Magnetic cork composites as biosorbents in dispersive solid-phase extraction of pesticides in water samples.

This study assessed the use of magnetic biosorbents in dispersive solid-phase extraction with a gas chromatograph-electron capture detector for the determination of trifluralin, chlorothalonil, transfluthrin, bromopropylate, and bifenthrin in water samples. To our knowledge, this is the first time that magnetic cork composites are used as an adsorbent in dispersive solid-phase extraction. The advantages of magnetic cork composites include their density regulation and high surface areas. The magnetic composites can be recovered using a magnetic field for desorption purposes, which can improve the operation process and reduce the extraction time. Moreover, the parameters affecting the extraction performances were optimized. The method has a limit of detection between 0.30 and 2.02 µg L-1. Good linearities (R2 > 0.99) were obtained in the linear range of 1.00 to 2000 µg L-1. The relative recoveries of the analytes in tap water, river, and lake water samples spiked at different concentrations ranged between 90% and 104%, and the relative standard deviations were less than 7.1%. Therefore, this study showed that Fe3O4/cork magnetic composites can be used as efficient and eco-friendly biosorbents in dispersive solid-phase extraction for the determination of pesticides in water samples. The use of these composites contributes to the current trend of green chemistry.

Magnetic Persimmon Leaf Composite: Preparation and Application in Magnetic Solid-Phase Extraction of Pesticides in Water Samples.

In recent years, the utilization of biomass materials for the removal and detection of water pollutants has garnered considerable attention. This study introduces, for the first time, the preparation of Fe3O4/persimmon leaf magnetic biomass composites. The magnetic composites were employed in a magnetic solid-phase extraction method, coupled with gas chromatography-electron capture detection (GC-ECD), for the analysis of four pesticides (trifluralin, triadimefon, permethrin, and fenvalerate) in environmental water samples. The innovative magnetic persimmon leaf composites were synthesized by in situ generation of Fe3O4 nanoparticles through coprecipitation and loaded onto persimmon leaves. These composites exhibit superparamagnetism with a saturation magnetization of 12.8 emu g-1, facilitating rapid phase separation using a magnetic field and reducing the extraction time to 10 min. Desorption can be achieved within 30 s by aspirating 20 times, eliminating the need for time-consuming and labor-intensive experimental steps like filtration and centrifugation. The specific surface area of the magnetic composite adsorbent increased from 1.3279 m2 g-1 for the original persimmon leaf to 5.4688 m2 g-1. The abundant hydroxyl and carboxyl groups on the composites provide ample adsorption sites, resulting in adsorption capacities ranging from 55.056 mg g-1 to 73.095 mg g-1 for the studied pesticides. The composites exhibited extraction recoveries ranging from 80% to 90% for the studied pesticides. Compared to certain previously reported MSPE methods, this approach achieves equivalent or higher extraction recoveries in a shorter operation time, demonstrating enhanced efficiency and convenience. Good linearity of the target analytes was obtained within the range of 0.75-1500 µg L-1, with a determination of coefficient (R2) greater than 0.999. These findings contribute to the use of magnetic persimmon leaf biomass materials as effective and environmentally friendly adsorbents for pollutant determination in water samples.

A Study on the Relationship between the Dynamic Behaviors of the Leader and Group Performance during Creativity.

The leader is considered to play key roles such as organization or management in promoting group creativity. Previous studies focused more on the psychological and behavioral characteristics rather than on the dynamic behaviors of leaders in group activity. In this study, two experiments were conducted to respectively explore the effects of emergent and elected leaders' problem-solving related utterances and turn-taking in conversation on group creativity. The results of Experiment 1 showed that, for emergent leaders, none of the utterances about problem solving of leaders was different from that of followers and leaders' utterances about retrospective summary were positively related to the appropriateness of group creativity; meanwhile, the frequency of turns of leaders was higher than that of followers and was positively related with the appropriateness of group creativity. The results of Experiment 2 showed that, for elected leaders, the utterances about problem analysis, strategy planning, control and reflection, and retrospective summary of leaders were more than that of followers and leaders' utterances about viewpoint generation were positively related to both novelty and appropriateness, while the frequency of turns of leaders was neither different from followers nor related to the novelty and appropriateness. This study focused on the dynamic behaviors of leaders in interpersonal interaction and revealed the role of leaders in group creativity.

