Clear aligner treatment is a novel technique in current orthodontic practice.Distinct from traditional fixed orthodontic appliances,clear aligners have different material features and biomechanical characteristics and...Clear aligner treatment is a novel technique in current orthodontic practice.Distinct from traditional fixed orthodontic appliances,clear aligners have different material features and biomechanical characteristics and treatment efficiencies,presenting new clinical challenges.Therefore,a comprehensive and systematic description of the key clinical aspects of clear aligner treatment is essential to enhance treatment efficacy and facilitate the advancement and wide adoption of this new technique.This expert consensus discusses case selection and grading of treatment difficulty,principle of clear aligner therapy,clinical procedures and potential complications,which are crucial to the clinical success of clear aligner treatment.展开更多
Maxillary protrusion combined with mandibular retraction is a highly prevalent but extremely complex maxillofacial deformity that can have a serious negative impact on patients’facial aesthetics and mental health.The...Maxillary protrusion combined with mandibular retraction is a highly prevalent but extremely complex maxillofacial deformity that can have a serious negative impact on patients’facial aesthetics and mental health.The traditional orthodontic treatment strategy often involves extracting 4 first premolars and conventional fixed techniques,combined with mini-implant screws,to retract the anterior teeth and improve facial protrusion.In recent years,an invisible orthodontic technique,without brackets,has become increasingly popular.However,while an invisible aligner has been used in some cases with reasonable results,there remain significant challenges in achieving a perfect outcome.This case report presents an adolescent patient with bimaxillary protrusion and mandibular retrognathia.Based on the characteristics of the invisible aligners and the growth characteristics of the adolescent’s teeth and jawbone,we designed precise three-dimensional tooth movement and corresponding resistance/over-correction for each tooth,while utilizing the patient’s jawbone growth potential to promote rapid development of the mandible,accurately and efficiently correcting bimaxillary protrusion and skeletal mandibular retrognathia.The patient’s facial aesthetics,especially the lateral morphology,have been greatly improved,and various aesthetic indicators have also shown significant changes,and to the patient’s great benefit,invasive mini-implant screws were not used during the treatment.This case highlights the advantages of using invisible aligners in adolescent maxillary protrusion combined with mandibular retraction patients.Furthermore,comprehensive and accurate design combined with good application of growth potential can also enable invisible orthodontic technology to achieve perfect treatment effects in tooth extractions,providing clinical guidance for orthodontists.展开更多
The aim of this study was to evaluate and compare the colour stabilities of three types of orthodontic clear aligners exposed to staining agents in vitro. Sixty clear orthodontic aligners produced by three manufacture...The aim of this study was to evaluate and compare the colour stabilities of three types of orthodontic clear aligners exposed to staining agents in vitro. Sixty clear orthodontic aligners produced by three manufacturers （Invisalign, Angelalign, and Smartee） were immersed in three staining solutions （coffee, black tea, and red wine） and one control solution （distilled water）. After 12-h and 7-day immersions, the aligners were washed in an ultrasonic cleaner and measured with a colourimeter. The colour changes （△E＊） were calculated on the basis of the Commission Internationale de I＇Eclairage L＊a＊b＊ colour system （CIE L＊a＊b＊）, and the results were then converted into National Bureau of Standards （NBS） units. Fourier transformation infrared （FT-IR） spectroscopy and scanning electron microscopy （SEM） were conducted to observe the molecular and morphologic alterations to the aligner surfaces, respectively. The three types of aligners exhibited slight colour changes after 12 h of staining, with the exception of the Invisalign aligners stained with coffee. The Invisalign aligners exhibited significantly higher AE＊ values （ranging from 0.30 to 27.81） than those of the Angelalign and Smartee aligners （AE＊ values ranging from 0.33 to 1.89 and 0.32 to 1.61, respectively, P〈O.05）. IFT-IR analysis confirmed that the polymer-based structure of aligners did not exhibit significant chemical differences before and after the immersions. The SEM results revealed different surface alterations to the three types of aligner materials after the 7-day staining. The three types of aesthetic orthodontic appliances exhibited colour stability after the 12-h immersion, with the exception of the Invisalign aligners stained by coffee. The Invisalign aligners were more prone than the Angelalign and Smartee aligners to pigmentation. Aligner materials may be improved by considering aesthetic colour stability properties.展开更多
This study was aimed at analysing the mechanical characteristics of different mandibular extraction modes using a clear aligner.Three experimental schemes of different extraction patterns were designed to treat mandib...This study was aimed at analysing the mechanical characteristics of different mandibular extraction modes using a clear aligner.Three experimental schemes of different extraction patterns were designed to treat mandibular crowding,including extraction of one mandibular central incisor,bilateral first premolars,and bilateral second premolars.The stress distribution during the space closing was analysed using the finite element method.When a central incisor was extracted,a significant retraction force was found in the anterior region,in line with the design expectation.The posterior teeth,which were designed to move mesially,acted as anchorage for anterior retraction,and were subjected to a mesial force.The anterior teeth were retracted when the bilateral first premolars were extracted.The lateral incisors and canines were subjected to a significant distal force and moment,while the central incisors and canines were subjected to lingual forces and moments.Additionally,the canines were subjected to a non-designated intruding force.The molars were designed to move mesially when the bilateral second premolars were extracted.All molars were subjected to a significant mesial force,while the lingual force on the front teeth was slight.The bilateral second molars were subjected to non-design mesial moment and extrusive force.The bilateral first molars were subjected to a non-designated mesial moment,and the bilateral first premolars on both sides were subjected to non-designated intrusive force and distal moment.When one incisor was extracted,attachments on the anterior teeth had a controlling effect on the tooth axis,but the anterior teeth still tended to tilt.When the bilateral first premolars were extracted,the anterior teeth showed a tendency for lingual inclination.The risk of distal inclination of the canines and lingual inclination of the central incisor increased.When the bilateral second premolars were extracted and the posterior teeth were designed to move mesially,the teeth on both sides of the extraction sites showed an obvious bowing effect.展开更多
