Endoscopic ultrasonography-guided fine-needle aspiration(EUS-FNA) has been applied to pancreaticobiliary lesions since the 1990 s and is in widespread use throughout the world today. We used this method to confirm the...Endoscopic ultrasonography-guided fine-needle aspiration(EUS-FNA) has been applied to pancreaticobiliary lesions since the 1990 s and is in widespread use throughout the world today. We used this method to confirm the pathological evidence of the pancreaticobiliary lesions and to perform suitable therapies. Complications of EUS-FNA are quite rare, but some of them are severe. Operators should master conventional EUS observation and experience a minimum of 20-30 cases of supervised EUS-FNA on non-pancreatic and pancreatic lesions before attempting solo EUSFNA. Studies conducted on pancreaticobiliary EUSFNA have focused on selection of suitable instruments(e.g., needle selection) and sampling techniques(e.g., fanning method, suction level, with or without a stylet, optimum number of passes). Today, the diagnostic ability of EUS-FNA is still improving; the detection of pancreatic cancer(PC) currently has a sensitivity of 90%-95% and specificity of 95%-100%. In addition to PC, a variety of rare pancreatic tumors can be discriminated by conducting immunohistochemistry on the FNA materials. A flexible, large caliber needle has been used to obtain a large piece of tissue, which can provide sufficient histological information to be helpful in classifying benign pancreatic lesions. EUSFNA can supply high diagnostic yields even for biliary lesions or peri-pancreaticobiliary lymph nodes. This review focuses on the clinical aspects of EUS-FNA in the pancreaticobiliary field, with the aim of providing information that can enable more accurate and efficient diagnosis.展开更多
Oxide dispersion strengthened （ODS） steels can be used as the structural materials in the future fusion reactors and the fuel cladding materials in the advanced fission reactors. However, the weldability of ODS stee...Oxide dispersion strengthened （ODS） steels can be used as the structural materials in the future fusion reactors and the fuel cladding materials in the advanced fission reactors. However, the weldability of ODS steels is a severe problem. In the present study, defect-free joints of the 15Cr-ODS ferritic steel were achieved by friction stir welding at different rotation speeds. The recrystallization, hardness and tensile properties are highly related with the rotation speed of the stir tool. The higher rotation speed results in coarser grains in the top SZ, while the grain size exhibits more complicated relation with the rotation speed in the SZ center. The joint welded at 250 rpm exhibits a maximum tensile strength of 974 MPa that reaches about 84% of that of the base metal.展开更多
Although hydroxyapatite is commonly used as a scaffold for bone regeneration, sponges may be suitable because of the adaptability to the defect. To use as a scaffold, the fiber of sponge would be coated with any adhes...Although hydroxyapatite is commonly used as a scaffold for bone regeneration, sponges may be suitable because of the adaptability to the defect. To use as a scaffold, the fiber of sponge would be coated with any adhesive to storage stem cells in the sponges. Fiber in the structure of commercially available sponges was coated by immersion in dextran solution and air dried. After seeding of rat bone marrow cells (rBMCs), the sponges were implanted subcutis of rats for estimate osteogenesis in vivo. The level of osteocalcin was 25.28 ±5.71 ng/scaffold and that of Ca was 129.20 ±19.69 μg/scaffold. These values were significantly high- er than those in sponges without dextran coating (p 【0.01). It was thought that rBMCs could be stored on the shelf by dextran deposition in the fiber of the sponge. In vivo examination, dextran induced osteogenesis by rBMCs in many spaces in the inner structure of the sponge.展开更多
We present new diagnostics for use in optical laser pump-X-ray Free Electron Laser(XFEL)probe experiments to monitor dimensions,intensity profile and focusability of the XFEL beam and to control initial quality and ho...We present new diagnostics for use in optical laser pump-X-ray Free Electron Laser(XFEL)probe experiments to monitor dimensions,intensity profile and focusability of the XFEL beam and to control initial quality and homogeneity of targets to be driven by optical laser pulse.By developing X-ray imaging,based on the use of an LiF crystal detector,we were able to measure the distribution of energy inside a hard X-ray beam with unprecedented high spatial resolution(~1 mm)and across a field of view larger than some millimetres.This diagnostic can be used in situ,provides a very high dynamic range,has an extremely limited cost,and is relatively easy to be implemented in pump-probe experiments.The proposed methods were successfully applied in pump-probe experiments at the SPring-8 Angstrom Compact free electron LAser(SACLA)XFEL facility and its potential was demonstrated for current and future High Energy Density Science experiments.展开更多