International trade, Chinese foreign direct investment and green innovation impact on consumption-based CO2 emissions: empirical estimation focusing on BRI countries.

Recently, The literature has directed concern towards the consumption-based carbon emission (CCE), which is adjusted for trade. This study aims to examine trade, Chinese foreign direct investment (CFDI), and green innovation (GI) to portray the overall impact of the factors influencing CCE in belt and road initiative (BRI) countries over the period 2003 to 2018. By employing the cross-sectional autoregressive distributed lag (CS-ARDL) model, the findings reveal that CFDI and imports positively influence the CCE both in the long run as well as in the short run. The results of GI and exports are found negatively significant in the host countries. The study further employs augmented mean group (AMG) and common correlated mean group (CCEMG) estimators for robustness. Like CS-ARDL, the outcomes of both estimators reveal the same findings that imports and CCE hold a positive relationship in all sample regions. Overall, the study exposes that strategies related to CCE accredited by trade and FDI should recognize their environmental repercussions and implement policies that are environmentally friendly such as green innovation and renewable energy sources to achieve a sustainable development.

Increased or decreased? Interpersonal neural synchronization in group creation.

Group creation is the process by which group members collaborate to produce novel and useful ideas or products, including ideas generation and evaluation. However, the interpersonal neural mechanism of group creation during natural communication remains unclear. In this study, two groups of same-sex dyads with similar individual creativity collaborated to complete the Product Improvement Task (creative condition) and the Item Purchase Plan Task (control condition), respectively. Functional near-infrared spectroscopy (fNIRS) was used to record both members' neural activity in the left prefrontal (lPFC) and right temporal-parietal junction (rTPJ) regions during the task. Considering that the role asymmetry of group members may have an impact on interpersonal neural patterns, we identified leaders and followers in the dyads based on participant performance. The results showed that leaders and followers in the creative condition had significantly lower interpersonal neural synchronization (INS) in the right superior temporal gyrus-left superior frontal gyrus, right supramarginal gyrus-left superior frontal gyrus, and right supramarginal gyrus-left middle frontal gyrus than in the control condition. Partial multivariate Granger causality analyses revealed the influence between dyads was bidirectional but was significantly stronger from the leaders to the followers than the other direction. In addition, in the creative task, the INS was significantly associated with novelty, appropriateness, and conflict of views. All these findings suggest that the ideas generation and ideas evaluation process in group creation have poor interpersonal neural activity coupling due to factors such as the difficulty of understanding novel ideas. However, performances may be improved when groups can better integrate views and reach collective understanding, intentions, and goals. Furthermore, we found that there are differences in the dynamics of INS in different brain regions. The INS related to the novelty of the group creation decreased in the early stages, while the INS related to the appropriateness decreased in the middle stages. Our findings reveal a unique interpersonal neural pattern of group creation processes in the context of natural communication.

On-site sample pretreatment: Natural deep eutectic solvent-based multiple air-assisted liquid-liquid microextraction.