Advancements in next-generation sequencer(NGS)platforms have improved NGS sequence data production and reduced the cost involved,which has resulted in the production of a large amount of genome data.The downstream ana...Advancements in next-generation sequencer(NGS)platforms have improved NGS sequence data production and reduced the cost involved,which has resulted in the production of a large amount of genome data.The downstream analysis of multiple associated sequences has become a bottleneck for the growing genomic data due to storage and space utilization issues in the domain of bioinformatics.The traditional string-matching algorithms are efficient for small sized data sequences and cannot process large amounts of data for downstream analysis.This study proposes a novel bit-parallelism algorithm called BitmapAligner to overcome the issues faced due to a large number of sequences and to improve the speed and quality of multiple sequence alignment(MSA).The input files(sequences)tested over BitmapAligner can be easily managed and organized using the Hadoop distributed file system.The proposed aligner converts the test file(the whole genome sequence)into binaries of an equal length of the sequence,line by line,before the sequence alignment processing.The Hadoop distributed file system splits the larger files into blocks,based on a defined block size,which is 128 MB by default.BitmapAligner can accurately process the sequence alignment using the bitmask approach on large-scale sequences after sorting the data.The experimental results indicate that BitmapAligner operates in real time,with a large number of sequences.Moreover,BitmapAligner achieves the exact start and end positions of the pattern sequence to test the MSA application in the whole genome query sequence.The MSA’s accuracy is verified by the bitmask indexing property of the bit-parallelism extended shifts(BXS)algorithm.The dynamic and exact approach of the BXS algorithm is implemented through the MapReduce function of Apache Hadoop.Conversely,the traditional seeds-and-extend approach faces the risk of errors while identifying the pattern sequences’positions.Moreover,the proposed model resolves the largescale data challenges that are covered through MapReduce in the Hadoop framework.Hive,Yarn,HBase,Cassandra,and many other pertinent flavors are to be used in the future for data structuring and annotations on the top layer of Hadoop since Hadoop is primarily used for data organization and handles text documents.展开更多
With the increasing demand for beauty and health,clear aligners(CAs)have been widely applied among patients with malocclusion.However,patients treated with CAs also face some potential complications,such as deminerali...With the increasing demand for beauty and health,clear aligners(CAs)have been widely applied among patients with malocclusion.However,patients treated with CAs also face some potential complications,such as demineralization,dental caries,and periodontal diseases.In addition,some patients have additional needs to improve their quality of life,such as bleaching teeth.In order to prevent or solve these problems,the modification of CAs is a promising method because their extensive long-term contact with tooth surfaces makes them ideal devices for implementing adjuvant medical functions.In this review,we discuss various advanced CAs with medical functions based on the clinical needs of patients.As far as we know,the additional functions of CAs mainly include antibacterial,remineralization,whitening,and accelerating tooth movement.These functions are achieved by two major pathways,the combination of CAs with drugs/biomaterials and increasing the capacity or affinity of drugs.In addition,we discuss the current limitations of in vitro experiments which are designed to explore the effectiveness and properties of novel CAs,and the challenges of bringing a multifunctional appliance from proposal to clinical application.At the end of this review,we provide insights into the broader prospects for the improvement of CAs.展开更多
Autografting is the gold standard for surgical repair of nerve defects>5 mm in length;however,autografting is associated with potential complications at the nerve donor site.As an alternative,nerve guidance conduit...Autografting is the gold standard for surgical repair of nerve defects>5 mm in length;however,autografting is associated with potential complications at the nerve donor site.As an alternative,nerve guidance conduits may be used.The ideal conduit should be flexible,resistant to kinks and lumen collapse,and provide physical cues to guide nerve regeneration.We designed a novel flexible conduit using electrospinning technology to create fibers on the innermost surface of the nerve guidance conduit and employed melt spinning to align them.Subsequently,we prepared disordered electrospun fibers outside the aligned fibers and helical melt-spun fibers on the outer wall of the electrospun fiber lumen.The presence of aligned fibers on the inner surface can promote the extension of nerve cells along the fibers.The helical melt-spun fibers on the outer surface can enhance resistance to kinking and compression and provide stability.Our novel conduit promoted nerve regeneration and functional recovery in a rat sciatic nerve defect model,suggesting that it has potential for clinical use in human nerve injuries.展开更多
The malalignment of teeth is treated classically by metal braces with alloy wires,which has an unfavorable influence on the patients appearance during the treatment.With the development of digitization,computer simula...The malalignment of teeth is treated classically by metal braces with alloy wires,which has an unfavorable influence on the patients appearance during the treatment.With the development of digitization,computer simulation and three-dimensional(3D)printing technology,herein,a modern treatment was tried using clear polymeric aligners,which were fabricated by molding polyurethane films via thermoforming on the 3D-printed personalized dental models.The key parameters of photocurable 3D printing of dental models and the mechanical properties of the clear aligner film material were examined.The precision of a 3D-printed dental model mainly relied on characteristics of photocurable resin,the resolution of light source and the exposure condition,which determined the eventual shape of the molded clear aligner and thus the orthodontic treatment efficacy.The biocompatibility of the polyurethane filmmaterial was confirmed through cytotoxicity and hemolysis tests in vitro.Following a series of 3D-printed personalized dental models and finite element analysis to predict and plan the fabrication and orthodontic processes,corresponding clear aligners were fabricated and applied in animal experiments,which proved the efficacy and biocompatibility in vivo.Clinical treatments of 120 orthodontic cases were finally carried out with success,which highlights the advantage of the clear aligners as an esthetic,compatible and efficient appliance.展开更多