A formalin-treated polyvinyl-alcohol (PVF) sponge is convenient as a scaffold because its configuration is easily modified. However, coating the sponge with an adhesive chemical agent is necessary to attach bone marro...A formalin-treated polyvinyl-alcohol (PVF) sponge is convenient as a scaffold because its configuration is easily modified. However, coating the sponge with an adhesive chemical agent is necessary to attach bone marrow cells (BMCs) to the sponge structure. Moreover, it was considered that a hybrid scaffold composed of a sponge and enveloped cylindrical porous hydroxyapatite (HA) would be convenient. In this study, the effect of leucine (Leu) coating on a PVF sponge was examined for osteogenesis on an HA/PVF hybrid scaffold by rat BMCs (rBMCs). In an in vivo assessment, the sponge immersed in Leu solution (10 mg/ml) was inserted into the hollow center of cylindrical HA. The sponge received 1.5 × 106 rBMCs obtained from male Fischer 344 rats. The hybrid scaffolds were then implanted subcutaneously of syngeneic rats for 6 weeks. In vitro assessment of Leu to hard tissue formation with coating on the well or addition in rBMC culture medium was also performed in a 6-well plate for 2 weeks. In vivo examinations showed the excellent effect of Leu coating on PVF sponge. Leu-coated PVF sponge in the scaffolds showed marked new bone formation in the pores by histological examination. Leu-coated PVF sponge showed a high quantity of osteocalcine (OC). HA might prevent the release of rBMCs from PVF as a barrier. In in vitro examinations, the quantity of OC in rBMC culture with and without the addition of Leu in culture medium showed no significant difference. However, addition of Leu showed significant ALP activity level in culture medium. Leu coating in culture plate wells showed no influence on the quantity of OC. It was concluded from the results that Leu might prevent the emigration of rBMCs to the outside of the scaffold and promote the differentiation of cells to osteoblasts in the scaffold.展开更多
IgG4-related disease(IgG4-RD) is an immune-mediated fibroinflammatory disorder that can occur in almost all systemic organs and generally responds to corticosteroid treatment. We report a rare case of an IgG4-related ...IgG4-related disease(IgG4-RD) is an immune-mediated fibroinflammatory disorder that can occur in almost all systemic organs and generally responds to corticosteroid treatment. We report a rare case of an IgG4-related intrapelvic mass lesion that responded to steroid therapy but caused a fistula between the sigmoid colon and bladder. A 71-year-old man was followed after treatment for hepatocellular carcinoma. Follow-up computed tomography(CT) incidentally depicted left hydronephrosis with an ill-demarcated intrapelvic mass lesion. This lesion was histologically diagnosed as IgG4-RD by open biopsy, and peroral steroid therapy was initiated. One month after starting steroids, a colovesical fistula was detected by follow-up CT. A colostomy and urethral catheterization were emergently performed. The patient recovered and the mass lesion was drastically minimized by the initiation of glucocorticoids; however, he still needs urethral catheterization. IgG4-RD develops in various systemic organs and generally responds well to steroids. Clinicians must be watchful for the complications of responses to corticosteroids, such as fistulization, when the mass lesion of IgG4-RD is adjacent to multiple luminal organs.展开更多
The effect of laminin on hard tissue formation using rat bone marrow cells was assessed. Rat bone marrow cells were obtained from femora of 6-week-old male Fischer 344 rats. In this in vivo examination, porous cylindr...The effect of laminin on hard tissue formation using rat bone marrow cells was assessed. Rat bone marrow cells were obtained from femora of 6-week-old male Fischer 344 rats. In this in vivo examination, porous cylindrical hydroxyapatite scaffolds with a hollow center were immersed in 100 mg/ml laminin solution and air-dried. Rat bone marrow cells in 200 ml culture medium at 1 × 106 cells/ml were seeded in the scaffolds. The scaffolds were implanted into the dorsal subcutis of 7-week-old male Fischer 344 rats for 6 weeks. The scaffolds were then removed and examined histologically. For in vitro examinations, 1 × 105 rat bone marrow cells in 2 ml culture medium were then cultured with the addition of dexamethasone and laminin. Rat bone marrow cells were also cultured in laminin-coated culture plates. In vitro examinations showed the effectiveness of laminin for hard tissue formation from the results of biochemical and immunochemical analysis. From the in vivo examination, laminin coating of the scaffolds induced hard tissue in the pores with the cells. It is concluded that laminin is useful for bone formation, as in an in vitro culture study using bone marrow cells, in hydroxyapatite scaffolds in vivo.展开更多
