Dear sir,Iam Dr.Wen-Wei Li,from the Department of Ophthalmology,Zhejiang Provincial People’s Hospital,Hangzhou,China.I write to present a case of ocular leech infestation initially misdiagnosed as conjunctival pigmen...Dear sir,Iam Dr.Wen-Wei Li,from the Department of Ophthalmology,Zhejiang Provincial People’s Hospital,Hangzhou,China.I write to present a case of ocular leech infestation initially misdiagnosed as conjunctival pigmented nevus.Although human interaction with leeches is not uncommon展开更多
The evolution of an initially squeezed electromagnetic field was studied by using two-photon interaction Dicke model and pertubation approach.It was found that under certain condition in two-photon Dicke model squeezi...The evolution of an initially squeezed electromagnetic field was studied by using two-photon interaction Dicke model and pertubation approach.It was found that under certain condition in two-photon Dicke model squeezing will be enhanced.The physical insight of this phenomenon is discussed.展开更多
Carbon fiber-reinforced plastic (CFRP) laminates with initially cut fibers (ICFs) have good formability without large degradation of static strength;however, their fatigue behavior has not been investigated thus far. ...Carbon fiber-reinforced plastic (CFRP) laminates with initially cut fibers (ICFs) have good formability without large degradation of static strength;however, their fatigue behavior has not been investigated thus far. In this paper, we investigated fatigue behavior and damage progress of open-holed CFRP laminates with ICFs having interlayers. Three types of CFRP laminates were employed: a laminate without ICF fabricated using an autoclave (Continuous-A), a laminate with ICF fabricated using an autoclave (ICF-A) and a laminate with ICF fabricated using press molding (ICF-P). First, fatigue test was conducted to obtain S (maximum stress)-N (the number of cycles to failure) curves in order to reveal fatigue strength. The fatigue tests for several specimens were interrupted at three prescribed numbers of cycles to observe damage progress. It is found that the Continuous-A laminate shows little strength degradation in the S-N curve while fatigue strength in both ICF laminates is decreased by approximately 30% at N of 106. In contrast, the damage progress of the ICF-P laminate is the least among the three laminates while the delamination progress at both edges and around the hole in the Continuous-A laminate is the most prominent.展开更多
A 72-year-old woman with a sigmoid colon cancer and a synchronous colorectal liver metastasis(CRLM),which involved the right hepatic vein(RHV)and the inferior vena cava(IVC),was referred to our hospital.The metastatic...A 72-year-old woman with a sigmoid colon cancer and a synchronous colorectal liver metastasis(CRLM),which involved the right hepatic vein(RHV)and the inferior vena cava(IVC),was referred to our hospital.The metastatic lesion was diagnosed as initially unresectable because of its invasion into the confluence of the RHV and IVC.After she had undergone laparoscopic sigmoidectomy for the original tumor,she consequently had 3 courses of modified 5-fluorouracil,leucovorin,and oxaliplatin(m FOLFOX6)plus cetuximab.Computed tomography revealed a partial response,and the confluence of the RHV and IVC got free from cancer invasion.After 3 additional courses of m FOLFOX6 plus cetuximab,preoperative percutaneous transhepatic portal vein embolization(PTPE)was performed to secure the future remnant liver volume.Finally,a right hemihepatectomy was performed.The postoperative course was uneventful.The patient was discharged from the hospital on postoperative day 13.She had neither local recurrence nor distant metastasis 18 mo after the last surgical intervention.This multidisciplinary strategy,consisting of conversion chemotherapy using FOLFOX plus cetuximab and PTPE,could contribute in facilitating curative hepatic resection for initially unresectable CRLM.展开更多
The bending of the Euler-Bernoulli micro-beam has been extensively modeled based on the modified couple stress(MCS)theory.Although many models have been incorporated into the literature,there is still room for introdu...The bending of the Euler-Bernoulli micro-beam has been extensively modeled based on the modified couple stress(MCS)theory.Although many models have been incorporated into the literature,there is still room for introducing an improved model in this context.In this work,we investigate the thermoelastic vibration of a micro-beam exposed to a varying temperature due to the application of the initial stress employing the MCS theory and generalized thermoelasticity.The MCS theory is used to investigate the material length scale effects.Using the Laplace transform,the temperature,deflection,displacement,flexure moment,and stress field variables of the micro-beam are derived.The effects of the temperature pulse and couple stress on the field distributions of the micro-beam are obtained numerically and graphically introduced.The numerical results indicate that the temperature pulse and couple stress have a significant effect on all field variables.展开更多
