The neutron-induced total cross-section of ^(209)Bi is crucial for the physical design and safety assessment of lead-based fast reactors, and the quality of experimental data should be improved for evaluation and appl...The neutron-induced total cross-section of ^(209)Bi is crucial for the physical design and safety assessment of lead-based fast reactors, and the quality of experimental data should be improved for evaluation and application.A recent experiment was conducted on the back-streaming white neutron beamline(Back-n) at the China Spallation Neutron Source(CSNS) using the neutron total cross-section spectrometer(NTOX). The neutron energy was determined using a fast multi-cell fission chamber and the time-of-flight technique. Two high-purity bismuth samples,6 mm and 20 mm in thickness, were chosen for neutron transmission measurements and comparisons. The neutron total cross-sections of ^(209)Bi, ranging from 0.3 e V to 20 Me V, were derived considering neutron flight time determination, flight path calibration, and background subtraction. A comparison of the experimental results with the data in the ENDF/B-VⅢ.0 library showed fair agreement, and the point-wise cross-sections were found to be consistent with existing experimental data. Special attention was given to the determination of resonance parameters, which were analyzed using the R-matrix code SAMMY and Bayesian method in the 0.5 ke V to 20 ke V energy range. The extracted resonance parameters were compared to previously reported results and evaluated data. This study is recognized as the first one where the neutron total cross-section of bismuth across such a broad energy spectrum is measured in a single measurement or experiment, and it provides valuable data for the assessment of related reaction information for evaluated libraries and the advancement of lead-bismuth-based nuclear systems.展开更多
The neutron total cross-section of ^(nat)Cr plays a crucial role in new nuclear engineering design and fundamental science.A new measurement of the neutron-induced total cross-sections of ^(nat)Cr was performed using ...The neutron total cross-section of ^(nat)Cr plays a crucial role in new nuclear engineering design and fundamental science.A new measurement of the neutron-induced total cross-sections of ^(nat)Cr was performed using the transmission method on the back-streaming white neutron beamline(Back-n)at the China Spallation Neutron Source(CSNS).The neutron energy was determined using the time-of-flight technique.The neutron total cross-sections of ^(nat)Cr were obtained across a broad energy range(0.3 eV−20 MeV)in one experiment for the first time.The resulting effective total cross-sections were compared with the existing experimental data in different energy ranges,which revealed good agreement with the evaluated libraries.Theoretical calculation of the total cross-section in the energy range of 1.5 to 20 MeV was then conducted using TALYS-1.96 and compared with the present results.The measurement provides a high-quality total cross-section of ^(nat)Cr,including detailed uncertainty data across a wide energy range,offering a valuable reference for nuclear data re-evaluation and nuclear engineering design.展开更多
Casting experiments and macro-micro numerical simulations were conducted to examine the microstructure characteristics of K439B nickel-based superalloy casting with varying cross-sections during the gravity investment...Casting experiments and macro-micro numerical simulations were conducted to examine the microstructure characteristics of K439B nickel-based superalloy casting with varying cross-sections during the gravity investment casting process.Firstly,microstructure analysis was conducted on the casting using scanning electron microscopy(SEM)and electron backscatter diffraction(EBSD).Subsequently,calculation of the phase diagram and differential scanning calorimetry(DSC)tests were conducted to determine the macro-micro simulation parameters of the K439B alloy,and the cellular automaton finite element(CAFE)method was employed to develop macro-micro modeling of K439B nickel-based superalloy casting with varying cross-sections.The experimental results revealed that the ratio of the average grain area increased from the edge to the center of the sections as the ratio of the cross-sectional area increased.The simulation results indicated that the average grain area increased from 0.885 to 0.956 mm^(2)as the ratio of the cross-sections increased from 6꞉1 to 12꞉1.The experiment and simulation results showed that the grain size became more heterogeneous and the grain shape became more irregular with an increase in the ratio of the cross-sectional area of the casting.CAFE modeling was an effective method to simulate the microstructure evolution of the K439B alloy and ensure the accuracy of the simulation.展开更多
The atom-bond sum-connectivity(ABS)index,put forward by[J.Math.Chem.,2022,60(10):20812093],exhibits a strong link with the acentric factor of octane isomers.The experimental physico-chemical properties of octane isome...The atom-bond sum-connectivity(ABS)index,put forward by[J.Math.Chem.,2022,60(10):20812093],exhibits a strong link with the acentric factor of octane isomers.The experimental physico-chemical properties of octane isomers,such as boiling point,of formation are found to be better measured by the ABS index than by the Randi,atom-bond connectivity(ABC),and sum-connectivity(SC)indices.One important source of information for researching the molecular structure is the bounds for its topological indices.The extrema of the ABS index of the line,total,and Mycielski graphs are calculated in this work.Moreover,the pertinent extremal graphs were illustrated.展开更多
Objective:To assess prenatal Bisphenol A(BPA)exposure levels and explore their preliminary associations with maternal and fetal characteristics in a population from Northeastern Yunnan.Methods:A cross-sectional analys...Objective:To assess prenatal Bisphenol A(BPA)exposure levels and explore their preliminary associations with maternal and fetal characteristics in a population from Northeastern Yunnan.Methods:A cross-sectional analysis was performed using data and urine samples from 70 pregnant women in their third trimester recruited at Qujing Central Hospital.Urinary BPA was measured by HPLC-MS/MS.Participants were stratified into high and low BPA exposure groups based on the median concentration.Results:BPA was detected in all samples(100%)with a median concentration of 2.41μg/L(IQR:0.68-4.96).The high BPA exposure group(≥2.41μg/L)had a significantly higher proportion of gestational diabetes mellitus(GDM)(42.9%vs.17.1%,p=0.021)and a lower median fetal birth weight(3250 g vs.3450 g,p=0.048)compared to the low exposure group.Conclusion:This pilot study reveals ubiquitous BPA exposure in pregnant women from Northeastern Yunnan.The observed preliminary associations with GDM and reduced fetal birth weight warrant further investigation in larger,longitudinal studies.展开更多
