This study intends to find out the correlation between the cover depth and the bond characteristics of UHPC through pull-out tests of UHPC specimens with different cover depths and bond tests of rebar using flexural m...This study intends to find out the correlation between the cover depth and the bond characteristics of UHPC through pull-out tests of UHPC specimens with different cover depths and bond tests of rebar using flexural members. In this experimental study, specimens are fabricated with the lap-splice length as test variable in relation with the calculation of the lap-splice length for 180- MPa UHPC. Moreover, specimens are also fabricated with the cover depth as test variable to evaluate the effect of the cover depth on the UHPC flexural members. The load-displacement curves are analyzed for each of these test variables to compute the lap-splice length proposed in the K-UHPC structural design guideline and to evaluate the influence of the cover depth on the flexural members. As a result, the stability of the structural behavior can be significantly enhanced by increasing slightly the cover depth specification of the current UHPC Structure Design Guideline from the maximum value between 1.5 times of rebar diameter and 20 mm to the maximum value between 1.5 times of rebar diameter and 25 mm.展开更多
The onset,cessation,and length of the rainy season are crucial for global water resources,agricultural practices,and food security.However,the response of precipitation seasonality to global warming remains uncertain....The onset,cessation,and length of the rainy season are crucial for global water resources,agricultural practices,and food security.However,the response of precipitation seasonality to global warming remains uncertain.In this study,we analyze how global warming levels(GWLs)of 1.5℃ and 2℃ could affect the timing of rainfall onset(RODs),rainfall cessation(RCDs),and the overall duration of the rainy season(LRS)over global land monsoon(GLM)regions using simulations from CMIP6 under the SSP2-4.5 and SSP5-8.5 scenarios.With high model consensus,our results reveal that RODs are projected to occur later over Southern Africa,North Africa,and South America,but earlier over South Asia and Australia,in a warmer climate.The projected early RODs in Australia are more pronounced at the 2℃ GWL under SSP5-8.5.On the other hand,early RCDs are projected over South America and East Asia,while late RCDs are projected over North Africa,with high inter-model agreement.These changes are associated with a future decrease in LRS in most GLM regions.Additionally,we found that continuous warming over 1.5℃ will further reduce the length of the rainy season,especially over the South America,North Africa,and Southern Africa monsoon regions.The findings underscore the urgent need to mitigate global warming.展开更多
Objective To identify risk factors contributing to prolonged postoperative length of stay(LOS)in very elderly patients following hip fracture surgery,with a focus on postoperative complications and the impact of diffe...Objective To identify risk factors contributing to prolonged postoperative length of stay(LOS)in very elderly patients following hip fracture surgery,with a focus on postoperative complications and the impact of different anesthesia approaches.Methods This retrospective single-center cohort study enrolled patients aged 90 years or older who underwent hip fracture surgery at Peking Union Medical College Hospital between January 31,2013 and December 31,2023.Relevant perioperative data were collected.The primary outcome was postoperative LOS,and the study cohort was divided into two groups:postoperative LOS≤7 days and LOS>7 days.Logistic regression was performed to identify factors related to prolonged postoperative LOS.Results A total of 155 patients were included.The average age was 92.7±2.6 years.There were 73(47%)patients with postoperative LOS>7 days.Postoperative pneumonia was the only factor associated with a prolonged postoperative LOS(OR=2.12,95%CI[1.09,4.16],P=0.028).Neither the type of anesthesia(regional vs.general anesthesia,OR=1.00,95%CI[0.53,1.90],P=0.993)nor the method of airway management(laryngeal mask ventilation vs.spontaneous breathing,OR=1.46,95%CI[0.58,3.76],P=0.424;endotracheal intubation vs.spontaneous breathing,OR=0.82,95%CI[0.39,1.69],P=0.592)showed a significant association with a prolonged postoperative LOS.Preoperative chronic obstructive pulmonary disease(OR=2.78,95%CI[1.05,7.65],P=0.040)and preoperative neutrophil count(OR=1.13,95%CI[1.01,1.26],P=0.029)were both significantly associated with the occurrence of postoperative pneumonia,while anesthesia type and airway management method were not.Conclusions Postoperative pneumonia was associated with prolonged postoperative LOS in very elderly patients undergoing hip fracture surgery,whereas anesthesia types and airway management methods show no association with prolonged postoperative LOS or postoperative pneumonia.Preoperative comorbidities,especially respiratory conditions and systemic inflammation,potentially play a substantial role in postoperative recovery.展开更多
Background:It is found to have association of facial parameters with trisomy 21 fetuses(T 21).We have compared prenasal thickness(PNT),nasal bone length(NBL),and the PNT:NBL ratio of normal fetuses with fetuses with t...Background:It is found to have association of facial parameters with trisomy 21 fetuses(T 21).We have compared prenasal thickness(PNT),nasal bone length(NBL),and the PNT:NBL ratio of normal fetuses with fetuses with trisomy 21(T 21)between 16 and 25 weeks of gestation as a diagnostic tool for T 21.Methods:Facial profile images in the two dimensional(2D)gray scale were assessed to measure fetal NBL and PNT between 16 and 25 weeks of gestation.The PNT:NBL ratio of the fetuses was calculated.Nomograms were constructed from the data of morphologically normal fetuses at live birth.The PNT,NBL,and PNT:NBL ratio of fetuses with confirmed T 21(n=31)and morphologically normal fetuses at live birth(controls,n=3485)were compared.Results:Nomograms for PNT,NBL,and the PNT:NBL ratio were constructed.In T 21 fetuses,PNT(>95th percentile),NBL(<5th percentile),and the PNT:NBL ratio(>95th percentile)showed a sensitivity of 25%,29%,and 45%for PNT,NBL,and PNT:NBL,respectively,and specificity of 95%,96%,and 94%,for PNT,NBL,and PNT:NBL,respectively.All of these markers showed a negative predictive value of 99%.Conclusion:PNT,NBL,and the PNT:NBL ratio have high diagnostic value for fetuses with Down syndrome and can be incorporated easily in the current second trimester screening protocol for T 21.PNT,NBL,and the PNT:NBL ratio are more specific markers for Down syndrome than those used in previous studies.展开更多
BACKGROUND Leg length discrepancy(LLD)following total hip arthroplasty(THA)is a common complaint,leading to decreased patient satisfaction.However,the effect of LLD before THA on outcomes and complications is not well...BACKGROUND Leg length discrepancy(LLD)following total hip arthroplasty(THA)is a common complaint,leading to decreased patient satisfaction.However,the effect of LLD before THA on outcomes and complications is not well defined.AIM To assess the effect of prior LLD on rates of falls,implant-related complications,stay length,readmissions,and implant survival following THA.METHODS A retrospective review of a nationwide insurance database was conducted from 2010 to 2021.All cases of THA and those with a prior diagnosis of LLD were identified.THA patients with LLD were matched to control patients 1:5 based on demographic and comorbidity profiles.Two-year fall rates and implant complications,lengths of stay,90-day readmissions,and time to revision were compared between cohorts.RESULTS A total of 2038 patients with LLD were matched to 10165 control patients.The LLD group showed significantly greater rates of falls[odds ratio(OR)=1.58;95%confidence interval(95%CI):1.24-2.01],dislocation(OR=2.61;95%CI:2.10-3.24),mechanical loosening(OR=4.58;95%CI:3.28-6.29),and periprosthetic fracture(OR=2.70;95%CI:1.96-3.72)compared to the control group(all P<0.001).Mean length of stay(LOS)was also significantly higher in the LLD group(3.1 days vs 2.8 days,P=0.034).No significant difference in 90-day readmission rates(7.75%vs 7.02%,P=0.244)was observed between the groups(P=0.244).Time to revision was significantly less in the LLD group(225 days vs 544 days,P<0.001).CONCLUSION LLD in patients having THA is related with significantly higher fall risk,rates of implant-related complications,LOS,and quicker time to revision.Identifying patients with LLD before their THA may help in identifying risks,better patient counselling,and more effective preoperative planning.However,the study have important limitations:Its design lacks information on the degree and cause of LLD,the time between diagnosis and surgery,and which leg with the discrepancy underwent the operation.Future well-designed studies should confirm the findings of this study.展开更多