The governing equations of a transversely isotropic dissipative medium are solved analytically to obtain the speeds of plane waves. The appropriate solutions satisfy the required boundary conditions at the stress-free...The governing equations of a transversely isotropic dissipative medium are solved analytically to obtain the speeds of plane waves. The appropriate solutions satisfy the required boundary conditions at the stress-free surface to obtain the expressions of the reflection coefficients of reflected quasi-P (qP) and quasi-SV (qSV) waves in closed form for the incidence of qP and qSV waves. A particular model is chosen for numerical computation of these reflection coefficients for a certain range of the angle of incidence. The numerical values of these reflection coefficients are shown graphically against the angle of incidence for different values of initial stress parameter. The impact of initial stress parameter on the reflection coefficients is observed significantly.展开更多
A theoretical model is proposed in this paper to predict the bi-stable states of initially stressed cylindrical shell structures attached by surface anisotropic piezoelectric layers.The condition for existence of bi-s...A theoretical model is proposed in this paper to predict the bi-stable states of initially stressed cylindrical shell structures attached by surface anisotropic piezoelectric layers.The condition for existence of bi-stability of the shell structural system is presented and analytical expressions for corresponding rolled-up radii of the stable shell are given based on the principle of minimum strain energy.The resulting solution indicates that the shell system may have two stable configurations besides its initial state under a combined action of the actuating electric field and initial stresses characterized by the bending moment.If the piezoelectric layer materials act as only sensor materials without the actuating electric field,initial stresses may produce the bi-stable states,but one corresponding to its initial state.For the shell without initial stresses,the magnitude in the actuating electric field determines the number of the stable states,one or two stable configurations besides the initial state.The theoretical prediction for the bi-stable states is verified by finite element method(FEM) simulation by using the ABAQUS code.展开更多
The governing equations of an initially stressed rotating orthotropic dissipative medium are solved analytically to obtain the velocity equation which indicates the existence of two quasi-planar waves. The appropriate...The governing equations of an initially stressed rotating orthotropic dissipative medium are solved analytically to obtain the velocity equation which indicates the existence of two quasi-planar waves. The appropriate particular solutions in the half-space satisfy the required boundary conditions at the stress-free surface to obtain the expressions of the reflec-tion coefficients of the reflected quasi-P (qP) and reflected quasi-SV (qSV) waves in closed form for the incidence of qP and qSV waves. A particular model is chosen for numerical computation of these reflection coefficients for a certain range of the angle of incidence. The numerical values of these reflection coefficients are shown graphically against the angle of incidence for different values of initial stress parameter and rotation parameter. The impact of initial stress and rotation parameters on the reflection coefficients is observed significantly.展开更多
The paper studies the propagation of torsional surface waves in an initially stressed anisotropic poro-elastic layer over a semi-infinite heterogeneous half space with linearly varying rigidity and density due to irre...The paper studies the propagation of torsional surface waves in an initially stressed anisotropic poro-elastic layer over a semi-infinite heterogeneous half space with linearly varying rigidity and density due to irregularity at the interface. The irregularity is taken in the half space in the form of a rectangle. It is observed that torsional surface waves propagate in this assumed medium. In the absence of the irregularity, the velocity equation of the torsional surface wave is also obtained. For a layer over a homogeneous half space, the velocity of torsional surface waves coincides with that of the Love waves.展开更多