Rapid technological improvements in biomaterials,computer-aided design(CAD)and manufacturing(CAM)have endorsed clear aligner therapy(CAT)as a mainstay of orthodontic treatment,and the materials employed for aligner fa...Rapid technological improvements in biomaterials,computer-aided design(CAD)and manufacturing(CAM)have endorsed clear aligner therapy(CAT)as a mainstay of orthodontic treatment,and the materials employed for aligner fabrication play an all-important role in determining the clinical performance of clear aligners.This narrative review has attempted to comprehensively encompass the entire gamut of materials currently used for the fabrication of clear aligners and elucidate their characteristics that are crucial in determining their performance in an oral environment.Historical developments and current protocols in aligner fabrication,features of contemporary bioactive materials,and emerging trends related to CAT are discussed.Advances in aligner material chemistry and engineering possess the potential to bring about radical transformations in the therapeutic applications of CAT;in the absence of which,clear aligners would continue to underperform clinically,due to their inherent biomechanical constraints.Finally,while innovations in aligner materials such as shape memory polymers,direct three-dimensional(3D)printed clear aligners and bioactive materials combined with clear aligner materials are essential to further advance the applications of CAT;increased awareness of environmental responsibilities among aligner manufacturers,aligner prescribing clinicians and aligner users is essential for better alignment of our climate change goals towards a sustainable planet.展开更多
Through strategies such as process optimization,solvent selection,and component tuning,the crystallization of perovskite materials has been effectively controlled,enabling perovskite solar cells(PSCs)to achieve over 2...Through strategies such as process optimization,solvent selection,and component tuning,the crystallization of perovskite materials has been effectively controlled,enabling perovskite solar cells(PSCs)to achieve over 25%power conversion efficiency(PCE).However,as PCE continues to improve,interfacial issues within the devices have emerged as critical bottlenecks,hindering further performance enhancements.Recently,interfacial engineering has driven transformative progress,pushing PCEs to nearly 27%.Building upon these developments,this review first summarizes the pivotal role of interfacial modifications in elevating device performance and then,as a starting point,provides a comprehensive overview of recent advancements in normal,inverted,and tandem structure devices.Finally,based on the current progress of PSCs,preliminary perspectives on future directions are presented.展开更多
A polarization-sensitive and flexible photodetector was fabricated through the precise alignment of perovskite nanowires(NWs)using a brush coating technique.The alignment of the NWs was meticulously examined,consideri...A polarization-sensitive and flexible photodetector was fabricated through the precise alignment of perovskite nanowires(NWs)using a brush coating technique.The alignment of the NWs was meticulously examined,considering various chemical properties of the solvent,such as boiling point,viscosity,and surface tension.Notably,when the NWs were brush-coated with toluene dispersion,the NWs were aligned in higher order than those processed from octane dispersion.The degree of alignment was correlated with the photodetector property.Especially,the well-aligned NW photodetector exhibited a two-fold disparity in current response contingent on the polarization direction.Furthermore,even after enduring 500 bending cycles,the device retained 80%of its photodetector performance.This approach underscores the potential of solution-processed flexible photodetectors for advanced optical applications under dynamic operating conditions.展开更多
Nanocrystals have emerged as cutting-edge functional materials benefiting from the increased surface and enhanced coupling of electronic states.High-resolution imaging in transmission electron microscope can provide i...Nanocrystals have emerged as cutting-edge functional materials benefiting from the increased surface and enhanced coupling of electronic states.High-resolution imaging in transmission electron microscope can provide invaluable structural information of crystalline materials,albeit it remains greatly challenging to nanocrystals due to the arduousness of accurate zone axis adjustment.Herein,a homemade software package,called SmartAxis,is developed for rapid yet accurate zone axis alignment of nanocrystals.Incident electron beam tilt is employed as an eccentric goniometer to measure the angular deviation of a crystal to a zone axis,and then serves as a linkage to calculate theαandβtilts of goniometer based on an accurate quantitative relationship.In this way,high-resolution imaging of one identical small Au nanocrystal,as well as electron beam-sensitive MIL-101 metal-organic framework crystals,along multiple zone axes,was performed successfully by using this accurate,time-and electron dose-saving zone axis alignment software package.展开更多
Van der Waals(vdW)ferroelectric-semiconductor heterojunction provides reconfigurable band alignment based on optical/electrical-assisted polarization switching,which shows great potential to construct artificial visua...Van der Waals(vdW)ferroelectric-semiconductor heterojunction provides reconfigurable band alignment based on optical/electrical-assisted polarization switching,which shows great potential to construct artificial visual neural systems.However,the mechanical exfoliation fabrication scheme for proof-of-concept demonstrations and fundamental studies is cumbersome and not scalable for practical application.Here,we present a synthetic strategy for the large-scale and high crystallinity growth of planar/verticalα-In_(2)Se_(3)/MoS_(2)heterojunctions by dynamically tuning the growth temperature.Furthermore,based on theα-In_(2)Se_(3)/MoS_(2)heterostructures,photo-synapse devices are designed and fabricated to simulate visual neural systems functions,including multistate storage,optical logic operation,potentiation and depression,paired-pulse facilitation(PPF),short-term memory(STM),long-term memory(LTM),and Learning-Forgetting-Relearning.By coupling the spatiotemporally relevant optical and electric information,the device can mimic the superior biological visual system’s light adaptation and Pavlovian conditioning.This work provides a strategy for dynamically tuning the orientation of ferroelectric-semiconductor heterojunction stacks and will give impetus to applying all-in-one sensing and memory-computing artificial vision systems.展开更多
