AIM: To identify risk factors to help predict which patients are likely to fail to appear for an endoscopic procedure. METHODS: This was a retrospective, chart review, cohort study in a Canadian, tertiary care, academ...AIM: To identify risk factors to help predict which patients are likely to fail to appear for an endoscopic procedure. METHODS: This was a retrospective, chart review, cohort study in a Canadian, tertiary care, academic, hospital-based endoscopy clinic. Patients included were: those undergoing esophagogastroduodenoscopy, colonoscopy or flexible sigmoidoscopy and patients who failed to appear were compared to a control group. The main outcome measure was a multivariate analysis of factors associated with truancy from scheduled endoscopic procedures. Factors analyzed included gender, age, waiting time, type of procedure, referring physician, distance to hospital, first or subsequent endoscopic procedure or encounter with gastroenterologist, and urgency of the procedure. RESULTS: Two hundred and thirty-four patients did not show up for their scheduled appointment. Compared to a control group, factors statistically significantly associated with truancy in the multivariate analysis were: non-urgent vs urgent procedure (OR 1.62, 95% CI 1.06, 2.450), referred by a specialist vs a family doctor (OR 2.76, 95% CI 1.31, 5.52) and office-based consult prior to endoscopy vs consult and endoscopic procedure during the same appointment (OR 2.24, 95% CI 1.33, 3.78). CONCLUSION: Identifying patients who are not scheduled for same-day consult and endoscopy, those referred by a specialist, and those with non-urgent referrals may help reduce patient truancy.展开更多
Integrative physical mapping is the centerpieceof and essential for advanced genomics research.Upland cotton(Gossypium hirsutum L.)geneticstandard line TM-1 is used as the referencegenotype to develop a whole-genome,B...Integrative physical mapping is the centerpieceof and essential for advanced genomics research.Upland cotton(Gossypium hirsutum L.)geneticstandard line TM-1 is used as the referencegenotype to develop a whole-genome,BAC/BIBAC-based integrated physical/genetic map ofthe cotton genome.From the TM-1 line we haveconstructed two BAC libraries with HindIII展开更多
Flash flood hazard mapping is a supporting component of non-structural measures for flash flood prevention. Pilot case studies are necessary to develop more practicable methods for the technical support systems of fla...Flash flood hazard mapping is a supporting component of non-structural measures for flash flood prevention. Pilot case studies are necessary to develop more practicable methods for the technical support systems of flash flood hazard mapping. In this study, the headwater catchment of the Xiapu River Basin in central China was selected as a pilot study area for flash flood hazard mapping. A conceptual distributed hydrological model was developed for flood calculation based on the framework of the Xinanjiang model, which is widely used in humid and semi-humid regions in China. The developed model employs the geomorphological unit hydrograph method, which is extremely valuable when simulating the overland flow process in ungauged catchments, as compared with the original Xinanjiang model. The model was tested in the pilot study area, and the results agree with the measured data on the whole. After calibration and validation, the model is shown to be a useful tool for flash flood calculation. A practicable method for flash flood hazard mapping using the calculated peak discharge and digital elevation model data was presented, and three levels of flood hazards were classified. The resulting flash flood hazard maps indicate that the method successfully predicts the spatial distribution of flash flood hazards, and it can meet the current requirements in China.展开更多
