment, development, and evaluation (GRADE) guidelines. A narrative synthesis of the data was generated and presented according to its application in surgical and non-surgical orthodontics. The search retrieved 2,106 articles, of which 16 articles were selected for final data synthesis of research conducted between 2011 and 2023 in Asia, Europe, and North America. The application of robotics in surgical orthodontics helps guide orthognathic surgeries by reducing the margin of error, but it does not replace the work of a clinician. In non-surgical orthodontics, robotics assists in performing customized bending of orthodontic wires and simulating orthodontic movements, but its application is expensive. The articles collected for this synthesis exhibited a low risk of bias and high certainty, and the results indicated that the advantages of the application of robotics in orthodontics outweigh the disadvantages. This project was self-financed, and a previous protocol was registered at the PROSPERO site (registration number: CRD42023463531).

Continuous Synthesis of a Macrocyclic Sulfite of Polyethylene Glycol by Cascaded Continuous Stirred Tank Reactors (CSTRs).

Invited for the cover of this issue is the group of Long Pan and co-workers at Asymchem Life Sciences (Tianjin) Co. Ltd. The image depicts a novel continuous process for the synthesis of a macrocyclic poly(ethylene glycol) (PEG) sulfite, the precursor to PEG macrocyclic sulfate, a useful building block in PEG chemistry. Read the full text of the article at 10.1002/chem.202304319.

Sources and transformations of riverine nitrogen across a coastal-plain river network of eastern China: New insights from multiple stable isotopes.

Riverine nitrogen pollution is ubiquitous and attracts considerable global attention. Nitrate is commonly the dominant total nitrogen (TN) constituent in surface and ground waters; thus, stable isotopes of nitrate (δ15N/δ18O-NO3-) are widely used to differentiate nitrate sources. However, δ15N/δ18O-NO3- approach fails to present a holistic perspective of nitrogen pollution for many coastal-plain river networks because diverse nitrogen species contribute to high TN loads. In this study, multiple isotopes, namely, δ15N/δ18O-NO3-, δ18O-H2O, δ15N-NH4+, δ15N-PN, and δ15Nbulk/δ18O/SP-N2O in the Wen-Rui Tang River, a typical coastal-plain river network of Eastern China, were investigated to identify transformation processes and sources of nitrogen. Then, a stable isotope analysis in R (SIAR) model-TN source apportionment method was developed to quantify the contributions of different nitrogen sources to riverine TN loads. Results showed that nitrogen pollution in the river network was serious with TN concentrations ranging from 1.71 to 8.09 mg/L (mean ± SD: 3.77 ± 1.39 mg/L). Ammonium, nitrate, and suspended particulate nitrogen were the most prominent nitrogen components during the study period, constituting 45.4 %, 28.9 %, and 19.9 % of TN, respectively. Multiple hydrochemical and isotopic analysis identified nitrification as the dominant N cycling process. Biological assimilation and denitrification were minor N cycling processes, whereas ammonia volatilization was deemed negligible. Isotopic evidence and SIAR modeling revealed municipal sewage was the dominant contributor to nitrogen pollution. Based on quantitative estimates from the SIAR model, nitrogen source contributions to the Wen-Rui Tang River watershed followed: municipal sewage (40.6 %) ≈ soil nitrogen (39.5 %) > nitrogen fertilizer (9.7 %) > atmospheric deposition (2.8 %) during wet season; and municipal sewage (59.1 %) > soil nitrogen (30.4 %) > nitrogen fertilizer (4.1 %) > atmospheric deposition (1.0 %) during dry season. This study provides a deeper understanding of nitrogen dynamics in eutrophic coastal-plain river networks, which informs strategies for efficient control and remediation of riverine nitrogen pollution.

Riverine nitrate source identification combining δ15N/δ18O-NO3- with Δ17O-NO3- and a nitrification 15N-enrichment factor in a drinking water source region.

