Aim:To evaluate the quantitative detection of human telomerase RNA(hTR)and human telomerase reverse tran-scriptase(hTERT)mRNA as diagnostic parameters in the workup of testicular tissue specimens from patients present...Aim:To evaluate the quantitative detection of human telomerase RNA(hTR)and human telomerase reverse tran-scriptase(hTERT)mRNA as diagnostic parameters in the workup of testicular tissue specimens from patients presentingwith non-obstructive azoospermia.Methods:hTR and hTERT mRNA expression were quantified in 38 cryopre-served testicular tissue specimens by fluorescence real-time reverse transcription-polymerase chain reaction(RT-PCR)in a LightCycler(r).This was paralleled by conventional histological workup in all tissue specimens and additionalsemithin sectioning preparation in cases with maturation arrest(n=12)and Sertoli-cell-only syndrome(n=12).Re-sults;The average normalized hTERT expression(N_(hTERT))was 131.9±48.0 copies(mean±SD)in tissue speci-mens with full spermatogenesis,N_(hTERT)=51.2±17.2 copies in those with maturation arrest and N_(hTERT)=2.7±2.4copies in those with Sertoli-cell-only syndrome(SCOS).The discriminant analysis showed that detection of N_(hTERT)(N_(hTR))had a predictive value of 86.8%(55.3%)for correct classification in one of the three histological subgroups.Conclusion;Our results demonstrate that quantitative detection of hTERT mRNA expression in testicular tissue en-ables a molecular-diagnostic classification of gametogenesis.Quantitative detection of hTERT in testicular biopsies isthus well suited for supplementing the histopathological evaluation.展开更多
To overcome the ever-growing organic pollutions in the water system,abundant efforts have been dedicated to fabricating efficient Fenton-like carbon catalysts.However,the rational design of carbon catalysts with high ...To overcome the ever-growing organic pollutions in the water system,abundant efforts have been dedicated to fabricating efficient Fenton-like carbon catalysts.However,the rational design of carbon catalysts with high intrinsic activity remains a long-term goal.Herein,we report a new N-molecule-assisted self-catalytic carbonization process in augmenting the intrinsic Fenton-like activity of metal-organic-framework-derived carbon hybrids.During carbonization,the N-molecules provide alkane/ammonia gases and the formed iron nanocrystals act as the in situ catalysts,which result in the elaborated formation of carbon nanotubes(in situ chemical vapor deposition from alkane/iron catalysts)and micro-/meso-porous structures(ammonia gas etching).The obtained catalysts exhibited with abundant Fe/Fe-Nx/pyridinic-N active species,micro-/meso-porous structures,and conductive carbon nanotubes.Consequently,the catalysts exhibit high efficiency toward the degradation of different organic pollutions,such as bisphenol A,methylene blue,and tetracycline.This study not only creates a new pathway for achieving highly active Fenton-like carbon catalysts but also takes a step toward the customized production of advanced carbon hybrids for diverse energy and environmental applications.展开更多
Increased knowledge of the elastic and geomechnical properties of rocks is important for numerous engineering and geoscience applications(e.g. petroleum geoscience, underground waste repositories,geothermal energy, ea...Increased knowledge of the elastic and geomechnical properties of rocks is important for numerous engineering and geoscience applications(e.g. petroleum geoscience, underground waste repositories,geothermal energy, earthquake studies, and hydrocarbon exploration). To assess the effect of pressure and temperature on seismic velocities and their anisotropy, laboratory experiments were conducted on metamorphic rocks. P-(Vp) and S-wave(Vs) velocities were determined on cubic samples of granulites and eclogites with an edge length of 43 mm in a triaxial multianvil apparatus using the ultrasonic pulse emission technique in dependence of changes in pressure and temperature. At successive isotropic pressure states up to 600 MPa and temperatures up to 600 ℃, measurements were performed related to the sample coordinates given by the three principal fabric directions(x, y, z) representing the foliation(xy-plane), the normal to the