Spiral patterns widely exist in both macroscopic and microscopic systems such as hearts,bacteria,and active matters but have never been reported at molecular length scale.The emergence of spiral patterns has considera...Spiral patterns widely exist in both macroscopic and microscopic systems such as hearts,bacteria,and active matters but have never been reported at molecular length scale.The emergence of spiral patterns has considerable impacts on the trajectories of the objects and thus usually relates to various physical,chemical,biological and physiological processes.In this paper,we show that,down to the length scale of only several Angstroms,asymmetric molecules exhibit spiral patterns in their trajectories within finite time based on the under-damped Langevin equation and demonstrated by molecular dynamics simulation.The key to this observation lies in the asymmetric molecular architecture that leads to a translation-rotation coupling.This finding enriches the knowledge of spiral patterns to the molecular length scale,provides a new insight into the understanding of various processes at the molecular level,and may evoke new ideas on the understanding of the vortices in turbulence.展开更多
Perfluorononanoic acid（PFNA） is a nine-carbon perfluoroalkyl acid widely used in industrial and domestic products. It is a persistent organic pollutant found in the environment as well as in the tissues of humans an...Perfluorononanoic acid（PFNA） is a nine-carbon perfluoroalkyl acid widely used in industrial and domestic products. It is a persistent organic pollutant found in the environment as well as in the tissues of humans and wildlife. There is a concern that this chemical might be a developmental toxicant and teratogen in various ecosystems. In the present study,the toxic effects of PFNA were evaluated in zebrafish（Danio rerio） embryos. One hour post-fertilization embryos were treated with 0, 25, 50, 100, 200, 300, 350, and 400 μmol/L PFNA for 96 hr in 6-well plates. Developmental phenotypes and hatching rates were observed and recorded. Nineteen genes related to oxidative stress and lipid metabolism were examined using Quantitative RT-PCR and confirmed by whole mount in situ hybridization（WISH）. Results showed that PFNA delayed the development of zebrafish embryos, reduced the hatching rate, and caused ventricular edema and malformation of the spine. In addition, the amount of reactive oxygen species in the embryo bodies increased significantly after exposure to PFNA compared with that of the control group. The Quantitative RT-PCR and WISH experiments demonstrated that m RNA expression of the lfabp and ucp2 genes increased significantly while that of sod1 and mt-nd1 decreased significantly after PFNA exposure. The m RNA expression levels of gpx1 and mt-atp6 decreased significantly in the high concentration group. However, the m RNA expression levels of both ppara and pparg did not show any significant variation after exposure. These findings suggest that PFNA affected the development of zebrafish embryos at relatively low concentrations.展开更多
Hydrophobic nanochannel plays a significant role in many physical, biological, and geological phenomena and ex- hibits impressive applications due to both its ubiquitous distribution and great ability to transport hyd...Hydrophobic nanochannel plays a significant role in many physical, biological, and geological phenomena and ex- hibits impressive applications due to both its ubiquitous distribution and great ability to transport hydrophobic molecules, including various oils and gases. Based on theoretical modeling, we herein reveal that the amphipathic Janus nanoparticles have a large probability to self-assemble into uninterrupted hydrophobic nanochannels inside the aqueous nano-space, al- though there are large portions of the Janus nanoparticles to be hydrophilic. The key to this observation is the attractions between the hydrophobic regimes on neighboring amphipathic Janus particles through hydrophobic interaction in aqueous nano-space. More surprisingly, the permeation efficiency of hydrophobic molecules through the uninterrupted hydrophobic channel in Janus particles aggregate is even higher than that in the aggregate of hydrophobic particles. We note that the proposed amphipathic Janus particles can be transported to the appropriate positions by the water since the hydrophilic regimes still remain a strong particle-water interaction. We also note that most natural subsurface rocks are not completely hydrophobic or hydrophilic but have complex surfaces with inhomogeneous wetting property. Our work therefore provides a detailed molecular level understanding of the formation of underground strata as well as the new insight for constructing the artificial hydrophobic channels for various applications, such as the design of proppants to enhance the recovery of the unconventional oil/gas.展开更多