Dual nitrate isotopes (δ15N/δ18O-NO3-) are an effective tool for tracing nitrate sources in freshwater systems worldwide. However, the initial δ15N/δ18O values of different nitrate sources might be altered by isotopic fractionation during nitrification, thereby limiting the efficiency of source apportionment results. This study integrated hydrochemical parameters, site-specific isotopic compositions of potential nitrate sources, multiple stable isotopes (δD/δ18O-H2O, δ15N/δ18O-NO3- and Δ17O-NO3-), soil incubation experiments assessing the nitrification 15N-enrichment factor (εN), and a Bayesian mixing model (MixSIAR) to reduce/eliminate the influence of 15N/18O-fractionations on nitrate source apportionment. Surface water samples from a typical drinking water source region were collected quarterly (June 2021 to March 2022). Nitrate concentrations ranged from 0.35 to 3.06 mg/L (mean = 0.78 ± 0.46 mg/L), constituting ∼70 % of total nitrogen. A MixSIAR model was developed based on δ15N/δ18O-NO3- values of surface waters and the incorporation of a nitrification εN (-6.9 ± 1.8 ‰). Model source apportionment followed: manure/sewage (46.2 ± 10.7 %) > soil organic nitrogen (32.3 ± 18.5 %) > nitrogen fertilizer (19.7 ± 13.1 %) > atmospheric deposition (1.8 ± 1.6 %). An additional MixSIAR model coupling δ15N/δ18O-NO3- with Δ17O-NO3- and εN was constructed to estimate the potential nitrate source contributions for the June 2021 water samples. Results revealed similar nitrate source contributions (manure/sewage = 43.4 ± 14.1 %, soil organic nitrogen = 29.3 ± 19.4 %, nitrogen fertilizer = 19.8 ± 13.8 %, atmospheric deposition = 7.5 ± 1.6 %) to the original MixSIAR model based on εN and δ15N/δ18O-NO3-. Finally, an uncertainty analysis indicated the MixSIAR model coupling δ15N/δ18O-NO3- with Δ17O-NO3- and εN performed better as it generated lower uncertainties with uncertainty index (UI90) of 0.435 compared with the MixSIAR model based on δ15N/δ18O-NO3- (UI90 = 0.522) and the MixSIAR model based on δ15N/δ18O-NO3- and εN (UI90 = 0.442).

Continuous Synthesis of a Macrocyclic Sulfite of Polyethylene Glycol by Cascaded Continuous Stirred Tank Reactors (CSTRs).

Many macrocyclic compounds are attractive drug-like molecules or intermediates due to their special properties. However, the bulk synthesis of such compounds are hindered by the necessity of using diluted solutions, in order to prevent intermolecular reactions that yields oligomer impurities, thereby resulting in a low production efficiency. Such challenge can be adequately addressed by using continuous reactors, allowing improved efficiency with smaller space footprints. In this work, we proposed a novel continuous process for the synthesis of a macrocyclic sulfite of tetraethylene glycol (PEG4-MCSi), which is a precursor to a very useful building block, PEG4-macrocyclic sulfate (PEG4-MCS). The basic reaction parameters, including stoichiometry and temperature, were first confirmed with small batch reactions, and the effectiveness of coiled reactors and continuous stirred tank reactors (CSTRs) were compared. Cascaded CSTRs were proven to be suitable, and the reaction parameters were subject to further optimization to give a robust continuous process. The process was then tested with 4 parallel runs for up to 64 h. Finally, the merits and demerits of batch and continuous reactions were also compared, demonstrating the suitability of latter in the bulk production of macrocyclic PEG-MCSi compounds.

Main-Chain Fluoropolymers with Alternating Sequence Control via Light-Driven Reversible-Deactivation Copolymerization in Batch and Flow.