Objective:To investigate the influence of axial length(AL),corneal curvature(CR),and the ratio of axial length to corneal radius of curvature(AL/CR)on myopia in children,and to evaluate the accuracy and specificity of...Objective:To investigate the influence of axial length(AL),corneal curvature(CR),and the ratio of axial length to corneal radius of curvature(AL/CR)on myopia in children,and to evaluate the accuracy and specificity of AL/CR in diagnosing myopia in children.Methods:A cross-sectional study was conducted.A total of 200 children(400 eyes)aged 6-12 years were recruited from the ophthalmology outpatient clinic of Fuling District People’s Hospital from December 2022 to December 2023.AL,CR,and AL/CR were measured,and comprehensive optometry was performed under cycloplegia,with the results recorded in spherical equivalent(SE)form.Results:A total of 200 subjects(400 eyes)were included in this study,of which 330 eyes(82.50%)were myopic.No significant differences in CR were observed among different refractive groups,while significant differences were noted in SE,AL,and AL/CR.The AL and AL/CR ratios were higher in myopic eyes compared to emmetropic and hyperopic eyes.Using cycloplegia as the gold standard,SE in the myopia group was correlated with AL,AL/CR,and CR,with stronger correlations observed with AL and AL/CR.An AL/CR value>3 demonstrated a sensitivity of 0.918,specificity of 0.786,misdiagnosis rate of 0.214,missed diagnosis rate of 0.082,and accuracy of 89.5%in diagnosing myopia.Conclusion:AL and AL/CR values are highly correlated with SE,with the strongest correlation observed in the myopia group.The AL/CR value exhibits high diagnostic value in determining myopia in children.展开更多
Objective:To explore the correlation between fetal foot length measured by ultrasound and gestational age.Methods:This study employed ultrasound to measure the fetal foot length,femoral length,and foot length/femoral ...Objective:To explore the correlation between fetal foot length measured by ultrasound and gestational age.Methods:This study employed ultrasound to measure the fetal foot length,femoral length,and foot length/femoral length ratio in 214 pregnant women from 12 to 40 weeks of gestation,all of whom had no pregnancy complications or obstetric complications,and whose fetuses were normal.Results:A significant positive correlation was found between fetal foot length and gestational age(r=0.967,p<0.001);a similarly significant positive correlation was observed between fetal femoral length and gestational age(r=0.972,p<0.001);and a non-significant positive correlation was noted between the foot length/femoral length ratio and gestational age(r=0.943,p<0.001).Conclusion:Ultrasound can accurately measure fetal foot length and femoral length,both of which exhibit a significant positive correlation with gestational age,making them important reference indicators for assessing fetal growth and development.展开更多
AIM:To investigate the ocular biological characteristics of children with myopia and rapid axial length(AL)changes prescribed spectacles with highly aspherical lenslets(HAL).METHODS:Data were collected from 156 childr...AIM:To investigate the ocular biological characteristics of children with myopia and rapid axial length(AL)changes prescribed spectacles with highly aspherical lenslets(HAL).METHODS:Data were collected from 156 children(252 eyes)with myopia and HAL treatment who were aged 7-13 and had rapid AL changes.The participants were divided into groups with AL reduction and elongation according to the changes in AL within 6mo.Paired t-tests were used to compare the ocular biological parameters at baseline and after rapid changes post-HAL treatment.Pearson’s correlation analysis was used to determine the association between the ocular parameters and AL changes.RESULTS:The ocular biological parameters significantly changed in the children with myopia and rapid AL changes after HAL treatment.In the group with AL reduction,the anterior chamber depth(ACD)and vitreous chamber depth(VCD)decreased.The crystalline lens thickness(CLT)increased,corneal flat keratometry(FK)decreased,and steep keratometry(SK)increased(all P<0.001).The eyes in the group with AL elongation had increased ACD and VCD and steepened SK,but the CLT or FK findings were not different.AL change was negatively associated with baseline astigmatism(r=-0.171;P=0.007).CONCLUSION:In the eyes with HAL treatment,decreased ACD and VCD,thickened CLT,flattened FK,and steepened SK are observed during AL reduction.Lower baseline astigmatism is associated with AL reduction.The AL reduction may suggest the potential efficacy of HAL intervention in myopia control,while providing evidence for optimizing personalized myopia management strategies.Further longitudinal studies are warranted to validate whether rapid AL changes predict sustained treatment efficacy.展开更多
We report an interesting and abnormal electromagnetic phenomenon with regard to a terajet(TJ)that is generated in a reflection mode,which is realized by placing a dielectric scatterer onto a metal reflection plate.We ...We report an interesting and abnormal electromagnetic phenomenon with regard to a terajet(TJ)that is generated in a reflection mode,which is realized by placing a dielectric scatterer onto a metal reflection plate.We show that the introduction of an air hollow into metal reflection plate beneath the scatterer does not induce an expected decrease but an abnormal increase of focal length of the TJ by as much as more than three times.This abnormal phenomenon takes place in case that the air hollow is shallow and there exists a critical hollow depth for a given lateral size of air hollow.Larger than the critical depth,the phenomenon no longer occurs.It is explained from viewpoints of both ray optics in terms of role of relative portion of central waves in TJ formation and electromagnetic field theory with regard to hollow-induced phase singularities.展开更多
Grain size is a crucial factor influencing both rice yield and appearance quality.In this study,we identified GL6.1 as a gene associated with rice grain size by map-based cloning.The GL6.1 encodes a protein with CC-NB...Grain size is a crucial factor influencing both rice yield and appearance quality.In this study,we identified GL6.1 as a gene associated with rice grain size by map-based cloning.The GL6.1 encodes a protein with CC-NB-LRR domain,a structural motif related to rice disease resistance.Genetic transformation experiments and the construction of gene pyramiding lines indicate that GL6.1 functions as a negative regulatory factor for rice grain length.By the analysis of SSSLs with diverse donor parents,a total of 11 single nucleotide polymorphisms(SNPs)are identified that are closely associated with the phenotype variations.A yeast one-hybrid library screening revealed that GL6.1 interacts with OsWRKY53,a transcription factor associated with rice disease resistance.Furthermore,RNA-seq assay also revealed the involvement of pathways associated with disease resistance,hinting at a multifaceted role for GL6.1 in both yield and stress tolerance traits in rice.These results indicate that the cloning and in-depth studies of GL6.1 would provide valuable insights into the interplay among high yield,superior quality,and stress tolerance,which are critical goals for rice breeding.展开更多
AIM:To evaluate the efficacy of the Tecnis Symfony ZXR00 lens in achieving optimal visual outcomes for cataract surgery patients with axial length(AL)shorter than 24 mm.METHODS:A total of 21 subjects(37 eyes)were subm...AIM:To evaluate the efficacy of the Tecnis Symfony ZXR00 lens in achieving optimal visual outcomes for cataract surgery patients with axial length(AL)shorter than 24 mm.METHODS:A total of 21 subjects(37 eyes)were submitted to cataract surgery and implantation of Tecnis Symfony ZXR00 lens(Johnson&Johnson Vision)was assessed.Patients were examined at 5 m,80 cm,and 40 cm for uncorrected distance visual acuity(UCDVA)and corrected distance visual acuity(CDVA),uncorrected intermediate(UCIVA),and uncorrected near visual acuity(UCNVA).Further,based on the optimal distance correction,the monocular defocusing curve in the range of+0.5 to-3.5 D was investigated.A simple patient-reported spectacle independence questionnaire(PRSIQ)was used to evaluate subjects’subjective feelings about their dependence on glasses at various distances.Multiple linear regression was employed to examine the association amony intraocular lenses(IOLs)diopter,AL,corneal curvature,anterior chamber depth,mean manifest refractive spherical equivalent,pupil,pupil/scan,target refraction,and near vision(logMAR).RESULTS:The study demonstrated enhanced UCNVA alongside comparable distant vision and UCIVA outcomes in eyes with AL shorter than 24 mm.Mean post-operative UCDVA significantly improved from preoperative levels 0.530±0.406(P=0.000).Notably,83.3%of eyes achieved 0.01 logMAR in UCNVA.Five unilateral cases with blended IOL implantation also showed satisfactory visual acuity and satisfaction.The 90.5%(19/21)achieved spectacle independence.The average score for self-reported spectacle-independence on the PRSIQ was 3.52 with a standard deviation of 0.98.The results of the regression analysis revealed that one predictor,the pupil/scan accounted for 27.6%of the variation in near vision[logMAR;F(1,35)=13.33,P<0.01].CONCLUSION:The results affirm the effectiveness of the Tecnis Symfony ZXR00 lens in enhancing visual outcomes for cataract surgery patients with AL shorter than 24 mm.Additionally,the pupil/scan emerges as a critical factor influencing postoperative near vision.展开更多