Ultra-high-strength aluminumalloy profile is an ideal choice for aerospace structuralmaterials due to its excellent specific strength and corrosion resistance.However,issues such as uneven metal flow,stress concentrat...Ultra-high-strength aluminumalloy profile is an ideal choice for aerospace structuralmaterials due to its excellent specific strength and corrosion resistance.However,issues such as uneven metal flow,stress concentration,and forming defects are prone to occur during their extrusion.This study focuses on an Al-Zn-Mg-Cu ultra-high-strength aluminum alloy profile with a double-U,multi-cavity thin-walled structure.Firstly,hot compression experiments were conducted at temperatures of 350○C,400○C,and 450○C,with strain rates of 0.01 and 1.0 s^(−1),to investigate the plastic deformation behavior of the material.Subsequently,a 3D coupled thermo-mechanical extrusion simulation model was established using Deform-3D to systematically analyze the influence of die structure and process parameters on metal flow velocity,effective stress/strain,and temperature distribution.The simulation revealed significant velocity differences,stress concentration,and uneven temperature distribution.Key parameters,including mesh density,extrusion ratio,die fillet,and bearing length,were optimized through full-factorial experiments.This optimization,combined with a stepped flow-guiding die design,effectively improved the metal flow pattern during extrusion.Trial production based on both the initial and optimized parameters were carried out.A comparative analysis demonstrates that the optimized scheme results in a final profile whose cross-section matches the target design closely,with complete filling of complex features and no obvious forming defects.This research provides a valuable reference for the extrusion process optimization and die design of complex-section profiles made from ultra-high-strength aluminum alloys.展开更多
ADPr-ATP is a natural nucleotide with three sugar rings and five pentavalent phosphorus,and can be produced through TIR-catalyzed ADP-ribosylation reactions for plant immunity.Here,we report the first total synthesis ...ADPr-ATP is a natural nucleotide with three sugar rings and five pentavalent phosphorus,and can be produced through TIR-catalyzed ADP-ribosylation reactions for plant immunity.Here,we report the first total synthesis of ADPr-ATP(1)with a total yield of 6.4%through 14 steps,featuring late-stage P(V)−N activation reaction of pyrophosphate(4)and 5′-phosphoromorpholidate(25).The protected adenosine 5′-phosphoromorpholidate(24)was prepared on the basis of a scalable to adenosine 5′′-monophosphate(2).The construction of P(V)−N bond in phosphoramidate is esteemed as a critical step as they are sufficiently stable in deprotection reactions.The chemical synthesis of ADPr-ATP can offer an appealing alternative to traditional enzymatic synthesis and fractionation methods.Furthermore,the pRib-AMP and its prodrug are also synthesized to evaluate cytotoxicity and anti-influenza activity in vitro.展开更多
Objective This study aimed to determine the temporal trends in sleep duration among Chinese adults.Methods In this series of repeated nationally representative cross-sectional surveys(China Chronic Disease and Risk Fa...Objective This study aimed to determine the temporal trends in sleep duration among Chinese adults.Methods In this series of repeated nationally representative cross-sectional surveys(China Chronic Disease and Risk Factors Surveillance)conducted between 2010 and 2018,a total of 645,420 adult participants(97,741 in 2010;175,749 in 2013;187,777 in 2015;and 184,153 in 2018)were included in the trend analysis.Linear and logistic regression models were utilized to assess trends in sleep duration.Results In 2018,the estimated overall mean sleep duration among the Chinese adult population was7.58(SD,1.45)hours per day,with no significant trend from 2010.A significant increase in short sleep duration(≤6 hours)was observed in the total population,from 15.3%(95%CI:14.1%–16.5%)in 2010 to18.5%(95%CI:17.7%–19.3%)in 2018(P<0.001).Similarly,the trend in long sleep duration(>9 hours)was also significant,increasing in weighted prevalence from 7.2%(95%CI:6.3%–8.1%)in 2010 to 9.0%(95%CI:8.2%–9.9%)in 2018(P<0.001).Conclusion The prevalence of both short and long sleep durations significantly increased among Chinese adults from 2010 to 2018,highlighting the urgency of health initiatives to promote optimal sleep duration in China.展开更多
BACKGROUND Aseptic loosening remains the leading cause of revision in primary total hip arthroplasty(pTHA).However,the literature demonstrates significant variability regarding the relative contributions of different ...BACKGROUND Aseptic loosening remains the leading cause of revision in primary total hip arthroplasty(pTHA).However,the literature demonstrates significant variability regarding the relative contributions of different factors.AIM To investigate the key determinants of aseptic loosening,we performed a systematic review and meta-analysis.METHODS A comprehensive search of PubMed,Web of Science,EMBASE,and the Cochrane Library was conducted,encompassing studies from database inception to January 1,2025.Meta-analyses were performed to evaluate factors associated with aseptic loosening following pTHA.Inclusion and exclusion criteria were systematically applied at each stage to ensure methodological transparency and reproducibility.Study quality was assessed using standardized categories.Pooled odds ratio(OR)with corresponding 95%confidence interval were calculated with random-or fixed-effects models to generate reliability estimates,and study heterogeneity was visualized using forest plots.Ten factors,categorized into patient-,surgeon-,and device-related domains,were reviewed and meta-analyzed.Funnel plot analysis demonstrated a relatively symmetrical distribution,suggesting minimal publication bias.RESULTS A meta-analysis of 20 studies(520789 participants)found a pooled prevalence of 1.96%.Significant risk factors for aseptic loosening after pTHA included elevated body mass index(OR=1.116,P<0.001),higher Charlson comorbidity index(OR=1.378,P<0.001),prosthesis-related factors(OR=1.497,P<0.001),and adverse lifestyles(OR=2.198,P=0.037).Protective factors were non-white race(OR=0.445,P<0.001)and favorable genetics(OR=0.723,P<0.001).Male sex increased risk(OR=1.232,P=0.016),while age and anatomy were not significant.Surgical expertise showed a slight protective effect(OR=1.048,P<0.001).A comprehensive understanding of the modifiable and non-modifiable factors contributing to aseptic loosening after pTHA requires consideration of patient-related factors,surgical expertise,and prosthesis characteristics.CONCLUSION The identification of these factors is critical for risk mitigation.High-risk patients should receive targeted counseling regarding individualized profiles.Further studies are warranted to establish clearer causal relationships and identify additional contributing factors.展开更多