The aim of this study was to estimate the effect of L-lysine on nodule formation by rat bone marrow cells in vitro. In this study, L-lysine was added to medium for mesenchymal stem cell culture to promote proliferatio...The aim of this study was to estimate the effect of L-lysine on nodule formation by rat bone marrow cells in vitro. In this study, L-lysine was added to medium for mesenchymal stem cell culture to promote proliferation and differentiation of the cells, and then nodule formation was estimated in an in vitro rat bone marrow cell culture. Bone marrow cells from the bone shafts of the femora of Fischer 344 rats were cultured in minimum essential medium with 20 μl of L-lysine solution at 10﹣4, 10﹣5, 10﹣6, 10﹣7 or 10﹣8 M. Dexamethasone was also added to the medium at 10 nM for differentiation of stem cells from bone marrow into osteoblast progenitor cells. The subculture was performed for 2 weeks. The quantity of osteocalcin in rat bone marrow cell culture with dexamethasone was 392 ng/ml. In the medium with dexamethasone and 10﹣8 M L-lysine, the quantity of osteocalcin was 437 ng/ml. Nodules only formed upon addition of 20 μl of L-lysine at 10﹣8 M. It was indicated that 10﹣8 M L-lysine should be the optimal concentration for calcification. For nodule formation by rat bone marrow cells in vitro, the optimum concentration of L-lysine in culture medium might be 20 μl of 10﹣8 M. L-lysine could play an important role in matrix production for bone formation in vitro.展开更多
Understanding the behavior of matter at extreme pressures of the order of a megabar(Mbar)is essential to gain insight into various physical phenomena at macroscales—the formation of planets,young stars,and the cores ...Understanding the behavior of matter at extreme pressures of the order of a megabar(Mbar)is essential to gain insight into various physical phenomena at macroscales—the formation of planets,young stars,and the cores of super-Earths,and at microscales—damage to ceramic materials and high-pressure plastic transformation and phase transitions in solids.Under dynamic compression of solids up to Mbar pressures,even a solid with high strength exhibits plastic properties,causing the induced shock wave to split in two:an elastic precursor and a plastic shock wave.This phenomenon is described by theoretical models based on indirect measurements of material response.The advent of x-ray free-electron lasers(XFELs)has made it possible to use their ultrashort pulses for direct observations of the propagation of shock waves in solid materials by the method of phase-contrast radiography.However,there is still a lack of comprehensive data for verification of theoretical models of different solids.Here,we present the results of an experiment in which the evolution of the coupled elastic-plastic wave structure in diamond was directly observed and studied with submicrometer spatial resolution,using the unique capabilities of the x-ray free-electron laser(XFEL).The direct measurements allowed,for the first time,the fitting and validation of the 2D failure model for diamond in the range of several Mbar.Our experimental approach opens new possibilities for the direct verification and construction of equations of state of matter in the ultra-high-stress range,which are relevant to solving a variety of problems in high-energy-density physics.展开更多
The development of an energy storage system with abundant elements is a key challenge for a sustainable society,and the interest of Na intercalation chemistry is extending throughout the research community.Herein,the ...The development of an energy storage system with abundant elements is a key challenge for a sustainable society,and the interest of Na intercalation chemistry is extending throughout the research community.Herein,the impact of Ti integration into NaMnO2 in a binary system of x NaMnO2–(1–x)TiO2(0:5≤x≤1)is systematically examined for rechargeable Na battery applications.Stoichiometric NaMnO2,which is classified as an in-plane distorted O′3-type layered structure,delivers a large initial discharge capacity of approximately 200 mAhg-1,but insufficient capacity retention is observed,most probably associated with dissolution of Mn ions on electrochemical cycles.Ti-substituted samples show highly improved electrode performance as electrode materials.However,the appearance of a sodium-deficient phase,Na4Mn4Ti5O18 with a tunnel-type structure,is observed for Ti-rich