The present paper contributes in studying the phase velocities of P- and S-waves in a half space subjected to a compressive initial stress and gravity field. The density and acceleration due to gravity vary quadratica...The present paper contributes in studying the phase velocities of P- and S-waves in a half space subjected to a compressive initial stress and gravity field. The density and acceleration due to gravity vary quadratically along the depth. The dispersion equation is derived in a closed form. It is shown that the phase velocities depend not only on the initial stress, gravity, and direction of propagation but also on the inhomogeneity parameter associated with the density and acceleration due to gravity. Various particular cases are obtained, and the results match with the classical results. Numerical investigations on the phase velocities of P- and S-waves against the wave number are made for various sets of values of the material parameters, and the results are illustrated graphically. The graphical user interface model is developed to generalize the effect.展开更多
The paper studies the propagation of Love waves in a non-homogeneous substratum over an initially stressed heterogeneous half-space. The dispersion equation of phase velocity is derived. The velocities of Love waves a...The paper studies the propagation of Love waves in a non-homogeneous substratum over an initially stressed heterogeneous half-space. The dispersion equation of phase velocity is derived. The velocities of Love waves are calculated numerically as a function of kH and presented in a number of graphs, where k is the wave number, and H is the thickness of the layer. The case of Gibson's half-space is also considered. It is observed that the speed of Love waves is finite in the vicinity of the surface of the half-space and vanishes as the depth increases for a particular wave number. It is also observed that an increase in compressive initial stresses causes decreases of Love waves velocity for the same frequency, and the tensile initial stress of small magnitude in the half-space causes increase of the velocity.展开更多
To analyze the impact of bubbles on the mechanical behavior of glasses,by controlling the refining time,we prepared three borosilicate glasses with the same composition and different porosity.By the analysis software ...To analyze the impact of bubbles on the mechanical behavior of glasses,by controlling the refining time,we prepared three borosilicate glasses with the same composition and different porosity.By the analysis software integrated within the optical microscope,the diameter and number of the bubbles on the surface of three borosilicate glasses were quantified.From the hardness and crack initiation resistance(CR),we built the relationship between the porosity and the mechanical performance of these borosilicate glasses.展开更多
The microstructural evolution of a cold-rolled and intercritical annealed medium-Mn steel(Fe-0.10C-5Mn)was investigated during uniaxial tensile testing.In-situ observations under scanning electron microscopy,transmiss...The microstructural evolution of a cold-rolled and intercritical annealed medium-Mn steel(Fe-0.10C-5Mn)was investigated during uniaxial tensile testing.In-situ observations under scanning electron microscopy,transmission electron microscopy,and X-ray diffraction analysis were conducted to characterize the progressive transformation-induced plasticity process and associated fracture initiation mechanisms.These findings were discussed with the local strain measurements via digital image correlation.The results indicated that Lüders band formation in the steel was limited to 1.5%strain,which was mainly due to the early-stage martensitic phase transformation of a very small amount of the less stable large-sized retained austenite(RA),which led to localized stress concentrations and strain hardening and further retardation of yielding.The small-sized RA exhibited high stability and progressively transformed into martensite and contributed to a stably extended Portevin-Le Chatelier effect.The volume fraction of RA gradually decreased from 26.8%to 8.2%prior to fracture.In the late deformation stage,fracture initiation primarily occurred at the austenite/martensite and ferrite/martensite interfaces and the ferrite phase.展开更多
Cause of death surveillance data is most important for developing effective health policies,whose quality is crucially affected by the accuracy of the underlying cause of death(UCOD)provided in death certificates.The ...Cause of death surveillance data is most important for developing effective health policies,whose quality is crucially affected by the accuracy of the underlying cause of death(UCOD)provided in death certificates.The World Health Organization(WHO)has clearly defined a UCOD as“the disease or injury which initiated the train of morbid events leading directly to death,or the circumstance of the accident or violence which produced the fatal injuries”[1].展开更多