With the rapid expansion of social media,analyzing emotions and their causes in texts has gained significant importance.Emotion-cause pair extraction enables the identification of causal relationships between emotions...With the rapid expansion of social media,analyzing emotions and their causes in texts has gained significant importance.Emotion-cause pair extraction enables the identification of causal relationships between emotions and their triggers within a text,facilitating a deeper understanding of expressed sentiments and their underlying reasons.This comprehension is crucial for making informed strategic decisions in various business and societal contexts.However,recent research approaches employing multi-task learning frameworks for modeling often face challenges such as the inability to simultaneouslymodel extracted features and their interactions,or inconsistencies in label prediction between emotion-cause pair extraction and independent assistant tasks like emotion and cause extraction.To address these issues,this study proposes an emotion-cause pair extraction methodology that incorporates joint feature encoding and task alignment mechanisms.The model consists of two primary components:First,joint feature encoding simultaneously generates features for emotion-cause pairs and clauses,enhancing feature interactions between emotion clauses,cause clauses,and emotion-cause pairs.Second,the task alignment technique is applied to reduce the labeling distance between emotion-cause pair extraction and the two assistant tasks,capturing deep semantic information interactions among tasks.The proposed method is evaluated on a Chinese benchmark corpus using 10-fold cross-validation,assessing key performance metrics such as precision,recall,and F1 score.Experimental results demonstrate that the model achieves an F1 score of 76.05%,surpassing the state-of-the-art by 1.03%.The proposed model exhibits significant improvements in emotion-cause pair extraction(ECPE)and cause extraction(CE)compared to existing methods,validating its effectiveness.This research introduces a novel approach based on joint feature encoding and task alignment mechanisms,contributing to advancements in emotion-cause pair extraction.However,the study’s limitation lies in the data sources,potentially restricting the generalizability of the findings.展开更多
This study aimed to explore the optimal invisible orthodontic force system during the en-mass distalization of two maxillary molars to minimize the side effect of anchorage loss by changing the direction of the applic...This study aimed to explore the optimal invisible orthodontic force system during the en-mass distalization of two maxillary molars to minimize the side effect of anchorage loss by changing the direction of the application of the orthodontic force system.A high bio-fidelity 3D finite element model including maxilla,periodontal ligament,dentition,clear aligner,3D anchorage attachment and mini-implant was established.Different lengths of lateral hooks of 3D-printed anchorage attachments and mini-implant positions into the palatal alveolus were considered.A 200 g distal force was applied to the lateral hooks of different horizontal lengths(3.26 mm,6.52 mm and 9.78 mm)with the mini-implant as the application point.Using ABAQUS software,orthodontic tooth movements under 12 different clinical treatment designs were analyzed and calculated.The 3D anchorage attachment enhanced the anchorage of anterior teeth and alleviated the tipping/extrusion of premolars.In contrast to without clear aligners,length of the lateral hook had a negligible effect on both mesial tipping and buccal tipping with clear aligners,which could then be ignored.The change in mesial tipping was less and nearly remained constant despite of the different heights of the mini-implant.The 3D anchorage attachment assisted clear aligner can avoid the side effects of anterior tooth proclination caused by insufficient anchorage.The length of the lateral hook,and height of the mini-implant in this invisible orthodontic force system hardly affects the tooth movement of anchorage units.Clear aligners can effectively control the rotation and tipping of anchorage units caused by 3D anchorage attachment.展开更多
Few-layer nanosheets(NSs)of hexagonal boron nitride(h-BN)and molybdenum disulfide(MoS_(2))display notable piezoelectric properties.Yet,their integration into polymers typically yields non-piezoelectric composites due ...Few-layer nanosheets(NSs)of hexagonal boron nitride(h-BN)and molybdenum disulfide(MoS_(2))display notable piezoelectric properties.Yet,their integration into polymers typically yields non-piezoelectric composites due to NSs’random distribution.We introduce a facile method for fabricating intrinsic piezoelectric composites incorporated with NSs without electric poling.Our innovative process aligns NSs within polyvinyl alcohol polymer,leveraging ice-water interfacial tension,water crystallization thrust,and directional cross-linking during freezing.The resulting PE composites exhibit a maximum piezoelectric coefficient of up to 25.5-28.4 pC N^(-1),comparable to polyvinylidene difluoride(PVDF),with significant costefficiency,safety,and scalability advantages over conventional materials.Using this composite,we develop highly sensitive wearable pressure and strain sensors,and an ultrasound energy harvester.These sensors detect finger bending and differentiate between walking and running,while the harvester generates1.18 V/2.31μA under 1Wcm^(-2)ultrasound input underwater.This universal method offers a novel manufacturing technique for piezoelectric composites,demonstrating remarkable effectiveness in synthesizing intrinsic piezoelectric composites based on 2D materials.Moreover,its potential extends to applications in wearable electronics and energy harvesting,promising significant advancements in these fields.展开更多
Active rods propelled along their long axis align their velocities and orientations simultaneously in collision.However,as the propulsion is perpendicular to the long axis,velocity alignment becomes dynamically diffic...Active rods propelled along their long axis align their velocities and orientations simultaneously in collision.However,as the propulsion is perpendicular to the long axis,velocity alignment becomes dynamically difficult.Here,we show that ellipsoidal Quincke roller propelled along their short-axis(perpendicular to the long axis)can align their velocities by flipping and form flocking with nematic order.The flipping arises from the reversible transition between the static parallel spinless state and the spinning transversal state of ellipsoidal Quincke rollers.This is possible only near(above)the critical field where both the parallel spinless state and the spinning transversal spinning are metastable.The flipping-facilitated alignment offers an extra aligning mechanism for elongate active agents,and the resulting active liquid crystals serve a model system to explore the defect dynamics as the propulsion deviates from the local nematic orientation which has not been addressed yet.展开更多
文摘Clear aligner treatment is a novel technique in current orthodontic practice.Distinct from traditional fixed orthodontic appliances,clear aligners have different material features and biomechanical characteristics and treatment efficiencies,presenting new clinical challenges.Therefore,a comprehensive and systematic description of the key clinical aspects of clear aligner treatment is essential to enhance treatment efficacy and facilitate the advancement and wide adoption of this new technique.This expert consensus discusses case selection and grading of treatment difficulty,principle of clear aligner therapy,clinical procedures and potential complications,which are crucial to the clinical success of clear aligner treatment.