Chemical protection is one of the most important methods to control forest pests. Since pesticides used in chemical protection might have significant adverse effects on aquatic organisms, it is essential to monitor and detect trace pesticides in environmental water. In this study, an on-site natural deep eutectic solvent-based multiple air-assisted liquid-liquid microextraction coupled with gas chromatography-electron capture detection was developed for determining triadimefon, bifenthrin, bromopropylate, and permethrin in water samples in the forest. A series of menthol-based deep eutectic solvents were synthesized for the first time to find green and efficient extractants. Moreover, a deep eutectic solvent with a 1:2 molar ratio of DL-menthol to citric acid was selected as the extractant due to its high stability and extraction performance. A portable modular array device based on air-assisted liquid-liquid microextraction was designed and manufactured to enable the simultaneous pretreatment of several samples. Although no electric equipment is required throughout the process, up to six samples were pretreated on-site within 20 min. Moreover, the average sample pretreatment time was less than 3.5 min, and the process was substantially simplified and enhanced. In addition, the parameters affecting the extraction performance were optimized. The extraction recoveries were in the range of 92-95% by using the optimized conditions, and the relative standard deviations of the intra-device, inter-device, intra-day, and inter-day factors were all less than 4.9%. The detection limits of the method ranged from 0.34 to 3.3 µg L-1. Good linearities (R2>0.999) were shown in the linear range of 1.13 to 2500 µg L-1 for the studied pesticides. Moreover, the proposed method was proved to be highly environmentally friendly by the Analytical Eco-Scale and Green Analytical Procedure Index. In summary, the proposed method is green, efficient, and flexible for on-site water sample pretreatment. The fact that tedious operations can be converted into standard operations provides a new perspective for on-site sample processing.

Switchable hydrophilic solvent-based dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography for the determination of four types of sulfonylurea herbicides in soils.

In this study, switchable hydrophilic solvent-based dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography was developed for the determination of four sulfonylurea herbicides in soils. For the first time, the sample pretreatment was achieved due to the similar acid-base status of sulfonylurea herbicides and switchable hydrophilic solvent. In the extraction step, sulfonylurea herbicides were extracted as anions and transferred to an alkaline solution with switchable hydrophilic solvent anions. In the concentration step, two types of anions were transformed to their molecular state after the aqueous solution was acidified. In addition, the dispersion and microextraction processes were completed efficiently with the simultaneous formation of analytes and extractants. The factors affecting the extraction performance were optimized. Under the optimized conditions, good linearity was observed for each herbicide with correlation coefficients ranging from 0.9952 to 0.9978. The limits of detection were in the range of 0.1-0.2 µg/g. Moreover, the relative recoveries of the sulfonylurea herbicides at spiking levels of 0.5, 1, and 1.5 µg/g in soil samples were between 75 and 111% (relative standard deviations: 0.4-11.4%). Therefore, the proposed method in this study could be successfully applied to the analysis of four types of sulfonylurea herbicides in soil samples.

The use of internet language enhances creative performance.

Internet language is a creative product of the rapid development of computer-mediated communication. The present study was to investigate whether the use of Internet language enhances creative problem solving. In Study 1, sixty-two selected participants were equally divided into two groups according to their use experience of Chinese Internet language, and then both more and less experienced groups were asked to complete Chinese remote associates test and Chinese chengyu riddles. Results showed that the more experienced group performed significantly better in both the creative tasks. In Study 2, forty-six participants were randomly divided into two groups. The experimental group was asked to learn Chinese Internet Language, while the control group was asked to learn scientific terminology. Two groups completed the aforementioned creative tasks in pretest and post-test. Results showed that the interaction between the group and test order was significant in Chinese chengyu riddle solving, in which the experimental group had a significantly higher average score in post-test than pretest. And there was no difference for the control group. These findings supported that Internet language use benefited creative problem solving, and it might be a convenient way in the practice of promoting creativity.

The Effect of "Novelty Input" and "Novelty Output" on Boredom During Home Quarantine in the COVID-19 Pandemic: The Moderating Effects of Trait Creativity.