New seismic imaging from the Mussau Trench confirms that,under horizontal compression on an oceanic plate boundary,it is within the young and weak oceanic plate that a trench will develop,and it is the young plate,not...New seismic imaging from the Mussau Trench confirms that,under horizontal compression on an oceanic plate boundary,it is within the young and weak oceanic plate that a trench will develop,and it is the young plate,not so long after its birth,that starts to subduct toward the old plate.The Mesozoic Pacific Plate cannot easily bend,under the joint horizontal compression and vertical gravity pull,even with a pre-existing weak zone in place and with a large age offset across the plate boundary.The bending of the Caroline Plate near the northern end of the Mussau Trench started only after a long-time span of trench migration,and/or after a prolonged transition from initial compression to trench development.Highly contrasting trench deformation and sedimentary accretion between two parallel seismic sections support an evident migration of underthrusting or significant longitudinal heterogeneity along the trench.The swift transition from underthrusting to non-thrusting can be explained by a counter-clockwise rotation of the Caroline Plate.That miniature accretionary wedges develop even before the subduction initiates imply strong compression and uplifting before the underthrusting can kick-start.Rotation of the Caroline Plate have been halted as the Mussau Trench is seismically rather quiet and the Lyra Trough to the east shows relaxational extension.展开更多
Dear editor,Vulvar sarcomas are rare and represent 1%–3%of cancers in this region.1 Leiomyosarcoma is the most common type of vulvar sarcoma.In contrast,epithelioid sarcoma(ES)is extremely rare,accounting for around ...Dear editor,Vulvar sarcomas are rare and represent 1%–3%of cancers in this region.1 Leiomyosarcoma is the most common type of vulvar sarcoma.In contrast,epithelioid sarcoma(ES)is extremely rare,accounting for around 1%of soft-tissue vulvar sarcomas.Among the ESs of the vulva,proximal variants tend to have a more aggressive clinical course,in comparison to distal variants.2 The treatment of choice in proximal-type ES of the vulva is surgical resection,usually with surgical margins greater than 2 cm.Due to the extreme rarity of these malignancies,clear algorithms for adjuvant treatment of these tumors have still not been established.Radiotherapy and/or chemotherapy may be indicated in some cases.展开更多
Evaluation of hydromechanical shear behavior of unsaturated soils is still a challenging issue. The time and cost needed for conducting precise experimental investigation on shear behavior of unsaturated soils have en...Evaluation of hydromechanical shear behavior of unsaturated soils is still a challenging issue. The time and cost needed for conducting precise experimental investigation on shear behavior of unsaturated soils have encouraged several investigators to develop analytical, empirical, or semi-empirical models for predicting the shear behavior of unsaturated soils. However, most of the previously proposed models are for specimens subjected to the isotropic state of stress, without considering the effect of initial shear stress. In this study, a hydromechanical constitutive model is proposed for unsaturated collapsible soils during shearing, with consideration of the effect of the initial shear stress. The model implements an effective stress-based disturbed state concept (DSC) to predict the stress-strain behavior of the soil. Accordingly, material/state variables were defined for both the start of the shearing stage and the critical state of the soil. A series of laboratory tests was performed using a fully automated unsaturated triaxial device to verify the proposed model. The experimental program included 23 suction-controlled unsaturated triaxial shear tests on reconstituted specimens of Gorgan clayey loess wetted to different levels of suctions under both isotropic and anisotropic stress states. The results show excellent agreement between the prediction by the proposed model and the experimental results.展开更多