AIM:To compare the effects of different types of negative pressure suction on the macular and optic disc retinal vessel density(VD)in myopic patients with different axial lengths(ALs)undergoing femtosecond laser-assis...AIM:To compare the effects of different types of negative pressure suction on the macular and optic disc retinal vessel density(VD)in myopic patients with different axial lengths(ALs)undergoing femtosecond laser-assisted excimer laser in situ keratomileusis(FS-LASIK)by optical coherence tomography angiography(OCTA).METHODS:A prospective,nonrandomized,controlled study.Participants underwent FS-LASIK surgery were divided into the short AL group(SAL,22≤AL<26 mm)and the long AL group(LAL,26≤AL<28 mm)according to the different ALs.Further,the two groups were divided into subgroups according to the corneal flap using VisuMax or WaveLight FS200 femtosecond laser(FS)platform.All patients underwent OCTA before the surgery and 1-day/1-week/1-month after the surgery.ANOVA statistically analyzed data with two-factor repeated measurement in SPSS.RESULTS:Totally 108 participants(108 eyes,18–35y)were divided into SAL group[22 patients(4 males and 18 females)were treated with VisuMax,and 24(3 males and 21 females)were treated with WaveLight FS200]and LAL group[34 patients(4 males and 30 females)were treated with VisuMax,and 28 patients(6 males and 22 females)were treated with WaveLight FS200].In the LAL group,there was no significant difference in macular superficial capillary plexuses vessel density(SCP-VD)in the fovea and perifovea region,but compared with the VisuMax subgroup,SCP-VD in the parafoveal region(t=2.647,P=0.010)and the whole area(t=2.030,P=0.047)in WaveLight FS200 subgroup decreased at one day after the operation and increased to a preoperative level at 1-week and 1-month after operation.There was no significant difference between SCP-VD in the two SAL subgroups,neither of deep capillary plexuses vessel density(DCP-VD)and optic nerve head vessel density(ONH-VD)in the SAL and LAL groups.CONCLUSION:With the increase of AL and suction intensity,a transient decrease of SCP-VD in the macular region is observed at 1d postoperatively during FS-LASIK,and it increases to preoperative level at 1-week and 1-month postoperatively.However,the AL and suction intensity do not affect the macular DCP-VD and ONH-VD.展开更多
The crystallization behavior of polymers is significantly influenced by molecular chain length and the dispersion of varying chain lengths.The complexity of studying crystallization arises from the dispersity of polym...The crystallization behavior of polymers is significantly influenced by molecular chain length and the dispersion of varying chain lengths.The complexity of studying crystallization arises from the dispersity of polymer materials and the typically slow cooling rates.Recent advancements in fast cooling techniques have rendered the investigation of polymer crystallization at varying cooling rates an attractive area of research;however,a systematic quantitative framework for this process is still lacking.We employ a coarse-grained model for polyvinyl alcohol(CGPVA)in molecular dynamics simulations to study the crystallization of linear polymers with varying chain lengths under variable cooling rates.Monodisperse,bidisperse and polydisperse samples are simulated.We propose two formulae based on a two-phase assumption to fit the exothermal curves obtained during cooling.Based on these formulae,better estimations of crystallization temperatures are obtained and the effects of chain lengths and cooling rates are studied.It is found that the crystallization temperature increases with chain length,similar to the Gibbs-Thomson relation formelting temperature,indicating a strong relation between fast crystallization and glass formation in linear polymers.Extrapolation to the infinitely slow cooling rate provides an easy way in simulations to estimate the equilibrium crystallization temperature.The effective chain lengths of polydisperse and bidisperse samples are found to be the number-averaged chain lengths compared to the weight-averaged ones.The chain length-dependent crystallization exhibits crossover behavior near the entanglement length,indicating the effects of entanglements under fast cooling conditions.The effect of chain length dispersity on crystallization becomes more obvious under fast cooling conditions.展开更多
Liquid cooling through a cold plate offers an efficient solution for battery thermal management.Excellent flow and heat transfer performance can be obtained by optimizing the flow channel structure of the cold plate u...Liquid cooling through a cold plate offers an efficient solution for battery thermal management.Excellent flow and heat transfer performance can be obtained by optimizing the flow channel structure of the cold plate using the topology optimization method.However,due to the uneven channel width of the optimized cold plate,there are some difficulties in processing,which affect its practical application in battery thermal management.In this study,the length scale control method is applied to a topology-optimized cold plate.An optimized cold plate considering length scale control is designed and processed,and its experimental results of flow and heat transfer are compared with those of a traditional cold plate and an optimized cold plate without length scale control.Results show that the relative deviations between the numerical and experimental results with length scale control are within 5%and 8%for temperature and pressure drop,respectively.The flow channel structure of the cold plate with length scale control is simpler and easier to process than that of the cold plate without length scale control.When the inlet velocity is 0.23 m/s,the maximum temperature,maximum temperature difference,and pressure drop of the cold plate with length scale control are 5.7 K,4.4 K,and 0.56 Pa lower than those of the traditional cold plate,respectively.This study provides valuable insights and practical guidance for the manufacturing and implementation of topology-optimized cold plates in battery thermal management systems.展开更多
The anchoring capacity of the anchor cable is closely related to the bonding length and radial pressure conditions.Through field pull-out tests,theoretical analysis,numerical simulation,and industrial tests,this study...The anchoring capacity of the anchor cable is closely related to the bonding length and radial pressure conditions.Through field pull-out tests,theoretical analysis,numerical simulation,and industrial tests,this study clarifies the relationship between radial pressure and bonding length for the ultimate pullout force and reveals the microscopic failure process of the resin-rock interface in the anchoring system.The results show that the ultimate load increases with the increase of bonding length in three different stages:rapid,slow,and uniform growth.The new mechanical model developed considering radial pressure describes the inverse relationship between radial pressure and the plastic zone on the bonding section,and quantifies the reinforcing effect of confining pressure on the anchoring force.During the pull-out process of the anchor cable,the generation of failure cracks is in the order of orifice,bottom,and middle of the hole.Radial pressure can effectively enhance the ultimate pull-out force,alleviate the oscillation increase of pull-out force,and inhibit resin cracking,but will produce an external crushing zone.It also reveals the synergistic effect between bonding length and radial pressure,and successfully carries out industrial tests of anchor cable support,which ensures the stability of the stope roof and provides an important reference for the design of anchor cable support in deep high-stress mines.展开更多