基金supported by grants from the Interdisciplinary Program of Wuhan National High Magnetic Field Center(No.WHMFC202207)China Oral Health Foundation(No.A2023-009).
文摘Maxillary protrusion combined with mandibular retraction is a highly prevalent but extremely complex maxillofacial deformity that can have a serious negative impact on patients’facial aesthetics and mental health.The traditional orthodontic treatment strategy often involves extracting 4 first premolars and conventional fixed techniques,combined with mini-implant screws,to retract the anterior teeth and improve facial protrusion.In recent years,an invisible orthodontic technique,without brackets,has become increasingly popular.However,while an invisible aligner has been used in some cases with reasonable results,there remain significant challenges in achieving a perfect outcome.This case report presents an adolescent patient with bimaxillary protrusion and mandibular retrognathia.Based on the characteristics of the invisible aligners and the growth characteristics of the adolescent’s teeth and jawbone,we designed precise three-dimensional tooth movement and corresponding resistance/over-correction for each tooth,while utilizing the patient’s jawbone growth potential to promote rapid development of the mandible,accurately and efficiently correcting bimaxillary protrusion and skeletal mandibular retrognathia.The patient’s facial aesthetics,especially the lateral morphology,have been greatly improved,and various aesthetic indicators have also shown significant changes,and to the patient’s great benefit,invasive mini-implant screws were not used during the treatment.This case highlights the advantages of using invisible aligners in adolescent maxillary protrusion combined with mandibular retraction patients.Furthermore,comprehensive and accurate design combined with good application of growth potential can also enable invisible orthodontic technology to achieve perfect treatment effects in tooth extractions,providing clinical guidance for orthodontists.
基金funded by the Orthodontic National Key Clinical Specialty Construction Program of Chinathe West China Hospital of Stomatology Sichuan Universitysupported by grants from the National Natural Science Foundation of China (Grant No. 31470904 and 81470722)
文摘The aim of this study was to evaluate and compare the colour stabilities of three types of orthodontic clear aligners exposed to staining agents in vitro. Sixty clear orthodontic aligners produced by three manufacturers （Invisalign, Angelalign, and Smartee） were immersed in three staining solutions （coffee, black tea, and red wine） and one control solution （distilled water）. After 12-h and 7-day immersions, the aligners were washed in an ultrasonic cleaner and measured with a colourimeter. The colour changes （△E＊） were calculated on the basis of the Commission Internationale de I＇Eclairage L＊a＊b＊ colour system （CIE L＊a＊b＊）, and the results were then converted into National Bureau of Standards （NBS） units. Fourier transformation infrared （FT-IR） spectroscopy and scanning electron microscopy （SEM） were conducted to observe the molecular and morphologic alterations to the aligner surfaces, respectively. The three types of aligners exhibited slight colour changes after 12 h of staining, with the exception of the Invisalign aligners stained with coffee. The Invisalign aligners exhibited significantly higher AE＊ values （ranging from 0.30 to 27.81） than those of the Angelalign and Smartee aligners （AE＊ values ranging from 0.33 to 1.89 and 0.32 to 1.61, respectively, P〈O.05）. IFT-IR analysis confirmed that the polymer-based structure of aligners did not exhibit significant chemical differences before and after the immersions. The SEM results revealed different surface alterations to the three types of aligner materials after the 7-day staining. The three types of aesthetic orthodontic appliances exhibited colour stability after the 12-h immersion, with the exception of the Invisalign aligners stained by coffee. The Invisalign aligners were more prone than the Angelalign and Smartee aligners to pigmentation. Aligner materials may be improved by considering aesthetic colour stability properties.
基金the Clinical Research Program of Ninth People’s Hospital affiliated to Shanghai Jiao Tong University School of Medicine(No.JYLJ-10)。
文摘This study was aimed at analysing the mechanical characteristics of different mandibular extraction modes using a clear aligner.Three experimental schemes of different extraction patterns were designed to treat mandibular crowding,including extraction of one mandibular central incisor,bilateral first premolars,and bilateral second premolars.The stress distribution during the space closing was analysed using the finite element method.When a central incisor was extracted,a significant retraction force was found in the anterior region,in line with the design expectation.The posterior teeth,which were designed to move mesially,acted as anchorage for anterior retraction,and were subjected to a mesial force.The anterior teeth were retracted when the bilateral first premolars were extracted.The lateral incisors and canines were subjected to a significant distal force and moment,while the central incisors and canines were subjected to lingual forces and moments.Additionally,the canines were subjected to a non-designated intruding force.The molars were designed to move mesially when the bilateral second premolars were extracted.All molars were subjected to a significant mesial force,while the lingual force on the front teeth was slight.The bilateral second molars were subjected to non-design mesial moment and extrusive force.The bilateral first molars were subjected to a non-designated mesial moment,and the bilateral first premolars on both sides were subjected to non-designated intrusive force and distal moment.When one incisor was extracted,attachments on the anterior teeth had a controlling effect on the tooth axis,but the anterior teeth still tended to tilt.When the bilateral first premolars were extracted,the anterior teeth showed a tendency for lingual inclination.The risk of distal inclination of the canines and lingual inclination of the central incisor increased.When the bilateral second premolars were extracted and the posterior teeth were designed to move mesially,the teeth on both sides of the extraction sites showed an obvious bowing effect.