BACKGROUND Polyneuropathy,organomegaly,endocrinopathy,M-protein,and skin changes(POEMS)syndrome is a rare paraneoplastic syndrome caused by a plasma cell proliferative disorder.The syndrome is characterized by elevate...BACKGROUND Polyneuropathy,organomegaly,endocrinopathy,M-protein,and skin changes(POEMS)syndrome is a rare paraneoplastic syndrome caused by a plasma cell proliferative disorder.The syndrome is characterized by elevated plasma cells,platelets,and vascular endothelial growth factor levels.Although heart disease rarely occurs in POEMS syndrome,the death rate increases sharply after heart failure.We report a patient who initially presented with an endocrine disease and developed congestive heart failure related to POEMS syndrome 9 years later.CASE SUMMARY A 23-year-old woman with no history of menstruation and a 9-year history of type I diabetes reported feeling breathless after activities.She could not lie down and rest at night.Three months prior,she experienced pain and increased tension in her left thigh accompanied by tenderness and edema in both lower extremities.The chief complaint upon hospital admission was that blood sugar has increased for more than 9 years,pain in the left thigh,and edema in both legs for more than 2 mo.After a multisystem evaluation,she was diagnosed with POEMS syndrome.Her echocardiogram showed left ventricular dilation with systolic dysfunction,and the left ventricular ejection fraction was only 38%with severely elevated brain natriuretic peptide.She received a combination of dexamethasone and thalidomide for 1 mo,but her symptoms did not improve.Therefore,we added a two-per-week bortezomib injection.After 2 wk,the patient’s heart function had improved significantly.CONCLUSION This case provides information about the treatment of POEMS syndrome with complications and highlights the challenges of developing a standardized treatment.展开更多
A concise synthetic route leading to highly functional erythrina alkaloid skeletons has been developed.The key process is an oxidative carbon-carbon coupling followed by a conjugated addition.Based on this new strateg...A concise synthetic route leading to highly functional erythrina alkaloid skeletons has been developed.The key process is an oxidative carbon-carbon coupling followed by a conjugated addition.Based on this new strategy,a formal synthesis of demethoxyerythratidinone was completed in only 6 steps from 4-aminophenol.展开更多
Four new bisabolane sesquiterpenoids daedatrins A-D(1-4),a cadinane sesquiterpene 12-hydroxy-α-cadinol(5),and a heptanorergosterane derivative daedatrin G(6)were isolated from cultures of the basidiomycete Daedaleops...Four new bisabolane sesquiterpenoids daedatrins A-D(1-4),a cadinane sesquiterpene 12-hydroxy-α-cadinol(5),and a heptanorergosterane derivative daedatrin G(6)were isolated from cultures of the basidiomycete Daedaleopsis tricolor.Their structures were elucidated by spectroscopic methods including extensive 2D NMR techniques and X-ray crystallography.All the compounds showed no significant activity against five human cancer cell lines.展开更多
This paper considers the stability analysis of uncertain discrete-time piecewise linear systems with time delays based on piecewise Lyapunov-Krasovskii functionals. It is shown that the stability can be established fo...This paper considers the stability analysis of uncertain discrete-time piecewise linear systems with time delays based on piecewise Lyapunov-Krasovskii functionals. It is shown that the stability can be established for the control systems if there is a piecewise Lyapunov-Krasovskii functional, and moreover, the functional can be obtained by solving a set of linear matrix inequalities （LMIs） that are numerically feasible. A numerical example is given to demonstrate the efficiency and advantage of the proposed method.展开更多
We are developing a whole-genome, BAC/BIBAC-based integrated physical/genetic map of the cotton (Gossypium hirsutum L. ) genome using its genetic standard line TM-1 as the reference genotype. Whole-genome physical... We are developing a whole-genome, BAC/BIBAC-based integrated physical/genetic map of the cotton (Gossypium hirsutum L. ) genome using its genetic standard line TM-1 as the reference genotype. Whole-genome physical maps integrated with genetic maps will provide revolutionized tools and platforms for all kinds of genomics research, including large-scale gene mapping, cloning and target DNA marker development.……展开更多