Polymers with regulated alternating structures are attractive in practical applications, particularly for main-chain fluoropolymers. We for the first time enabled controlled fluoropolymer synthesis with alternating sequence regulation using a novel fluorinated xanthate agent via a light-driven process, which achieved on-demand copolymerization of chlorotrifluoroethylene and vinyl esters/amides under both batch and flow conditions at ambient pressure. This method creates a facile access to fluoropolymers with a broad fraction range of alternating units, low dispersities and high chain-end fidelity. Moreover, a two-step photo-flow platform was established to streamline the in-situ chain-extension toward unprecedented block copolymers continuously from fluoroethylene. Influences of structural control were illustrated with thermal and surface properties. We anticipate that this work will promote advanced material engineering with customized fluoropolymers.

Basic Amino Acid-Modified Lignin-Based Biomass Adjuvants: Synthesis, Emulsifying Activity, Ultraviolet Protection, and Controlled Release of Avermectin.

Avermectin (AVM) is a highly effective and safe biopesticide but is very sensitive to ultraviolet (UV) light and exhibits poor water solubility. Developing green and multifunctional adjuvants is important for the protection and controlled release of AVM. In this work, a number of water-soluble enzymatic hydrolysis lignins (W-EHLs) were prepared via grafting basic amino acids and used as emulsifiers with co-surfactants to prepare high-internal phase emulsions (HIPEs). The results showed that W-EHLs with co-surfactants could be prepared with HIPEs that contained 90 vol % green oil phases such as turpentine, and the stability of the HIPEs first increased and then decreased when the rate of grafting of basic amino acids on lignin increased from 0.26 to 1.46 mmol/g. The more polar oil droplets were less deformable due to their higher viscosity, thereby affording a stability advantage to HIPEs. Subsequently, the relations between the stability and interfacial viscoelasticity of the emulsion were effectively correlated by interfacial rheology, droplet size, and physical stability tests. The results showed that HIPEs with smaller droplets had poor fluidity and strong interfacial viscoelasticity due to their higher droplet packing density, which resulted in good macroscopic stability. Like the AVM carrier, the retention rate of AVM in HIPEs was 80.1% after UV radiation for 72 h, which represented the highest UV protection efficiency in AVM delivery systems. The release curves showed that the rate of release of AVM from HIPEs was adjusted by controlling the pH value of the medium. In addition, the release of HIPEs is completely in accord with both diffusion and the matrix erosion mechanism. The strategy could be extended to other sensitive pesticides and used to promote the development of sustainable agriculture.

Morphologic and Aerodynamic Changes of Upper Airway in Pediatric Hemifacial Microsomia Patients Undergoing Distraction Osteogenesis.

Current studies on hemifacial microsomia (HFM) patients undergoing unilateral distraction osteogenesis (DO) mainly confined to description of facial morphology. This study was to investigate the effect of unilateral DO on upper airway in pediatric HFM patients using computational fluid dynamics. The investigators implemented the present retrospective study composed of 20 patients (age 9.5 ±â€Š2.5 years, 11 males, 9 females) with moderate HFM performed unilateral DO on the ramus of mandible. Computational fluid dynamics models of the upper airway were obtained based on the computed tomography data sets which were taken before and 6 months after distraction. Morphologic and aerodynamic parameters were respectively computed and compared at peak inspiration. Paired t-tests were used to compare the differences between the before and after parameters with the significance set at P < 0.05. The authors observed that after DO, oropharynx and nasopharynx were the major expanded regions, average pressure increased in all cross-sections, average velocity decreased significantly except in the superior border of the epiglottis plane, and the airflow resistance significantly reduced in the whole upper airway (P < 0.05). The results indicate that unilateral DO may expand the constricted oropharynx and nasopharynx, obtain a relatively symmetrical airway shape and decrease the airflow resistance which consequently reduce the workload necessary for breathing and facilitate inspiration.

One-pot fabrication of antibacterial ß-cyclodextrin-based nanoparticles and their superfast, broad-spectrum adsorption towards pollutants.