The development of lightweight,flexible,and stretchable energy storage systems is essential for state-of-the-art electronic devices.We propose a new and broad strategy to fabricate a stretchable and conductive GO/CNTs...The development of lightweight,flexible,and stretchable energy storage systems is essential for state-of-the-art electronic devices.We propose a new and broad strategy to fabricate a stretchable and conductive GO/CNTs-TPU fiber electrode by direct wet spinning,from which a flexible fibrous supercapacitor is fabricated.The fibrous electrode exhibits a high strength of 11.68 MPa,high conductivity of 342 S/cm,and high specific capacitances(21.8 mF/cm,36.45 F/cm^3,and 95 F/g).The specific capacitance of the assembled all-solid-state hybrid fiber-shaped supercapacitor reaches 14.3 F/cm^3.After 5000 charge-discharge cycles,97%of the capacitance of the hybrid supercapacitor is maintained.These high-strength electrochemical electrode materials could be potential candidates for applications in practical and large-scale energy storage systems and textile clothes.展开更多
Engineering unique electronic structure of catalyst to boost catalytic performance is of prime scientific and industrial importance.Herein,the identification of intrinsic electronic sensitivity for direct propene epox...Engineering unique electronic structure of catalyst to boost catalytic performance is of prime scientific and industrial importance.Herein,the identification of intrinsic electronic sensitivity for direct propene epoxidation was first achieved over highly stable Au/wormhole-like TS-1 catalyst.Results show that the electron transfer of Au species can be regulated by manipulating the dynamic evolutions and contents of Au valence states,thus resulting in different catalytic performance in 100 h time-on-stream.By DFT calculations,kinetic analysis and multicharacterizations,it is found that the Au^(0) species with higher electronic population can easily transfer more electrons to activate surface O_(2) compared with Au^(1+) and Au^(3+) species.Moreover,there is a positive correlation between Au^(0) content and activity.Based on this correlation,a facile strategy is further proposed to boost Au^(0) percentage,resulting in the reported highest PO formation rate without adding promoters.This work harbors tremendous guiding significance to the design of highly efficient Au/Ti-containing catalyst for propene epoxidation with H_(2) and O_(2).展开更多
The advocacy of green chemical industry has led to the development of highly efficient catalysts for direct gas-phase propene epoxidation with green,sustainable and simple essence.The S-1/TS-1@dendritic-SiO_(2) materi...The advocacy of green chemical industry has led to the development of highly efficient catalysts for direct gas-phase propene epoxidation with green,sustainable and simple essence.The S-1/TS-1@dendritic-SiO_(2) material with three-layer core–shell structure was developed and used as the support for Au catalysts,which showed simultaneously fantastic PO formation rate,PO selectivity and stability(over 100 h)for propene epoxidation with H_(2) and O_(2).It is found that silicalite-1(S-1)core and the middle thin layer of TS-1 offer great mass transfer ability,which could be responsible for the excellent stability.The designed dendritic SiO_(2) shell covers part of the acid sites on the external surface of TS-1,inhibiting the side reactions and improving the PO selectivity.Furthermore,three kinds of SiO_(2) shell morphologies(i.e.,dendritic,net,mesoporous shell)were designed,and relationship between shell morphology and catalytic performance was elucidated.The results in this paper harbour tremendous guiding significance for the design of highly efficient epoxidation catalysts.展开更多
Phthalates are a large family of ubiquitous environmental pollutants suspected of being endocrine disruptors. Epidemiological studies have associated phthalate metabolites with decreased reproductive parameters and li...Phthalates are a large family of ubiquitous environmental pollutants suspected of being endocrine disruptors. Epidemiological studies have associated phthalate metabolites with decreased reproductive parameters and linked phthalate exposure with the level of urinary 5-methyl-2′-deoxycytidine（5mdC, a product of methylated DNA）. In this study, adult male mice were exposed to 450 mg di-isobutyl phthalate（DiBP）/（kg·day） via dietary exposure for 28 days. Mono-isobutyl phthalate（Mi BP, the urinary metabolite） and reproductive function parameters were determined. The levels of 5mdC and 5-hydroxymethyl-2′-deoxycytidine（5hmdC） were measured in urine to evaluate if their contents were also altered by DiBP exposure in this animal model. Results showed that DiBP exposure led to a significant increase in the urinary 5mdC level and significant decreases in sperm concentration and motility in the epididymis, accompanied with reduced testosterone levels and downregulation of the P450 cholesterol side-chain cleavage enzyme（P450scc） gene in the mice testes. Our findings indicated that exposure to DiBP increased the urinary 5mdC levels,which supported our recent epidemiological study about the associations of urinary 5mdC with phthalate exposure in the male human population. In addition, DiBP exposure impaired male reproductive function, possibly by disturbing testosterone levels; P450scc might be a major steroidogenic enzyme targeted by DiBP or other phthalates.展开更多