foliation(z-direction), and the lineation direction(x-direction). Progressive volumetric strain was logged by the discrete piston displacements. Cumulative errors in Vpand Vsare estimated to be <1%. Microcrack closure significantly contributes to the increase in seismic velocities and decrease in anisotropies for pressures up to 200-250 MPa. Characteristic P-wave anisotropies of about 10% are obtained for eclogite and 3-4% in a strongly retrogressed eclogite as well as granulites. The wave velocities were used to calculate the geomechanical properties(e.g. density, Poisson’s ratio, volumetric strain, and elastic moduli) at different pressure and temperature conditions. These results contribute to the reliable estimate of geomechanical properties of rocks.展开更多
The Ejina( Gaxun Nur) Basin-enclosed by the Tibetan Plateau in the south and the Gobi Altay in the north hascontinuously evolved as a strong continental endorheic depositional environment. Medium scale geomorphologica...The Ejina( Gaxun Nur) Basin-enclosed by the Tibetan Plateau in the south and the Gobi Altay in the north hascontinuously evolved as a strong continental endorheic depositional environment. Medium scale geomorphological mappingby Landsat- and Corona-Images as well as SRTM-topographic data, combined with field-surveys and geophysicalinvestigation provides evidence for tectonic impact on sedimentary processes during the Late Quaternary.Analyses of SRTM-Data and Landsat-Images reveal a system of up to 20m high inverted channels developed on theinactive eastern part of the large Hei river drainage delta south of the ancient lake Juyanze. The complex evolution of theselandforms requires a relative lowering of the lake basin at least two times since the last 40ka. A 26m high cliff section ofgravel-covered lake sediments within the Juyanze paleolake indicates a strong subsidence of the lake bottom of 10m/1000yrssince 18kaB. P.North of Ejina river oasis a distinct north-south striking scarp up to 13m high constitutes the eastern margin of theGaxun Nur. Palaeodrainage channels derived from the Gobi Altay. They display a sinistral offset of some decametres alonga set of WE-trending faults. The rhombic shape of the modern dry Gaxun Nur, fossil cliffs,well preserved beach ridges alongthe margins of the palaeolake system as well as gravel covered topsets of lacustrine sediments indicate local displacements ofmorphological features. The displacements of lake sediments at the southern margin of the modern Gaxun Nur Basin imply asubsidence of at least 0.81m/1000 yrs since 25kaB. P. as a result of a pull-apart development due to the left stepping faultsin a sinistral system.展开更多
Recently emerged cancer immunochemotherapy has provided enormous new possibilities to replace traditional chemotherapy in fighting tumor.However,the treatment efficacy is hampered by tumor hypoxiainduced immunosuppres...Recently emerged cancer immunochemotherapy has provided enormous new possibilities to replace traditional chemotherapy in fighting tumor.However,the treatment efficacy is hampered by tumor hypoxiainduced immunosuppression in tumor microenvironment(TME).Herein,we fabricated a self-oxygenation/degradable inorganic nanozyme with a core-shell structure to relieve tumor hypoxia in cancer immunochemotherapy.By integrating the biocompatible CaO2 as the oxygen-storing component,this strategy is more effective than the earlier designed nanocarriers for delivering oxygen or H2O2,and thus provides remarkable oxygenation and long-term capability in relieving hypoxia throughout the tumor tissue.Consequently,in vivo tests validate that the delivery system can successfully relieve hypoxia and reverse the immunosuppressive TME to favor antitumor immune responses,leading to enhanced chemoimmunotherapy with cytotoxic T lymphocyte-associated antigen 4 blockade.Overall,a facile,robust and effective strategy is proposed to improve tumor oxygenation by using self-decomposable and biocompatible inorganic nanozyme reactor,which will not only provide an innovative pathway to relieve intratumoral hypoxia,but also present potential applications in other oxygen-favored cancer therapies or oxygen deficiency-originated diseases.展开更多