We investigated the impact of convexity and isoperimetric deficits on the accuracy of sectional area estimates of tree stems using traditional methods(caliper,tape,formulas based on stem diameter and circumference).In...We investigated the impact of convexity and isoperimetric deficits on the accuracy of sectional area estimates of tree stems using traditional methods(caliper,tape,formulas based on stem diameter and circumference).In two complementary experiments,the use of photographs to estimate cross-sectional areas was first validated,then the use of a caliper and diameter tape was computer-simulated.The results indicated that the photographic method offers high precision,with mean relative errors below 0.1%,minimal deviation,and no significant bias,and the traditional methods led to substantial and systematic errors,with deviations from circularity and convexity significantly increasing the errors in area estimation.展开更多
The micro-riblet structures have been demonstrated effective in controlling the Total Pressure Loss(TPL)of aero-engine blades.However,due to the considerable scale gap between micro-texture and an actual aero-engine b...The micro-riblet structures have been demonstrated effective in controlling the Total Pressure Loss(TPL)of aero-engine blades.However,due to the considerable scale gap between micro-texture and an actual aero-engine blade,wind tunnel tests and numerical simulations with massive grids directly describing the global flow field are costly for aerodynamic evaluation.Furthermore,the fine micro surface structure brings unavoidable manufacturing errors,and the probability prediction contributes to gaining the confidence interval of the results.Therefore,a novel relay-based probabilistic model for multi-fidelity scenarios in the TPL prediction of a compressor cascade with micro-riblet surfaces is proposed to trade off accuracy and efficiency.Combined with the low-fidelity flow data generated by an aerodynamic solution strategy using the boundary surrogate model and the high-fidelity flow data from the experiment,the relay-based modeling has been achieved through knowledge transferring,and the confidence interval can be provided by the Gaussian Process Regression(GPR)model.The TPL of compressor cascades with micro-riblet surfaces under different surface structures at March number Ma=0.64,0.74,0.84 have been evaluated using the Relay-Based Probabilistic(RBP)model.The results illustrate that the RBP model could provide higher accuracy than the Single-Fidelity-Data-Driven(SFDD)prediction model,which show the promising potential of multi-fidelity scenarios data fusion in the aerodynamic evaluation of multi-scale configurations.展开更多
Objective:To systematically summarize and evaluate the evidence on discharge preparation services for patients undergoing total knee arthroplasty,providing an evidence-based foundation for developing scientific and st...Objective:To systematically summarize and evaluate the evidence on discharge preparation services for patients undergoing total knee arthroplasty,providing an evidence-based foundation for developing scientific and standardized discharge preparation intervention programs in clinical practice.Methods:Following the“5S”evidence model,literature such as guidelines,expert consensuses,evidence summaries and randomized controlled trials related to discharge preparation services for total knee arthroplasty patients were retrieved from relevant websites and databases,both domestic and international,from database inception to August 31,2025.Two researchers independently screened the literature,conducted quality appraisals,and extracted and synthesized the evidence.Results:A total of 15 articles were included,comprising 3 guidelines,4 expert consensuses,3 evidence summaries,3 systematic reviews and 2 randomized controlled trials.Ultimately,23 pieces of evidence were summarized across five aspects.Conclusion:This study synthesizes the evidence on discharge preparation services for patients undergoing total knee arthroplasty.It is recommended that healthcare professionals apply this evidence in clinical practice,considering specific circumstances and patient needs.展开更多
Leg-length discrepancy(LLD)in individuals experiencing total hip arthroplasty(THA)is related to a substantially higher fall risk,length of post-operative hospital in-patient stay,elevated implant-related adverse event...Leg-length discrepancy(LLD)in individuals experiencing total hip arthroplasty(THA)is related to a substantially higher fall risk,length of post-operative hospital in-patient stay,elevated implant-related adverse events,and earlier revision.Therefore,it is essential to try to avoid LLD when implanting a THA.Several studies focus on this issue,including the following:Accelerometer-based portable navigation system,preoperative digital templating,robot-assisted surgery,the anatomical marker positioning method(shoulder-to-shoulder)and the artificial intelligence-based three-dimensional planning software system.The aforementioned methods should be familiar to surgeons who perform THA procedures,as a fundamental objective of this surgical intervention is to avoid LLD.展开更多
BACKGROUND Salvage of the infected long stem revision total knee arthroplasty is challenging due to the presence of well-fixed ingrown or cemented stems.Reconstructive options are limited.Above knee amputation(AKA)is ...BACKGROUND Salvage of the infected long stem revision total knee arthroplasty is challenging due to the presence of well-fixed ingrown or cemented stems.Reconstructive options are limited.Above knee amputation(AKA)is often recommended.We present a surgical technique that was successfully used on four such patients to convert them to a knee fusion(KF)using a cephalomedullary nail.CASE SUMMARY Four patients with infected long stem revision knee replacements that refused AKA had a single stage removal of their infected revision total knee followed by a KF.They were all treated with a statically locked antegrade cephalomedullary fusion nail,augmented with antibiotic impregnated bone cement.All patients had successful limb salvage and were ambulatory with assistive devices at the time of last follow-up.All were infection free at an average follow-up of 25.5 months(range 16-31).CONCLUSION Single stage cephalomedullary nailing can result in a successful KF in patients with infected long stem revision total knees.展开更多
