A lot of research has been focused on the necking process during the plastic deformation of sheet metals, but the localized necking is rarely distinguished form diffused necking by experiments, due to the limit of mea...A lot of research has been focused on the necking process during the plastic deformation of sheet metals, but the localized necking is rarely distinguished form diffused necking by experiments, due to the limit of measurement equipment and method. Quenching and Partitioning (Q&P) steel is a 3rd generation advanced high strength steel (AHSS). Its good combination of high strength and ductility ensures potential application in automobile industry. Uniaxial tensile tests of QP980 steel sheet at five strain rates are performed to investigate the necking process and the effect of strain rate on necking behavior of Q&P steel. Digital image correlation (DIC) method is applied during tensile tests, and evolutions of major strain, minor strain and normal strain distributions along gauge section of the tensile specimens are obtained. The diffused and localized necking strains are determined according to SWIFT necking theory and HILL necking theory respectively. The test results indicate that with the increasing of strain rate in the investigated range, the diffused necking strain decreases from 0.152 to 0.120 and localized necking strain decreases from 0.245 to 0.137. Meanwhile, the difference of the two strains decreases form 0.096 to 0.017. Thus it can be concluded that strain rate has an influence on both necking strains during the deformation of QP980 steel sheet. Diffused and localized necking strains are determined by uniaxial tensile tests with the aid of DIC technique and the effect of strain rate on necking strains is evaluated.展开更多
Necking defects have long troubled the application of cross-wedge rolling technology in aluminium alloy shaft parts.To accurately predict necking defects,new judgement conditions are established based on the thermal p...Necking defects have long troubled the application of cross-wedge rolling technology in aluminium alloy shaft parts.To accurately predict necking defects,new judgement conditions are established based on the thermal performance of 6082 aluminium alloy.The limit-sectional shrinkage without necking defects is achieved by combining theoretical calculation and finite-element model analysis,which couples heat transfer and deformation.In this paper,a 6082 aluminium alloy extruded rod with a 40 mm diameter rolled at a preheated temperature of 500℃and a rolling angular velocity of 1 rad/s is taken as an example.The simulation and experimental results show that necking defects do not occur on the rolled pieces if the sectional shrinkage is below the limit-sectional shrinkage but will occur when the sectional shrinkage is above it.The results prove that the prediction model of necking defects in cross-wedge rolling of 6082 aluminum alloy is feasible,and this research provides a theoretical basis for the qualified aluminum alloy shafts produced by the cross-wedge rolling.展开更多
The spinning deformation of thin walled tube in necking process is simulated with a dynamic explicit FEM program,LS DYNA3D and the distributions of Cauchy strains and thickness are analyzed through time history to a...The spinning deformation of thin walled tube in necking process is simulated with a dynamic explicit FEM program,LS DYNA3D and the distributions of Cauchy strains and thickness are analyzed through time history to achieve a good understanding of the deformation in necking process by spinning and the numerical simulation results are in good agreement with the test results.展开更多
Cross-over method is established to predict necking point for PET high- speed fiber spinning. Even slowly crystallizing polymers such as PET can crystallize on the spinline at sufficiently high spinning speed. The dev...Cross-over method is established to predict necking point for PET high- speed fiber spinning. Even slowly crystallizing polymers such as PET can crystallize on the spinline at sufficiently high spinning speed. The development of rtmning velocity, temperature, crystallinity and theological force is investigated for the take-up velocity over a range of 6 000 - 10 000 m/min. The position of necking point, temperature rise and abrupt increase of crystallinity move closer to the spinneret with the increase of take-up velocity,展开更多