Background The CHA 2 DS 2-VASc schema has recently been introduced to complement the CHADS2 score and improve the identification of atrial fibrillation (AF) patients at 'truly low risk' for thromboembolism.We test...Background The CHA 2 DS 2-VASc schema has recently been introduced to complement the CHADS2 score and improve the identification of atrial fibrillation (AF) patients at 'truly low risk' for thromboembolism.We tested the predictive ability of the CHA 2 DS 2-VASc,CHADS2 and van Walraven risk stratification schemes in a cohort of 'lone' AF patients with a 12-year follow-up.Methods and Results We conducted a registry-based,observational cohort study of 345 patients initially diagnosed with 'lone' AF between 1992 and 2007.At baseline,all patients had the CHADS2 and van Walraven scores of 0,and 262 (75.9%) had a CHA 2 DS 2VASc score=0.During follow-up (or within a year prior to stroke),228 (66.1%),234 (67.8%) and 150 patients (43.5%) retained the CHADS2,van Walraven and CHA 2 DS 2VASc scores of 0,respectively.The overall rate of ischemic stroke was 0.19 (95%CI:0.18-0.20) per 100 patient-years.In the multivariable analysis,only the CHA 2 DS 2-VASc score of 0 was significantly related to the absence of stroke (OR 5.1,95%CI:1.5-16.8,P=0.008).Only the CHA 2 DS 2-VASc score had a significant prediction ability (c-statistic 0.72 [0.61-0.84],P=0.031).Conclusions The CHA 2 DS 2-VASc score reliably identified the 'lone' AF patients who were at 'truly low risk' for thromboembolism,and was the only tested risk stratification scheme with a significant predictive ability for thromboembolism amongst lone AF patients.展开更多
Abstract Objectives The authors sought to describe the association between post-procedural bleeding and long-term recurrent bleeding, major adverse cardiac events (MACE), and mortality among older patients undergoin...Abstract Objectives The authors sought to describe the association between post-procedural bleeding and long-term recurrent bleeding, major adverse cardiac events (MACE), and mortality among older patients undergoing per-cutaneous coronary intervention (PCI).展开更多
文摘Dear sir,Iam Dr.Wen-Wei Li,from the Department of Ophthalmology,Zhejiang Provincial People’s Hospital,Hangzhou,China.I write to present a case of ocular leech infestation initially misdiagnosed as conjunctival pigmented nevus.Although human interaction with leeches is not uncommon
基金Supported by the National Natural Science Foundation of China.
文摘The evolution of an initially squeezed electromagnetic field was studied by using two-photon interaction Dicke model and pertubation approach.It was found that under certain condition in two-photon Dicke model squeezing will be enhanced.The physical insight of this phenomenon is discussed.
文摘Carbon fiber-reinforced plastic (CFRP) laminates with initially cut fibers (ICFs) have good formability without large degradation of static strength;however, their fatigue behavior has not been investigated thus far. In this paper, we investigated fatigue behavior and damage progress of open-holed CFRP laminates with ICFs having interlayers. Three types of CFRP laminates were employed: a laminate without ICF fabricated using an autoclave (Continuous-A), a laminate with ICF fabricated using an autoclave (ICF-A) and a laminate with ICF fabricated using press molding (ICF-P). First, fatigue test was conducted to obtain S (maximum stress)-N (the number of cycles to failure) curves in order to reveal fatigue strength. The fatigue tests for several specimens were interrupted at three prescribed numbers of cycles to observe damage progress. It is found that the Continuous-A laminate shows little strength degradation in the S-N curve while fatigue strength in both ICF laminates is decreased by approximately 30% at N of 106. In contrast, the damage progress of the ICF-P laminate is the least among the three laminates while the delamination progress at both edges and around the hole in the Continuous-A laminate is the most prominent.
文摘A 72-year-old woman with a sigmoid colon cancer and a synchronous colorectal liver metastasis(CRLM),which involved the right hepatic vein(RHV)and the inferior vena cava(IVC),was referred to our hospital.The metastatic lesion was diagnosed as initially unresectable because of its invasion into the confluence of the RHV and IVC.After she had undergone laparoscopic sigmoidectomy for the original tumor,she consequently had 3 courses of modified 5-fluorouracil,leucovorin,and oxaliplatin(m FOLFOX6)plus cetuximab.Computed tomography revealed a partial response,and the confluence of the RHV and IVC got free from cancer invasion.After 3 additional courses of m FOLFOX6 plus cetuximab,preoperative percutaneous transhepatic portal vein embolization(PTPE)was performed to secure the future remnant liver volume.Finally,a right hemihepatectomy was performed.The postoperative course was uneventful.The patient was discharged from the hospital on postoperative day 13.She had neither local recurrence nor distant metastasis 18 mo after the last surgical intervention.This multidisciplinary strategy,consisting of conversion chemotherapy using FOLFOX plus cetuximab and PTPE,could contribute in facilitating curative hepatic resection for initially unresectable CRLM.
