Reconstruction of a traumatic distal femur defect remains a therapeutic challenge.Bone defect implants have been proposed to substitute the bone defect,and their biomechanical performances can be analyzed via a numeri...Reconstruction of a traumatic distal femur defect remains a therapeutic challenge.Bone defect implants have been proposed to substitute the bone defect,and their biomechanical performances can be analyzed via a numerical approach.However,the material assumptions for past computational human femur simulations were mainly homogeneous.Thus,this study aimed to design and analyze scaffolds for reconstructing the distal femur defect using a patient-specific finite element modeling technique.A three-dimensional finite element model of the human femur with accurate geometry and material distribution was developed using the finite element method and material mapping technique.An intact femur and a distal femur defect model treated with nine microstructure scaffolds and two solid scaffolds were investigated and compared under a single-leg stance loading.The results showed that the metal solid scaffold design could provide the most stable fixation for reconstructing the distal femur defect.However,the fixation stability was affected by various microstructure designs and pillar diameters.A microstructure scaffold can be designed to satisfy all the biomechanical indexes,opening up future possibilities for more stable reconstructions.A three-dimensional finite element model of the femur with real bone geometry and bone material distribution can be developed,and this patient-specific femur model can be used for studying other femoral fractures or injuries,paving the way for more comprehensive research in the field.Besides,this patient-specific finite element modeling technique can also be applied to developing other human or animal bone models,expanding the scope of biomechanical research.展开更多
BACKGROUND Heart rate variability(HRV) and pulse-wave velocity(PWV),indicators of cardiac function,are altered in patients with spinal cord injury(SCI),suggesting that autonomic cardiac function and arterial stiffness...BACKGROUND Heart rate variability(HRV) and pulse-wave velocity(PWV),indicators of cardiac function,are altered in patients with spinal cord injury(SCI),suggesting that autonomic cardiac function and arterial stiffness may underlie the high risk of cardiovascular complications in these patients.No study has simultaneously investigated HRV and PWV in the same patients.AIM To evaluate cardiovascular complications in SCI patients by comparing HRV and PWV between patients with and without SCI.METHODS In this cross-sectional pilot study,patients with(n = 60) and without SCI(n = 60) were recruited from December 7,2019 to January 21,2020.Each participant received a five-minute assessment of HRV and the cardiovascular system using the Medicore HRV Analyzer SA-3000 P.Differences in HRV and PWV parameters between participants with and without SCI were statistically examined.RESULTS We observed a significant difference between participants with and without SCI with respect to the standard deviation of all normal-to-normal intervals,square root of the mean sum of squared successive risk ratio interval differences,physical stress index,total power,very-low frequency,low frequency,high frequency,and arterial elasticity.CONCLUSION Patients with SCI have weaker sympathetic and parasympathetic activity as well as lower arterial elasticity compared to those without,suggesting that SCI may increase cardiac function loading.展开更多
Dichroic behaviors of layered ReS2 have been characterized using angular dependent polarizedabsorption and resistivity measurements in the van der Waal plane. The angular dependent optical and electrical measurements ...Dichroic behaviors of layered ReS2 have been characterized using angular dependent polarizedabsorption and resistivity measurements in the van der Waal plane. The angular dependent optical and electrical measurements are carried out with angles ranging from θ= 0°(E || b) to θ= 90°(E ^b) with respect to the layer crystal’s b-axis. The angular de pendence of polarized energy gaps of ReS2 shows a sinusoidal variation of energies from ~1.341 eV (E ||b to ~1.391 eV (E ^ b). The experimental evidence of polarized energy gap leaves ReS2 apotential usage for fabrication of a polarized optical switch suitable for polarized optical communication in nearinfrared (NIR) region. Angular dependence of resistivities of ReS2 in?the vander Waal plane has also been evaluated. The relationship of inplane resistivities shows a sinusoidallike variation from θ= 0°(E ||b) to 90°(E ^ b) and repeated periodically to 360°. The experimental results of optical and electrical measurements indicated that ReS2 is not only an opticaldichroic layer but also an electricaldichroism material presented in the layer plane.展开更多