A new species of the genus Tipulodina Enderlein, 1912, Tipulodina simianshanensis Men sp. nov.(South China: Chongqing) is described and illustrated. A key to known species of the genus in China is provided. The new sp...A new species of the genus Tipulodina Enderlein, 1912, Tipulodina simianshanensis Men sp. nov.(South China: Chongqing) is described and illustrated. A key to known species of the genus in China is provided. The new species represents the first record of Tipulodina species from Chongqing, China.展开更多
Recently,there are great efforts that have been taken to suppressing/controlling the coffee ring effect,but it is of challenge to achieve inexpensive and efficient control with less disturbance,suitable for scalable p...Recently,there are great efforts that have been taken to suppressing/controlling the coffee ring effect,but it is of challenge to achieve inexpensive and efficient control with less disturbance,suitable for scalable production and highly enhancing the printing/dyeing color fastness.By only adding trace amounts of salt into the suspensions,here we experimentally achieve the facile and highly efficient control of the coffee ring effect of suspended matter on substrates of graphene,natural graphite,and polyethylene terephthalate surfaces.Notably,friction force measurements show that ion-controlled uniform patterns also greatly enhance color fastness.Molecular dynamics simulations reveal that,due to strong hydrated cation-π interactions between hydrated cations and aromatic rings in the substrate surface,the suspended matters are adsorbed on the surfaces mediated by cations so that the suspended matters are uniformly distributed.These findings will open new avenues for fabricating functional patterns on graphene substrates and will benefit practical applications including printing,coating,and dyeing.展开更多
Mechanical adaptation of tissue engineering scaffolds is critically important since natural tissue regeneration is highly regulated by mechanical signals.Herein,we report a facile and convenient strategy to tune the m...Mechanical adaptation of tissue engineering scaffolds is critically important since natural tissue regeneration is highly regulated by mechanical signals.Herein,we report a facile and convenient strategy to tune the modulus of waterborne biodegradable polyurethanes(WBPU)via cross-linking manipulation of phase separation and water infiltration for constructing mechanically adaptable tissue engineering scaffolds.Amorphous aliphatic polycarbonate and trifunctional trimethylolpropane were introduced to polycaprolactone-based WBPUs to interrupt interchain hydrogen bonds in the polymer segments and suppress microphase separation,inhibiting the crystallization process and enhancing covalent cross-linking.Intriguingly,as the crosslinking density of WBPU increases and the extent of microphase separation decreases,the material exhibits a surprisingly soft modulus and enhanced water infiltration.Based on this strategy,we constructed WBPU scaffolds with a tunable modulus to adapt various cells for tissue regeneration and regulate the immune response.As a representative application of brain tissue regeneration model in vivo,it was demonstrated that the mechanically adaptable WBPU scaffolds can guide the migration and differentiation of endogenous neural progenitor cells into mature neurons and neuronal neurites and regulate immunostimulation with low inflammation.Therefore,the proposed strategy of tuning the modulus of WBPU can inspire the development of novel mechanically adaptable biomaterials,which has very broad application value.展开更多
Using molecular dynamics simulations,we show that an asymmetrically shaped nanoparticle in dilute solution possesses a spontaneously curved trajectory within a finite time interval,instead of the generally expected ra...Using molecular dynamics simulations,we show that an asymmetrically shaped nanoparticle in dilute solution possesses a spontaneously curved trajectory within a finite time interval,instead of the generally expected random walk.This unexpected dynamic behavior has a similarity to that of active matters,such as swimming bacteria,cells,or even fish,but is of a different physical origin.The key to the curved trajectory lies in the non-zero resultant force originated from the imbalance of the collision forces acted by surrounding solvent molecules on the asymmetrically shaped nanoparticle during its orientation regulation.Theoretical formulae based on microscopic observations have been derived to describe this non-zero force and the resulting motion of the asymmetrically shaped nanoparticle.展开更多