BACKGROUND The optimal surgical approach for patients with primary glenohumeral osteoarthritis(GHOA)and an intact rotator cuff remains debated.While anatomic total shoulder arthroplasty(TSA)has traditionally been favo...BACKGROUND The optimal surgical approach for patients with primary glenohumeral osteoarthritis(GHOA)and an intact rotator cuff remains debated.While anatomic total shoulder arthroplasty(TSA)has traditionally been favoured,reverse TSA(RTSA)is increasingly utilized.AIM To systematically compare the outcomes of RTSA and TSA in this specific patient population.METHODS A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines.Retrospective comparative studies evaluating RTSA and TSA in patients with GHOA and intact rotator cuff were included.Key outcomes assessed included complication and reoperation rates,patient-reported outcome measures(PROMs),and range of motion.Risk of bias was assessed using the Risk of Bias in Non-randomized Studies of Interventions tool.RESULTS Twelve studies encompassing 1608 patients(580 RTSA,1028 TSA)met inclusion criteria.RTSA was associated with a lower reoperation rate compared to TSA[odds ratio=0.37;95%confidence interval(CI):0.14-0.94;P value=0.04],while no significant difference in overall complication rates was observed(odds ratio=0.47;95%CI:0.19-1.16;P value=0.10).RTSA patients showed superior outcomes in University of California Los Angeles,Simple Shoulder Test,and Shoulder Pain and Disability Index scores;however,the differences did not exceed the minimal clinically important difference.TSA patients had significantly better external rotation(mean difference=-9.0°;95%CI:-13.21 to-5.02;P value<0.0001).No significant differences were found in other range of motion measures or satisfaction scores.The overall methodological quality of included studies was moderate to serious.CONCLUSION In patients with GHOA and an intact rotator cuff,RTSA may offer comparable or improved outcomes to TSA with lower reoperation rates and similar complication profiles.Functional outcomes favour RTSA in certain patientreported outcome measures,while TSA retains an advantage in external rotation.Surgical decision-making should remain individualized based on patient characteristics and functional demands.展开更多
BACKGROUND Medial dished(MD)liner designs for cruciate-retaining(CR)total knee arthroplasty(TKA)are a relatively novel development.MD tibial inserts have a more constraining medial side,which allows for more similar k...BACKGROUND Medial dished(MD)liner designs for cruciate-retaining(CR)total knee arthroplasty(TKA)are a relatively novel development.MD tibial inserts have a more constraining medial side,which allows for more similar kinematics and function to a native knee.AIM To evaluate the clinical results and patient-reported outcomes after CR TKA procedures utilizing a kinematically designed medial dish system.METHODS A multicenter,retrospective cohort review of 139 primary elective TKAs utilizing a kinematically designed CR Knee System(JOURNEY™II CR MD;Smith and Nephew,Memphis,TN,United States)at three different institutions with a minimum of two years of follow-up.Demographic information,clinical outcomes,and patient-reported outcome measures were collected and analyzed.RESULTS With up to 3.7 years from surgery,overall implant survivorship was 98.6%.There were significant postoperative increases in the average Knee Injury and Osteoarthritis Outcome Score for Joint Replacement scores(17.4 at 6 months,26.1 points at two years or more,P<0.001).CONCLUSION The combination of high implant survivorship and substantial improvements in patient-reported outcome measures suggests that the medial dish tibial insert represents a safe and effective option within TKA.Additional investigation is necessary to evaluate the long-term survivorship of this design.展开更多
A bimorph piezoelectric beam with periodically variable cross-sections is used for the vibration energy harvesting. The effects of two geometrical parameters on the first band gap of this periodic beam are investigate...A bimorph piezoelectric beam with periodically variable cross-sections is used for the vibration energy harvesting. The effects of two geometrical parameters on the first band gap of this periodic beam are investigated by the generalized differential quadrature rule （GDQR） method. The GDQR method is also used to calculate the forced vibration response of the beam and voltage of each piezoelectric layer when the beam is subject to a sinusoidal base excitation. Results obtained from the analytical method are compared with those obtained from the finite element simulation with ANSYS, and good agreement is found. The voltage output of this periodic beam over its first band gap is calculated and compared with the voltage output of the uniform piezoelectric beam. It is concluded that this periodic beam has three advantages over the uniform piezoelectric beam, i.e., generating more voltage outputs over a wide frequency range, absorbing vibration, and being less weight.展开更多
Tunnel deformation monitoring is a crucial task to evaluate tunnel stability during the metro operation period.Terrestrial Laser Scanning(TLS)can collect high density and high accuracy point cloud data in a few minute...Tunnel deformation monitoring is a crucial task to evaluate tunnel stability during the metro operation period.Terrestrial Laser Scanning(TLS)can collect high density and high accuracy point cloud data in a few minutes as an innovation technique,which provides promising applications in tunnel deformation monitoring.Here,an efficient method for extracting tunnel cross-sections and convergence analysis using dense TLS point cloud data is proposed.First,the tunnel orientation is determined using principal component analysis(PCA)in the Euclidean plane.Two control points are introduced to detect and remove the unsuitable points by using point cloud division and then the ground points are removed by defining an elevation value width of 0.5 m.Next,a z-score method is introduced to detect and remove the outlies.Because the tunnel cross-section’s standard shape is round,the circle fitting is implemented using the least-squares method.Afterward,the convergence analysis is made at the angles of 0°,30°and 150°.The proposed approach’s feasibility is tested on a TLS point cloud of a Nanjing subway tunnel acquired using a FARO X330 laser scanner.The results indicate that the proposed methodology achieves an overall accuracy of 1.34 mm,which is also in agreement with the measurements acquired by a total station instrument.The proposed methodology provides new insights and references for the applications of TLS in tunnel deformation monitoring,which can also be extended to other engineering applications.展开更多
In this study,K and L shell photoeffect cross-sections were measured for the elements in the range of 50≤Z≤65at 59.5keV.These photoeffect cross-sections were measured by using the experimentalσKαproduction cross-s...In this study,K and L shell photoeffect cross-sections were measured for the elements in the range of 50≤Z≤65at 59.5keV.These photoeffect cross-sections were measured by using the experimentalσKαproduction cross-section values measured in this paper and two different K shell fluorescence yield values in the literature.The results were compared with the calculated theoretical values.The values were plotted versus atomic number.展开更多