Design and implementation of a personal computer (PC) based measurement circuits & system that containing signals’ sensing and generation are demonstrated in this study. The instrument can be easily operated via ...Design and implementation of a personal computer (PC) based measurement circuits & system that containing signals’ sensing and generation are demonstrated in this study. The instrument can be easily operated via a user-friendly interface consisted of some functional keys displayed on the PC screen. Compact design of the hardware for the two units (signals’ sensing and generation) is made in a plug-in style of PC input/output (I/O) card so that no extra space for the instrument is needed. Design concepts for the hardware and software of the instrument are described. Functional performances of the setup of signals’ sensing and generation are tested. The results show user-friendly function and well-behaved performance for the package design.展开更多
Nanocomposites of high-density polyethylene(HDPE)modified with 0.2 phr graphene-zinc oxide(GN-ZnO)exhibited optimal mechanical properties and thermal stability.Two other nano-materials—GN and nano-ZnO—were also used...Nanocomposites of high-density polyethylene(HDPE)modified with 0.2 phr graphene-zinc oxide(GN-ZnO)exhibited optimal mechanical properties and thermal stability.Two other nano-materials—GN and nano-ZnO—were also used to compare them with GN-ZnO.increasing the content of GN-ZnO gradually enhanced the antibacterial and barrier properties,but the addition of 0.3 phr GN-ZnO led to agglomeration that caused defects in the nanocomposites.Herein,we investigated the antibacterial and barrier properties of HDPE nanocomposites infused with different nanoparticles(GN,ZnO,GN-ZnO)of varying concentrations.HDPE and the nanoparticles were meltblended together in a Haake-Buchler Rheomixer to produce a new environment-friendly nano-material with improved physical and chemical properties.The following characterizations were conducted:tensile test,thermogravimetric analysis,morphology,differential scanning calorimetry,X-ray diffraction,antibacterial test,and oxygen and water vapor permeation test.The results showed that the crystallinity of HDPE was affected with the addition of GN-ZnO,and the nanocomposites had effective antibacterial capacity,strong mechanical properties,high thermal stability,and excellent barrier performance.This type of HDPE nanocomposites reinforced with GN-ZnO would be attractive for packaging industries.展开更多
In the current extensive studies of layered two-dimensional （2D） materials, compared to hexagonal structures such as graphene, hBN, and MoS2, low- symmetry 2D materials have shown great potential for applications in...In the current extensive studies of layered two-dimensional （2D） materials, compared to hexagonal structures such as graphene, hBN, and MoS2, low- symmetry 2D materials have shown great potential for applications in anisotropic devices. Rhenium diselenide （ReSe2） possesses the bulk space group P1 and belongs to the triclinic crystal system with a deformed cadmium-iodide-type structure. Here, we propose an electron diffraction-based method to distinguish the monolayer ReSe2 membrane from multilayer ReSe2 and its two different vertical orientations. Our method is also applicable to other low-symmetry crystal systems, including both triclinic and monoclinic lattices, as long as their third unit-cell basis vectors are not perpendicular to the basal plane. Our experimental results are well explained by kinematical electron diffraction theory and the corresponding simulations. Generalization of our method to other 2D materials, such as ~：raphene, is also discussed.展开更多
We report Q-switched and mode-locked erbium-doped all-fiber lasers using ternary ReS_(2(1-x))Se_(2x) as saturable absorbers(SAs). The modulation depth and saturable intensity of the film SA are 1.8% and 0.046 MW∕cm2....We report Q-switched and mode-locked erbium-doped all-fiber lasers using ternary ReS_(2(1-x))Se_(2x) as saturable absorbers(SAs). The modulation depth and saturable intensity of the film SA are 1.8% and 0.046 MW∕cm2.In Q-switched mechanism output, the pulse was centered at 1531.1 nm with maximum pulse energy and minimum pulse width of 28.29 nJ and 1.07 μs, respectively. In mode-locked operation, the pulse was centered at1561.15 nm with pulse width of 888 fs, repetition rate of 2.95 MHz, and maximum pulse energy of 0.275 nJ. To the best of our knowledge, this is the first report on the mode-locked Er^(3+)-doped fiber laser using ternary transition metal dichalcogenides. This work suggests prospective 2 D-material SAs can be widely used in versatile fields due to their attractive optoelectronic and tunable energy bandgap properties.展开更多