文摘The bending of the Euler-Bernoulli micro-beam has been extensively modeled based on the modified couple stress(MCS)theory.Although many models have been incorporated into the literature,there is still room for introducing an improved model in this context.In this work,we investigate the thermoelastic vibration of a micro-beam exposed to a varying temperature due to the application of the initial stress employing the MCS theory and generalized thermoelasticity.The MCS theory is used to investigate the material length scale effects.Using the Laplace transform,the temperature,deflection,displacement,flexure moment,and stress field variables of the micro-beam are derived.The effects of the temperature pulse and couple stress on the field distributions of the micro-beam are obtained numerically and graphically introduced.The numerical results indicate that the temperature pulse and couple stress have a significant effect on all field variables.
文摘The governing equations of a transversely isotropic dissipative medium are solved analytically to obtain the speeds of plane waves. The appropriate solutions satisfy the required boundary conditions at the stress-free surface to obtain the expressions of the reflection coefficients of reflected quasi-P (qP) and quasi-SV (qSV) waves in closed form for the incidence of qP and qSV waves. A particular model is chosen for numerical computation of these reflection coefficients for a certain range of the angle of incidence. The numerical values of these reflection coefficients are shown graphically against the angle of incidence for different values of initial stress parameter. The impact of initial stress parameter on the reflection coefficients is observed significantly.
文摘A theoretical model is proposed in this paper to predict the bi-stable states of initially stressed cylindrical shell structures attached by surface anisotropic piezoelectric layers.The condition for existence of bi-stability of the shell structural system is presented and analytical expressions for corresponding rolled-up radii of the stable shell are given based on the principle of minimum strain energy.The resulting solution indicates that the shell system may have two stable configurations besides its initial state under a combined action of the actuating electric field and initial stresses characterized by the bending moment.If the piezoelectric layer materials act as only sensor materials without the actuating electric field,initial stresses may produce the bi-stable states,but one corresponding to its initial state.For the shell without initial stresses,the magnitude in the actuating electric field determines the number of the stable states,one or two stable configurations besides the initial state.The theoretical prediction for the bi-stable states is verified by finite element method(FEM) simulation by using the ABAQUS code.
文摘The governing equations of an initially stressed rotating orthotropic dissipative medium are solved analytically to obtain the velocity equation which indicates the existence of two quasi-planar waves. The appropriate particular solutions in the half-space satisfy the required boundary conditions at the stress-free surface to obtain the expressions of the reflec-tion coefficients of the reflected quasi-P (qP) and reflected quasi-SV (qSV) waves in closed form for the incidence of qP and qSV waves. A particular model is chosen for numerical computation of these reflection coefficients for a certain range of the angle of incidence. The numerical values of these reflection coefficients are shown graphically against the angle of incidence for different values of initial stress parameter and rotation parameter. The impact of initial stress and rotation parameters on the reflection coefficients is observed significantly.
基金for providing financial support through Project No.SR/S4/ES-246/2006 with title "Investigation of torsional surface waves in nonhomogeneous layered earth".
文摘The paper studies the propagation of torsional surface waves in an initially stressed anisotropic poro-elastic layer over a semi-infinite heterogeneous half space with linearly varying rigidity and density due to irregularity at the interface. The irregularity is taken in the half space in the form of a rectangle. It is observed that torsional surface waves propagate in this assumed medium. In the absence of the irregularity, the velocity equation of the torsional surface wave is also obtained. For a layer over a homogeneous half space, the velocity of torsional surface waves coincides with that of the Love waves.
基金supported by the Research Fellow of Indian School of Mines in Dhanbad (No. 2010DR0016)
文摘The present paper contributes in studying the phase velocities of P- and S-waves in a half space subjected to a compressive initial stress and gravity field. The density and acceleration due to gravity vary quadratically along the depth. The dispersion equation is derived in a closed form. It is shown that the phase velocities depend not only on the initial stress, gravity, and direction of propagation but also on the inhomogeneity parameter associated with the density and acceleration due to gravity. Various particular cases are obtained, and the results match with the classical results. Numerical investigations on the phase velocities of P- and S-waves against the wave number are made for various sets of values of the material parameters, and the results are illustrated graphically. The graphical user interface model is developed to generalize the effect.