A mid-Holocene tufa section at 3,815 m altitude in the Qilian Mountains at the northeastern margin of the Tibetan Plateau was tested as a possibly important new climate archive. The tufa carbonate displays a distinct ...A mid-Holocene tufa section at 3,815 m altitude in the Qilian Mountains at the northeastern margin of the Tibetan Plateau was tested as a possibly important new climate archive. The tufa carbonate displays a distinct alternation of white and dark layers most probably representing annually deposited sparry and microgranular calcite which is formed during the warm and relatively wet summer and the drier and cooler spring and autumn season with an interruption of tufa formation during the freezing period. The δ^18O record of the tufa site comprises probably 357 years of annually deposited car-bonate-about 4, 000 years bejCore present, which indicates the prevalence of wetter climatic con- ditions in comparison to the present-day situation. This inference is confirmed by palynological data and lake-level reconstructions from a number of sites in the northern foreland of the Qilian Mountains, highlighting the large potential of longer tufa sequences for high-resolution palaeoclimate studies in the future.展开更多
A single small population of chasmophytic plants is described as Mojiangia oreophila,a monotypic genus in the subtribe Crepidinae,characterised by a unique combination of morphological features,in particular densely l...A single small population of chasmophytic plants is described as Mojiangia oreophila,a monotypic genus in the subtribe Crepidinae,characterised by a unique combination of morphological features,in particular densely long-papillose homomorphic achenes with five main ribs each accompanied by two secondary ribs,coarse brownish pappus bristles,moderately many-flowered capitula,a small involucre with numerous outer phyllaries,perennial rosette herb growth and brown-woolly caudex and leaf axils.Molecular phylogenetic analysis detected that in the nrlTS phylogeny M.oreophila forms a clade of its own in the Crepidinae;in the plastid DNA phylogeny it is nested in the clade formed by the hybrid-ogenous genus Faberia,the maternal ancestor of which comes from the Crepidinae and the paternal ancestor from the Lactucinae,where Faberia is placed in nrlTS phylogenies.M.oreophila shares several morphological features with Faberia and also shares the expected chromosome number of 2n=16 with its hitherto unknown maternal ancestor.M.oreophila may therefore be a successor of the maternal ancestor of Faberia.Alternatively,cytonuclear discordance is to be assumed in Mojiangia,caused by chloroplast capture as a result of hybridisation and introgression with Faberia.展开更多
The interaction between a molecular cloud and an external agent(e.g.,a supernova remnant,plasma jet,radiation,or another cloud)is a common phenomenon throughout the Universe and can significantly change the star forma...The interaction between a molecular cloud and an external agent(e.g.,a supernova remnant,plasma jet,radiation,or another cloud)is a common phenomenon throughout the Universe and can significantly change the star formation rate within a galaxy.This process leads to fragmentation of the cloud and to its subsequent compression and can,eventually,initiate the gravitational collapse of a stable molecular cloud.It is,however,difficult to study such systems in detail using conventional techniques(numerical simulations and astronomical observations),since complex interactions of flows occur.In this paper,we experimentally investigate the compression of a foam ball by Taylor–Sedov blast waves,as an analog of supernova remnants interacting with a molecular cloud.The formation of a compression wave is observed in the foam ball,indicating the importance of such experiments for understanding how star formation is triggered by external agents.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