Governments have adopted strict home quarantine measures during the COVID-19 pandemic. A monotonous, barren, and under-stimulating environment can cause state boredom, and people often deal with boredom via novelty-seeking behavior. Novelty-seeking behavior can be divided into "novelty input" and "novelty output." The former refers to obtaining novel information such as browsing the Web; the latter refers to engaging in creative behavior such as literary creation. This study explores the relationship between two types of novelty-seeking behavior and individual state boredom during home quarantine, along with the moderation effect of trait creativity. The study sample consists of 582 Chinese college students who were quarantined at home during the COVID-19 pandemic. Participants completed the Multidimensional State Boredom Scale, the Williams Creativity Aptitude Test, and self-compiled questionnaires of novelty input and novelty output. The results show that there is no significant relationship between novelty input or novelty output and boredom during the COVID-19 quarantine. Trait creativity is found to negatively moderate the relationship between the two means of novelty seeking and boredom. Specifically, novelty output negatively predicts the state boredom of individuals with high creativity, while novelty input positively predicts the state boredom of individuals with low creativity. Our findings suggest that different novelty-seeking behaviors may have different effects on the boredom level of individuals with high versus low creativity during quarantine. During a quarantine period, individuals should avoid excessively engaging in novelty input behaviors aimed at escaping boring situations.

Dynamic cognitive processes of text-picture integration revealed by event-related potentials.

The integration of text and picture is the core of multimedia information processing. Relevant theories suggest that text and picture are processed through different channels in the early stage, and integrated in the late stage of processing. Based on these theories, the current study adopted measures of event-related potentials to examine the cognitive and neural processes of text-picture integration. The results showed that in the early stage of text-picture integration, picture processing evoked a more negative N1 over the occipital area and a N300 over the prefrontal area, which might reflect the discrimination process of visual stimuli and the imagery representation of the picture, respectively; in the late stage, the text-picture induced a N400 in the central area and an LPC over the central, parietal and temporal areas, which might be associated with the semantic activation and integration of text and picture, respectively. These results not only provide support for existing theories, but also further elucidate the dynamic neural processing of text-picture integration in terms of its temporal and spatial characteristics.

A New GPS SNR-based Combination Approach for Land Surface Snow Depth Monitoring.

Snow is not only a critical storage component in the hydrologic cycle but also an important data for climate research; however, snowfall observations are only sparsely available. Signal-to-noise ratio (SNR) has recently been applied for sensing snow depths. Most studies only consider either global positioning system (GPS) L1 or L2 SNR data. In the current study, a new snow depth estimation approach is proposed using multipath reflectometry and SNR combination of GPS triple frequency (i.e. L1, L2 and L5) signals. The SNR combination method describes the relationship between antenna height variation and spectral peak frequency. Snow depths are retrieved from the SNR combination data at YEL2 and KIRU sites and validated by comparing it with in situ observations. The elevation angle ranges from 5° to 25°. The correlations for the two sites are 0.99 and 0.97. The performance of the new approach is assessed by comparing it with existing models. The proposed approach presents a high correlation of 0.95 and an accuracy (in terms of Root Mean Square Error) improvement of over 30%. Findings indicate that the new approach could potentially be applied to monitor snow depths and may serve as a reference for building multi-system and multi-frequency global navigation satellite system reflectometry models.

In vitro selection of DNA aptamers recognizing drug-resistant ovarian cancer by cell-SELEX.

Ovarian cancer is regarded as the most lethal gynecologic malignancy with poor prognosis and high mortality rate. Drug-resistance was thought to be the main obstacle to improving overall survival rate of ovarian cancer. New ligands for drug-resistant ovarian cancer cells have potential for the development of diagnosis and therapy of ovarian cancer. In present work, we reported two aptamers, HF3-58 and HA5-68 generated by cell-SELEX, against a paclitaxel-resistant ovarian cancer cell line (A2780T). Both two aptamers exhibited high selectivity and strong affinity to target cells with low nanomolar dissociation constants. The binding of aptamers to target cells was independent of divalent ions, and was tolerant of incubation temperature and nucleases in serum. Molecular targets of the two aptamers were preliminarily demonstrated to be two different glycoproteins on cell surface of A2780T cells. Owing to the structure stability and high resistance to nuclease, these two aptamers had good performance in the detection of drug-resistant ovarian cancer cells in human serum.