文摘The paper studies the propagation of Love waves in a non-homogeneous substratum over an initially stressed heterogeneous half-space. The dispersion equation of phase velocity is derived. The velocities of Love waves are calculated numerically as a function of kH and presented in a number of graphs, where k is the wave number, and H is the thickness of the layer. The case of Gibson's half-space is also considered. It is observed that the speed of Love waves is finite in the vicinity of the surface of the half-space and vanishes as the depth increases for a particular wave number. It is also observed that an increase in compressive initial stresses causes decreases of Love waves velocity for the same frequency, and the tensile initial stress of small magnitude in the half-space causes increase of the velocity.
基金Funded by the National Natural Science Foundation of China(No.52172007)。
文摘To analyze the impact of bubbles on the mechanical behavior of glasses,by controlling the refining time,we prepared three borosilicate glasses with the same composition and different porosity.By the analysis software integrated within the optical microscope,the diameter and number of the bubbles on the surface of three borosilicate glasses were quantified.From the hardness and crack initiation resistance(CR),we built the relationship between the porosity and the mechanical performance of these borosilicate glasses.
基金supported by the National Key R&D Program of China(No.2017YFB0304402)。
文摘The microstructural evolution of a cold-rolled and intercritical annealed medium-Mn steel(Fe-0.10C-5Mn)was investigated during uniaxial tensile testing.In-situ observations under scanning electron microscopy,transmission electron microscopy,and X-ray diffraction analysis were conducted to characterize the progressive transformation-induced plasticity process and associated fracture initiation mechanisms.These findings were discussed with the local strain measurements via digital image correlation.The results indicated that Lüders band formation in the steel was limited to 1.5%strain,which was mainly due to the early-stage martensitic phase transformation of a very small amount of the less stable large-sized retained austenite(RA),which led to localized stress concentrations and strain hardening and further retardation of yielding.The small-sized RA exhibited high stability and progressively transformed into martensite and contributed to a stably extended Portevin-Le Chatelier effect.The volume fraction of RA gradually decreased from 26.8%to 8.2%prior to fracture.In the late deformation stage,fracture initiation primarily occurred at the austenite/martensite and ferrite/martensite interfaces and the ferrite phase.
基金supported by State Key Laboratory Special Fund(2060204)Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(2023-I2M-2-001)+1 种基金The Collaborative Innovation Team Project:Health Effect of Environmental Factors and Gut Microbiome on Digestive Tract-Related Diseases:Population-Based Cohort Studies(2016-12M-3-001)supported by CAMS Innovation Fund for Medical SciencesStrengthen Capacity of Study and Application on the Burden of Disease in Health Care Systems in China:Establishment and Development of Chinese Burden of Disease Research and Dissemination Center(15-208)supported by the China Medical Board(CMB).
文摘Cause of death surveillance data is most important for developing effective health policies,whose quality is crucially affected by the accuracy of the underlying cause of death(UCOD)provided in death certificates.The World Health Organization(WHO)has clearly defined a UCOD as“the disease or injury which initiated the train of morbid events leading directly to death,or the circumstance of the accident or violence which produced the fatal injuries”[1].
基金supported by the National Key Research and Development Program of China(Grant Nos.2023YFF0803400,2023YFF0803404)the National Natural Science Foundation of China(Grant No.91858213)+2 种基金the Natural Science Foundation of Hainan Province(Grant No.421CXTD441)the Zhoushan Science and Technology Bureau Program(Grant No.2020C81058)the Shiptime Sharing Project from National Natural Science Foundation of China(Grant No.41949581)。
文摘New seismic imaging from the Mussau Trench confirms that,under horizontal compression on an oceanic plate boundary,it is within the young and weak oceanic plate that a trench will develop,and it is the young plate,not so long after its birth,that starts to subduct toward the old plate.The Mesozoic Pacific Plate cannot easily bend,under the joint horizontal compression and vertical gravity pull,even with a pre-existing weak zone in place and with a large age offset across the plate boundary.The bending of the Caroline Plate near the northern end of the Mussau Trench started only after a long-time span of trench migration,and/or after a prolonged transition from initial compression to trench development.Highly contrasting trench deformation and sedimentary accretion between two parallel seismic sections support an evident migration of underthrusting or significant longitudinal heterogeneity along the trench.The swift transition from underthrusting to non-thrusting can be explained by a counter-clockwise rotation of the Caroline Plate.That miniature accretionary wedges develop even before the subduction initiates imply strong compression and uplifting before the underthrusting can kick-start.Rotation of the Caroline Plate have been halted as the Mussau Trench is seismically rather quiet and the Lyra Trough to the east shows relaxational extension.