AIM: To investigate neural and behavioral correlates of emotional experiences as potential vulnerability markers in remitted depression. METHODS: Fourteen remitted participants with a history of major depression and f...AIM: To investigate neural and behavioral correlates of emotional experiences as potential vulnerability markers in remitted depression. METHODS: Fourteen remitted participants with a history of major depression and fourteen closely matched healthy control participants took part in the study. We used two psychiatric interviews(Hamilton Depression Rating Scale, Montgomery-Asberg Depression Rating Scale) and one self-report scale(Beck Depression Inventory) to assess remission. Healthy control participants were interviewed by an experienced psychiatrist to exclude those who showed any current or lifetime psychiatric or neurological disorders. To explore psychosocialand cognitive-interpersonal underpinnings of potential vulnerability markers of depression, early life stress, coping styles and alexithymia were also assessed. We induced pleasant and unpleasant emotional states using congruent combinations of music and human emotional faces to investigate neural and behavioral correlates of emotional experiences; neutral stimuli were used as a control condition. Brain responses were recorded using functional magnetic resonance imaging. Behavioral responses of pleasantness, arousal, joy and fear were measured via button-press inside the resonance imaging scanner. RESULTS: The mean age of the sample was 54.9(± 11.3) years. There were no differences between remitted depressed(RD)(n = 14; 9 females and 5 males) and healthy participants(n = 14; 8 females and 6 males) regarding age, current degree of depression, early life stress, coping styles and alexithymia. On a neural level, RD participants showed reduced activations in the pregenual anterior cingulate cortex(pg ACC) in response to pleasant [parameter estimates:-0.78 vs 0.32; t(26) =-3.41, P < 0.05] and unpleasant [parameter estimates:-0.88 vs 0.56; t(26)=-4.02, P < 0.05] emotional stimuli. Linear regression analysis revealed that pg ACC activity was modulated by early life stress [β =-0.48; R2 = 0.23, F(1,27) = 7.83, P < 0.01] and taskoriented coping style [β = 0.63; R2 = 0.37, F(1,27) = 16.91, P < 0.001]. Trait anxiety modulated hippocampal responses to unpleasant stimuli [β = 0.62; R2= 0.38, F(1,27) = 15.95, P < 0.001]. Interestingly, in their reported experiences of pleasantness, arousal, happiness and fear in response to pleasant, unpleasant and neutral stimuli, RD participants did not differ significantly from healthy control participants. Adding trait anxiety or alexithymia as a covariate did not change the results.CONCLUSION: The present study indicates that, in euthymic individuals, depression history alters neural correlates, but not the subjective dimension of pleasant and unpleasant emotional experiences.展开更多
文摘Aim:To evaluate the quantitative detection of human telomerase RNA(hTR)and human telomerase reverse tran-scriptase(hTERT)mRNA as diagnostic parameters in the workup of testicular tissue specimens from patients presentingwith non-obstructive azoospermia.Methods:hTR and hTERT mRNA expression were quantified in 38 cryopre-served testicular tissue specimens by fluorescence real-time reverse transcription-polymerase chain reaction(RT-PCR)in a LightCycler(r).This was paralleled by conventional histological workup in all tissue specimens and additionalsemithin sectioning preparation in cases with maturation arrest(n=12)and Sertoli-cell-only syndrome(n=12).Re-sults;The average normalized hTERT expression(N_(hTERT))was 131.9±48.0 copies(mean±SD)in tissue speci-mens with full spermatogenesis,N_(hTERT)=51.2±17.2 copies in those with maturation arrest and N_(hTERT)=2.7±2.4copies in those with Sertoli-cell-only syndrome(SCOS).The discriminant analysis showed that detection of N_(hTERT)(N_(hTR))had a predictive value of 86.8%(55.3%)for correct classification in one of the three histological subgroups.Conclusion;Our results demonstrate that quantitative detection of hTERT mRNA expression in testicular tissue en-ables a molecular-diagnostic classification of gametogenesis.Quantitative detection of hTERT in testicular biopsies isthus well suited for supplementing the histopathological evaluation.
基金supported by the National Key R&D Program of China(2019YFA0110600 and 2019YFA0110601)National Natural Science Foundation of China(Nos.51603134,51903178,51803134,and 51703141)+1 种基金Sichuan Province’s Science and Technology Planning Project(No.2016GZ0350)the Postgraduate Course Construction Project of Sichuan University(No.2017KCSJ036)and for their financial support.