The self-assembly of zinc-organic coordination polymers[Zn2(1,3-bdc)2(bpda)2]·3DMF·0.5H_(2)O(1,1,3-bdc=1,3-benzenedicarboxylate;bpda=N,N’-bis(pyridine-4-yl)-1,4-benzenedicarboxamide)and[Zn2(1,4-ndc)(dmc)2(b...The self-assembly of zinc-organic coordination polymers[Zn2(1,3-bdc)2(bpda)2]·3DMF·0.5H_(2)O(1,1,3-bdc=1,3-benzenedicarboxylate;bpda=N,N’-bis(pyridine-4-yl)-1,4-benzenedicarboxamide)and[Zn2(1,4-ndc)(dmc)2(bpda)2](2,1,4-ndc=1,4-naphthalenedicarboxylate;dmc=dimethylcarbamate)through mixed-ligand coordination under hydro(solvo)thermal conditions is reported.Both compounds 1 and 2 are made up of a two-dimensional layered network with a decorated 44-sql topology from the associated dinuclear two-blade paddlewheel building units.The bis-amide groups of the bpda ligands in the layered structures of 1 and 2 are sheltered and participate in multiple hydrogen-bonding interactions.Compounds 1 and 2 are both highly thermally stable at temperatures over 300°C and exhibit solid-state luminescence properties.In comparison with the CO_(2)adsorption behavior of the related compound{[Zn4(1,4-bdc)4(bpda)4]·5DMF·3H_(2)O}n(3,1,4-bdc=1,4-benzenedicarboxylate),both the desolvated sample of 1 and the thermally-activated sample of 2 show a lower CO_(2)uptake capacity and a decreased Qst trace with increasing CO_(2)uptake.These results show that no meaningful cooperative binding occurs between the amide groups and CO_(2)molecules in the condensed 2D structures of 1 and 2.By varying the dicarboxylate ligand from 1,3-bdc,1,4-ndc to 1,4-bdc,the amide-functionalized products 1-3 induce subtle changes in their structures.In particular,the intimate interrelationship between the structural characteristics of amide groups and the CO_(2)adsorption behavior of such compounds is clearly demonstrated.展开更多
基金funded by the TaipeiMedical University-National Taiwan University of Science and Technology joint research program under Grant No.TMU-NTUST-109-09.
文摘Reconstruction of a traumatic distal femur defect remains a therapeutic challenge.Bone defect implants have been proposed to substitute the bone defect,and their biomechanical performances can be analyzed via a numerical approach.However,the material assumptions for past computational human femur simulations were mainly homogeneous.Thus,this study aimed to design and analyze scaffolds for reconstructing the distal femur defect using a patient-specific finite element modeling technique.A three-dimensional finite element model of the human femur with accurate geometry and material distribution was developed using the finite element method and material mapping technique.An intact femur and a distal femur defect model treated with nine microstructure scaffolds and two solid scaffolds were investigated and compared under a single-leg stance loading.The results showed that the metal solid scaffold design could provide the most stable fixation for reconstructing the distal femur defect.However,the fixation stability was affected by various microstructure designs and pillar diameters.A microstructure scaffold can be designed to satisfy all the biomechanical indexes,opening up future possibilities for more stable reconstructions.A three-dimensional finite element model of the femur with real bone geometry and bone material distribution can be developed,and this patient-specific femur model can be used for studying other femoral fractures or injuries,paving the way for more comprehensive research in the field.Besides,this patient-specific finite element modeling technique can also be applied to developing other human or animal bone models,expanding the scope of biomechanical research.
文摘BACKGROUND Heart rate variability(HRV) and pulse-wave velocity(PWV),indicators of cardiac function,are altered in patients with spinal cord injury(SCI),suggesting that autonomic cardiac function and arterial stiffness may underlie the high risk of cardiovascular complications in these patients.No study has simultaneously investigated HRV and PWV in the same patients.AIM To evaluate cardiovascular complications in SCI patients by comparing HRV and PWV between patients with and without SCI.METHODS In this cross-sectional pilot study,patients with(n = 60) and without SCI(n = 60) were recruited from December 7,2019 to January 21,2020.Each participant received a five-minute assessment of HRV and the cardiovascular system using the Medicore HRV Analyzer SA-3000 P.Differences in HRV and PWV parameters between participants with and without SCI were statistically examined.RESULTS We observed a significant difference between participants with and without SCI with respect to the standard deviation of all normal-to-normal intervals,square root of the mean sum of squared successive risk ratio interval differences,physical stress index,total power,very-low frequency,low frequency,high frequency,and arterial elasticity.CONCLUSION Patients with SCI have weaker sympathetic and parasympathetic activity as well as lower arterial elasticity compared to those without,suggesting that SCI may increase cardiac function loading.