A large number of criteria has been developed to predict material instabilities, but their choice is limited by the lack of existing comparison of their theoretical basis and application domains. To overcome this limi...A large number of criteria has been developed to predict material instabilities, but their choice is limited by the lack of existing comparison of their theoretical basis and application domains. To overcome this limitation, a theoretical and numerical comparison of two major models used to predict diffuse necking is present in this paper. Limit Point Bifurcation criterion is first introduced. An original formulation of the Maximum Force Criterion (MFC), taking into account the effects of damage and isotropic and kinematic hardenings, is then proposed. Strong connections are shown between them by comparing their theoretical basis. Numerical Forming Limit Diagrams at diffuse necking obtained with these criteria for different metallic materials are given. They illustrate the theoretical link and similar predictions are shown for both models.展开更多
BACKGROUND Dislocation rates after hemiarthroplasty reportedly vary from 1%to 17%.This serious complication is associated with increased morbidity and mortality rates.Approaches to this surgery are still debated,with ...BACKGROUND Dislocation rates after hemiarthroplasty reportedly vary from 1%to 17%.This serious complication is associated with increased morbidity and mortality rates.Approaches to this surgery are still debated,with no consensus regarding the superiority of any single approach.AIM To compare early postoperative complications after implementing the direct anterior and posterior approaches(PL)for hip hemiarthroplasty after femoral neck fractures.METHODS This is a comparative,retrospective,single-center cohort study conducted at a university hospital.Between March 2008 and December 2018,273 patients(a total of 280 hips)underwent bipolar hemiarthroplasties(n=280)for displaced femoral neck fractures using either the PL(n=171)or the minimally invasive direct anterior approach(DAA)(n=109).The choice of approach was related to the surgeons’practices;the implant types were similar and unrelated to the approach.Dislocation rates and other complications were reviewed after a minimum followup of 6 mo.RESULTS Both treatment groups had similarly aged patients(mean age:82 years),sex ratios,patient body mass indexes,and patient comorbidities.Surgical data(surgery delay time,operative time,and blood loss volume)did not differ significantly between the groups.The 30 d mortality rate was higher in the PL group(9.9%)than in the DAA group(3.7%),but the difference was not statistically significant(P=0.052).Among the one-month survivors,a significantly higher rate of dislocation was observed in the PL group(14/154;9.1%)than in the DAA group(0/105;0%)(P=0.002).Of the 14 patients with dislocation,8 underwent revision surgery for recurrent instability(posterior group),and one of them had 2 additional procedures due to a deep infection.The rate of other complications(e.g.,perioperative and early postoperative periprosthetic fractures and infection-related complications)did not differ significantly between the groups.CONCLUSION These findings suggest that the DAA to bipolar hemiarthroplasty for patients with femoral neck fractures is associated with a lower dislocation rate(<1%)than the PL.展开更多
Modern medicine is reliant on various medical imaging technologies for non-invasively observing patients’anatomy.However,the interpretation of medical images can be highly subjective and dependent on the expertise of...Modern medicine is reliant on various medical imaging technologies for non-invasively observing patients’anatomy.However,the interpretation of medical images can be highly subjective and dependent on the expertise of clinicians.Moreover,some potentially useful quantitative information in medical images,especially that which is not visible to the naked eye,is often ignored during clinical practice.In contrast,radiomics performs high-throughput feature extraction from medical images,which enables quantitative analysis of medical images and prediction of various clinical endpoints.Studies have reported that radiomics exhibits promising performance in diagnosis and predicting treatment responses and prognosis,demonstrating its potential to be a non-invasive auxiliary tool for personalized medicine.However,radiomics remains in a developmental phase as numerous technical challenges have yet to be solved,especially in feature engineering and statistical modeling.In this review,we introduce the current utility of radiomics by summarizing research on its application in the diagnosis,prognosis,and prediction of treatment responses in patients with cancer.We focus on machine learning approaches,for feature extraction and selection during feature engineering and for imbalanced datasets and multi-modality fusion during statistical modeling.Furthermore,we introduce the stability,reproducibility,and interpretability of features,and the generalizability and interpretability of models.Finally,we offer possible solutions to current challenges in radiomics research.展开更多