Large grain is a favorable trait for appearance quality and a large sink potential in wheat breeding.The stable QTL QGl.caas-5BS for grain length was previously identified in a recombinant inbred line population from ...Large grain is a favorable trait for appearance quality and a large sink potential in wheat breeding.The stable QTL QGl.caas-5BS for grain length was previously identified in a recombinant inbred line population from the cross of Zhongmai 871(ZM871)and its sister line Zhongmai 895(ZM895).Here,a BC_(1)F_6 residual heterozygous line was selected from the cross of a ZM871/ZM895//ZM871 population,and six heterozygous recombinant plants were identified in the BC_(1)F_(7)population from self-pollination of the heterozygous line.QGl.caas-5BS was delimited into an interval of approximately 2.2 Mb flanked by markers Kasp_5B33 and Kasp_5B2(25.3-27.5 Mb)by phenotyping and genotyping the secondary mapping populations derived from these heterozygous recombinant plants.Five genes were predicted as candidates of QGl.caas-5BS based on sequence polymorphism and differential expression analyses.Further mutation analysis showed that TraesCS5B02G026800 is likely the causal gene of QGl.caas-5BS.The gene-specific marker Kasp_5B_Gl for TraesCS5B02G026800 was developed,and a significant genetic effect of QGl.caas-5BS on grain length was identified in a validation population of 166 cultivars using this marker.These findings lay a good foundation for map-based cloning of QGl.caas-5BS and provide a breeding-applicable marker for the improvement of grain length in wheat.展开更多
BACKGROUND:The problem of prolonged emergency department length of stay(EDLOS) is becoming increasingly crucial.This study aims to develop a machine learning(ML) model to predict EDLOS,with EDLOS as the outcome variab...BACKGROUND:The problem of prolonged emergency department length of stay(EDLOS) is becoming increasingly crucial.This study aims to develop a machine learning(ML) model to predict EDLOS,with EDLOS as the outcome variable and demographic characteristics,triage level,and medical resource utilization as predictive factors.METHODS:A retrospective analysis was performed on the patients who visited the emergency department of the Second Affiliated Hospital of Guangzhou Medical University from March 2019to September 2021,and a total of 321,012 cases were identified.According to the inclusion and exclusion criteria,187,028 cases were finally included in the analysis.ML analysis was performed using R-squared(R^(2)),and the predictive factors and the EDLOS were used as independent variables and dependent variables,respectively,to establish models.The performance evaluation of the ML models was conducted through the utilization of the mean absolute error(MAE),root mean square error(RMSE),and R^(2),enabling an objective comparative analysis.RESULTS:In the comparative analysis of the six ML models,light gradient boosting machine(LightGBM) model demonstrated the lowest MAE(443.519) and RMSE(826.783),and the highest R^(2) value(0.48),indicating better model fit and predictive performance.Among the top 10 predictive factors associated with EDLOS according to the LightGBM model,the emergency waiting time,age,and emergency arrival time had the most significant impact on the EDLOS.CONCLUSION:The LightGBM model suggests that the emergency waiting time,age,and emergency arrival time may be used to predict the EDLOS.展开更多
AIM:To determine the utility of the RS-1 spectral domain optical coherence tomography(SD-OCT),which incorporates an“OCT Analysis Correction Parameter”for approximating axial length,in comparison with measurements ob...AIM:To determine the utility of the RS-1 spectral domain optical coherence tomography(SD-OCT),which incorporates an“OCT Analysis Correction Parameter”for approximating axial length,in comparison with measurements obtained from the OA-2000.METHODS:Twenty-five right eyes of healthy individuals were included.Two horizontal line scans were conducted using the RS-1,and OCT Analysis Correction Parameters were recorded.Axial length was measured twice per eye using the OA-2000.Correlation between devices was assessed using Pearson correlation coefficient,coefficient of repeatability(CR%),and Bland-Altman analysis.RESULTS:High correlation was found between axial length measurements from RS-1 and OA-2000(r=0.986,P<0.0001).The coefficient of repeatability was 1.56%for RS-1 and 0.115%for OA-2000.Mean axial length was 25.12±1.38 mm for RS-1 and 24.90±1.54 mm for OA-2000,with RS-1 showing a statistically significant larger value(paired t-test,P=0.0009).CONCLUSION:The axial length measurements of RS-1 demonstrate a strong positive correlation with those from the OA-2000.This indicates that it could potentially be used to forecast scan ranges and choose suitable databases according to axial length categories.展开更多
Objective Telomere length is a key aging biomarker,but its sex-specific impact on individualized life expectancy remains uncertain.This study explores sex differences in leukocyte telomere length(LTL)and individualize...Objective Telomere length is a key aging biomarker,but its sex-specific impact on individualized life expectancy remains uncertain.This study explores sex differences in leukocyte telomere length(LTL)and individualized expected years of life lost(YLL).Methods A prospective cohort of 445,399 participants(203,731 males and 241,668 females)from the UK Biobank was analyzed.LTL values were log-transformed,and YLL was calculated using life tables.Multiple linear regression was applied to examine sex-specific associations.Results In males,each standard deviation(S.D.)increase in LTL was linked to a 0.965-year decrease in YLL(95%CI:–1.025,–0.900;P<0.001).In females,longer LTL was related to a 0.102-year increase in YLL(95%CI:0.057,0.146;P<0.001).Among postmenopausal females,LTL showed a protective effect similar to that in males(0.387-year decrease,95%CI:−0.446,–0.328;P<0.001),while premenopausal females exhibited a detrimental association(0.705-year increase,95%CI:0.625,0.785;P<0.001).Comparable trends were observed across major aging-related diseases,pointing to a consistent biological pattern.Conclusion The influence of LTL on life expectancy varies significantly by sex,with protective associations seen in males and postmenopausal females.This suggests hormonal involvement in telomere dynamics.The results support integrating sex-specific perspectives into aging and telomere research and clinical practice.展开更多
Accurate measurement of anchor rod length is crucial for ensuring structural safety in tunnel engineering,yet conventional destructive techniques face limitations in efficiency and adaptability to complex underground ...Accurate measurement of anchor rod length is crucial for ensuring structural safety in tunnel engineering,yet conventional destructive techniques face limitations in efficiency and adaptability to complex underground environments.This study presents a novel wireless instrument based on the standing wave principle to enable remote,non-destructive length assessment.The system employs a master-slave architecture,where a handheld transmitter unit initiates measurements through robust 433 MHz wireless communication,optimized for signal penetration in obstructed spaces.The embedded measurement unit,integrated with anchor rods during installation,utilizes frequency-scanning technology to excite structural resonances.By analyzing standing wave characteristics,anchor length is derived from a calibrated frequency-length relationship.Power management adopts a standby-activation strategy to minimize energy consumption while maintaining operational readiness.Experimental validation confirms the system effectively measures anchor lengths with high precision and maintains reliable signal transmission through thick concrete barriers,demonstrating suitability for tunnel deployment.The non-destructive approach eliminates structural damage risks associated with traditional pull-out tests,while wireless operation enhances inspection efficiency in confined spaces.Thiswork establishes a paradigmfor embedded structural healthmonitoring in tunneling,offering significant improvements over existing methods in safety,cost-effectiveness,and scalability.The technology holds promise for broad applications in mining,underground infrastructure,and geotechnical engineering.展开更多
文摘This study intends to find out the correlation between the cover depth and the bond characteristics of UHPC through pull-out tests of UHPC specimens with different cover depths and bond tests of rebar using flexural members. In this experimental study, specimens are fabricated with the lap-splice length as test variable in relation with the calculation of the lap-splice length for 180- MPa UHPC. Moreover, specimens are also fabricated with the cover depth as test variable to evaluate the effect of the cover depth on the UHPC flexural members. The load-displacement curves are analyzed for each of these test variables to compute the lap-splice length proposed in the K-UHPC structural design guideline and to evaluate the influence of the cover depth on the flexural members. As a result, the stability of the structural behavior can be significantly enhanced by increasing slightly the cover depth specification of the current UHPC Structure Design Guideline from the maximum value between 1.5 times of rebar diameter and 20 mm to the maximum value between 1.5 times of rebar diameter and 25 mm.