The aim of this study was to compare mandibular form （i.e., size and shape） between patients with agenesis of the lower second premolar （P2） and a control group with no agenesis. Three hypotheses were tested： （H...The aim of this study was to compare mandibular form （i.e., size and shape） between patients with agenesis of the lower second premolar （P2） and a control group with no agenesis. Three hypotheses were tested： （H1） agenesis causes a change in mandibular morphology because of inadequate alveolar ridge development in the area of the missing tooth （mandibular plasticity）; （H2） agenesis is caused by spatial limitations within the mandible （dental plasticity）; and （H3） common genetic/ epigenetic factors cause agenesis and affect mandibular form （pleiotropy）. A geometric morphometric analysis was applied to cross-sectional images of computed tomography （CT） scans of three matched groups （n= 50 each）： （1） regularly erupted P2; （2） agenesis of P2 and the primary second molar in situ; and （3） agenesis of P2 and the primary second molar missing for 〉3 months. Cross-sections of the three areas of interest （first premolar, P2, first molar） were digitized with 23 landmarks and superimposed by a generalized Procrustes analysis. On average, the mandibular cross-sections were narrower and shorter in patients with P2 agenesis compared with that in the control group. Both agenesis groups featured a pronounced submandibular fossa. These differences extended at least one tooth beyond the agenesis-affected region. Taken together with the large interindividual variation that resulted in massively overlapping group distributions, these findings support genetic and/or epigenetic pleiotropy （H3） as the most likely origin of the observed covariation between mandibular form and odontogenesis. Clinically, reduced dimensions and greater variability of mandibular form, as well as a pronounced submandibular fossa, should be expected during the treatment planning of patients with P2 agenesis.展开更多
基金the National Natural Science Foundation of China(12375296)the Key Laboratory of Nuclear Data Foundation(JCKY2022201C153)+1 种基金the National Key Research and Development Plan(2022YFA1603303)the Natural Science Foundation of Hunan Province of China(2021JJ40444,2020RC3054)。
文摘The neutron-induced total cross-section of ^(209)Bi is crucial for the physical design and safety assessment of lead-based fast reactors, and the quality of experimental data should be improved for evaluation and application.A recent experiment was conducted on the back-streaming white neutron beamline(Back-n) at the China Spallation Neutron Source(CSNS) using the neutron total cross-section spectrometer(NTOX). The neutron energy was determined using a fast multi-cell fission chamber and the time-of-flight technique. Two high-purity bismuth samples,6 mm and 20 mm in thickness, were chosen for neutron transmission measurements and comparisons. The neutron total cross-sections of ^(209)Bi, ranging from 0.3 e V to 20 Me V, were derived considering neutron flight time determination, flight path calibration, and background subtraction. A comparison of the experimental results with the data in the ENDF/B-VⅢ.0 library showed fair agreement, and the point-wise cross-sections were found to be consistent with existing experimental data. Special attention was given to the determination of resonance parameters, which were analyzed using the R-matrix code SAMMY and Bayesian method in the 0.5 ke V to 20 ke V energy range. The extracted resonance parameters were compared to previously reported results and evaluated data. This study is recognized as the first one where the neutron total cross-section of bismuth across such a broad energy spectrum is measured in a single measurement or experiment, and it provides valuable data for the assessment of related reaction information for evaluated libraries and the advancement of lead-bismuth-based nuclear systems.
基金Supported by the National Natural Science Foundation of China(12375296)the Educational Commission of Hunan Province,China(21A0281)+2 种基金the Youth Innovation Promotion Association CAS(2023014)the Key Laboratory of Nuclear Data Foundation(JCKY2022201C153)the Natural Science Foundation of Hunan Province,China(2024RC3205,2024JJ2044)。
文摘The neutron total cross-section of ^(nat)Cr plays a crucial role in new nuclear engineering design and fundamental science.A new measurement of the neutron-induced total cross-sections of ^(nat)Cr was performed using the transmission method on the back-streaming white neutron beamline(Back-n)at the China Spallation Neutron Source(CSNS).The neutron energy was determined using the time-of-flight technique.The neutron total cross-sections of ^(nat)Cr were obtained across a broad energy range(0.3 eV−20 MeV)in one experiment for the first time.The resulting effective total cross-sections were compared with the existing experimental data in different energy ranges,which revealed good agreement with the evaluated libraries.Theoretical calculation of the total cross-section in the energy range of 1.5 to 20 MeV was then conducted using TALYS-1.96 and compared with the present results.The measurement provides a high-quality total cross-section of ^(nat)Cr,including detailed uncertainty data across a wide energy range,offering a valuable reference for nuclear data re-evaluation and nuclear engineering design.
基金supported by the National Science and Technology Major Project of China(No.J2019-VI-0004-0117)。
文摘Casting experiments and macro-micro numerical simulations were conducted to examine the microstructure characteristics of K439B nickel-based superalloy casting with varying cross-sections during the gravity investment casting process.Firstly,microstructure analysis was conducted on the casting using scanning electron microscopy(SEM)and electron backscatter diffraction(EBSD).Subsequently,calculation of the phase diagram and differential scanning calorimetry(DSC)tests were conducted to determine the macro-micro simulation parameters of the K439B alloy,and the cellular automaton finite element(CAFE)method was employed to develop macro-micro modeling of K439B nickel-based superalloy casting with varying cross-sections.The experimental results revealed that the ratio of the average grain area increased from the edge to the center of the sections as the ratio of the cross-sectional area increased.The simulation results indicated that the average grain area increased from 0.885 to 0.956 mm^(2)as the ratio of the cross-sections increased from 6꞉1 to 12꞉1.The experiment and simulation results showed that the grain size became more heterogeneous and the grain shape became more irregular with an increase in the ratio of the cross-sectional area of the casting.CAFE modeling was an effective method to simulate the microstructure evolution of the K439B alloy and ensure the accuracy of the simulation.
基金Supported by Ningbo NSF(No.2021J234)Zhejiang Provincial Philosophy and Social Sciences Planning Project(No.24NDJC057YB)。
文摘The atom-bond sum-connectivity(ABS)index,put forward by[J.Math.Chem.,2022,60(10):20812093],exhibits a strong link with the acentric factor of octane isomers.The experimental physico-chemical properties of octane isomers,such as boiling point,of formation are found to be better measured by the ABS index than by the Randi,atom-bond connectivity(ABC),and sum-connectivity(SC)indices.One important source of information for researching the molecular structure is the bounds for its topological indices.The extrema of the ABS index of the line,total,and Mycielski graphs are calculated in this work.Moreover,the pertinent extremal graphs were illustrated.