Objective:Bladder neck contracture and vesicourethral anastomotic stenosis are difficult to manage endoscopically,and open repair is associated with high rates of incontinence.In recent years,there have been increasin...Objective:Bladder neck contracture and vesicourethral anastomotic stenosis are difficult to manage endoscopically,and open repair is associated with high rates of incontinence.In recent years,there have been increasing reports of robotic-assisted bladder neck reconstruction in the literature.However,existing studies are small,heterogeneous case series.The objective of this study was to perform a systematic review of robotic-assisted bladder neck reconstruction to better evaluate patency and incontinence outcomes.Methods:We performed a systematic review of PubMed from first available date to May 2023 for all studies evaluating robotic-assisted reconstructive surgery of the bladder neck in adult men.Articles in non-English,author replies,editorials,pediatric-based studies,and reviews were excluded.Outcomes of interest were patency and incontinence rates,which were pooled when appropriate.Results:After identifying 158 articles on initial search,we included only ten studies that fit all aforementioned criteria for robotic-assisted bladder neck reconstruction.All were case series published from March 2018 to March 2022 ranging from six to 32 men,with the median follow-up of 5e23 months.A total of 119 patients were included in our analysis.A variety of etiologies and surgical techniques were described.Patency rates ranged from 50%to 100%,and pooled patency was 80%(95/119).De novo incontinence rates ranged from 0%to 33%,and pooled incontinence was 17%(8/47).Our findings were limited by small sample sizes,relatively short follow-ups,and heterogeneity between studies.展开更多
Laryngopharyngeal reflux disease(LPRD)is an inflammatory condition in the laryngopharynx and upper aerodigestive tract mucosa caused by reflux of stomach contents beyond the esophagus.LPRD commonly presents with sympt...Laryngopharyngeal reflux disease(LPRD)is an inflammatory condition in the laryngopharynx and upper aerodigestive tract mucosa caused by reflux of stomach contents beyond the esophagus.LPRD commonly presents with symptoms such as hoarseness,cough,sore throat,a feeling of throat obstruction,excessive throat mucus.This complex condition is thought to involve both reflux and reflex mechanisms,but a clear understanding of its molecular mechanisms is still lacking.Currently,there is no standardized diagnosis or treatment protocol.Therapeutic strategies for LPRD mainly include lifestyle modifications,proton pump inhibitors and endoscopic surgery.This paper seeks to provide a comprehensive overview of the existing literature regarding the mechanisms,pathophysiology and treatment of LPRD.We also provide an in-depth exploration of the association between LPRD and gastroesophageal reflux disease.展开更多
目的 分析甲状腺乳头状癌(PTC)超声图像表现在预测颈部Ⅵ区淋巴结转移(lymph node metastasis in the cervicalregion Ⅵ,CLNM-Ⅵ)危险度的临床价值。方法 选取2022年4月~2023年6月在河北省沧州中西医结合医院接受手术治疗并经病理证实...目的 分析甲状腺乳头状癌(PTC)超声图像表现在预测颈部Ⅵ区淋巴结转移(lymph node metastasis in the cervicalregion Ⅵ,CLNM-Ⅵ)危险度的临床价值。方法 选取2022年4月~2023年6月在河北省沧州中西医结合医院接受手术治疗并经病理证实的350例PTC患者,根据术后病理结果,将患者分为CLNM-Ⅵ组和非CLNM-Ⅵ组。收集并对比两组术前超声图像表现及临床病理特征,应用Logistic回归分析PTC患者CLNM-Ⅵ危险因素,受试者工作特征(ROC)曲线分析PTC超声图像表现对CLNM-Ⅵ的预测价值。结果 单因素分析显示,CLNM-Ⅵ组男性、实性或囊实性、年龄≤45岁、低回声、甲状腺背景正常、点状强回声的构成比均大于非CLNM-Ⅵ组(P均<0.05)。Logistic回归分析显示,男性、实性或囊实性、年龄≤45岁、低回声、甲状腺背景正常、病灶内可见点状强回声是CLNM-Ⅵ的独立危险因素(P均<0.05);进一步经ROC曲线分析显示,以上预测CLNM-Ⅵ的AUC分别为0.565、0.580、0.529、0.585、0.582、0.582,联合预测AUC为0.708。结论PTC超声图像表现在CLNM-Ⅵ风险评估中具有重要意义,可为PTC的预后判断提供一定的参考依据。展开更多
The formability of the material determines the amount of available deformation before failure and thus is important for the production of various structural components in industries. The workability of materiMs is com...The formability of the material determines the amount of available deformation before failure and thus is important for the production of various structural components in industries. The workability of materiMs is commonly evaluated by different forms of failure mod- els during sheet metal forming （SMF） processes. In order to provide a whole picture about the prediction models for SMF failure, necking-related formability and ductile fracture-related forma- bility studies in SMF processes are systematically summarized, the applicability and limitation of each model are highlighted, and the link between forming limit diagram and ductile fracture criterion is pointed out, Conclusions about some critical issues on failure in SMF are made.展开更多