基金supported by the Australian Research Council(Grant No.CE230100012)。
文摘The onset,cessation,and length of the rainy season are crucial for global water resources,agricultural practices,and food security.However,the response of precipitation seasonality to global warming remains uncertain.In this study,we analyze how global warming levels(GWLs)of 1.5℃ and 2℃ could affect the timing of rainfall onset(RODs),rainfall cessation(RCDs),and the overall duration of the rainy season(LRS)over global land monsoon(GLM)regions using simulations from CMIP6 under the SSP2-4.5 and SSP5-8.5 scenarios.With high model consensus,our results reveal that RODs are projected to occur later over Southern Africa,North Africa,and South America,but earlier over South Asia and Australia,in a warmer climate.The projected early RODs in Australia are more pronounced at the 2℃ GWL under SSP5-8.5.On the other hand,early RCDs are projected over South America and East Asia,while late RCDs are projected over North Africa,with high inter-model agreement.These changes are associated with a future decrease in LRS in most GLM regions.Additionally,we found that continuous warming over 1.5℃ will further reduce the length of the rainy season,especially over the South America,North Africa,and Southern Africa monsoon regions.The findings underscore the urgent need to mitigate global warming.
文摘Objective To identify risk factors contributing to prolonged postoperative length of stay(LOS)in very elderly patients following hip fracture surgery,with a focus on postoperative complications and the impact of different anesthesia approaches.Methods This retrospective single-center cohort study enrolled patients aged 90 years or older who underwent hip fracture surgery at Peking Union Medical College Hospital between January 31,2013 and December 31,2023.Relevant perioperative data were collected.The primary outcome was postoperative LOS,and the study cohort was divided into two groups:postoperative LOS≤7 days and LOS>7 days.Logistic regression was performed to identify factors related to prolonged postoperative LOS.Results A total of 155 patients were included.The average age was 92.7±2.6 years.There were 73(47%)patients with postoperative LOS>7 days.Postoperative pneumonia was the only factor associated with a prolonged postoperative LOS(OR=2.12,95%CI[1.09,4.16],P=0.028).Neither the type of anesthesia(regional vs.general anesthesia,OR=1.00,95%CI[0.53,1.90],P=0.993)nor the method of airway management(laryngeal mask ventilation vs.spontaneous breathing,OR=1.46,95%CI[0.58,3.76],P=0.424;endotracheal intubation vs.spontaneous breathing,OR=0.82,95%CI[0.39,1.69],P=0.592)showed a significant association with a prolonged postoperative LOS.Preoperative chronic obstructive pulmonary disease(OR=2.78,95%CI[1.05,7.65],P=0.040)and preoperative neutrophil count(OR=1.13,95%CI[1.01,1.26],P=0.029)were both significantly associated with the occurrence of postoperative pneumonia,while anesthesia type and airway management method were not.Conclusions Postoperative pneumonia was associated with prolonged postoperative LOS in very elderly patients undergoing hip fracture surgery,whereas anesthesia types and airway management methods show no association with prolonged postoperative LOS or postoperative pneumonia.Preoperative comorbidities,especially respiratory conditions and systemic inflammation,potentially play a substantial role in postoperative recovery.
文摘Background:It is found to have association of facial parameters with trisomy 21 fetuses(T 21).We have compared prenasal thickness(PNT),nasal bone length(NBL),and the PNT:NBL ratio of normal fetuses with fetuses with trisomy 21(T 21)between 16 and 25 weeks of gestation as a diagnostic tool for T 21.Methods:Facial profile images in the two dimensional(2D)gray scale were assessed to measure fetal NBL and PNT between 16 and 25 weeks of gestation.The PNT:NBL ratio of the fetuses was calculated.Nomograms were constructed from the data of morphologically normal fetuses at live birth.The PNT,NBL,and PNT:NBL ratio of fetuses with confirmed T 21(n=31)and morphologically normal fetuses at live birth(controls,n=3485)were compared.Results:Nomograms for PNT,NBL,and the PNT:NBL ratio were constructed.In T 21 fetuses,PNT(>95th percentile),NBL(<5th percentile),and the PNT:NBL ratio(>95th percentile)showed a sensitivity of 25%,29%,and 45%for PNT,NBL,and PNT:NBL,respectively,and specificity of 95%,96%,and 94%,for PNT,NBL,and PNT:NBL,respectively.All of these markers showed a negative predictive value of 99%.Conclusion:PNT,NBL,and the PNT:NBL ratio have high diagnostic value for fetuses with Down syndrome and can be incorporated easily in the current second trimester screening protocol for T 21.PNT,NBL,and the PNT:NBL ratio are more specific markers for Down syndrome than those used in previous studies.
文摘BACKGROUND Leg length discrepancy(LLD)following total hip arthroplasty(THA)is a common complaint,leading to decreased patient satisfaction.However,the effect of LLD before THA on outcomes and complications is not well defined.AIM To assess the effect of prior LLD on rates of falls,implant-related complications,stay length,readmissions,and implant survival following THA.METHODS A retrospective review of a nationwide insurance database was conducted from 2010 to 2021.All cases of THA and those with a prior diagnosis of LLD were identified.THA patients with LLD were matched to control patients 1:5 based on demographic and comorbidity profiles.Two-year fall rates and implant complications,lengths of stay,90-day readmissions,and time to revision were compared between cohorts.RESULTS A total of 2038 patients with LLD were matched to 10165 control patients.The LLD group showed significantly greater rates of falls[odds ratio(OR)=1.58;95%confidence interval(95%CI):1.24-2.01],dislocation(OR=2.61;95%CI:2.10-3.24),mechanical loosening(OR=4.58;95%CI:3.28-6.29),and periprosthetic fracture(OR=2.70;95%CI:1.96-3.72)compared to the control group(all P<0.001).Mean length of stay(LOS)was also significantly higher in the LLD group(3.1 days vs 2.8 days,P=0.034).No significant difference in 90-day readmission rates(7.75%vs 7.02%,P=0.244)was observed between the groups(P=0.244).Time to revision was significantly less in the LLD group(225 days vs 544 days,P<0.001).CONCLUSION LLD in patients having THA is related with significantly higher fall risk,rates of implant-related complications,LOS,and quicker time to revision.Identifying patients with LLD before their THA may help in identifying risks,better patient counselling,and more effective preoperative planning.However,the study have important limitations:Its design lacks information on the degree and cause of LLD,the time between diagnosis and surgery,and which leg with the discrepancy underwent the operation.Future well-designed studies should confirm the findings of this study.