phases.Among the samples in this binary system,Na0.8Mn0.8Ti0.2O2(x=0:8),which is a mixture of a partially Ti-substituted O′3-type layered oxide(Na0.88Mn0.88Ti0.12O2)and tunnel-type Na4Mn4Ti5O18 as a minor phase elucidated by Rietveld analysis on both neutron and X-ray diffraction patterns,shows good electrode performance on the basis of energy density and cyclability.Both phases are electrochemically active as evidenced by in situ X-ray diffraction study,and the improvement of reversibility originates from the suppression of Mn dissolution on electrochemical cycles.From these results,the feasibility of Mn-based electrode materials for high-energy rechargeable Na batteries made from only abundant elements is discussed in detail.展开更多
The first cell fate choice in the mammalian embryo, the segregation of the inner cell mass （ICM） and trophectoderm （TE）, is regulated by the mutually antagonistic effects of the transcription factors, Oct4 and Cdx...The first cell fate choice in the mammalian embryo, the segregation of the inner cell mass （ICM） and trophectoderm （TE）, is regulated by the mutually antagonistic effects of the transcription factors, Oct4 and Cdx2, while the pluripotency factor, Nanog, is essential to specify the epiblast. We have analyzed the promoters of Nanog and Cdx2, and have found that these two transcription factors are likewise regulated reciprocally. Using an embryonic stem cell line with conditional TE differentiation, we show that Nanog overexpression suppresses the upregulation of TE markers, while Nanog knockdown upregulates the expression of TE markers. We further show that Nanog and Cdx2 bind to and repress each other＇s promoters. However, whereas Nanog knockout results in detectable Cdx2 expression in the ICM, we observe no overt disruption of blastocyst development, indicating that Nanog plays a subservient role to Oct4 in segregation of the ICM and TE.展开更多
In the article titled“Efficient Stabilization of Na Storage Reversibility by Ti Integration into O′3-Type NaMnO2”[1],there was an error in Figure 4.In panel(a),the“x=0:2”should have read“x=0:8.”This is shown co...In the article titled“Efficient Stabilization of Na Storage Reversibility by Ti Integration into O′3-Type NaMnO2”[1],there was an error in Figure 4.In panel(a),the“x=0:2”should have read“x=0:8.”This is shown corrected in Figure 4 below。展开更多
文摘Endoscopic ultrasonography-guided fine-needle aspiration(EUS-FNA) has been applied to pancreaticobiliary lesions since the 1990 s and is in widespread use throughout the world today. We used this method to confirm the pathological evidence of the pancreaticobiliary lesions and to perform suitable therapies. Complications of EUS-FNA are quite rare, but some of them are severe. Operators should master conventional EUS observation and experience a minimum of 20-30 cases of supervised EUS-FNA on non-pancreatic and pancreatic lesions before attempting solo EUSFNA. Studies conducted on pancreaticobiliary EUSFNA have focused on selection of suitable instruments(e.g., needle selection) and sampling techniques(e.g., fanning method, suction level, with or without a stylet, optimum number of passes). Today, the diagnostic ability of EUS-FNA is still improving; the detection of pancreatic cancer(PC) currently has a sensitivity of 90%-95% and specificity of 95%-100%. In addition to PC, a variety of rare pancreatic tumors can be discriminated by conducting immunohistochemistry on the FNA materials. A flexible, large caliber needle has been used to obtain a large piece of tissue, which can provide sufficient histological information to be helpful in classifying benign pancreatic lesions. EUSFNA can supply high diagnostic yields even for biliary lesions or peri-pancreaticobiliary lymph nodes. This review focuses on the clinical aspects of EUS-FNA in the pancreaticobiliary field, with the aim of providing information that can enable more accurate and efficient diagnosis.
基金support of the National Magnet Confinement Fusion Energy Research Program(Grand No.2013GB108001)
文摘Oxide dispersion strengthened （ODS） steels can be used as the structural materials in the future fusion reactors and the fuel cladding materials in the advanced fission reactors. However, the weldability of ODS steels is a severe problem. In the present study, defect-free joints of the 15Cr-ODS ferritic steel were achieved by friction stir welding at different rotation speeds. The recrystallization, hardness and tensile properties are highly related with the rotation speed of the stir tool. The higher rotation speed results in coarser grains in the top SZ, while the grain size exhibits more complicated relation with the rotation speed in the SZ center. The joint welded at 250 rpm exhibits a maximum tensile strength of 974 MPa that reaches about 84% of that of the base metal.