This paper focuses on the study of mechanical design and control measures in smart home systems.First of all,it elaborates on the theoretical foundation of mechatronics technology,including its multidisciplinary integ...This paper focuses on the study of mechanical design and control measures in smart home systems.First of all,it elaborates on the theoretical foundation of mechatronics technology,including its multidisciplinary integration characteristics,system design principles,and constituent elements.It then reviews the research progress in this field,followed by a detailed analysis of mechatronics design in systems such as smart lighting and smart security,as well as the application of control algorithms and communication protocols in smart homes.Finally,it discusses challenges such as system compatibility and data security risks,proposing corresponding solutions to provide theoretical and practical references for the development of smart home systems.展开更多
High-performance yarn artificial muscles are highly desirable as miniature actuators,sensors,energy harvesters,and soft robotics.However,achieving a yarn artificial muscle that covers all the properties of excellent a...High-performance yarn artificial muscles are highly desirable as miniature actuators,sensors,energy harvesters,and soft robotics.However,achieving a yarn artificial muscle that covers all the properties of excellent actuation performance,mechanical robustness,structural stability,and high scalability by a low-cost strategy is still a great challenge.Herein,a bio-inspired fasciated yarn structure is first reported for creating robust high-performance yarn artificial muscles.Unlike conventional strategies that leverage costly materials or complex processing,the developed yarn artificial muscles are constructed by hierarchically helical and sheath-core assembly design of cost-effective common fibers,such as viscose and polyester.The hierarchically helical sheath structure pushes the theoretical limit of the inserted twist in yarns and endows the yarn muscles with large stroke(5815°cm^(-1))and high work capacity(23.5 J kg^(-1)).Due to the rapid water transfer and efficient energy conversion of inter-sheath-core coupling,the as-prepared yarn muscles possess fast response,high rotation accelerated speed,and low recovery hysteresis.Moreover,the inactive core yarn serves as support for internal tethering and load-bearing,enabling these yarn muscles to maintain a self-stable structure,robust life cycle and mechanics.We show that the yarn muscle fabricated in this method is readily available and highly scalable for achieving high-dimensional actuation deformations,which considerably broadens the application scenarios of artificial muscles.展开更多
Self-diffusion of water has been investigated by molecular dynamics simulations. It was found that the preference of the direction in self-diffusion of water is orientation dependent in a finite time. For a time of-lO...Self-diffusion of water has been investigated by molecular dynamics simulations. It was found that the preference of the direction in self-diffusion of water is orientation dependent in a finite time. For a time of-lO0 ps, there are more possibilities for water molecules moving along the initial dipole orientation than in the opposite direction. This reveals that self-diffusion of water molecules is asymmetric in a finite time. We tested four water models and found that they all show similar asymmetric diffusion, indicating that asymmetric diffusion of water is intrinsic behavior rather than induced by the water model. These results are important for understanding and application of asymmetric diffusion in research fields such as biological water and confined water in small dimensions.展开更多
The directional drifting of particles/molecules with broken symmetry has received increasing attention. Through molecular dynamics simulations, we investigate the effects of various solvents on the time-dependent dire...The directional drifting of particles/molecules with broken symmetry has received increasing attention. Through molecular dynamics simulations, we investigate the effects of various solvents on the time-dependent directional drifting of a particle with broken symmetry. Our simulations show that the distance of directional drift of the asymmetrical particle is reduced while the ratio of the drift to the mean displacement of the particle is enhanced with increasing mass, size, and interaction strength of the solvent atoms in a short time range. Among the parameters considered, solvent atom size is a particularly influential factor for enhancing the directional drift of asymmetrical particles, while the effects of the interaction strength and the mass of the solvent atoms are relatively weaker. These findings are of great importance to the understanding and control of the Brownian motion of particles in various physical, chemical, and biological processes within finite time spans.展开更多