基金Chongqing Fuling District Science and Health Joint Medical Research Project(2022KWLH069)。
文摘Objective:To investigate the influence of axial length(AL),corneal curvature(CR),and the ratio of axial length to corneal radius of curvature(AL/CR)on myopia in children,and to evaluate the accuracy and specificity of AL/CR in diagnosing myopia in children.Methods:A cross-sectional study was conducted.A total of 200 children(400 eyes)aged 6-12 years were recruited from the ophthalmology outpatient clinic of Fuling District People’s Hospital from December 2022 to December 2023.AL,CR,and AL/CR were measured,and comprehensive optometry was performed under cycloplegia,with the results recorded in spherical equivalent(SE)form.Results:A total of 200 subjects(400 eyes)were included in this study,of which 330 eyes(82.50%)were myopic.No significant differences in CR were observed among different refractive groups,while significant differences were noted in SE,AL,and AL/CR.The AL and AL/CR ratios were higher in myopic eyes compared to emmetropic and hyperopic eyes.Using cycloplegia as the gold standard,SE in the myopia group was correlated with AL,AL/CR,and CR,with stronger correlations observed with AL and AL/CR.An AL/CR value>3 demonstrated a sensitivity of 0.918,specificity of 0.786,misdiagnosis rate of 0.214,missed diagnosis rate of 0.082,and accuracy of 89.5%in diagnosing myopia.Conclusion:AL and AL/CR values are highly correlated with SE,with the strongest correlation observed in the myopia group.The AL/CR value exhibits high diagnostic value in determining myopia in children.
文摘Objective:To explore the correlation between fetal foot length measured by ultrasound and gestational age.Methods:This study employed ultrasound to measure the fetal foot length,femoral length,and foot length/femoral length ratio in 214 pregnant women from 12 to 40 weeks of gestation,all of whom had no pregnancy complications or obstetric complications,and whose fetuses were normal.Results:A significant positive correlation was found between fetal foot length and gestational age(r=0.967,p<0.001);a similarly significant positive correlation was observed between fetal femoral length and gestational age(r=0.972,p<0.001);and a non-significant positive correlation was noted between the foot length/femoral length ratio and gestational age(r=0.943,p<0.001).Conclusion:Ultrasound can accurately measure fetal foot length and femoral length,both of which exhibit a significant positive correlation with gestational age,making them important reference indicators for assessing fetal growth and development.
基金Supported by the Medical Science and Technology Project of Zhejiang Province of China(No.2020KY191).
文摘AIM:To investigate the ocular biological characteristics of children with myopia and rapid axial length(AL)changes prescribed spectacles with highly aspherical lenslets(HAL).METHODS:Data were collected from 156 children(252 eyes)with myopia and HAL treatment who were aged 7-13 and had rapid AL changes.The participants were divided into groups with AL reduction and elongation according to the changes in AL within 6mo.Paired t-tests were used to compare the ocular biological parameters at baseline and after rapid changes post-HAL treatment.Pearson’s correlation analysis was used to determine the association between the ocular parameters and AL changes.RESULTS:The ocular biological parameters significantly changed in the children with myopia and rapid AL changes after HAL treatment.In the group with AL reduction,the anterior chamber depth(ACD)and vitreous chamber depth(VCD)decreased.The crystalline lens thickness(CLT)increased,corneal flat keratometry(FK)decreased,and steep keratometry(SK)increased(all P<0.001).The eyes in the group with AL elongation had increased ACD and VCD and steepened SK,but the CLT or FK findings were not different.AL change was negatively associated with baseline astigmatism(r=-0.171;P=0.007).CONCLUSION:In the eyes with HAL treatment,decreased ACD and VCD,thickened CLT,flattened FK,and steepened SK are observed during AL reduction.Lower baseline astigmatism is associated with AL reduction.The AL reduction may suggest the potential efficacy of HAL intervention in myopia control,while providing evidence for optimizing personalized myopia management strategies.Further longitudinal studies are warranted to validate whether rapid AL changes predict sustained treatment efficacy.
基金Project supported by the National Natural Science Foundation of China(Grant No.61875148)the Key Awards Program of Cultivating Outstanding Innovative Postgraduates in Arts and Sciences of Tianjin University(Grant No.C1-2022002)+3 种基金the Talent Project of Anhui Science and Technology University(Grant No.DQYJ202304)the University-Level Research Project of Tianjin Sino-German University of Applied Sciences(Grant No.zdkt2018-007)China Association for Science and Technology Young Talent Support Project Doctoral Special Programthe National High-level University Scholarship Program for Graduate Students of China Scholarship Council(Grant No.202406250166)。
文摘We report an interesting and abnormal electromagnetic phenomenon with regard to a terajet(TJ)that is generated in a reflection mode,which is realized by placing a dielectric scatterer onto a metal reflection plate.We show that the introduction of an air hollow into metal reflection plate beneath the scatterer does not induce an expected decrease but an abnormal increase of focal length of the TJ by as much as more than three times.This abnormal phenomenon takes place in case that the air hollow is shallow and there exists a critical hollow depth for a given lateral size of air hollow.Larger than the critical depth,the phenomenon no longer occurs.It is explained from viewpoints of both ray optics in terms of role of relative portion of central waves in TJ formation and electromagnetic field theory with regard to hollow-induced phase singularities.
基金supported by STI 2030-Major Project(2023ZD04069)the National Natural Science Foundation of China(32472129,U24A20392,32201841)+1 种基金Regional Joint Youth Fund for Basic and Applied Basic Research Foundation of Guangdong Province(2022 A1515110454)Science and Technology Projects in Guangzhou(2023B03J1355).
文摘Grain size is a crucial factor influencing both rice yield and appearance quality.In this study,we identified GL6.1 as a gene associated with rice grain size by map-based cloning.The GL6.1 encodes a protein with CC-NB-LRR domain,a structural motif related to rice disease resistance.Genetic transformation experiments and the construction of gene pyramiding lines indicate that GL6.1 functions as a negative regulatory factor for rice grain length.By the analysis of SSSLs with diverse donor parents,a total of 11 single nucleotide polymorphisms(SNPs)are identified that are closely associated with the phenotype variations.A yeast one-hybrid library screening revealed that GL6.1 interacts with OsWRKY53,a transcription factor associated with rice disease resistance.Furthermore,RNA-seq assay also revealed the involvement of pathways associated with disease resistance,hinting at a multifaceted role for GL6.1 in both yield and stress tolerance traits in rice.These results indicate that the cloning and in-depth studies of GL6.1 would provide valuable insights into the interplay among high yield,superior quality,and stress tolerance,which are critical goals for rice breeding.