基金This work was supported in part by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2018R1C1B5084424)in part by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2019R1A6A1A03032119).
文摘Advancements in next-generation sequencer(NGS)platforms have improved NGS sequence data production and reduced the cost involved,which has resulted in the production of a large amount of genome data.The downstream analysis of multiple associated sequences has become a bottleneck for the growing genomic data due to storage and space utilization issues in the domain of bioinformatics.The traditional string-matching algorithms are efficient for small sized data sequences and cannot process large amounts of data for downstream analysis.This study proposes a novel bit-parallelism algorithm called BitmapAligner to overcome the issues faced due to a large number of sequences and to improve the speed and quality of multiple sequence alignment(MSA).The input files(sequences)tested over BitmapAligner can be easily managed and organized using the Hadoop distributed file system.The proposed aligner converts the test file(the whole genome sequence)into binaries of an equal length of the sequence,line by line,before the sequence alignment processing.The Hadoop distributed file system splits the larger files into blocks,based on a defined block size,which is 128 MB by default.BitmapAligner can accurately process the sequence alignment using the bitmask approach on large-scale sequences after sorting the data.The experimental results indicate that BitmapAligner operates in real time,with a large number of sequences.Moreover,BitmapAligner achieves the exact start and end positions of the pattern sequence to test the MSA application in the whole genome query sequence.The MSA’s accuracy is verified by the bitmask indexing property of the bit-parallelism extended shifts(BXS)algorithm.The dynamic and exact approach of the BXS algorithm is implemented through the MapReduce function of Apache Hadoop.Conversely,the traditional seeds-and-extend approach faces the risk of errors while identifying the pattern sequences’positions.Moreover,the proposed model resolves the largescale data challenges that are covered through MapReduce in the Hadoop framework.Hive,Yarn,HBase,Cassandra,and many other pertinent flavors are to be used in the future for data structuring and annotations on the top layer of Hadoop since Hadoop is primarily used for data organization and handles text documents.
基金supported by Postdoctoral Science Foundation of China(Nos.2018M630883 and 2019T120688)Hubei Province Chinese Medicine Research Project(No.ZY2023Q015)Natural Science Foundation of Hubei Province(No.2023AFB665)。
文摘With the increasing demand for beauty and health,clear aligners(CAs)have been widely applied among patients with malocclusion.However,patients treated with CAs also face some potential complications,such as demineralization,dental caries,and periodontal diseases.In addition,some patients have additional needs to improve their quality of life,such as bleaching teeth.In order to prevent or solve these problems,the modification of CAs is a promising method because their extensive long-term contact with tooth surfaces makes them ideal devices for implementing adjuvant medical functions.In this review,we discuss various advanced CAs with medical functions based on the clinical needs of patients.As far as we know,the additional functions of CAs mainly include antibacterial,remineralization,whitening,and accelerating tooth movement.These functions are achieved by two major pathways,the combination of CAs with drugs/biomaterials and increasing the capacity or affinity of drugs.In addition,we discuss the current limitations of in vitro experiments which are designed to explore the effectiveness and properties of novel CAs,and the challenges of bringing a multifunctional appliance from proposal to clinical application.At the end of this review,we provide insights into the broader prospects for the improvement of CAs.
基金supported by the National Natural Science Foundation of China,No.82202718the Natural Science Foundation of Beijing,No.L212050the China Postdoctoral Science Foundation,Nos.2019M664007,2021T140793(all to ZL)。
文摘Autografting is the gold standard for surgical repair of nerve defects>5 mm in length;however,autografting is associated with potential complications at the nerve donor site.As an alternative,nerve guidance conduits may be used.The ideal conduit should be flexible,resistant to kinks and lumen collapse,and provide physical cues to guide nerve regeneration.We designed a novel flexible conduit using electrospinning technology to create fibers on the innermost surface of the nerve guidance conduit and employed melt spinning to align them.Subsequently,we prepared disordered electrospun fibers outside the aligned fibers and helical melt-spun fibers on the outer wall of the electrospun fiber lumen.The presence of aligned fibers on the inner surface can promote the extension of nerve cells along the fibers.The helical melt-spun fibers on the outer surface can enhance resistance to kinking and compression and provide stability.Our novel conduit promoted nerve regeneration and functional recovery in a rat sciatic nerve defect model,suggesting that it has potential for clinical use in human nerve injuries.
基金supports from NSF of China(grants No.52130302,21961160721)National Key R&D Program of China(grant No.2016YFC1100300)。
文摘The malalignment of teeth is treated classically by metal braces with alloy wires,which has an unfavorable influence on the patients appearance during the treatment.With the development of digitization,computer simulation and three-dimensional(3D)printing technology,herein,a modern treatment was tried using clear polymeric aligners,which were fabricated by molding polyurethane films via thermoforming on the 3D-printed personalized dental models.The key parameters of photocurable 3D printing of dental models and the mechanical properties of the clear aligner film material were examined.The precision of a 3D-printed dental model mainly relied on characteristics of photocurable resin,the resolution of light source and the exposure condition,which determined the eventual shape of the molded clear aligner and thus the orthodontic treatment efficacy.The biocompatibility of the polyurethane filmmaterial was confirmed through cytotoxicity and hemolysis tests in vitro.Following a series of 3D-printed personalized dental models and finite element analysis to predict and plan the fabrication and orthodontic processes,corresponding clear aligners were fabricated and applied in animal experiments,which proved the efficacy and biocompatibility in vivo.Clinical treatments of 120 orthodontic cases were finally carried out with success,which highlights the advantage of the clear aligners as an esthetic,compatible and efficient appliance.