Genetic interaction of hnRNPA2B1 and DNAJB6 in a Drosophila model of multisystem proteinopathy.

Adult-onset inherited myopathies with similar pathological features, including hereditary inclusion body myopathy (hIBM) and limb-girdle muscular dystrophy (LGMD), are a genetically heterogeneous group of muscle diseases. It is unclear whether these inherited myopathies initiated by mutations in distinct classes of genes are etiologically related. Here, we exploit a genetic model system to establish a mechanistic link between diseases caused by mutations in two distinct genes, hnRNPA2B1 and DNAJB6. Hrb98DE and mrj are the Drosophila melanogaster homologs of human hnRNPA2B1 and DNAJB6, respectively. We introduced disease-homologous mutations to Hrb98DE, thus capturing mutation-dependent phenotypes in a genetically tractable model system. Ectopic expression of the disease-associated mutant form of hnRNPA2B1 or Hrb98DE in fly muscle resulted in progressive, age-dependent cytoplasmic inclusion pathology, as observed in humans with hnRNPA2B1-related myopathy. Cytoplasmic inclusions consisted of hnRNPA2B1 or Hrb98DE protein in association with the stress granule marker ROX8 and additional endogenous RNA-binding proteins (RBPs), suggesting that these pathological inclusions are related to stress granules. Notably, TDP-43 was also recruited to these cytoplasmic inclusions. Remarkably, overexpression of MRJ rescued this phenotype and suppressed the formation of cytoplasmic inclusions, whereas reduction of endogenous MRJ by a classical loss of function allele enhanced it. Moreover, wild-type, but not disease-associated, mutant forms of MRJ interacted with RBPs after heat shock and prevented their accumulation in aggregates. These results indicate both genetic and physical interactions between disease-linked RBPs and DNAJB6/mrj, suggesting etiologic overlap between the pathogenesis of hIBM and LGMD initiated by mutations in hnRNPA2B1 and DNAJB6.

In situ metathesis reaction combined with liquid-phase microextraction based on the solidification of sedimentary ionic liquids for the determination of pyrethroid insecticides in water samples.

A novel dispersion liquid-liquid microextraction method based on the solidification of sedimentary ionic liquids (SSIL-DLLME), in which an in situ metathesis reaction forms an ionic liquid (IL) extraction phase, was developed to determine four pyrethroid insecticides (i.e., permethrin, cyhalothrin, fenpropathrin, and transfluthrin) in water followed by separation using high-performance liquid chromatography. In the developed method, in situ DLLME was used to enhance the extraction efficiency and yield. After centrifugation, the extraction solvent, tributyldodecylphosphonium hexafluorophosphate ([P44412][PF6]), was easily collected by solidification in the bottom of the tube. The effects of various experimental parameters, the quantity of tributyldodecylphosphonium bromide ([P44412]Br), the molar ratio of [P44412]Br to potassium hexafluorophosphate (KPF6), the ionic strength, the temperature of the sample solution, and the centrifugation time, were optimized using a Plackett-Burman design to identify the significant factors that affected the extraction efficiency. These significant factors were then optimized using a central composite design. Under the optimized conditions, the recoveries of the four pyrethroid insecticides at four spiked levels ranged from 87.1% to 101.7%, with relative standard deviations (RSDs) ranging from 0.1% to 5.5%. At concentration levels between 1 and 500 µg/L, good linearity was obtained, with coefficients of determination greater than 0.9995. The limits of detection (LODs) for the four pyrethroid insecticides were in the range of 0.71-1.54 µg/L. The developed method was then successfully used for the determination of pyrethroid insecticides in environmental samples.

Extensible automated dispersive liquid-liquid microextraction.