文摘Dichroic behaviors of layered ReS2 have been characterized using angular dependent polarizedabsorption and resistivity measurements in the van der Waal plane. The angular dependent optical and electrical measurements are carried out with angles ranging from θ= 0°(E || b) to θ= 90°(E ^b) with respect to the layer crystal’s b-axis. The angular de pendence of polarized energy gaps of ReS2 shows a sinusoidal variation of energies from ~1.341 eV (E ||b to ~1.391 eV (E ^ b). The experimental evidence of polarized energy gap leaves ReS2 apotential usage for fabrication of a polarized optical switch suitable for polarized optical communication in nearinfrared (NIR) region. Angular dependence of resistivities of ReS2 in?the vander Waal plane has also been evaluated. The relationship of inplane resistivities shows a sinusoidallike variation from θ= 0°(E ||b) to 90°(E ^ b) and repeated periodically to 360°. The experimental results of optical and electrical measurements indicated that ReS2 is not only an opticaldichroic layer but also an electricaldichroism material presented in the layer plane.
文摘Design and implementation of a personal computer (PC) based measurement circuits & system that containing signals’ sensing and generation are demonstrated in this study. The instrument can be easily operated via a user-friendly interface consisted of some functional keys displayed on the PC screen. Compact design of the hardware for the two units (signals’ sensing and generation) is made in a plug-in style of PC input/output (I/O) card so that no extra space for the instrument is needed. Design concepts for the hardware and software of the instrument are described. Functional performances of the setup of signals’ sensing and generation are tested. The results show user-friendly function and well-behaved performance for the package design.
基金The authors would like to acknowledge the financial support from the following organizations:Wuliangye Group Co.,Ltd.(No.CXY2019ZR001)Sichuan Province Science and Technology Support Program(No.2019JDRC0029)+2 种基金Zigong City Science and Technology(Nos.2017XC16,2019CXRC01)Opening Project of Material Corrosion and Protection Key Laboratory of Sichuan Province(Nos.2016CL10,2017CL03,2019CL05,2018CL08,2018CL07)Opening Project of Sichuan Province,the Foundation of Introduced Talent of Sichuan University of Science and Engineering(Nos.2014RC31,2017RCL31,2017RCL36,2017RCL16,2019RC05,2019RC07).Appreciation is also extended to Apex Nanotek Co.,Ltd.
文摘Nanocomposites of high-density polyethylene(HDPE)modified with 0.2 phr graphene-zinc oxide(GN-ZnO)exhibited optimal mechanical properties and thermal stability.Two other nano-materials—GN and nano-ZnO—were also used to compare them with GN-ZnO.increasing the content of GN-ZnO gradually enhanced the antibacterial and barrier properties,but the addition of 0.3 phr GN-ZnO led to agglomeration that caused defects in the nanocomposites.Herein,we investigated the antibacterial and barrier properties of HDPE nanocomposites infused with different nanoparticles(GN,ZnO,GN-ZnO)of varying concentrations.HDPE and the nanoparticles were meltblended together in a Haake-Buchler Rheomixer to produce a new environment-friendly nano-material with improved physical and chemical properties.The following characterizations were conducted:tensile test,thermogravimetric analysis,morphology,differential scanning calorimetry,X-ray diffraction,antibacterial test,and oxygen and water vapor permeation test.The results showed that the crystallinity of HDPE was affected with the addition of GN-ZnO,and the nanocomposites had effective antibacterial capacity,strong mechanical properties,high thermal stability,and excellent barrier performance.This type of HDPE nanocomposites reinforced with GN-ZnO would be attractive for packaging industries.