The tension necking of FCC copper single crystal specimen with a square cross section was analyzed under the slip deformation mechanism. The actual clamp manner of the specimen was modeled by setting correlative bound...The tension necking of FCC copper single crystal specimen with a square cross section was analyzed under the slip deformation mechanism. The actual clamp manner of the specimen was modeled by setting correlative boundary condition,and the small angle deflection between tension loading axis and crystallography axis [100] was taken into account. The finite deformation numerical analysis of three-dimensional necking deformation for the specimen was performed by apply-ing crystal plasticity theory associated with a numerical algorithm suggested by the first author. According to the comparison with experimental observation,the fact was confirmed that the numerical results could describe the loading elongation curve of the copper single crystal specimen under large strain tension reasonably,and the method could be used to investigate the necking characteristic in neck shape and the effect due to the small angle deflection. Further,the investigation into the influence of specimen cross-section shape on necking was also performed;the results on mechanical response and neck profile evolution obtained through modeling of cylindrical specimen were compared with those obtained with square cross-section specimen.展开更多
Objective In kinesin-3,the neck coil correlates with the following segments to form an extended neck that contains a characteristic hinge diverse from a proline in KIF13B to a long flexible linker in KIF1A.The functio...Objective In kinesin-3,the neck coil correlates with the following segments to form an extended neck that contains a characteristic hinge diverse from a proline in KIF13B to a long flexible linker in KIF1A.The function of this neck hinge for controlling processive movement,however,remains unclear.Methods We made a series of modifications to the neck hinges of KIF13B and KIF1A and tested their movement using a single-molecule motility assay.Results In KIF13B,the insertion of flexible residues before or after the proline differentially impacts the processivity or velocity,while the removal of this proline increases the both.In KIF1A,the deletion of entire flexible neck hinge merely enhances the processivity.The engineering of these hinge-truncated necks of kinesin-3 into kinesin-1 similarly boosts the processive movement of kinesin-1.Conclusion The neck hinge in kinesin-3 controls its processive movement and proper modifications tune the motor motility,which provides a novel strategy to reshape the processive movement of kinesin motors.展开更多
文摘A lot of research has been focused on the necking process during the plastic deformation of sheet metals, but the localized necking is rarely distinguished form diffused necking by experiments, due to the limit of measurement equipment and method. Quenching and Partitioning (Q&P) steel is a 3rd generation advanced high strength steel (AHSS). Its good combination of high strength and ductility ensures potential application in automobile industry. Uniaxial tensile tests of QP980 steel sheet at five strain rates are performed to investigate the necking process and the effect of strain rate on necking behavior of Q&P steel. Digital image correlation (DIC) method is applied during tensile tests, and evolutions of major strain, minor strain and normal strain distributions along gauge section of the tensile specimens are obtained. The diffused and localized necking strains are determined according to SWIFT necking theory and HILL necking theory respectively. The test results indicate that with the increasing of strain rate in the investigated range, the diffused necking strain decreases from 0.152 to 0.120 and localized necking strain decreases from 0.245 to 0.137. Meanwhile, the difference of the two strains decreases form 0.096 to 0.017. Thus it can be concluded that strain rate has an influence on both necking strains during the deformation of QP980 steel sheet. Diffused and localized necking strains are determined by uniaxial tensile tests with the aid of DIC technique and the effect of strain rate on necking strains is evaluated.