文摘Rapid technological improvements in biomaterials,computer-aided design(CAD)and manufacturing(CAM)have endorsed clear aligner therapy(CAT)as a mainstay of orthodontic treatment,and the materials employed for aligner fabrication play an all-important role in determining the clinical performance of clear aligners.This narrative review has attempted to comprehensively encompass the entire gamut of materials currently used for the fabrication of clear aligners and elucidate their characteristics that are crucial in determining their performance in an oral environment.Historical developments and current protocols in aligner fabrication,features of contemporary bioactive materials,and emerging trends related to CAT are discussed.Advances in aligner material chemistry and engineering possess the potential to bring about radical transformations in the therapeutic applications of CAT;in the absence of which,clear aligners would continue to underperform clinically,due to their inherent biomechanical constraints.Finally,while innovations in aligner materials such as shape memory polymers,direct three-dimensional(3D)printed clear aligners and bioactive materials combined with clear aligner materials are essential to further advance the applications of CAT;increased awareness of environmental responsibilities among aligner manufacturers,aligner prescribing clinicians and aligner users is essential for better alignment of our climate change goals towards a sustainable planet.
基金supported by National Natural Science Foundation of China(52302229,62404072)the Key Lab of Modern Optical Technologies of Education Ministry of China,Soochow University(KJS2425)+1 种基金Doctoral Foundation of Henan Polytech-nic University(B2024-72)Science and Technology Research Project of Jiangxi Provincial Department of Education(Grant No.GJJ2400702).
文摘Through strategies such as process optimization,solvent selection,and component tuning,the crystallization of perovskite materials has been effectively controlled,enabling perovskite solar cells(PSCs)to achieve over 25%power conversion efficiency(PCE).However,as PCE continues to improve,interfacial issues within the devices have emerged as critical bottlenecks,hindering further performance enhancements.Recently,interfacial engineering has driven transformative progress,pushing PCEs to nearly 27%.Building upon these developments,this review first summarizes the pivotal role of interfacial modifications in elevating device performance and then,as a starting point,provides a comprehensive overview of recent advancements in normal,inverted,and tandem structure devices.Finally,based on the current progress of PSCs,preliminary perspectives on future directions are presented.
基金supported by a Commercialization Promotion Agency for R&D Outcomes(COMPA)Grant funded by the Korean Government(Ministry of Science and ICT)(No.RS-2023-00304743)the National Research Foundation of Korea(NRF)Grant funded by the Korean Government(MSIT)(No.2022M3J7A1066428)"Regional Innovation Strategy(RIS)"through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(MOE)(No.2023RIS-008).
文摘A polarization-sensitive and flexible photodetector was fabricated through the precise alignment of perovskite nanowires(NWs)using a brush coating technique.The alignment of the NWs was meticulously examined,considering various chemical properties of the solvent,such as boiling point,viscosity,and surface tension.Notably,when the NWs were brush-coated with toluene dispersion,the NWs were aligned in higher order than those processed from octane dispersion.The degree of alignment was correlated with the photodetector property.Especially,the well-aligned NW photodetector exhibited a two-fold disparity in current response contingent on the polarization direction.Furthermore,even after enduring 500 bending cycles,the device retained 80%of its photodetector performance.This approach underscores the potential of solution-processed flexible photodetectors for advanced optical applications under dynamic operating conditions.
基金supported by the National Key R&D Program of China(No.2021YFA1501002)Thousand Talents Program for Distinguished Young Scholars.X.Li thanks the National Natural Science Foundation of China(No.22309021).
文摘Nanocrystals have emerged as cutting-edge functional materials benefiting from the increased surface and enhanced coupling of electronic states.High-resolution imaging in transmission electron microscope can provide invaluable structural information of crystalline materials,albeit it remains greatly challenging to nanocrystals due to the arduousness of accurate zone axis adjustment.Herein,a homemade software package,called SmartAxis,is developed for rapid yet accurate zone axis alignment of nanocrystals.Incident electron beam tilt is employed as an eccentric goniometer to measure the angular deviation of a crystal to a zone axis,and then serves as a linkage to calculate theαandβtilts of goniometer based on an accurate quantitative relationship.In this way,high-resolution imaging of one identical small Au nanocrystal,as well as electron beam-sensitive MIL-101 metal-organic framework crystals,along multiple zone axes,was performed successfully by using this accurate,time-and electron dose-saving zone axis alignment software package.
基金supported by the National Natural Science Foundation of China(Nos.52371245,12174237,12241403)the National Key Research and Development Program of China(No.2022YFB3505301).
文摘Van der Waals(vdW)ferroelectric-semiconductor heterojunction provides reconfigurable band alignment based on optical/electrical-assisted polarization switching,which shows great potential to construct artificial visual neural systems.However,the mechanical exfoliation fabrication scheme for proof-of-concept demonstrations and fundamental studies is cumbersome and not scalable for practical application.Here,we present a synthetic strategy for the large-scale and high crystallinity growth of planar/verticalα-In_(2)Se_(3)/MoS_(2)heterojunctions by dynamically tuning the growth temperature.Furthermore,based on theα-In_(2)Se_(3)/MoS_(2)heterostructures,photo-synapse devices are designed and fabricated to simulate visual neural systems functions,including multistate storage,optical logic operation,potentiation and depression,paired-pulse facilitation(PPF),short-term memory(STM),long-term memory(LTM),and Learning-Forgetting-Relearning.By coupling the spatiotemporally relevant optical and electric information,the device can mimic the superior biological visual system’s light adaptation and Pavlovian conditioning.This work provides a strategy for dynamically tuning the orientation of ferroelectric-semiconductor heterojunction stacks and will give impetus to applying all-in-one sensing and memory-computing artificial vision systems.