The urgent demand of extreme(ultra-high/low)thermal conductivity materials is triggered by the high-power device,where exploring the theories and mechanisms of regulating thermal transport properties plays a key role....The urgent demand of extreme(ultra-high/low)thermal conductivity materials is triggered by the high-power device,where exploring the theories and mechanisms of regulating thermal transport properties plays a key role.Herein,we elaborately investigate the effect of vertical(out-of-plane)piezoelectric characteristics on thermal transport,which is historically undiscovered.The different stacking-order(AA and AB)bilayer boron nitride(Bi-BN)in two-dimensional(2D)materials are selected as study cases.By performing state-of-the-art first-principles calculations,it is found that the polarization charge along the out-of-plane orientation ascends significantly with the increasing piezoelectric response in AB stacked Bi-BN(Bi-BN-AB)followed by the enhanced interlayer B–N atomic interactions.Consequently,the amplitude of phonon anharmonicity in Bi-BN-AB increases larger than that in the AA stacked Bi-BN(Bi-BN-AA),resulting in the dramatic weakening of the thermal conductivity by 20.34%under 18%strain.Our research reveals the significant role of the vertical(out-of-plane)piezoelectric characteristic in regulating thermal transport and provides new insight into accurately exploring the thermal transport performance of 2D van der Waals materials.展开更多
The design of novel devices with specific technical interests through modulating structural properties and bonding characteristics promotes the vigorous development of materials informatics.Boron arsenide and boron ni...The design of novel devices with specific technical interests through modulating structural properties and bonding characteristics promotes the vigorous development of materials informatics.Boron arsenide and boron nitride,as remarkably high thermal conductivity(κ)materials,are unfavorable for thermal insulation applications as well as thermoelectric devices.In this study,based on first-principles calculations,we identify a group of novel borides with ultra-lowκ,i.e.,g-B_(3)X_(5)(X=N,P,and As).Theκof g-B_(3)N_(5),g-B_(3)P_(5),and g-B_(3)As_(5)are 21.08,2.50,and 1.85 W·m^(-1)·K^(-1),respectively,which are boron nitride and boron arsenide systems with the lowestκreported so far.The ultra-lowκis attributed to the synergy effect of electronics(lone-pair electrons)and geometry(buckling structures)on thermal transport.The discovery of the ultralowκof boron nitride and boron arsenide systems can well fill the gaps in applications of thermal insulation and thermoelectric devices.展开更多
CrFeNi2V0.5Wx(x=0,0.25)alloys based on these parameters of mixing enthalpy(△Hmix,mixing entropy(△Smix,atomic radius difference(δ),valance electron concentration,and electronegativity difference(△χ)were designed a...CrFeNi2V0.5Wx(x=0,0.25)alloys based on these parameters of mixing enthalpy(△Hmix,mixing entropy(△Smix,atomic radius difference(δ),valance electron concentration,and electronegativity difference(△χ)were designed and prepared.The microstructure and room-temperature mechanical behavior of both alloys were investigated.Compressive test results showed that the CrFeNi2V0.5W0.25 alloy had higher yield strength than that of the W-free CrFeNi2V0.5 alloy,although they all exhibited quite larger compressive plasticity(ε>70%).Compression fracture surface of CrFeNi2V0.5W0.25 alloy revealed a ductile fracture in the face-centered cubic(FCC)phase and a brittle-like fracture in theσphase.Moreover,tensile test results indicated that the CrFeNi2V0.5W0.25 alloy exhibited excellent mechanical property with an ultimate tensile strength of 640 MPa and a high tensile elongation of 15.7%.The tensile deformation mode of the FCC phase in the CrFeNi2V0.5W0.25alloy is dominated by planar glide,relating to dislocation configurations,high-density dislocations,and dislocation wall.Therefore,dislocation slip plays a significant role in tensile deformation of CrFeNi2V0.5W0.25 high-entropy alloy.The higher strength of CrFeNi2V0.5W0.25 alloy is predominantly due to the solid solution strengthening of W element andσphase precipitation strengthening.Combination of the higher tensile strength and plasticity suggests that the CrFeNi2V0.5W0.25 alloy can be a promising aerospace material.展开更多