文摘Although hydroxyapatite is commonly used as a scaffold for bone regeneration, sponges may be suitable because of the adaptability to the defect. To use as a scaffold, the fiber of sponge would be coated with any adhesive to storage stem cells in the sponges. Fiber in the structure of commercially available sponges was coated by immersion in dextran solution and air dried. After seeding of rat bone marrow cells (rBMCs), the sponges were implanted subcutis of rats for estimate osteogenesis in vivo. The level of osteocalcin was 25.28 ±5.71 ng/scaffold and that of Ca was 129.20 ±19.69 μg/scaffold. These values were significantly high- er than those in sponges without dextran coating (p 【0.01). It was thought that rBMCs could be stored on the shelf by dextran deposition in the fiber of the sponge. In vivo examination, dextran induced osteogenesis by rBMCs in many spaces in the inner structure of the sponge.
基金The XFEL experiments were performed at the BL3 of SACLA with the approval of the Japan Synchrotron Radiation Research Institute(JASRI)(Proposals Nos.2014A8045,and 2014B8068)This research was partially supported by grants from Grants-in-Aid for Scientific Research(Kakenhi Grant Nos.15H02153 and 17K05729)+1 种基金the Core-to-Core Program on International Alliance for Material Science in Extreme States with High Power Laser of the Japan Society for the Promotion of Science(JSPS),from the X-ray Free Electron Laser Priority Strategy Program of the MEXT,contract 12005014,and within the state assignment of FASO of Russia(theme N01201357846)The part of work was supported by the Agence Nationale de la Recherche in the frame of the ANR project TurboHEDP(ANR-15-CE30-0011).
文摘We present new diagnostics for use in optical laser pump-X-ray Free Electron Laser(XFEL)probe experiments to monitor dimensions,intensity profile and focusability of the XFEL beam and to control initial quality and homogeneity of targets to be driven by optical laser pulse.By developing X-ray imaging,based on the use of an LiF crystal detector,we were able to measure the distribution of energy inside a hard X-ray beam with unprecedented high spatial resolution(~1 mm)and across a field of view larger than some millimetres.This diagnostic can be used in situ,provides a very high dynamic range,has an extremely limited cost,and is relatively easy to be implemented in pump-probe experiments.The proposed methods were successfully applied in pump-probe experiments at the SPring-8 Angstrom Compact free electron LAser(SACLA)XFEL facility and its potential was demonstrated for current and future High Energy Density Science experiments.
文摘A formalin-treated polyvinyl-alcohol (PVF) sponge is convenient as a scaffold because its configuration is easily modified. However, coating the sponge with an adhesive chemical agent is necessary to attach bone marrow cells (BMCs) to the sponge structure. Moreover, it was considered that a hybrid scaffold composed of a sponge and enveloped cylindrical porous hydroxyapatite (HA) would be convenient. In this study, the effect of leucine (Leu) coating on a PVF sponge was examined for osteogenesis on an HA/PVF hybrid scaffold by rat BMCs (rBMCs). In an in vivo assessment, the sponge immersed in Leu solution (10 mg/ml) was inserted into the hollow center of cylindrical HA. The sponge received 1.5 × 106 rBMCs obtained from male Fischer 344 rats. The hybrid scaffolds were then implanted subcutaneously of syngeneic rats for 6 weeks. In vitro assessment of Leu to hard tissue formation with coating on the well or addition in rBMC culture medium was also performed in a 6-well plate for 2 weeks. In vivo examinations showed the excellent effect of Leu coating on PVF sponge. Leu-coated PVF sponge in the scaffolds showed marked new bone formation in the pores by histological examination. Leu-coated PVF sponge showed a high quantity of osteocalcine (OC). HA might prevent the release of rBMCs from PVF as a barrier. In in vitro examinations, the quantity of OC in rBMC culture with and without the addition of Leu in culture medium showed no significant difference. However, addition of Leu showed significant ALP activity level in culture medium. Leu coating in culture plate wells showed no influence on the quantity of OC. It was concluded from the results that Leu might prevent the emigration of rBMCs to the outside of the scaffold and promote the differentiation of cells to osteoblasts in the scaffold.