The current water treatment technology is still based on low energy efficient processes due to the complex composition of wastewater. To achieve high energy efficiency, many micro-porous materials with complex functional groups have been fabricated because of their high pollutant adsorption capabilities. In this work, antibacterial ß-cyclodextrin-based nanoparticles (E-ß-CDN) were prepared via one-pot method to explore their adsorption performance to pollutants in wastewater. The resulting nanoparticles exhibited superfast adsorption kinetics to pollutants with removal efficiency of over 95% within 10 s. The nanoparticles also presented broad-spectrum adsorption to organic pollutants and heavy metal ions, and their maximum adsorption capacity was 3289.6 mg g-1 towards methyl orange (MO) and 970.8 mg g-1 towards Pb(II), much higher than that of many other adsorbents. Easy cyclic adsorption-desorption was another distinguishing feature of the nanoparticles, whose removal efficiency to these pollutants hardly varied after 10 cycles of regeneration. Interestingly, the resulting nanoparticles showed prominent antibacterial activity of 99.99% bacterial inhibitive rate against both gram-negative bacteria Escherichia coli (E. coli) and gram-positive bacteria Staphylococcus aureus (S. aureus). These results suggest that the resulting nanoparticles have great potential in the purification of the wastewater.

ß-Cyclodextrin-based hollow nanoparticles with excellent adsorption performance towards organic and inorganic pollutants.

In this work, ß-cyclodextrin (ß-CD) based hollow nanoparticles (denoted as ß-CDHN) with abundant active sites and high specific surface area were first fabricated via a facile one-step method. The ß-CDHN presented a maximum adsorption capacity of 2080.35, 427.35 and 120.48 mg g-1 towards the cationic dye methylene blue (MB), heavy metal ions (Pb2+) and bisphenol A (BPA), respectively, much higher than those of many other adsorbents. Furthermore, ß-CDHN also exhibited fast adsorption kinetics towards these pollutants with adsorption rate constants 6 to 200 times higher than those of activated carbon and other ß-CD-based adsorbents, meaning the former can remove these pollutants at a much faster adsorption rate than the latter adsorbents. More importantly, the removal efficiency of these pollutants on ß-CDHN almost remained stable after 10 regeneration cycles with favorable recyclability. The prepared ß-CDHN show great potential in practical applications due to their low costs and high efficiency in the treatment of organic and inorganic pollutants from wastewater.

Direct and Regioselective C-H Oxidative Difluoromethylation of Heteroarenes.

The difluoromethyl group (CF2H) is of great interest in the area of medicinal chemistry. However, the investigation of molecular scaffolds containing this group has been hampered by the limitation of synthetic methods for the introduction of CF2H into heteroarenes. Herein we disclose a new strategy for the direct introduction of a difluoromethyl group into heteroarenes via the copper-mediated C-H oxidative difluoromethylation of heteroarenes with TMSCF2H. This mild and regioselective method enables the convenient synthesis of a range of difluoromethylated heteroarenes in high yields. The usage of 9,10-phenanthrenequinone (PQ) as an oxidant is critical to the success of this new difluoromethylation reaction.

Fabrication of eco-friendly nanofibrous membranes functionalized with carboxymethyl-ß-cyclodextrin for efficient removal of methylene blue with good recyclability.

Considering the excellent thermo-mechanical properties, chemical stability and low cost of biodegradable aliphatic-aromatic copolyesters, they are an ideal matrix when functionalized for capturing pollutants in wastewater. In this work, biodegradable poly((butylene succinate-co-terephthalate)-co-serinol terephthalate) (PBSST) copolyesters with amino side group (-NH2) were first synthesized through copolymerization, followed by grafting carboxymethyl-ß-cyclodextrin (CM-ß-CD) into PBSST molecular chains via amidation reaction to prepare PBSST-g-ß-CD. The corresponding nanofibrous membranes were then fabricated by electrospinning as adsorbents for efficiently removing cationic dye methyl blue (MB) from aqueous solutions. The adsorption performance of the nanofibrous membranes was fitted well with pseudo-second-order model and Langmuir isotherm model. The maximum adsorption capacity was 543.48 mg g-1 for MB along with a removal efficiency of 98% after five regeneration cycles, indicating the high adsorption capacity and good recyclability of nanofibrous membranes. The adsorbents possess features of high adsorption capacity, eco-friendliness and easy operation, and exhibit great potential for disposing of printing-dying wastewater.