The Dzyaloshinskii–Moriya interaction(DMI)is well known to favor a chiral rotation of the magnetic moments,which accounts for the emergence of the skyrmions.The DMI is a combined effect of spin–orbit coupling with b...The Dzyaloshinskii–Moriya interaction(DMI)is well known to favor a chiral rotation of the magnetic moments,which accounts for the emergence of the skyrmions.The DMI is a combined effect of spin–orbit coupling with broken inversion symmetry in magnets.Most of the noncentrosymmetric magnetic materials that bear skyrmions involve nonmagnetic elements.This work shows that strong DMIs exist in elemental cobalt with a β-Mn-type metastable structure.The variation of DMI among different cobalt pairs largely follows the variation of hopping magnitude in which p electrons play an important role.Although the DMIs between different atomic pairs partly cancels with each other,the net interaction is sufficient to result in a left-handed Bloch-type spiral.Spin dynamics simulation shows that a critical magnetic field of 2.9 T stabilizes skyrmions at 0 K.展开更多
文摘AIM: To identify risk factors to help predict which patients are likely to fail to appear for an endoscopic procedure. METHODS: This was a retrospective, chart review, cohort study in a Canadian, tertiary care, academic, hospital-based endoscopy clinic. Patients included were: those undergoing esophagogastroduodenoscopy, colonoscopy or flexible sigmoidoscopy and patients who failed to appear were compared to a control group. The main outcome measure was a multivariate analysis of factors associated with truancy from scheduled endoscopic procedures. Factors analyzed included gender, age, waiting time, type of procedure, referring physician, distance to hospital, first or subsequent endoscopic procedure or encounter with gastroenterologist, and urgency of the procedure. RESULTS: Two hundred and thirty-four patients did not show up for their scheduled appointment. Compared to a control group, factors statistically significantly associated with truancy in the multivariate analysis were: non-urgent vs urgent procedure (OR 1.62, 95% CI 1.06, 2.450), referred by a specialist vs a family doctor (OR 2.76, 95% CI 1.31, 5.52) and office-based consult prior to endoscopy vs consult and endoscopic procedure during the same appointment (OR 2.24, 95% CI 1.33, 3.78). CONCLUSION: Identifying patients who are not scheduled for same-day consult and endoscopy, those referred by a specialist, and those with non-urgent referrals may help reduce patient truancy.
文摘Integrative physical mapping is the centerpieceof and essential for advanced genomics research.Upland cotton(Gossypium hirsutum L.)geneticstandard line TM-1 is used as the referencegenotype to develop a whole-genome,BAC/BIBAC-based integrated physical/genetic map ofthe cotton genome.From the TM-1 line we haveconstructed two BAC libraries with HindIII
基金supported by the Key Project in the National Science and Technology Pillar Program during the Twelfth Five-Year Plan Period(Grant No.2012BAK10B04)the Specific Research Fund of the China Institute of Water Resources and Hydropower Research(Grant No.JZ0145B032014)
文摘Flash flood hazard mapping is a supporting component of non-structural measures for flash flood prevention. Pilot case studies are necessary to develop more practicable methods for the technical support systems of flash flood hazard mapping. In this study, the headwater catchment of the Xiapu River Basin in central China was selected as a pilot study area for flash flood hazard mapping. A conceptual distributed hydrological model was developed for flood calculation based on the framework of the Xinanjiang model, which is widely used in humid and semi-humid regions in China. The developed model employs the geomorphological unit hydrograph method, which is extremely valuable when simulating the overland flow process in ungauged catchments, as compared with the original Xinanjiang model. The model was tested in the pilot study area, and the results agree with the measured data on the whole. After calibration and validation, the model is shown to be a useful tool for flash flood calculation. A practicable method for flash flood hazard mapping using the calculated peak discharge and digital elevation model data was presented, and three levels of flood hazards were classified. The resulting flash flood hazard maps indicate that the method successfully predicts the spatial distribution of flash flood hazards, and it can meet the current requirements in China.