文摘To overcome the ever-growing organic pollutions in the water system,abundant efforts have been dedicated to fabricating efficient Fenton-like carbon catalysts.However,the rational design of carbon catalysts with high intrinsic activity remains a long-term goal.Herein,we report a new N-molecule-assisted self-catalytic carbonization process in augmenting the intrinsic Fenton-like activity of metal-organic-framework-derived carbon hybrids.During carbonization,the N-molecules provide alkane/ammonia gases and the formed iron nanocrystals act as the in situ catalysts,which result in the elaborated formation of carbon nanotubes(in situ chemical vapor deposition from alkane/iron catalysts)and micro-/meso-porous structures(ammonia gas etching).The obtained catalysts exhibited with abundant Fe/Fe-Nx/pyridinic-N active species,micro-/meso-porous structures,and conductive carbon nanotubes.Consequently,the catalysts exhibit high efficiency toward the degradation of different organic pollutions,such as bisphenol A,methylene blue,and tetracycline.This study not only creates a new pathway for achieving highly active Fenton-like carbon catalysts but also takes a step toward the customized production of advanced carbon hybrids for diverse energy and environmental applications.
文摘Increased knowledge of the elastic and geomechnical properties of rocks is important for numerous engineering and geoscience applications(e.g. petroleum geoscience, underground waste repositories,geothermal energy, earthquake studies, and hydrocarbon exploration). To assess the effect of pressure and temperature on seismic velocities and their anisotropy, laboratory experiments were conducted on metamorphic rocks. P-(Vp) and S-wave(Vs) velocities were determined on cubic samples of granulites and eclogites with an edge length of 43 mm in a triaxial multianvil apparatus using the ultrasonic pulse emission technique in dependence of changes in pressure and temperature. At successive isotropic pressure states up to 600 MPa and temperatures up to 600 ℃, measurements were performed related to the sample coordinates given by the three principal fabric directions(x, y, z) representing the foliation(xy-plane), the normal to the foliation(z-direction), and the lineation direction(x-direction). Progressive volumetric strain was logged by the discrete piston displacements. Cumulative errors in Vpand Vsare estimated to be <1%. Microcrack closure significantly contributes to the increase in seismic velocities and decrease in anisotropies for pressures up to 200-250 MPa. Characteristic P-wave anisotropies of about 10% are obtained for eclogite and 3-4% in a strongly retrogressed eclogite as well as granulites. The wave velocities were used to calculate the geomechanical properties(e.g. density, Poisson’s ratio, volumetric strain, and elastic moduli) at different pressure and temperature conditions. These results contribute to the reliable estimate of geomechanical properties of rocks.
基金supported by DFG (PA 131 16/1-4)NSFC(40871096 & 40371117)
文摘The Ejina( Gaxun Nur) Basin-enclosed by the Tibetan Plateau in the south and the Gobi Altay in the north hascontinuously evolved as a strong continental endorheic depositional environment. Medium scale geomorphological mappingby Landsat- and Corona-Images as well as SRTM-topographic data, combined with field-surveys and geophysicalinvestigation provides evidence for tectonic impact on sedimentary processes during the Late Quaternary.Analyses of SRTM-Data and Landsat-Images reveal a system of up to 20m high inverted channels developed on theinactive eastern part of the large Hei river drainage delta south of the ancient lake Juyanze. The complex evolution of theselandforms requires a relative lowering of the lake basin at least two times since the last 40ka. A 26m high cliff section ofgravel-covered lake sediments within the Juyanze paleolake indicates a strong subsidence of the lake bottom of 10m/1000yrssince 18kaB. P.North of Ejina river oasis a distinct north-south striking scarp up to 13m high constitutes the eastern margin of theGaxun Nur. Palaeodrainage channels derived from the Gobi Altay. They display a sinistral offset of some decametres alonga set of WE-trending faults. The rhombic shape of the modern dry Gaxun Nur, fossil cliffs,well preserved beach ridges alongthe margins of the palaeolake system as well as gravel covered topsets of lacustrine sediments indicate local displacements ofmorphological features. The displacements of lake sediments at the southern margin of the modern Gaxun Nur Basin imply asubsidence of at least 0.81m/1000 yrs since 25kaB. P. as a result of a pull-apart development due to the left stepping faultsin a sinistral system.