基金Project(51975301)supported by the National Natural Science Foundation of ChinaProject(LZ17E050001)supported by the National Natural Science Foundation of Zhejiang Province of China。
文摘Necking defects have long troubled the application of cross-wedge rolling technology in aluminium alloy shaft parts.To accurately predict necking defects,new judgement conditions are established based on the thermal performance of 6082 aluminium alloy.The limit-sectional shrinkage without necking defects is achieved by combining theoretical calculation and finite-element model analysis,which couples heat transfer and deformation.In this paper,a 6082 aluminium alloy extruded rod with a 40 mm diameter rolled at a preheated temperature of 500℃and a rolling angular velocity of 1 rad/s is taken as an example.The simulation and experimental results show that necking defects do not occur on the rolled pieces if the sectional shrinkage is below the limit-sectional shrinkage but will occur when the sectional shrinkage is above it.The results prove that the prediction model of necking defects in cross-wedge rolling of 6082 aluminum alloy is feasible,and this research provides a theoretical basis for the qualified aluminum alloy shafts produced by the cross-wedge rolling.
文摘The spinning deformation of thin walled tube in necking process is simulated with a dynamic explicit FEM program,LS DYNA3D and the distributions of Cauchy strains and thickness are analyzed through time history to achieve a good understanding of the deformation in necking process by spinning and the numerical simulation results are in good agreement with the test results.
文摘Cross-over method is established to predict necking point for PET high- speed fiber spinning. Even slowly crystallizing polymers such as PET can crystallize on the spinline at sufficiently high spinning speed. The development of rtmning velocity, temperature, crystallinity and theological force is investigated for the take-up velocity over a range of 6 000 - 10 000 m/min. The position of necking point, temperature rise and abrupt increase of crystallinity move closer to the spinneret with the increase of take-up velocity,
文摘A large number of criteria has been developed to predict material instabilities, but their choice is limited by the lack of existing comparison of their theoretical basis and application domains. To overcome this limitation, a theoretical and numerical comparison of two major models used to predict diffuse necking is present in this paper. Limit Point Bifurcation criterion is first introduced. An original formulation of the Maximum Force Criterion (MFC), taking into account the effects of damage and isotropic and kinematic hardenings, is then proposed. Strong connections are shown between them by comparing their theoretical basis. Numerical Forming Limit Diagrams at diffuse necking obtained with these criteria for different metallic materials are given. They illustrate the theoretical link and similar predictions are shown for both models.
基金This study was reviewed and approved by the Ethics Committee of the HUB-Hospital Erasme.
文摘BACKGROUND Dislocation rates after hemiarthroplasty reportedly vary from 1%to 17%.This serious complication is associated with increased morbidity and mortality rates.Approaches to this surgery are still debated,with no consensus regarding the superiority of any single approach.AIM To compare early postoperative complications after implementing the direct anterior and posterior approaches(PL)for hip hemiarthroplasty after femoral neck fractures.METHODS This is a comparative,retrospective,single-center cohort study conducted at a university hospital.Between March 2008 and December 2018,273 patients(a total of 280 hips)underwent bipolar hemiarthroplasties(n=280)for displaced femoral neck fractures using either the PL(n=171)or the minimally invasive direct anterior approach(DAA)(n=109).The choice of approach was related to the surgeons’practices;the implant types were similar and unrelated to the approach.Dislocation rates and other complications were reviewed after a minimum followup of 6 mo.RESULTS Both treatment groups had similarly aged patients(mean age:82 years),sex ratios,patient body mass indexes,and patient comorbidities.Surgical data(surgery delay time,operative time,and blood loss volume)did not differ significantly between the groups.The 30 d mortality rate was higher in the PL group(9.9%)than in the DAA group(3.7%),but the difference was not statistically significant(P=0.052).Among the one-month survivors,a significantly higher rate of dislocation was observed in the PL group(14/154;9.1%)than in the DAA group(0/105;0%)(P=0.002).Of the 14 patients with dislocation,8 underwent revision surgery for recurrent instability(posterior group),and one of them had 2 additional procedures due to a deep infection.The rate of other complications(e.g.,perioperative and early postoperative periprosthetic fractures and infection-related complications)did not differ significantly between the groups.CONCLUSION These findings suggest that the DAA to bipolar hemiarthroplasty for patients with femoral neck fractures is associated with a lower dislocation rate(<1%)than the PL.