基金This work is financially supported by the National Basic Research Program of China （Nos. 2014CB932500 and 2015CB921004）, the National Natural Science Foundation of China （Nos. 51472215, 51222202, 61571197 and 61172011）, the 111 project （No. B16042） and MOST 104-2112-M-011-002-MY3. The authors would like to thank Prof. Christoph Koch fromHumbold University of Berlin for the fruitful dis- cussions on multislice simulations. J. Y. acknowledges the EPSRC （UK） funding （Nos. EP/G070326 and EP/ J022098） and supports from Pao Yu-Kong International Foundation for a Chair Professorship in ZJU. This work made use of the resources of the Center of Electron Microscopy of Zhejiang University
文摘In the current extensive studies of layered two-dimensional （2D） materials, compared to hexagonal structures such as graphene, hBN, and MoS2, low- symmetry 2D materials have shown great potential for applications in anisotropic devices. Rhenium diselenide （ReSe2） possesses the bulk space group P1 and belongs to the triclinic crystal system with a deformed cadmium-iodide-type structure. Here, we propose an electron diffraction-based method to distinguish the monolayer ReSe2 membrane from multilayer ReSe2 and its two different vertical orientations. Our method is also applicable to other low-symmetry crystal systems, including both triclinic and monoclinic lattices, as long as their third unit-cell basis vectors are not perpendicular to the basal plane. Our experimental results are well explained by kinematical electron diffraction theory and the corresponding simulations. Generalization of our method to other 2D materials, such as ~：raphene, is also discussed.
基金National Key R&D Program of China(2018YFB1107200)National Natural Science Foundation of China(NSFC)(61675158,21673058)+1 种基金Chinese Academy of Sciences Key Project(CAS Key Project)(QYZDBSSW-SYS031)Chinese Academy of Sciences(CAS)(XDB30000000)
文摘We report Q-switched and mode-locked erbium-doped all-fiber lasers using ternary ReS_(2(1-x))Se_(2x) as saturable absorbers(SAs). The modulation depth and saturable intensity of the film SA are 1.8% and 0.046 MW∕cm2.In Q-switched mechanism output, the pulse was centered at 1531.1 nm with maximum pulse energy and minimum pulse width of 28.29 nJ and 1.07 μs, respectively. In mode-locked operation, the pulse was centered at1561.15 nm with pulse width of 888 fs, repetition rate of 2.95 MHz, and maximum pulse energy of 0.275 nJ. To the best of our knowledge, this is the first report on the mode-locked Er^(3+)-doped fiber laser using ternary transition metal dichalcogenides. This work suggests prospective 2 D-material SAs can be widely used in versatile fields due to their attractive optoelectronic and tunable energy bandgap properties.
文摘The self-assembly of zinc-organic coordination polymers[Zn2(1,3-bdc)2(bpda)2]·3DMF·0.5H_(2)O(1,1,3-bdc=1,3-benzenedicarboxylate;bpda=N,N’-bis(pyridine-4-yl)-1,4-benzenedicarboxamide)and[Zn2(1,4-ndc)(dmc)2(bpda)2](2,1,4-ndc=1,4-naphthalenedicarboxylate;dmc=dimethylcarbamate)through mixed-ligand coordination under hydro(solvo)thermal conditions is reported.Both compounds 1 and 2 are made up of a two-dimensional layered network with a decorated 44-sql topology from the associated dinuclear two-blade paddlewheel building units.The bis-amide groups of the bpda ligands in the layered structures of 1 and 2 are sheltered and participate in multiple hydrogen-bonding interactions.Compounds 1 and 2 are both highly thermally stable at temperatures over 300°C and exhibit solid-state luminescence properties.In comparison with the CO_(2)adsorption behavior of the related compound{[Zn4(1,4-bdc)4(bpda)4]·5DMF·3H_(2)O}n(3,1,4-bdc=1,4-benzenedicarboxylate),both the desolvated sample of 1 and the thermally-activated sample of 2 show a lower CO_(2)uptake capacity and a decreased Qst trace with increasing CO_(2)uptake.These results show that no meaningful cooperative binding occurs between the amide groups and CO_(2)molecules in the condensed 2D structures of 1 and 2.By varying the dicarboxylate ligand from 1,3-bdc,1,4-ndc to 1,4-bdc,the amide-functionalized products 1-3 induce subtle changes in their structures.In particular,the intimate interrelationship between the structural characteristics of amide groups and the CO_(2)adsorption behavior of such compounds is clearly demonstrated.