文摘IgG4-related disease(IgG4-RD) is an immune-mediated fibroinflammatory disorder that can occur in almost all systemic organs and generally responds to corticosteroid treatment. We report a rare case of an IgG4-related intrapelvic mass lesion that responded to steroid therapy but caused a fistula between the sigmoid colon and bladder. A 71-year-old man was followed after treatment for hepatocellular carcinoma. Follow-up computed tomography(CT) incidentally depicted left hydronephrosis with an ill-demarcated intrapelvic mass lesion. This lesion was histologically diagnosed as IgG4-RD by open biopsy, and peroral steroid therapy was initiated. One month after starting steroids, a colovesical fistula was detected by follow-up CT. A colostomy and urethral catheterization were emergently performed. The patient recovered and the mass lesion was drastically minimized by the initiation of glucocorticoids; however, he still needs urethral catheterization. IgG4-RD develops in various systemic organs and generally responds well to steroids. Clinicians must be watchful for the complications of responses to corticosteroids, such as fistulization, when the mass lesion of IgG4-RD is adjacent to multiple luminal organs.
文摘The effect of laminin on hard tissue formation using rat bone marrow cells was assessed. Rat bone marrow cells were obtained from femora of 6-week-old male Fischer 344 rats. In this in vivo examination, porous cylindrical hydroxyapatite scaffolds with a hollow center were immersed in 100 mg/ml laminin solution and air-dried. Rat bone marrow cells in 200 ml culture medium at 1 × 106 cells/ml were seeded in the scaffolds. The scaffolds were implanted into the dorsal subcutis of 7-week-old male Fischer 344 rats for 6 weeks. The scaffolds were then removed and examined histologically. For in vitro examinations, 1 × 105 rat bone marrow cells in 2 ml culture medium were then cultured with the addition of dexamethasone and laminin. Rat bone marrow cells were also cultured in laminin-coated culture plates. In vitro examinations showed the effectiveness of laminin for hard tissue formation from the results of biochemical and immunochemical analysis. From the in vivo examination, laminin coating of the scaffolds induced hard tissue in the pores with the cells. It is concluded that laminin is useful for bone formation, as in an in vitro culture study using bone marrow cells, in hydroxyapatite scaffolds in vivo.
文摘The aim of this study was to estimate the effect of L-lysine on nodule formation by rat bone marrow cells in vitro. In this study, L-lysine was added to medium for mesenchymal stem cell culture to promote proliferation and differentiation of the cells, and then nodule formation was estimated in an in vitro rat bone marrow cell culture. Bone marrow cells from the bone shafts of the femora of Fischer 344 rats were cultured in minimum essential medium with 20 μl of L-lysine solution at 10﹣4, 10﹣5, 10﹣6, 10﹣7 or 10﹣8 M. Dexamethasone was also added to the medium at 10 nM for differentiation of stem cells from bone marrow into osteoblast progenitor cells. The subculture was performed for 2 weeks. The quantity of osteocalcin in rat bone marrow cell culture with dexamethasone was 392 ng/ml. In the medium with dexamethasone and 10﹣8 M L-lysine, the quantity of osteocalcin was 437 ng/ml. Nodules only formed upon addition of 20 μl of L-lysine at 10﹣8 M. It was indicated that 10﹣8 M L-lysine should be the optimal concentration for calcification. For nodule formation by rat bone marrow cells in vitro, the optimum concentration of L-lysine in culture medium might be 20 μl of 10﹣8 M. L-lysine could play an important role in matrix production for bone formation in vitro.
基金We thank the technical staff of SACLA for their support during the experiment.The experiment was performed at BL3 of SACLA with the approval of the Japan Synchrotron Radiation Research Institute(Proposal Nos.2021A8004 and 2021B8002).The high-power drive laser installed in SACLA EH5 was developed with the cooperation of Hamamatsu Photonics.The installation of diffractive optical elements to improve the smoothness of the drive laser-pattern was supported by the SACLA Basic Development ProgramThe work was carried out with the financial support of the Russian Federation represented by the Ministry of Science and Higher Education of the Russian Federation(Grant No.075-15-2021-1352)This work was supported by KAKENHI(Grant Nos.17K05729 and 21K03499)from the Japan Society for the Promotion of Science(JSPS).