文摘BACKGROUND Polyneuropathy,organomegaly,endocrinopathy,M-protein,and skin changes(POEMS)syndrome is a rare paraneoplastic syndrome caused by a plasma cell proliferative disorder.The syndrome is characterized by elevated plasma cells,platelets,and vascular endothelial growth factor levels.Although heart disease rarely occurs in POEMS syndrome,the death rate increases sharply after heart failure.We report a patient who initially presented with an endocrine disease and developed congestive heart failure related to POEMS syndrome 9 years later.CASE SUMMARY A 23-year-old woman with no history of menstruation and a 9-year history of type I diabetes reported feeling breathless after activities.She could not lie down and rest at night.Three months prior,she experienced pain and increased tension in her left thigh accompanied by tenderness and edema in both lower extremities.The chief complaint upon hospital admission was that blood sugar has increased for more than 9 years,pain in the left thigh,and edema in both legs for more than 2 mo.After a multisystem evaluation,she was diagnosed with POEMS syndrome.Her echocardiogram showed left ventricular dilation with systolic dysfunction,and the left ventricular ejection fraction was only 38%with severely elevated brain natriuretic peptide.She received a combination of dexamethasone and thalidomide for 1 mo,but her symptoms did not improve.Therefore,we added a two-per-week bortezomib injection.After 2 wk,the patient’s heart function had improved significantly.CONCLUSION This case provides information about the treatment of POEMS syndrome with complications and highlights the challenges of developing a standardized treatment.
基金This work was supported by grants(20925205,21062026,2010GA014 and 2009CB522300) from National Natural Science Foundation of China,Yunnan Province and National Basic Research Program of China(973 Program).
文摘A concise synthetic route leading to highly functional erythrina alkaloid skeletons has been developed.The key process is an oxidative carbon-carbon coupling followed by a conjugated addition.Based on this new strategy,a formal synthesis of demethoxyerythratidinone was completed in only 6 steps from 4-aminophenol.
基金This work was financially supported by the National Natural Science Foundation of China(U1132607).
文摘Four new bisabolane sesquiterpenoids daedatrins A-D(1-4),a cadinane sesquiterpene 12-hydroxy-α-cadinol(5),and a heptanorergosterane derivative daedatrin G(6)were isolated from cultures of the basidiomycete Daedaleopsis tricolor.Their structures were elucidated by spectroscopic methods including extensive 2D NMR techniques and X-ray crystallography.All the compounds showed no significant activity against five human cancer cell lines.
文摘This paper considers the stability analysis of uncertain discrete-time piecewise linear systems with time delays based on piecewise Lyapunov-Krasovskii functionals. It is shown that the stability can be established for the control systems if there is a piecewise Lyapunov-Krasovskii functional, and moreover, the functional can be obtained by solving a set of linear matrix inequalities （LMIs） that are numerically feasible. A numerical example is given to demonstrate the efficiency and advantage of the proposed method.
文摘 We are developing a whole-genome, BAC/BIBAC-based integrated physical/genetic map of the cotton (Gossypium hirsutum L. ) genome using its genetic standard line TM-1 as the reference genotype. Whole-genome physical maps integrated with genetic maps will provide revolutionized tools and platforms for all kinds of genomics research, including large-scale gene mapping, cloning and target DNA marker development.……
基金This study was financially supported by the National Natural Science Foundation of China(Nos.52006057,51906097 and 11904324)the Fundamental Research Funds for the Central Universities(Nos.531119200237 and 541109010001)the State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body at Hunan University(No.52175013).
文摘The urgent demand of extreme(ultra-high/low)thermal conductivity materials is triggered by the high-power device,where exploring the theories and mechanisms of regulating thermal transport properties plays a key role.Herein,we elaborately investigate the effect of vertical(out-of-plane)piezoelectric characteristics on thermal transport,which is historically undiscovered.The different stacking-order(AA and AB)bilayer boron nitride(Bi-BN)in two-dimensional(2D)materials are selected as study cases.By performing state-of-the-art first-principles calculations,it is found that the polarization charge along the out-of-plane orientation ascends significantly with the increasing piezoelectric response in AB stacked Bi-BN(Bi-BN-AB)followed by the enhanced interlayer B–N atomic interactions.Consequently,the amplitude of phonon anharmonicity in Bi-BN-AB increases larger than that in the AA stacked Bi-BN(Bi-BN-AA),resulting in the dramatic weakening of the thermal conductivity by 20.34%under 18%strain.Our research reveals the significant role of the vertical(out-of-plane)piezoelectric characteristic in regulating thermal transport and provides new insight into accurately exploring the thermal transport performance of 2D van der Waals materials.