基金financially supported by the National Natural Science Foundation of China(Nos.81371627 and 81727804)the Jiangsu Provincial Natural Science Fund for Distinguished Young Scholars(BK201900)the“Double First-Class”University project(Nos.CPU2018GY24 and CPU2018GY20).
文摘Recently emerged cancer immunochemotherapy has provided enormous new possibilities to replace traditional chemotherapy in fighting tumor.However,the treatment efficacy is hampered by tumor hypoxiainduced immunosuppression in tumor microenvironment(TME).Herein,we fabricated a self-oxygenation/degradable inorganic nanozyme with a core-shell structure to relieve tumor hypoxia in cancer immunochemotherapy.By integrating the biocompatible CaO2 as the oxygen-storing component,this strategy is more effective than the earlier designed nanocarriers for delivering oxygen or H2O2,and thus provides remarkable oxygenation and long-term capability in relieving hypoxia throughout the tumor tissue.Consequently,in vivo tests validate that the delivery system can successfully relieve hypoxia and reverse the immunosuppressive TME to favor antitumor immune responses,leading to enhanced chemoimmunotherapy with cytotoxic T lymphocyte-associated antigen 4 blockade.Overall,a facile,robust and effective strategy is proposed to improve tumor oxygenation by using self-decomposable and biocompatible inorganic nanozyme reactor,which will not only provide an innovative pathway to relieve intratumoral hypoxia,but also present potential applications in other oxygen-favored cancer therapies or oxygen deficiency-originated diseases.
文摘A mid-Holocene tufa section at 3,815 m altitude in the Qilian Mountains at the northeastern margin of the Tibetan Plateau was tested as a possibly important new climate archive. The tufa carbonate displays a distinct alternation of white and dark layers most probably representing annually deposited sparry and microgranular calcite which is formed during the warm and relatively wet summer and the drier and cooler spring and autumn season with an interruption of tufa formation during the freezing period. The δ^18O record of the tufa site comprises probably 357 years of annually deposited car-bonate-about 4, 000 years bejCore present, which indicates the prevalence of wetter climatic con- ditions in comparison to the present-day situation. This inference is confirmed by palynological data and lake-level reconstructions from a number of sites in the northern foreland of the Qilian Mountains, highlighting the large potential of longer tufa sequences for high-resolution palaeoclimate studies in the future.
文摘A single small population of chasmophytic plants is described as Mojiangia oreophila,a monotypic genus in the subtribe Crepidinae,characterised by a unique combination of morphological features,in particular densely long-papillose homomorphic achenes with five main ribs each accompanied by two secondary ribs,coarse brownish pappus bristles,moderately many-flowered capitula,a small involucre with numerous outer phyllaries,perennial rosette herb growth and brown-woolly caudex and leaf axils.Molecular phylogenetic analysis detected that in the nrlTS phylogeny M.oreophila forms a clade of its own in the Crepidinae;in the plastid DNA phylogeny it is nested in the clade formed by the hybrid-ogenous genus Faberia,the maternal ancestor of which comes from the Crepidinae and the paternal ancestor from the Lactucinae,where Faberia is placed in nrlTS phylogenies.M.oreophila shares several morphological features with Faberia and also shares the expected chromosome number of 2n=16 with its hitherto unknown maternal ancestor.M.oreophila may therefore be a successor of the maternal ancestor of Faberia.Alternatively,cytonuclear discordance is to be assumed in Mojiangia,caused by chloroplast capture as a result of hybridisation and introgression with Faberia.