文摘AIM:To evaluate the efficacy of the Tecnis Symfony ZXR00 lens in achieving optimal visual outcomes for cataract surgery patients with axial length(AL)shorter than 24 mm.METHODS:A total of 21 subjects(37 eyes)were submitted to cataract surgery and implantation of Tecnis Symfony ZXR00 lens(Johnson&Johnson Vision)was assessed.Patients were examined at 5 m,80 cm,and 40 cm for uncorrected distance visual acuity(UCDVA)and corrected distance visual acuity(CDVA),uncorrected intermediate(UCIVA),and uncorrected near visual acuity(UCNVA).Further,based on the optimal distance correction,the monocular defocusing curve in the range of+0.5 to-3.5 D was investigated.A simple patient-reported spectacle independence questionnaire(PRSIQ)was used to evaluate subjects’subjective feelings about their dependence on glasses at various distances.Multiple linear regression was employed to examine the association amony intraocular lenses(IOLs)diopter,AL,corneal curvature,anterior chamber depth,mean manifest refractive spherical equivalent,pupil,pupil/scan,target refraction,and near vision(logMAR).RESULTS:The study demonstrated enhanced UCNVA alongside comparable distant vision and UCIVA outcomes in eyes with AL shorter than 24 mm.Mean post-operative UCDVA significantly improved from preoperative levels 0.530±0.406(P=0.000).Notably,83.3%of eyes achieved 0.01 logMAR in UCNVA.Five unilateral cases with blended IOL implantation also showed satisfactory visual acuity and satisfaction.The 90.5%(19/21)achieved spectacle independence.The average score for self-reported spectacle-independence on the PRSIQ was 3.52 with a standard deviation of 0.98.The results of the regression analysis revealed that one predictor,the pupil/scan accounted for 27.6%of the variation in near vision[logMAR;F(1,35)=13.33,P<0.01].CONCLUSION:The results affirm the effectiveness of the Tecnis Symfony ZXR00 lens in enhancing visual outcomes for cataract surgery patients with AL shorter than 24 mm.Additionally,the pupil/scan emerges as a critical factor influencing postoperative near vision.
基金Supported by Wu Jieping Medical Foundation(No.320.6750.2021-4-15).
文摘AIM:To compare the effects of different types of negative pressure suction on the macular and optic disc retinal vessel density(VD)in myopic patients with different axial lengths(ALs)undergoing femtosecond laser-assisted excimer laser in situ keratomileusis(FS-LASIK)by optical coherence tomography angiography(OCTA).METHODS:A prospective,nonrandomized,controlled study.Participants underwent FS-LASIK surgery were divided into the short AL group(SAL,22≤AL<26 mm)and the long AL group(LAL,26≤AL<28 mm)according to the different ALs.Further,the two groups were divided into subgroups according to the corneal flap using VisuMax or WaveLight FS200 femtosecond laser(FS)platform.All patients underwent OCTA before the surgery and 1-day/1-week/1-month after the surgery.ANOVA statistically analyzed data with two-factor repeated measurement in SPSS.RESULTS:Totally 108 participants(108 eyes,18–35y)were divided into SAL group[22 patients(4 males and 18 females)were treated with VisuMax,and 24(3 males and 21 females)were treated with WaveLight FS200]and LAL group[34 patients(4 males and 30 females)were treated with VisuMax,and 28 patients(6 males and 22 females)were treated with WaveLight FS200].In the LAL group,there was no significant difference in macular superficial capillary plexuses vessel density(SCP-VD)in the fovea and perifovea region,but compared with the VisuMax subgroup,SCP-VD in the parafoveal region(t=2.647,P=0.010)and the whole area(t=2.030,P=0.047)in WaveLight FS200 subgroup decreased at one day after the operation and increased to a preoperative level at 1-week and 1-month after operation.There was no significant difference between SCP-VD in the two SAL subgroups,neither of deep capillary plexuses vessel density(DCP-VD)and optic nerve head vessel density(ONH-VD)in the SAL and LAL groups.CONCLUSION:With the increase of AL and suction intensity,a transient decrease of SCP-VD in the macular region is observed at 1d postoperatively during FS-LASIK,and it increases to preoperative level at 1-week and 1-month postoperatively.However,the AL and suction intensity do not affect the macular DCP-VD and ONH-VD.
基金National Natural Science Foundation of China No.22341302.
文摘The crystallization behavior of polymers is significantly influenced by molecular chain length and the dispersion of varying chain lengths.The complexity of studying crystallization arises from the dispersity of polymer materials and the typically slow cooling rates.Recent advancements in fast cooling techniques have rendered the investigation of polymer crystallization at varying cooling rates an attractive area of research;however,a systematic quantitative framework for this process is still lacking.We employ a coarse-grained model for polyvinyl alcohol(CGPVA)in molecular dynamics simulations to study the crystallization of linear polymers with varying chain lengths under variable cooling rates.Monodisperse,bidisperse and polydisperse samples are simulated.We propose two formulae based on a two-phase assumption to fit the exothermal curves obtained during cooling.Based on these formulae,better estimations of crystallization temperatures are obtained and the effects of chain lengths and cooling rates are studied.It is found that the crystallization temperature increases with chain length,similar to the Gibbs-Thomson relation formelting temperature,indicating a strong relation between fast crystallization and glass formation in linear polymers.Extrapolation to the infinitely slow cooling rate provides an easy way in simulations to estimate the equilibrium crystallization temperature.The effective chain lengths of polydisperse and bidisperse samples are found to be the number-averaged chain lengths compared to the weight-averaged ones.The chain length-dependent crystallization exhibits crossover behavior near the entanglement length,indicating the effects of entanglements under fast cooling conditions.The effect of chain length dispersity on crystallization becomes more obvious under fast cooling conditions.
基金supported by the National Natural Science Foundation of China(No.52206271)Guangxi Science and Technology Major Program(GK-AA23062070)+2 种基金the National Natural Science Foundation of China(No.52306266)the Key Project of Natural Science Funds of Tianjin City(No.24JCZDJC01060)funded by the Key Laboratory of Shallow Geothermal Energy,Ministry of Natural Resources of the People’s Republic of China(No.KLSGE202401-04).
文摘Liquid cooling through a cold plate offers an efficient solution for battery thermal management.Excellent flow and heat transfer performance can be obtained by optimizing the flow channel structure of the cold plate using the topology optimization method.However,due to the uneven channel width of the optimized cold plate,there are some difficulties in processing,which affect its practical application in battery thermal management.In this study,the length scale control method is applied to a topology-optimized cold plate.An optimized cold plate considering length scale control is designed and processed,and its experimental results of flow and heat transfer are compared with those of a traditional cold plate and an optimized cold plate without length scale control.Results show that the relative deviations between the numerical and experimental results with length scale control are within 5%and 8%for temperature and pressure drop,respectively.The flow channel structure of the cold plate with length scale control is simpler and easier to process than that of the cold plate without length scale control.When the inlet velocity is 0.23 m/s,the maximum temperature,maximum temperature difference,and pressure drop of the cold plate with length scale control are 5.7 K,4.4 K,and 0.56 Pa lower than those of the traditional cold plate,respectively.This study provides valuable insights and practical guidance for the manufacturing and implementation of topology-optimized cold plates in battery thermal management systems.
基金Financial supports for this work,provided by the National Natural Science Foundation Project of China(No.52374152)the Guangxi Science and Technology Plan Project of China(No.2022AB31023)the National Basic Research Development Program of China(No.2022YFC2904602)are gratefully acknowledged。
文摘The anchoring capacity of the anchor cable is closely related to the bonding length and radial pressure conditions.Through field pull-out tests,theoretical analysis,numerical simulation,and industrial tests,this study clarifies the relationship between radial pressure and bonding length for the ultimate pullout force and reveals the microscopic failure process of the resin-rock interface in the anchoring system.The results show that the ultimate load increases with the increase of bonding length in three different stages:rapid,slow,and uniform growth.The new mechanical model developed considering radial pressure describes the inverse relationship between radial pressure and the plastic zone on the bonding section,and quantifies the reinforcing effect of confining pressure on the anchoring force.During the pull-out process of the anchor cable,the generation of failure cracks is in the order of orifice,bottom,and middle of the hole.Radial pressure can effectively enhance the ultimate pull-out force,alleviate the oscillation increase of pull-out force,and inhibit resin cracking,but will produce an external crushing zone.It also reveals the synergistic effect between bonding length and radial pressure,and successfully carries out industrial tests of anchor cable support,which ensures the stability of the stope roof and provides an important reference for the design of anchor cable support in deep high-stress mines.