High-Throughput Chiral LC-MS/MS Method Using Overlapping Injection Mode for the Determination of Pantoprazole Enantiomers in Human Plasma with Application to Pharmacokinetic Study.

A sensitive and high-throughput chiral liquid chromatography-tandem mass spectrometry method was developed and validated for the quantification of R-pantoprazole and S-pantoprazole in human plasma. Sample extraction was carried out by using ethyl acetate liquid-liquid extraction in 96-well plate format. The separation of pantoprazole enantiomers was performed on a CHIRALCEL OJ-RH column and an overlapping injection mode was used to achieve a run time of 5.0 min/sample. The mobile phase consisted of 1) 10 mM ammonium acetate in methanol: acetonitrile (1:1, v/v) and 2) 20 mM ammonium acetate in water. Isocratic elution was used with flow rate at 500 µL/min. The enantiomers were quantified on a triple-quadrupole mass spectrometer under multiple reaction monitoring (MRM) mode with m/z 382.1/230.0 for pantoprazole and m/z 388.4/230.1 for pantoprazole-d7. Linearity from 20.0 to 5000 ng/mL was established for each enantiomer (r(2)  > 0.99). Extraction recovery ranged from 91.7% to 96.4% for R-pantoprazole and from 92.5% to 96.5% for S-pantoprazole and the IS-normalized matrix factor was 0.98 to 1.07 for R-pantoprazole and S-pantoprazole, respectively. The method was demonstrated with acceptable accuracy, precision, selectivity, and stability and the method was applied to support a pharmacokinetic study of a phase I clinical trial of racemic pantoprazole in healthy Chinese subjects. Chirality 28:569-575, 2016. © 2016 Wiley Periodicals, Inc.

Electronic storage capacity of ceria: role of peroxide in Aux supported on CeO2(111) facet and CO adsorption.

Density functional theory (DFT+U) was used to study the adsorption of Aux (x = 1-4) clusters on the defective CeO2(111) facet and CO adsorption on the corresponding Aux/CeO2-x catalyst, in this work Aux clusters are adsorbed onto the CeO2-x + superoxide/peroxide surface. When Au1 is supported on the CeO2(111) facet with an O vacancy, the strong electronegative Au(δ-) formed is not favorable for CO adsorption. When peroxide is adsorbed on the CeO2(111) facet with the O vacancy, Aux was oxidized, resulting in stable Aux adsorption on the defective ceria surface with peroxide, which promotes CO adsorption on the Aux/CeO2-x catalyst. With more Au atoms in supported Aux clusters, CO adsorption on this surface becomes stronger. During both the Au being supported on CeO2-x and CO being adsorbed on Aux/CeO2-x, CeO2 acts as an electron buffer that can store/release the electrons. These results provide a scientific understanding for the development of high-performance rare earth catalytic materials.

Evaluation of Tetrahydropalmatine Enantiomers on the Activity of Five Cytochrome P450 Isozymes in Rats Using a Liquid Chromatography / Mass Spectrometric Method and a Cocktail Approach.