文摘Objective:To assess prenatal Bisphenol A(BPA)exposure levels and explore their preliminary associations with maternal and fetal characteristics in a population from Northeastern Yunnan.Methods:A cross-sectional analysis was performed using data and urine samples from 70 pregnant women in their third trimester recruited at Qujing Central Hospital.Urinary BPA was measured by HPLC-MS/MS.Participants were stratified into high and low BPA exposure groups based on the median concentration.Results:BPA was detected in all samples(100%)with a median concentration of 2.41μg/L(IQR:0.68-4.96).The high BPA exposure group(≥2.41μg/L)had a significantly higher proportion of gestational diabetes mellitus(GDM)(42.9%vs.17.1%,p=0.021)and a lower median fetal birth weight(3250 g vs.3450 g,p=0.048)compared to the low exposure group.Conclusion:This pilot study reveals ubiquitous BPA exposure in pregnant women from Northeastern Yunnan.The observed preliminary associations with GDM and reduced fetal birth weight warrant further investigation in larger,longitudinal studies.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFB3710805).
文摘Ultra-high-strength aluminumalloy profile is an ideal choice for aerospace structuralmaterials due to its excellent specific strength and corrosion resistance.However,issues such as uneven metal flow,stress concentration,and forming defects are prone to occur during their extrusion.This study focuses on an Al-Zn-Mg-Cu ultra-high-strength aluminum alloy profile with a double-U,multi-cavity thin-walled structure.Firstly,hot compression experiments were conducted at temperatures of 350○C,400○C,and 450○C,with strain rates of 0.01 and 1.0 s^(−1),to investigate the plastic deformation behavior of the material.Subsequently,a 3D coupled thermo-mechanical extrusion simulation model was established using Deform-3D to systematically analyze the influence of die structure and process parameters on metal flow velocity,effective stress/strain,and temperature distribution.The simulation revealed significant velocity differences,stress concentration,and uneven temperature distribution.Key parameters,including mesh density,extrusion ratio,die fillet,and bearing length,were optimized through full-factorial experiments.This optimization,combined with a stepped flow-guiding die design,effectively improved the metal flow pattern during extrusion.Trial production based on both the initial and optimized parameters were carried out.A comparative analysis demonstrates that the optimized scheme results in a final profile whose cross-section matches the target design closely,with complete filling of complex features and no obvious forming defects.This research provides a valuable reference for the extrusion process optimization and die design of complex-section profiles made from ultra-high-strength aluminum alloys.
基金supported by the National Natural Science Foundation of China(Nos.82204209 and 82130103)Natural Science Foundation of Henna Province(No.242300421084).
文摘ADPr-ATP is a natural nucleotide with three sugar rings and five pentavalent phosphorus,and can be produced through TIR-catalyzed ADP-ribosylation reactions for plant immunity.Here,we report the first total synthesis of ADPr-ATP(1)with a total yield of 6.4%through 14 steps,featuring late-stage P(V)−N activation reaction of pyrophosphate(4)and 5′-phosphoromorpholidate(25).The protected adenosine 5′-phosphoromorpholidate(24)was prepared on the basis of a scalable to adenosine 5′′-monophosphate(2).The construction of P(V)−N bond in phosphoramidate is esteemed as a critical step as they are sufficiently stable in deprotection reactions.The chemical synthesis of ADPr-ATP can offer an appealing alternative to traditional enzymatic synthesis and fractionation methods.Furthermore,the pRib-AMP and its prodrug are also synthesized to evaluate cytotoxicity and anti-influenza activity in vitro.
基金supported by the National Natural Science Foundation of China(82341245,82371491)the Chinese Central Government(Key Project of Public Health Program)the National Key Research and Development Program of China(2018YFC1311706,2018YFC1311702)。
文摘Objective This study aimed to determine the temporal trends in sleep duration among Chinese adults.Methods In this series of repeated nationally representative cross-sectional surveys(China Chronic Disease and Risk Factors Surveillance)conducted between 2010 and 2018,a total of 645,420 adult participants(97,741 in 2010;175,749 in 2013;187,777 in 2015;and 184,153 in 2018)were included in the trend analysis.Linear and logistic regression models were utilized to assess trends in sleep duration.Results In 2018,the estimated overall mean sleep duration among the Chinese adult population was7.58(SD,1.45)hours per day,with no significant trend from 2010.A significant increase in short sleep duration(≤6 hours)was observed in the total population,from 15.3%(95%CI:14.1%–16.5%)in 2010 to18.5%(95%CI:17.7%–19.3%)in 2018(P<0.001).Similarly,the trend in long sleep duration(>9 hours)was also significant,increasing in weighted prevalence from 7.2%(95%CI:6.3%–8.1%)in 2010 to 9.0%(95%CI:8.2%–9.9%)in 2018(P<0.001).Conclusion The prevalence of both short and long sleep durations significantly increased among Chinese adults from 2010 to 2018,highlighting the urgency of health initiatives to promote optimal sleep duration in China.
基金Supported by the National Natural Science Foundation of China,No.82402789Beijing Jishuitan Hospital Youcai Plan,No.KYYC202402+1 种基金Beijing Jishuitan Research Funding,No.HL202402and Beijing Natural Science Foundation,No.L232062,No.L222063.
文摘BACKGROUND Aseptic loosening remains the leading cause of revision in primary total hip arthroplasty(pTHA).However,the literature demonstrates significant variability regarding the relative contributions of different factors.AIM To investigate the key determinants of aseptic loosening,we performed a systematic review and meta-analysis.METHODS A comprehensive search of PubMed,Web of Science,EMBASE,and the Cochrane Library was conducted,encompassing studies from database inception to January 1,2025.Meta-analyses were performed to evaluate factors associated with aseptic loosening following pTHA.Inclusion and exclusion criteria were systematically applied at each stage to ensure methodological transparency and reproducibility.Study quality was assessed using standardized categories.Pooled odds ratio(OR)with corresponding 95%confidence interval were calculated with random-or fixed-effects models to generate reliability estimates,and study heterogeneity was visualized using forest plots.Ten factors,categorized into patient-,surgeon-,and device-related domains,were reviewed and meta-analyzed.Funnel plot analysis demonstrated a relatively symmetrical distribution,suggesting minimal publication bias.RESULTS A meta-analysis of 20 studies(520789 participants)found a pooled prevalence of 1.96%.Significant risk factors for aseptic loosening after pTHA included elevated body mass index(OR=1.116,P<0.001),higher Charlson comorbidity index(OR=1.378,P<0.001),prosthesis-related factors(OR=1.497,P<0.001),and adverse lifestyles(OR=2.198,P=0.037).Protective factors were non-white race(OR=0.445,P<0.001)and favorable genetics(OR=0.723,P<0.001).Male sex increased risk(OR=1.232,P=0.016),while age and anatomy were not significant.Surgical expertise showed a slight protective effect(OR=1.048,P<0.001).A comprehensive understanding of the modifiable and non-modifiable factors contributing to aseptic loosening after pTHA requires consideration of patient-related factors,surgical expertise,and prosthesis characteristics.CONCLUSION The identification of these factors is critical for risk mitigation.High-risk patients should receive targeted counseling regarding individualized profiles.Further studies are warranted to establish clearer causal relationships and identify additional contributing factors.