基金the support of Investissements d’Avenir of LabEx PALM(Grant No.ANR-10-LABX-0039-PALM)the Ministry of Science and Higher Education of the Russian Federation(Agreement with Joint Institute for High Temperatures RAS No.075-15-2020-785)G.G.acknowledges support from the UK EPSRC(Grant Nos.EP/M022331/1 and EP/N014472/1)。
文摘The interaction between a molecular cloud and an external agent(e.g.,a supernova remnant,plasma jet,radiation,or another cloud)is a common phenomenon throughout the Universe and can significantly change the star formation rate within a galaxy.This process leads to fragmentation of the cloud and to its subsequent compression and can,eventually,initiate the gravitational collapse of a stable molecular cloud.It is,however,difficult to study such systems in detail using conventional techniques(numerical simulations and astronomical observations),since complex interactions of flows occur.In this paper,we experimentally investigate the compression of a foam ball by Taylor–Sedov blast waves,as an analog of supernova remnants interacting with a molecular cloud.The formation of a compression wave is observed in the foam ball,indicating the importance of such experiments for understanding how star formation is triggered by external agents.
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Supported by German Research Foundation(Cluster of Excellence"Languages of Emotion",EXC302 and KFO247)
文摘AIM: To investigate neural and behavioral correlates of emotional experiences as potential vulnerability markers in remitted depression. METHODS: Fourteen remitted participants with a history of major depression and fourteen closely matched healthy control participants took part in the study. We used two psychiatric interviews(Hamilton Depression Rating Scale, Montgomery-Asberg Depression Rating Scale) and one self-report scale(Beck Depression Inventory) to assess remission. Healthy control participants were interviewed by an experienced psychiatrist to exclude those who showed any current or lifetime psychiatric or neurological disorders. To explore psychosocialand cognitive-interpersonal underpinnings of potential vulnerability markers of depression, early life stress, coping styles and alexithymia were also assessed. We induced pleasant and unpleasant emotional states using congruent combinations of music and human emotional faces to investigate neural and behavioral correlates of emotional experiences; neutral stimuli were used as a control condition. Brain responses were recorded using functional magnetic resonance imaging. Behavioral responses of pleasantness, arousal, joy and fear were measured via button-press inside the resonance imaging scanner. RESULTS: The mean age of the sample was 54.9(± 11.3) years. There were no differences between remitted depressed(RD)(n = 14; 9 females and 5 males) and healthy participants(n = 14; 8 females and 6 males) regarding age, current degree of depression, early life stress, coping styles and alexithymia. On a neural level, RD participants showed reduced activations in the pregenual anterior cingulate cortex(pg ACC) in response to pleasant [parameter estimates:-0.78 vs 0.32; t(26) =-3.41, P < 0.05] and unpleasant [parameter estimates:-0.88 vs 0.56; t(26)=-4.02, P < 0.05] emotional stimuli. Linear regression analysis revealed that pg ACC activity was modulated by early life stress [β =-0.48; R2 = 0.23, F(1,27) = 7.83, P < 0.01] and taskoriented coping style [β = 0.63; R2 = 0.37, F(1,27) = 16.91, P < 0.001]. Trait anxiety modulated hippocampal responses to unpleasant stimuli [β = 0.62; R2= 0.38, F(1,27) = 15.95, P < 0.001]. Interestingly, in their reported experiences of pleasantness, arousal, happiness and fear in response to pleasant, unpleasant and neutral stimuli, RD participants did not differ significantly from healthy control participants. Adding trait anxiety or alexithymia as a covariate did not change the results.CONCLUSION: The present study indicates that, in euthymic individuals, depression history alters neural correlates, but not the subjective dimension of pleasant and unpleasant emotional experiences.