基金supported in part by the National Natural Science Foundation of China(82072019)the Shenzhen Basic Research Program(JCYJ20210324130209023)+5 种基金the Shenzhen-Hong Kong-Macao S&T Program(Category C)(SGDX20201103095002019)the Mainland-Hong Kong Joint Funding Scheme(MHKJFS)(MHP/005/20),the Project of Strategic Importance Fund(P0035421)the Projects of RISA(P0043001)from the Hong Kong Polytechnic University,the Natural Science Foundation of Jiangsu Province(BK20201441)the Provincial and Ministry Co-constructed Project of Henan Province Medical Science and Technology Research(SBGJ202103038,SBGJ202102056)the Henan Province Key R&D and Promotion Project(Science and Technology Research)(222102310015)the Natural Science Foundation of Henan Province(222300420575),and the Henan Province Science and Technology Research(222102310322).
文摘Modern medicine is reliant on various medical imaging technologies for non-invasively observing patients’anatomy.However,the interpretation of medical images can be highly subjective and dependent on the expertise of clinicians.Moreover,some potentially useful quantitative information in medical images,especially that which is not visible to the naked eye,is often ignored during clinical practice.In contrast,radiomics performs high-throughput feature extraction from medical images,which enables quantitative analysis of medical images and prediction of various clinical endpoints.Studies have reported that radiomics exhibits promising performance in diagnosis and predicting treatment responses and prognosis,demonstrating its potential to be a non-invasive auxiliary tool for personalized medicine.However,radiomics remains in a developmental phase as numerous technical challenges have yet to be solved,especially in feature engineering and statistical modeling.In this review,we introduce the current utility of radiomics by summarizing research on its application in the diagnosis,prognosis,and prediction of treatment responses in patients with cancer.We focus on machine learning approaches,for feature extraction and selection during feature engineering and for imbalanced datasets and multi-modality fusion during statistical modeling.Furthermore,we introduce the stability,reproducibility,and interpretability of features,and the generalizability and interpretability of models.Finally,we offer possible solutions to current challenges in radiomics research.
文摘Objective:Bladder neck contracture and vesicourethral anastomotic stenosis are difficult to manage endoscopically,and open repair is associated with high rates of incontinence.In recent years,there have been increasing reports of robotic-assisted bladder neck reconstruction in the literature.However,existing studies are small,heterogeneous case series.The objective of this study was to perform a systematic review of robotic-assisted bladder neck reconstruction to better evaluate patency and incontinence outcomes.Methods:We performed a systematic review of PubMed from first available date to May 2023 for all studies evaluating robotic-assisted reconstructive surgery of the bladder neck in adult men.Articles in non-English,author replies,editorials,pediatric-based studies,and reviews were excluded.Outcomes of interest were patency and incontinence rates,which were pooled when appropriate.Results:After identifying 158 articles on initial search,we included only ten studies that fit all aforementioned criteria for robotic-assisted bladder neck reconstruction.All were case series published from March 2018 to March 2022 ranging from six to 32 men,with the median follow-up of 5e23 months.A total of 119 patients were included in our analysis.A variety of etiologies and surgical techniques were described.Patency rates ranged from 50%to 100%,and pooled patency was 80%(95/119).De novo incontinence rates ranged from 0%to 33%,and pooled incontinence was 17%(8/47).Our findings were limited by small sample sizes,relatively short follow-ups,and heterogeneity between studies.
基金Supported by National Natural Science Foundation of China,2020YFC2005202.
文摘Laryngopharyngeal reflux disease(LPRD)is an inflammatory condition in the laryngopharynx and upper aerodigestive tract mucosa caused by reflux of stomach contents beyond the esophagus.LPRD commonly presents with symptoms such as hoarseness,cough,sore throat,a feeling of throat obstruction,excessive throat mucus.This complex condition is thought to involve both reflux and reflex mechanisms,but a clear understanding of its molecular mechanisms is still lacking.Currently,there is no standardized diagnosis or treatment protocol.Therapeutic strategies for LPRD mainly include lifestyle modifications,proton pump inhibitors and endoscopic surgery.This paper seeks to provide a comprehensive overview of the existing literature regarding the mechanisms,pathophysiology and treatment of LPRD.We also provide an in-depth exploration of the association between LPRD and gastroesophageal reflux disease.