文摘Understanding the behavior of matter at extreme pressures of the order of a megabar(Mbar)is essential to gain insight into various physical phenomena at macroscales—the formation of planets,young stars,and the cores of super-Earths,and at microscales—damage to ceramic materials and high-pressure plastic transformation and phase transitions in solids.Under dynamic compression of solids up to Mbar pressures,even a solid with high strength exhibits plastic properties,causing the induced shock wave to split in two:an elastic precursor and a plastic shock wave.This phenomenon is described by theoretical models based on indirect measurements of material response.The advent of x-ray free-electron lasers(XFELs)has made it possible to use their ultrashort pulses for direct observations of the propagation of shock waves in solid materials by the method of phase-contrast radiography.However,there is still a lack of comprehensive data for verification of theoretical models of different solids.Here,we present the results of an experiment in which the evolution of the coupled elastic-plastic wave structure in diamond was directly observed and studied with submicrometer spatial resolution,using the unique capabilities of the x-ray free-electron laser(XFEL).The direct measurements allowed,for the first time,the fitting and validation of the 2D failure model for diamond in the range of several Mbar.Our experimental approach opens new possibilities for the direct verification and construction of equations of state of matter in the ultra-high-stress range,which are relevant to solving a variety of problems in high-energy-density physics.
基金the partial support from Japan Society for the Promotion of Science(JSPS),Grant-in-Aid for Scientific Research(Grant Numbers 15H05701,18H02076,and 19H05816)MEXT program“Elements Strategy Initiative to Form Core Research Center(JPMXP0112101003),”Ministry of Education,Culture,Sports,Science and Technology,Japan.
文摘The development of an energy storage system with abundant elements is a key challenge for a sustainable society,and the interest of Na intercalation chemistry is extending throughout the research community.Herein,the impact of Ti integration into NaMnO2 in a binary system of x NaMnO2–(1–x)TiO2(0:5≤x≤1)is systematically examined for rechargeable Na battery applications.Stoichiometric NaMnO2,which is classified as an in-plane distorted O′3-type layered structure,delivers a large initial discharge capacity of approximately 200 mAhg-1,but insufficient capacity retention is observed,most probably associated with dissolution of Mn ions on electrochemical cycles.Ti-substituted samples show highly improved electrode performance as electrode materials.However,the appearance of a sodium-deficient phase,Na4Mn4Ti5O18 with a tunnel-type structure,is observed for Ti-rich phases.Among the samples in this binary system,Na0.8Mn0.8Ti0.2O2(x=0:8),which is a mixture of a partially Ti-substituted O′3-type layered oxide(Na0.88Mn0.88Ti0.12O2)and tunnel-type Na4Mn4Ti5O18 as a minor phase elucidated by Rietveld analysis on both neutron and X-ray diffraction patterns,shows good electrode performance on the basis of energy density and cyclability.Both phases are electrochemically active as evidenced by in situ X-ray diffraction study,and the improvement of reversibility originates from the suppression of Mn dissolution on electrochemical cycles.From these results,the feasibility of Mn-based electrode materials for high-energy rechargeable Na batteries made from only abundant elements is discussed in detail.
文摘The first cell fate choice in the mammalian embryo, the segregation of the inner cell mass （ICM） and trophectoderm （TE）, is regulated by the mutually antagonistic effects of the transcription factors, Oct4 and Cdx2, while the pluripotency factor, Nanog, is essential to specify the epiblast. We have analyzed the promoters of Nanog and Cdx2, and have found that these two transcription factors are likewise regulated reciprocally. Using an embryonic stem cell line with conditional TE differentiation, we show that Nanog overexpression suppresses the upregulation of TE markers, while Nanog knockdown upregulates the expression of TE markers. We further show that Nanog and Cdx2 bind to and repress each other＇s promoters. However, whereas Nanog knockout results in detectable Cdx2 expression in the ICM, we observe no overt disruption of blastocyst development, indicating that Nanog plays a subservient role to Oct4 in segregation of the ICM and TE.
文摘In the article titled“Efficient Stabilization of Na Storage Reversibility by Ti Integration into O′3-Type NaMnO2”[1],there was an error in Figure 4.In panel(a),the“x=0:2”should have read“x=0:8.”This is shown corrected in Figure 4 below。