基金funded by the National Natural Science Foundation of China(31961143007)the Key Research and Development Program of Xinjiang Uygur Autonomous Region,China(2023B02006)+1 种基金the Core Research Budget of the Non-profit Governmental Research Institutions,Institute of Crop Sciences,Chinese Academy of Agricultural Sciences(S2021ZD04 and S2022ZD04)the Natural Science Foundation of Hebei Province,China(C2021205013)。
文摘Large grain is a favorable trait for appearance quality and a large sink potential in wheat breeding.The stable QTL QGl.caas-5BS for grain length was previously identified in a recombinant inbred line population from the cross of Zhongmai 871(ZM871)and its sister line Zhongmai 895(ZM895).Here,a BC_(1)F_6 residual heterozygous line was selected from the cross of a ZM871/ZM895//ZM871 population,and six heterozygous recombinant plants were identified in the BC_(1)F_(7)population from self-pollination of the heterozygous line.QGl.caas-5BS was delimited into an interval of approximately 2.2 Mb flanked by markers Kasp_5B33 and Kasp_5B2(25.3-27.5 Mb)by phenotyping and genotyping the secondary mapping populations derived from these heterozygous recombinant plants.Five genes were predicted as candidates of QGl.caas-5BS based on sequence polymorphism and differential expression analyses.Further mutation analysis showed that TraesCS5B02G026800 is likely the causal gene of QGl.caas-5BS.The gene-specific marker Kasp_5B_Gl for TraesCS5B02G026800 was developed,and a significant genetic effect of QGl.caas-5BS on grain length was identified in a validation population of 166 cultivars using this marker.These findings lay a good foundation for map-based cloning of QGl.caas-5BS and provide a breeding-applicable marker for the improvement of grain length in wheat.
基金supported by Guangzhou Municipal Health Science and Technology General Program (20221A011083)the Key Medical Disciplines and Specialties Program of Guangzhou(2021-2023)Guangdong University Innovation Team Project(2024KCXTD029)。
文摘BACKGROUND:The problem of prolonged emergency department length of stay(EDLOS) is becoming increasingly crucial.This study aims to develop a machine learning(ML) model to predict EDLOS,with EDLOS as the outcome variable and demographic characteristics,triage level,and medical resource utilization as predictive factors.METHODS:A retrospective analysis was performed on the patients who visited the emergency department of the Second Affiliated Hospital of Guangzhou Medical University from March 2019to September 2021,and a total of 321,012 cases were identified.According to the inclusion and exclusion criteria,187,028 cases were finally included in the analysis.ML analysis was performed using R-squared(R^(2)),and the predictive factors and the EDLOS were used as independent variables and dependent variables,respectively,to establish models.The performance evaluation of the ML models was conducted through the utilization of the mean absolute error(MAE),root mean square error(RMSE),and R^(2),enabling an objective comparative analysis.RESULTS:In the comparative analysis of the six ML models,light gradient boosting machine(LightGBM) model demonstrated the lowest MAE(443.519) and RMSE(826.783),and the highest R^(2) value(0.48),indicating better model fit and predictive performance.Among the top 10 predictive factors associated with EDLOS according to the LightGBM model,the emergency waiting time,age,and emergency arrival time had the most significant impact on the EDLOS.CONCLUSION:The LightGBM model suggests that the emergency waiting time,age,and emergency arrival time may be used to predict the EDLOS.
文摘AIM:To determine the utility of the RS-1 spectral domain optical coherence tomography(SD-OCT),which incorporates an“OCT Analysis Correction Parameter”for approximating axial length,in comparison with measurements obtained from the OA-2000.METHODS:Twenty-five right eyes of healthy individuals were included.Two horizontal line scans were conducted using the RS-1,and OCT Analysis Correction Parameters were recorded.Axial length was measured twice per eye using the OA-2000.Correlation between devices was assessed using Pearson correlation coefficient,coefficient of repeatability(CR%),and Bland-Altman analysis.RESULTS:High correlation was found between axial length measurements from RS-1 and OA-2000(r=0.986,P<0.0001).The coefficient of repeatability was 1.56%for RS-1 and 0.115%for OA-2000.Mean axial length was 25.12±1.38 mm for RS-1 and 24.90±1.54 mm for OA-2000,with RS-1 showing a statistically significant larger value(paired t-test,P=0.0009).CONCLUSION:The axial length measurements of RS-1 demonstrate a strong positive correlation with those from the OA-2000.This indicates that it could potentially be used to forecast scan ranges and choose suitable databases according to axial length categories.
基金supported by the National Natural Science Foundation of China(82192903,82192904)the National Science and Technology Major Projects of China(2023ZD0510103)。
文摘Objective Telomere length is a key aging biomarker,but its sex-specific impact on individualized life expectancy remains uncertain.This study explores sex differences in leukocyte telomere length(LTL)and individualized expected years of life lost(YLL).Methods A prospective cohort of 445,399 participants(203,731 males and 241,668 females)from the UK Biobank was analyzed.LTL values were log-transformed,and YLL was calculated using life tables.Multiple linear regression was applied to examine sex-specific associations.Results In males,each standard deviation(S.D.)increase in LTL was linked to a 0.965-year decrease in YLL(95%CI:–1.025,–0.900;P<0.001).In females,longer LTL was related to a 0.102-year increase in YLL(95%CI:0.057,0.146;P<0.001).Among postmenopausal females,LTL showed a protective effect similar to that in males(0.387-year decrease,95%CI:−0.446,–0.328;P<0.001),while premenopausal females exhibited a detrimental association(0.705-year increase,95%CI:0.625,0.785;P<0.001).Comparable trends were observed across major aging-related diseases,pointing to a consistent biological pattern.Conclusion The influence of LTL on life expectancy varies significantly by sex,with protective associations seen in males and postmenopausal females.This suggests hormonal involvement in telomere dynamics.The results support integrating sex-specific perspectives into aging and telomere research and clinical practice.
基金supported in part by the Natural Science Foundation of Gansu Province(Nos.20JR10RA614,22YF7GA182,22JR11RA042,22JR5RA1006,24CXGA024)the National Natural Science Foundation of China under Grant 61804071.
文摘Accurate measurement of anchor rod length is crucial for ensuring structural safety in tunnel engineering,yet conventional destructive techniques face limitations in efficiency and adaptability to complex underground environments.This study presents a novel wireless instrument based on the standing wave principle to enable remote,non-destructive length assessment.The system employs a master-slave architecture,where a handheld transmitter unit initiates measurements through robust 433 MHz wireless communication,optimized for signal penetration in obstructed spaces.The embedded measurement unit,integrated with anchor rods during installation,utilizes frequency-scanning technology to excite structural resonances.By analyzing standing wave characteristics,anchor length is derived from a calibrated frequency-length relationship.Power management adopts a standby-activation strategy to minimize energy consumption while maintaining operational readiness.Experimental validation confirms the system effectively measures anchor lengths with high precision and maintains reliable signal transmission through thick concrete barriers,demonstrating suitability for tunnel deployment.The non-destructive approach eliminates structural damage risks associated with traditional pull-out tests,while wireless operation enhances inspection efficiency in confined spaces.Thiswork establishes a paradigmfor embedded structural healthmonitoring in tunneling,offering significant improvements over existing methods in safety,cost-effectiveness,and scalability.The technology holds promise for broad applications in mining,underground infrastructure,and geotechnical engineering.