文摘We investigated the impact of convexity and isoperimetric deficits on the accuracy of sectional area estimates of tree stems using traditional methods(caliper,tape,formulas based on stem diameter and circumference).In two complementary experiments,the use of photographs to estimate cross-sectional areas was first validated,then the use of a caliper and diameter tape was computer-simulated.The results indicated that the photographic method offers high precision,with mean relative errors below 0.1%,minimal deviation,and no significant bias,and the traditional methods led to substantial and systematic errors,with deviations from circularity and convexity significantly increasing the errors in area estimation.
基金supported by the National Natural Science Foundation of China(No.12301672)the Shanghai Science and Technology Innovation Action Plan(Yangfan Special Project),China(No.23YF1401300)。
文摘The micro-riblet structures have been demonstrated effective in controlling the Total Pressure Loss(TPL)of aero-engine blades.However,due to the considerable scale gap between micro-texture and an actual aero-engine blade,wind tunnel tests and numerical simulations with massive grids directly describing the global flow field are costly for aerodynamic evaluation.Furthermore,the fine micro surface structure brings unavoidable manufacturing errors,and the probability prediction contributes to gaining the confidence interval of the results.Therefore,a novel relay-based probabilistic model for multi-fidelity scenarios in the TPL prediction of a compressor cascade with micro-riblet surfaces is proposed to trade off accuracy and efficiency.Combined with the low-fidelity flow data generated by an aerodynamic solution strategy using the boundary surrogate model and the high-fidelity flow data from the experiment,the relay-based modeling has been achieved through knowledge transferring,and the confidence interval can be provided by the Gaussian Process Regression(GPR)model.The TPL of compressor cascades with micro-riblet surfaces under different surface structures at March number Ma=0.64,0.74,0.84 have been evaluated using the Relay-Based Probabilistic(RBP)model.The results illustrate that the RBP model could provide higher accuracy than the Single-Fidelity-Data-Driven(SFDD)prediction model,which show the promising potential of multi-fidelity scenarios data fusion in the aerodynamic evaluation of multi-scale configurations.
文摘Objective:To systematically summarize and evaluate the evidence on discharge preparation services for patients undergoing total knee arthroplasty,providing an evidence-based foundation for developing scientific and standardized discharge preparation intervention programs in clinical practice.Methods:Following the“5S”evidence model,literature such as guidelines,expert consensuses,evidence summaries and randomized controlled trials related to discharge preparation services for total knee arthroplasty patients were retrieved from relevant websites and databases,both domestic and international,from database inception to August 31,2025.Two researchers independently screened the literature,conducted quality appraisals,and extracted and synthesized the evidence.Results:A total of 15 articles were included,comprising 3 guidelines,4 expert consensuses,3 evidence summaries,3 systematic reviews and 2 randomized controlled trials.Ultimately,23 pieces of evidence were summarized across five aspects.Conclusion:This study synthesizes the evidence on discharge preparation services for patients undergoing total knee arthroplasty.It is recommended that healthcare professionals apply this evidence in clinical practice,considering specific circumstances and patient needs.
文摘Leg-length discrepancy(LLD)in individuals experiencing total hip arthroplasty(THA)is related to a substantially higher fall risk,length of post-operative hospital in-patient stay,elevated implant-related adverse events,and earlier revision.Therefore,it is essential to try to avoid LLD when implanting a THA.Several studies focus on this issue,including the following:Accelerometer-based portable navigation system,preoperative digital templating,robot-assisted surgery,the anatomical marker positioning method(shoulder-to-shoulder)and the artificial intelligence-based three-dimensional planning software system.The aforementioned methods should be familiar to surgeons who perform THA procedures,as a fundamental objective of this surgical intervention is to avoid LLD.
文摘BACKGROUND Salvage of the infected long stem revision total knee arthroplasty is challenging due to the presence of well-fixed ingrown or cemented stems.Reconstructive options are limited.Above knee amputation(AKA)is often recommended.We present a surgical technique that was successfully used on four such patients to convert them to a knee fusion(KF)using a cephalomedullary nail.CASE SUMMARY Four patients with infected long stem revision knee replacements that refused AKA had a single stage removal of their infected revision total knee followed by a KF.They were all treated with a statically locked antegrade cephalomedullary fusion nail,augmented with antibiotic impregnated bone cement.All patients had successful limb salvage and were ambulatory with assistive devices at the time of last follow-up.All were infection free at an average follow-up of 25.5 months(range 16-31).CONCLUSION Single stage cephalomedullary nailing can result in a successful KF in patients with infected long stem revision total knees.