文摘Dear editor,Vulvar sarcomas are rare and represent 1%–3%of cancers in this region.1 Leiomyosarcoma is the most common type of vulvar sarcoma.In contrast,epithelioid sarcoma(ES)is extremely rare,accounting for around 1%of soft-tissue vulvar sarcomas.Among the ESs of the vulva,proximal variants tend to have a more aggressive clinical course,in comparison to distal variants.2 The treatment of choice in proximal-type ES of the vulva is surgical resection,usually with surgical margins greater than 2 cm.Due to the extreme rarity of these malignancies,clear algorithms for adjuvant treatment of these tumors have still not been established.Radiotherapy and/or chemotherapy may be indicated in some cases.
文摘Evaluation of hydromechanical shear behavior of unsaturated soils is still a challenging issue. The time and cost needed for conducting precise experimental investigation on shear behavior of unsaturated soils have encouraged several investigators to develop analytical, empirical, or semi-empirical models for predicting the shear behavior of unsaturated soils. However, most of the previously proposed models are for specimens subjected to the isotropic state of stress, without considering the effect of initial shear stress. In this study, a hydromechanical constitutive model is proposed for unsaturated collapsible soils during shearing, with consideration of the effect of the initial shear stress. The model implements an effective stress-based disturbed state concept (DSC) to predict the stress-strain behavior of the soil. Accordingly, material/state variables were defined for both the start of the shearing stage and the critical state of the soil. A series of laboratory tests was performed using a fully automated unsaturated triaxial device to verify the proposed model. The experimental program included 23 suction-controlled unsaturated triaxial shear tests on reconstituted specimens of Gorgan clayey loess wetted to different levels of suctions under both isotropic and anisotropic stress states. The results show excellent agreement between the prediction by the proposed model and the experimental results.
文摘Background The CHA 2 DS 2-VASc schema has recently been introduced to complement the CHADS2 score and improve the identification of atrial fibrillation (AF) patients at 'truly low risk' for thromboembolism.We tested the predictive ability of the CHA 2 DS 2-VASc,CHADS2 and van Walraven risk stratification schemes in a cohort of 'lone' AF patients with a 12-year follow-up.Methods and Results We conducted a registry-based,observational cohort study of 345 patients initially diagnosed with 'lone' AF between 1992 and 2007.At baseline,all patients had the CHADS2 and van Walraven scores of 0,and 262 (75.9%) had a CHA 2 DS 2VASc score=0.During follow-up (or within a year prior to stroke),228 (66.1%),234 (67.8%) and 150 patients (43.5%) retained the CHADS2,van Walraven and CHA 2 DS 2VASc scores of 0,respectively.The overall rate of ischemic stroke was 0.19 (95%CI:0.18-0.20) per 100 patient-years.In the multivariable analysis,only the CHA 2 DS 2-VASc score of 0 was significantly related to the absence of stroke (OR 5.1,95%CI:1.5-16.8,P=0.008).Only the CHA 2 DS 2-VASc score had a significant prediction ability (c-statistic 0.72 [0.61-0.84],P=0.031).Conclusions The CHA 2 DS 2-VASc score reliably identified the 'lone' AF patients who were at 'truly low risk' for thromboembolism,and was the only tested risk stratification scheme with a significant predictive ability for thromboembolism amongst lone AF patients.
文摘Abstract Objectives The authors sought to describe the association between post-procedural bleeding and long-term recurrent bleeding, major adverse cardiac events (MACE), and mortality among older patients undergoing per-cutaneous coronary intervention (PCI).