文摘目的 分析甲状腺乳头状癌(PTC)超声图像表现在预测颈部Ⅵ区淋巴结转移(lymph node metastasis in the cervicalregion Ⅵ,CLNM-Ⅵ)危险度的临床价值。方法 选取2022年4月~2023年6月在河北省沧州中西医结合医院接受手术治疗并经病理证实的350例PTC患者,根据术后病理结果,将患者分为CLNM-Ⅵ组和非CLNM-Ⅵ组。收集并对比两组术前超声图像表现及临床病理特征,应用Logistic回归分析PTC患者CLNM-Ⅵ危险因素,受试者工作特征(ROC)曲线分析PTC超声图像表现对CLNM-Ⅵ的预测价值。结果 单因素分析显示,CLNM-Ⅵ组男性、实性或囊实性、年龄≤45岁、低回声、甲状腺背景正常、点状强回声的构成比均大于非CLNM-Ⅵ组(P均<0.05)。Logistic回归分析显示,男性、实性或囊实性、年龄≤45岁、低回声、甲状腺背景正常、病灶内可见点状强回声是CLNM-Ⅵ的独立危险因素(P均<0.05);进一步经ROC曲线分析显示,以上预测CLNM-Ⅵ的AUC分别为0.565、0.580、0.529、0.585、0.582、0.582,联合预测AUC为0.708。结论PTC超声图像表现在CLNM-Ⅵ风险评估中具有重要意义,可为PTC的预后判断提供一定的参考依据。
基金financial support from National Natural Science Foundation of China through Grant U1737210
文摘The formability of the material determines the amount of available deformation before failure and thus is important for the production of various structural components in industries. The workability of materiMs is commonly evaluated by different forms of failure mod- els during sheet metal forming （SMF） processes. In order to provide a whole picture about the prediction models for SMF failure, necking-related formability and ductile fracture-related forma- bility studies in SMF processes are systematically summarized, the applicability and limitation of each model are highlighted, and the link between forming limit diagram and ductile fracture criterion is pointed out, Conclusions about some critical issues on failure in SMF are made.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 10472092 and 10662001)the Aviation Science Foundation of China (Grant No. 04C53027)
文摘The tension necking of FCC copper single crystal specimen with a square cross section was analyzed under the slip deformation mechanism. The actual clamp manner of the specimen was modeled by setting correlative boundary condition,and the small angle deflection between tension loading axis and crystallography axis [100] was taken into account. The finite deformation numerical analysis of three-dimensional necking deformation for the specimen was performed by apply-ing crystal plasticity theory associated with a numerical algorithm suggested by the first author. According to the comparison with experimental observation,the fact was confirmed that the numerical results could describe the loading elongation curve of the copper single crystal specimen under large strain tension reasonably,and the method could be used to investigate the necking characteristic in neck shape and the effect due to the small angle deflection. Further,the investigation into the influence of specimen cross-section shape on necking was also performed;the results on mechanical response and neck profile evolution obtained through modeling of cylindrical specimen were compared with those obtained with square cross-section specimen.
文摘Objective In kinesin-3,the neck coil correlates with the following segments to form an extended neck that contains a characteristic hinge diverse from a proline in KIF13B to a long flexible linker in KIF1A.The function of this neck hinge for controlling processive movement,however,remains unclear.Methods We made a series of modifications to the neck hinges of KIF13B and KIF1A and tested their movement using a single-molecule motility assay.Results In KIF13B,the insertion of flexible residues before or after the proline differentially impacts the processivity or velocity,while the removal of this proline increases the both.In KIF1A,the deletion of entire flexible neck hinge merely enhances the processivity.The engineering of these hinge-truncated necks of kinesin-3 into kinesin-1 similarly boosts the processive movement of kinesin-1.Conclusion The neck hinge in kinesin-3 controls its processive movement and proper modifications tune the motor motility,which provides a novel strategy to reshape the processive movement of kinesin motors.