The aim was to evaluate the effects of tetrahydropalmatine (THP) enantiomers on the activity of five cytochrome P450 (CYP450) isozymes in vivo. A liquid chromatography / mass spectrometric (LC-MS) method was developed for simultaneous determination of five specific probe substrates including metoprolol (2D6), caffeine (1A2), dapsone (3A4), chlorzoxazone (2E1), and tolbutamide (2C9) in rat plasma. Analytes were separated with the mobile phase consisting of 0.1% acetic acid aqueous solution and acetonitrile in a gradient elution. The mass spectrometric detection via selected ion monitoring (SIM) was operated in both positive ion mode (for metoprolol m/z 268, caffeine m/z 195, and dapsone m/z 249) and negative ion mode (for chlorzoxazone m/z 168 and tolbutamide m/z 269) in the same run. Linear correlation was obtained (r(2) > 0.99) over the concentration range of 0.050-25.0 µg/mL for caffeine and dapsone, 0.025-10.0 µg/mL for metoprolol, 0.050-50.0 µg/mL for chlorzoxazone, and 0.25-100.0 µg/mL for tolbutamide. Intra- and interday precision were less than 12.09%. The matrix effect ranged from 87.50% to 109.25% and the absolute recoveries were greater than 70%. The method was successfully applied to evaluate the effect of THP enantiomers on the activity of CYP450 isozymes by a cocktail approach. The pharmacokinetic results of five probe drugs indicated that there were stereoselective differences between the two THP enantiomers, i.e., d-THP had the potential to inhibit the activities of CYP2D6 and CYP1A2 isozymes, while l-THP inhibited CYP1A2 isozyme and induced CYP3A4 and CYP2C9 isozymes.

Rapid and sensitive liquid chromatography with tandem mass spectrometry method for the simultaneous determination of 11 major components of Yuanhu-Baizhi herb-pair in rat perfusion fluids.

A rapid and sensitive liquid chromatography with tandem mass spectrometry method has been developed and validated for the simultaneous quantification of 11 major compounds in Yuanhu-Bazhi herb-pair from a rat intestinal perfusion experiment, including eight alkaloids and three coumarins using diazepam as the internal standard. The analysis was performed on an Agilent Poroshell 120EC-C18 column using a gradient elution of acetonitrile/H2 O with 0.0015% formic acid and 2 mM ammonium formate buffer additive (pH 4.2). All compounds were detected by tandem mass spectrometry in positive ionization mode and quantified using multiple reaction monitoring mode. Good linearity in the related range of each compound was presented. The validation data, such as accuracy and precision, were within the required limits. The lower limit of quantification of each analyte was less than 10 ng/mL. Intra-day and inter-day precisions were less than 12.84%. The relative errors of accuracy were in the range of -13.31 to 13.19%. The recoveries of analytes were greater than 84.08%. The method has been successfully applied to an intestinal absorption study of major components following intestinal perfusion of Yuanhu-Bazhi herb-pair extract to rats.

A practical strategy for characterization of the metabolic profile of chiral drugs using combinatory liquid chromatography-mass spectrometric techniques: application to tetrahydropalmatine enantiomers and their metabolites in rat urine.

The characterization and quantification of the metabolites of chiral drugs still remain a great challenge due to the complexity of the metabolites and most of them are not commercially available. In this study, a practical approach based on the combinatory liquid chromatography-mass spectrometric techniques has been proposed for the evaluation of metabolism profiles and urinary excretion kinetics of chiral drugs and their metabolites. Racemic tetrahydropalmatine (rac-THP), a biologically active ingredient isolated from a traditional Chinese herb Rhizoma Corydalis, was chosen as the model chiral drug. Ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) was applied to characterize the metabolites of THP enantiomers in rat urine after administration of (+)-THP or (-)-THP. Accurate mass measurement was used to determine the elemental composition of metabolites and thus to confirm the proposed structures of these metabolites. More than 30 potential metabolites were found in rat urine, most of which were identified for the first time, and the metabolic pathways in vivo were involved in demethylation, oxidation, glucuronide conjugation and sulfation, etc. And the tridesmethlyzed metabolite and didesmethlyzed coupled with oxidation metabolite were found only in (+)-THP treated rats. Afterwards, a liquid chromatography tandem mass spectrometry (LC-QqQ/MS) assay was developed and validated for the determination of the urine level of THP enantiomers and their metabolites. Semi-quantification of three phase I metabolites and two phase II metabolites were performed. Enantiomeric (-/+) cumulative urinary excretion ratios of THP and its five metabolites were obtained, which indicated the stereoselective aspects of metabolites of THP enantiomers in vivo. The study demonstrated the enormous potential of this strategy for the qualitative characterization, quantitative assay and the stereoselectivity of chiral drugs and their metabolites.