文摘BACKGROUND The optimal surgical approach for patients with primary glenohumeral osteoarthritis(GHOA)and an intact rotator cuff remains debated.While anatomic total shoulder arthroplasty(TSA)has traditionally been favoured,reverse TSA(RTSA)is increasingly utilized.AIM To systematically compare the outcomes of RTSA and TSA in this specific patient population.METHODS A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines.Retrospective comparative studies evaluating RTSA and TSA in patients with GHOA and intact rotator cuff were included.Key outcomes assessed included complication and reoperation rates,patient-reported outcome measures(PROMs),and range of motion.Risk of bias was assessed using the Risk of Bias in Non-randomized Studies of Interventions tool.RESULTS Twelve studies encompassing 1608 patients(580 RTSA,1028 TSA)met inclusion criteria.RTSA was associated with a lower reoperation rate compared to TSA[odds ratio=0.37;95%confidence interval(CI):0.14-0.94;P value=0.04],while no significant difference in overall complication rates was observed(odds ratio=0.47;95%CI:0.19-1.16;P value=0.10).RTSA patients showed superior outcomes in University of California Los Angeles,Simple Shoulder Test,and Shoulder Pain and Disability Index scores;however,the differences did not exceed the minimal clinically important difference.TSA patients had significantly better external rotation(mean difference=-9.0°;95%CI:-13.21 to-5.02;P value<0.0001).No significant differences were found in other range of motion measures or satisfaction scores.The overall methodological quality of included studies was moderate to serious.CONCLUSION In patients with GHOA and an intact rotator cuff,RTSA may offer comparable or improved outcomes to TSA with lower reoperation rates and similar complication profiles.Functional outcomes favour RTSA in certain patientreported outcome measures,while TSA retains an advantage in external rotation.Surgical decision-making should remain individualized based on patient characteristics and functional demands.
文摘BACKGROUND Medial dished(MD)liner designs for cruciate-retaining(CR)total knee arthroplasty(TKA)are a relatively novel development.MD tibial inserts have a more constraining medial side,which allows for more similar kinematics and function to a native knee.AIM To evaluate the clinical results and patient-reported outcomes after CR TKA procedures utilizing a kinematically designed medial dish system.METHODS A multicenter,retrospective cohort review of 139 primary elective TKAs utilizing a kinematically designed CR Knee System(JOURNEY™II CR MD;Smith and Nephew,Memphis,TN,United States)at three different institutions with a minimum of two years of follow-up.Demographic information,clinical outcomes,and patient-reported outcome measures were collected and analyzed.RESULTS With up to 3.7 years from surgery,overall implant survivorship was 98.6%.There were significant postoperative increases in the average Knee Injury and Osteoarthritis Outcome Score for Joint Replacement scores(17.4 at 6 months,26.1 points at two years or more,P<0.001).CONCLUSION The combination of high implant survivorship and substantial improvements in patient-reported outcome measures suggests that the medial dish tibial insert represents a safe and effective option within TKA.Additional investigation is necessary to evaluate the long-term survivorship of this design.
文摘A bimorph piezoelectric beam with periodically variable cross-sections is used for the vibration energy harvesting. The effects of two geometrical parameters on the first band gap of this periodic beam are investigated by the generalized differential quadrature rule （GDQR） method. The GDQR method is also used to calculate the forced vibration response of the beam and voltage of each piezoelectric layer when the beam is subject to a sinusoidal base excitation. Results obtained from the analytical method are compared with those obtained from the finite element simulation with ANSYS, and good agreement is found. The voltage output of this periodic beam over its first band gap is calculated and compared with the voltage output of the uniform piezoelectric beam. It is concluded that this periodic beam has three advantages over the uniform piezoelectric beam, i.e., generating more voltage outputs over a wide frequency range, absorbing vibration, and being less weight.
基金National Natural Science Foundation of China(No.41801379)Fundamental Research Funds for the Central Universities(No.2019B08414)National Key R&D Program of China(No.2016YFC0401801)。
文摘Tunnel deformation monitoring is a crucial task to evaluate tunnel stability during the metro operation period.Terrestrial Laser Scanning(TLS)can collect high density and high accuracy point cloud data in a few minutes as an innovation technique,which provides promising applications in tunnel deformation monitoring.Here,an efficient method for extracting tunnel cross-sections and convergence analysis using dense TLS point cloud data is proposed.First,the tunnel orientation is determined using principal component analysis(PCA)in the Euclidean plane.Two control points are introduced to detect and remove the unsuitable points by using point cloud division and then the ground points are removed by defining an elevation value width of 0.5 m.Next,a z-score method is introduced to detect and remove the outlies.Because the tunnel cross-section’s standard shape is round,the circle fitting is implemented using the least-squares method.Afterward,the convergence analysis is made at the angles of 0°,30°and 150°.The proposed approach’s feasibility is tested on a TLS point cloud of a Nanjing subway tunnel acquired using a FARO X330 laser scanner.The results indicate that the proposed methodology achieves an overall accuracy of 1.34 mm,which is also in agreement with the measurements acquired by a total station instrument.The proposed methodology provides new insights and references for the applications of TLS in tunnel deformation monitoring,which can also be extended to other engineering applications.
文摘In this study,K and L shell photoeffect cross-sections were measured for the elements in the range of 50≤Z≤65at 59.5keV.These photoeffect cross-sections were measured by using the experimentalσKαproduction cross-section values measured in this paper and two different K shell fluorescence yield values in the literature.The results were compared with the calculated theoretical values.The values were plotted versus atomic number.
文摘The aim of this study was to compare mandibular form （i.e., size and shape） between patients with agenesis of the lower second premolar （P2） and a control group with no agenesis. Three hypotheses were tested： （H1） agenesis causes a change in mandibular morphology because of inadequate alveolar ridge development in the area of the missing tooth （mandibular plasticity）; （H2） agenesis is caused by spatial limitations within the mandible （dental plasticity）; and （H3） common genetic/ epigenetic factors cause agenesis and affect mandibular form （pleiotropy）. A geometric morphometric analysis was applied to cross-sectional images of computed tomography （CT） scans of three matched groups （n= 50 each）： （1） regularly erupted P2; （2） agenesis of P2 and the primary second molar in situ; and （3） agenesis of P2 and the primary second molar missing for 〉3 months. Cross-sections of the three areas of interest （first premolar, P2, first molar） were digitized with 23 landmarks and superimposed by a generalized Procrustes analysis. On average, the mandibular cross-sections were narrower and shorter in patients with P2 agenesis compared with that in the control group. Both agenesis groups featured a pronounced submandibular fossa. These differences extended at least one tooth beyond the agenesis-affected region. Taken together with the large interindividual variation that resulted in massively overlapping group distributions, these findings support genetic and/or epigenetic pleiotropy （H3） as the most likely origin of the observed covariation between mandibular form and odontogenesis. Clinically, reduced dimensions and greater variability of mandibular form, as well as a pronounced submandibular fossa, should be expected during the treatment planning of patients with P2 agenesis.