In this study, a convenient and extensible automated ionic liquid-based in situ dispersive liquid-liquid microextraction (automated IL-based in situ DLLME) was developed. 1-Octyl-3-methylimidazolium bis[(trifluoromethane)sulfonyl]imide ([C8MIM]NTf2) is formed through the reaction between [C8MIM]Cl and lithium bis[(trifluoromethane)sulfonyl]imide (LiNTf2) to extract the analytes. Using a fully automatic SPE workstation, special SPE columns packed with nonwoven polypropylene (NWPP) fiber, and a modified operation program, the procedures of the IL-based in situ DLLME, including the collection of a water sample, injection of an ion exchange solvent, phase separation of the emulsified solution, elution of the retained extraction phase, and collection of the eluent into vials, can be performed automatically. The developed approach, coupled with high-performance liquid chromatography-diode array detection (HPLC-DAD), was successfully applied to the detection and concentration determination of benzoylurea (BU) insecticides in water samples. Parameters affecting the extraction performance were investigated and optimized. Under the optimized conditions, the proposed method achieved extraction recoveries of 80% to 89% for water samples. The limits of detection (LODs) of the method were in the range of 0.16-0.45 ng mL(-1). The intra-column and inter-column relative standard deviations (RSDs) were <8.6%. Good linearity (r>0.9986) was obtained over the calibration range from 2 to 500 ng mL(-1). The proposed method opens a new avenue for automated DLLME that not only greatly expands the range of viable extractants, especially functional ILs but also enhances its application for various detection methods. Furthermore, multiple samples can be processed simultaneously, which accelerates the sample preparation and allows the examination of a large number of samples.

Nonwoven polypropylene as a novel extractant phase holder for the determination of insecticides in environmental water samples.

In this work, a novel liquid-phase microextraction approach using nonwoven polypropylene as the extraction solvent holder was developed. Nonwoven polypropylene, a hydrophobic material, is widely used in the cleanup of oil spills. Due to its large surface area, efficient, and full extraction can be achieved. Nonwoven polypropylene containing an ionic liquid was used to extract benzoylurea insecticides (diflubenzuron, teflubenzuron, flufenoxuron, and chlorfluazuron) through vortex-assisted liquid-liquid microextraction. The parameters that affected the extraction efficiency included the type and volume of the extractant, the extraction time, the time and solvent volume for desorption and the mass and surface area of the nonwoven polypropylene. Under the optimized conditions, good linearity was obtained, with coefficients of determination greater than 0.9996, and the limit of detections of these compounds, calculated at S/N = 3, were in the range of 0.73-5.0 ng/mL. The recoveries of the four insecticides at two spiked levels ranged from 93.3 to 102.0%, with relative standard deviations of less than 4.0%. The proposed method was then successfully used for the rapid determination of benzoylurea insecticides in spiked real water samples before liquid chromatographic analysis. The procedure is simple, inexpensive, easy to execute, and can be widely used.

Optimization of dispersive liquid-liquid microextraction based on the solidification of floating organic droplets using an orthogonal array design and its application for the determination of fungicide concentrations in environmental water samples.

A dispersive liquid-liquid microextraction method based on the solidification of floating organic droplets was developed as a simple and sensitive method for the simultaneous determination of the concentrations of multiple fungicides (triazolone, chlorothalonil, cyprodinil, and trifloxystrobin) in water by high-performance liquid chromatography with variable-wavelength detection. After an approach varying one factor at a time was used, an orthogonal array design [L25 (5(5))] was employed to optimize the method and to determine the interactions between the parameters. The significance of the effects of the different factors was determined using analysis of variance. The results indicated that the extraction solvent volume significantly affects the efficiency of the extraction. Under optimal conditions, the relative standard deviation (n = 5) varied from 2.3 to 5.5% at 0.1 µg/mL for each analyte. Low limits of detection were obtained and ranged from 0.02 to 0.2 ng/mL. In addition, the proposed method was applied to the analysis of fungicides in real water samples. The results show that the dispersive liquid-liquid microextraction based on the solidification of floating organic droplets is a potential method for detecting fungicides in environmental water samples, with recoveries of the target analytes ranging from 70.1 to 102.5%.