基金financially supported by the National Natural Science Foundation of China(Nos.52006057,52006059 and 51906097)the Fundamental Research Funds for the Central Universities(Nos.531119200237 and 541109010001531118010490)+1 种基金the State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body at Hunan University(No.52175011)RWTH Aachen University under project bund0011。
文摘The design of novel devices with specific technical interests through modulating structural properties and bonding characteristics promotes the vigorous development of materials informatics.Boron arsenide and boron nitride,as remarkably high thermal conductivity(κ)materials,are unfavorable for thermal insulation applications as well as thermoelectric devices.In this study,based on first-principles calculations,we identify a group of novel borides with ultra-lowκ,i.e.,g-B_(3)X_(5)(X=N,P,and As).Theκof g-B_(3)N_(5),g-B_(3)P_(5),and g-B_(3)As_(5)are 21.08,2.50,and 1.85 W·m^(-1)·K^(-1),respectively,which are boron nitride and boron arsenide systems with the lowestκreported so far.The ultra-lowκis attributed to the synergy effect of electronics(lone-pair electrons)and geometry(buckling structures)on thermal transport.The discovery of the ultralowκof boron nitride and boron arsenide systems can well fill the gaps in applications of thermal insulation and thermoelectric devices.
基金the National Natural Science Foundation of China(No.51901116)。
文摘CrFeNi2V0.5Wx(x=0,0.25)alloys based on these parameters of mixing enthalpy(△Hmix,mixing entropy(△Smix,atomic radius difference(δ),valance electron concentration,and electronegativity difference(△χ)were designed and prepared.The microstructure and room-temperature mechanical behavior of both alloys were investigated.Compressive test results showed that the CrFeNi2V0.5W0.25 alloy had higher yield strength than that of the W-free CrFeNi2V0.5 alloy,although they all exhibited quite larger compressive plasticity(ε>70%).Compression fracture surface of CrFeNi2V0.5W0.25 alloy revealed a ductile fracture in the face-centered cubic(FCC)phase and a brittle-like fracture in theσphase.Moreover,tensile test results indicated that the CrFeNi2V0.5W0.25 alloy exhibited excellent mechanical property with an ultimate tensile strength of 640 MPa and a high tensile elongation of 15.7%.The tensile deformation mode of the FCC phase in the CrFeNi2V0.5W0.25alloy is dominated by planar glide,relating to dislocation configurations,high-density dislocations,and dislocation wall.Therefore,dislocation slip plays a significant role in tensile deformation of CrFeNi2V0.5W0.25 high-entropy alloy.The higher strength of CrFeNi2V0.5W0.25 alloy is predominantly due to the solid solution strengthening of W element andσphase precipitation strengthening.Combination of the higher tensile strength and plasticity suggests that the CrFeNi2V0.5W0.25 alloy can be a promising aerospace material.
基金We acknowledge the financial support from the Ningbo Scientific and Technological Project under Grant No.2011B82004 and NSFC under Grant No.51401227.H.B.L acknowledges the continuous support of computing resource from CCMS of the IMR in Tohoku UniversityJ.P.L thanks US/DoD/ARO support under grant W911NF-11-1-0507H.B.L thanks Gideon Müller from Forschungszentrum Jülich and JARA for offering help to use the SPIRIT code.
文摘The Dzyaloshinskii–Moriya interaction(DMI)is well known to favor a chiral rotation of the magnetic moments,which accounts for the emergence of the skyrmions.The DMI is a combined effect of spin–orbit coupling with broken inversion symmetry in magnets.Most of the noncentrosymmetric magnetic materials that bear skyrmions involve nonmagnetic elements.This work shows that strong DMIs exist in elemental cobalt with a β-Mn-type metastable structure.The variation of DMI among different cobalt pairs largely follows the variation of hopping magnitude in which p electrons play an important role.Although the DMIs between different atomic pairs partly cancels with each other,the net interaction is sufficient to result in a left-handed Bloch-type spiral.Spin dynamics simulation shows that a critical magnetic field of 2.9 T stabilizes skyrmions at 0 K.