文摘With the rapid expansion of social media,analyzing emotions and their causes in texts has gained significant importance.Emotion-cause pair extraction enables the identification of causal relationships between emotions and their triggers within a text,facilitating a deeper understanding of expressed sentiments and their underlying reasons.This comprehension is crucial for making informed strategic decisions in various business and societal contexts.However,recent research approaches employing multi-task learning frameworks for modeling often face challenges such as the inability to simultaneouslymodel extracted features and their interactions,or inconsistencies in label prediction between emotion-cause pair extraction and independent assistant tasks like emotion and cause extraction.To address these issues,this study proposes an emotion-cause pair extraction methodology that incorporates joint feature encoding and task alignment mechanisms.The model consists of two primary components:First,joint feature encoding simultaneously generates features for emotion-cause pairs and clauses,enhancing feature interactions between emotion clauses,cause clauses,and emotion-cause pairs.Second,the task alignment technique is applied to reduce the labeling distance between emotion-cause pair extraction and the two assistant tasks,capturing deep semantic information interactions among tasks.The proposed method is evaluated on a Chinese benchmark corpus using 10-fold cross-validation,assessing key performance metrics such as precision,recall,and F1 score.Experimental results demonstrate that the model achieves an F1 score of 76.05%,surpassing the state-of-the-art by 1.03%.The proposed model exhibits significant improvements in emotion-cause pair extraction(ECPE)and cause extraction(CE)compared to existing methods,validating its effectiveness.This research introduces a novel approach based on joint feature encoding and task alignment mechanisms,contributing to advancements in emotion-cause pair extraction.However,the study’s limitation lies in the data sources,potentially restricting the generalizability of the findings.
基金This work was supported by the National Natural Science Foundation of China(Grant No.12072055,11872135,U20A20390,U22A20314)Natural Science Foundation of Beijing(Grant No.L212063)+3 种基金the Fundamental Research Funds for the Central Universities,the 111 Project(No.B13003)the National Research Program of China(Grant No.2022YFC2504200)Orthodontic research project of youth clinical research fund of Chinese Stomatological Association(Grant No.CSA-O2020-07)Municipal graduate tutor team construction project(dstd201903).
文摘This study aimed to explore the optimal invisible orthodontic force system during the en-mass distalization of two maxillary molars to minimize the side effect of anchorage loss by changing the direction of the application of the orthodontic force system.A high bio-fidelity 3D finite element model including maxilla,periodontal ligament,dentition,clear aligner,3D anchorage attachment and mini-implant was established.Different lengths of lateral hooks of 3D-printed anchorage attachments and mini-implant positions into the palatal alveolus were considered.A 200 g distal force was applied to the lateral hooks of different horizontal lengths(3.26 mm,6.52 mm and 9.78 mm)with the mini-implant as the application point.Using ABAQUS software,orthodontic tooth movements under 12 different clinical treatment designs were analyzed and calculated.The 3D anchorage attachment enhanced the anchorage of anterior teeth and alleviated the tipping/extrusion of premolars.In contrast to without clear aligners,length of the lateral hook had a negligible effect on both mesial tipping and buccal tipping with clear aligners,which could then be ignored.The change in mesial tipping was less and nearly remained constant despite of the different heights of the mini-implant.The 3D anchorage attachment assisted clear aligner can avoid the side effects of anterior tooth proclination caused by insufficient anchorage.The length of the lateral hook,and height of the mini-implant in this invisible orthodontic force system hardly affects the tooth movement of anchorage units.Clear aligners can effectively control the rotation and tipping of anchorage units caused by 3D anchorage attachment.
基金funded by the Key Research Project of Zhejiang(LD22E030007)the“Leading Goose”R&D Program of Zhejiang Province(No.2022C01136)+2 种基金National Science Foundation of China(NSFC No.61974037,No.61904042,No.62274049)Zhejiang University Education Foundation Global Partnership Fund(No.100000-11320)the support of the Micro-nano Fabrication Center of International campus of Zhejiang University.
文摘Few-layer nanosheets(NSs)of hexagonal boron nitride(h-BN)and molybdenum disulfide(MoS_(2))display notable piezoelectric properties.Yet,their integration into polymers typically yields non-piezoelectric composites due to NSs’random distribution.We introduce a facile method for fabricating intrinsic piezoelectric composites incorporated with NSs without electric poling.Our innovative process aligns NSs within polyvinyl alcohol polymer,leveraging ice-water interfacial tension,water crystallization thrust,and directional cross-linking during freezing.The resulting PE composites exhibit a maximum piezoelectric coefficient of up to 25.5-28.4 pC N^(-1),comparable to polyvinylidene difluoride(PVDF),with significant costefficiency,safety,and scalability advantages over conventional materials.Using this composite,we develop highly sensitive wearable pressure and strain sensors,and an ultrasound energy harvester.These sensors detect finger bending and differentiate between walking and running,while the harvester generates1.18 V/2.31μA under 1Wcm^(-2)ultrasound input underwater.This universal method offers a novel manufacturing technique for piezoelectric composites,demonstrating remarkable effectiveness in synthesizing intrinsic piezoelectric composites based on 2D materials.Moreover,its potential extends to applications in wearable electronics and energy harvesting,promising significant advancements in these fields.
基金financial support of the National Natural Science Foundation of China(Grant No.11974255)。
文摘Active rods propelled along their long axis align their velocities and orientations simultaneously in collision.However,as the propulsion is perpendicular to the long axis,velocity alignment becomes dynamically difficult.Here,we show that ellipsoidal Quincke roller propelled along their short-axis(perpendicular to the long axis)can align their velocities by flipping and form flocking with nematic order.The flipping arises from the reversible transition between the static parallel spinless state and the spinning transversal state of ellipsoidal Quincke rollers.This is possible only near(above)the critical field where both the parallel spinless state and the spinning transversal spinning are metastable.The flipping-facilitated alignment offers an extra aligning mechanism for elongate active agents,and the resulting active liquid crystals serve a model system to explore the defect dynamics as the propulsion deviates from the local nematic orientation which has not been addressed yet.