Borohydride ionic liquids and borane/ionic-liquid solutions as hypergolic fuels with superior low ignition-delay times.

In propellant systems, fuels of choice continue to be hydrazine and its derivatives, even though they comprise a class of acutely carcinogenic and toxic substances which exhibit rather high vapor pressures and require expensive handling procedures and costly safety precautions. Hypergolic ionic liquids tend to have low volatility and high thermal and chemical stability, and often exhibit wide liquid ranges, which could allow the use of these substances as bipropellant fuels under a variety of conditions. A new family of borohydride ionic liquids and borane-ionic-liquid solutions is described which meets nearly all of the desired important criteria for well-performing fuels. They exhibit ignition-delay times that are superior to that of any known hypergolic ionic liquid and may thus be legitimate replacements for hydrazine and its derivatives.

Slow-injection ultrasound-assisted emulsification-microextraction for determination of phthalate esters in water.

A type of ultrasound-assisted emulsification-microextraction (USAEME) was applied for the extraction and determination of four phthalate esters (e.g., dimethyl phthalate, diethyl phthalate, dibutyl phthalate and benzyl butyl phthalate) in aqueous samples prior to quantification using HPLC-UV. The simultaneous injection of the extraction solvent and ultrasonication of the mixture results in an efficient extraction with the extractant well-dispersed in the sample. The parameters affecting the experimental results were analyzed and optimized through the design of the experiment. Using a central composite face-centered design, the results of 28 experimental data points were analyzed and validated. An optimal set of operating conditions was obtained using 40 µL of 1,1,2,2-tetrachloroethane and 1% NaCl subjected to 2.0 min of ultrasonication under natural pH. Under optimized conditions, the extractions resulted in analyte recoveries of 75-87% and high enrichment factors of 356-415. The calibration curves were linear, and the correlation coefficients ranged from 0.9992 to 0.9997 at concentrations of 5 to 300 µg L(-1). The RSDs (n = 5) were 5.6-7.9%. The limits of detection for the four phthalate esters ranged from 0.26 to 1.46 µg L(-1).

[Three-dimensional finite element study on the change of glossopharyngeum in patient with obstructive sleep apnea hypopnea syndrome during titrated mandible advancement].

OBJECTIVE: To construct a three-dimensional finite element model of the upper airway and adjacent structure of an obstructive sleep apnea hypopnea syndrome (OSAHS) patient for biomechanical analysis. And to study the influence of glossopharyngeum of an OSAHS patient with three-dimensional finite element model during titrated mandible advancement. METHODS: DICOM format image information of an OSAHS patient's upper airway was obtained by thin-section CT scanning and digital image processing were utilized to construct a three-dimensional finite element model by Mimics 10.0, Imageware 10.0 and Ansys software. The changes and the law of glossopharyngeum were observed by biomechanics and morphology after loading with titrated mandible advancement. RESULTS: A three-dimensional finite element model of the adjacent upper airway structure of OSAHS was established successfully. After loading, the transverse diameter of epiglottis tip of glossopharyngeum increased significantly, although the sagittal diameter decreased correspondingly. The principal stress was mainly distributed in anterior wall of the upper airway. The location of principal stress concentration did not change significantly with the increasing of distance. The stress of glossopharyngeum increased during titrated mandible advancement. CONCLUSION: A more precise three-dimensional finite model of upper airway and adjacent structure of an OSAHS patient is established and improved efficiency by Mimics, Imageware and Ansys software. The glossopharyngeum of finite element model of OSAHS is analyzed by titrated mandible advancement and can effectively show the relationship between mandible advancement and the glossopharyngeum.