Introduction Pyoderma gangrenosum (PG) is a chronic skin disease characterized by progressive lesions that present as painful suppurative ulcers and tend to recur. The pathogenesis of the disease is incompletely under...Introduction Pyoderma gangrenosum (PG) is a chronic skin disease characterized by progressive lesions that present as painful suppurative ulcers and tend to recur. The pathogenesis of the disease is incompletely under-stood;however, 50%to 70%of affected persons have an associated concomitant systemic disease such as inflammatory bowel disease (IBD) (1)Any site of the body can be affected;however, involvement of the oropharynx is rare. Here, we present a patient with disseminated PG with oropharyngeal involvement.展开更多
基金supported by the National Natural Science Foun-dation of China(Grant Nos.12475032 and 12005062)the Supercomputing Center of the Chinese Academy of Sciences,Shanghai Snowlake Technology Co.,Ltd.,and the Shanghai Super-Computer Center of China。
文摘Spiral patterns widely exist in both macroscopic and microscopic systems such as hearts,bacteria,and active matters but have never been reported at molecular length scale.The emergence of spiral patterns has considerable impacts on the trajectories of the objects and thus usually relates to various physical,chemical,biological and physiological processes.In this paper,we show that,down to the length scale of only several Angstroms,asymmetric molecules exhibit spiral patterns in their trajectories within finite time based on the under-damped Langevin equation and demonstrated by molecular dynamics simulation.The key to this observation lies in the asymmetric molecular architecture that leads to a translation-rotation coupling.This finding enriches the knowledge of spiral patterns to the molecular length scale,provides a new insight into the understanding of various processes at the molecular level,and may evoke new ideas on the understanding of the vortices in turbulence.
基金supported by the National Basic Research Program (973) of China (No. 2013CB945204)the National Natural Science Foundation of China (Nos. 31320103915 and 21377128)
文摘Perfluorononanoic acid（PFNA） is a nine-carbon perfluoroalkyl acid widely used in industrial and domestic products. It is a persistent organic pollutant found in the environment as well as in the tissues of humans and wildlife. There is a concern that this chemical might be a developmental toxicant and teratogen in various ecosystems. In the present study,the toxic effects of PFNA were evaluated in zebrafish（Danio rerio） embryos. One hour post-fertilization embryos were treated with 0, 25, 50, 100, 200, 300, 350, and 400 μmol/L PFNA for 96 hr in 6-well plates. Developmental phenotypes and hatching rates were observed and recorded. Nineteen genes related to oxidative stress and lipid metabolism were examined using Quantitative RT-PCR and confirmed by whole mount in situ hybridization（WISH）. Results showed that PFNA delayed the development of zebrafish embryos, reduced the hatching rate, and caused ventricular edema and malformation of the spine. In addition, the amount of reactive oxygen species in the embryo bodies increased significantly after exposure to PFNA compared with that of the control group. The Quantitative RT-PCR and WISH experiments demonstrated that m RNA expression of the lfabp and ucp2 genes increased significantly while that of sod1 and mt-nd1 decreased significantly after PFNA exposure. The m RNA expression levels of gpx1 and mt-atp6 decreased significantly in the high concentration group. However, the m RNA expression levels of both ppara and pparg did not show any significant variation after exposure. These findings suggest that PFNA affected the development of zebrafish embryos at relatively low concentrations.
基金Project supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB10040304)the National Natural Science Foundation of China(Grant Nos.51490654,11290164,and U1262109)the Key Research Program of Chinese Academy of Sciences(Grant No.KJZDEW-M03)
文摘Hydrophobic nanochannel plays a significant role in many physical, biological, and geological phenomena and ex- hibits impressive applications due to both its ubiquitous distribution and great ability to transport hydrophobic molecules, including various oils and gases. Based on theoretical modeling, we herein reveal that the amphipathic Janus nanoparticles have a large probability to self-assemble into uninterrupted hydrophobic nanochannels inside the aqueous nano-space, al- though there are large portions of the Janus nanoparticles to be hydrophilic. The key to this observation is the attractions between the hydrophobic regimes on neighboring amphipathic Janus particles through hydrophobic interaction in aqueous nano-space. More surprisingly, the permeation efficiency of hydrophobic molecules through the uninterrupted hydrophobic channel in Janus particles aggregate is even higher than that in the aggregate of hydrophobic particles. We note that the proposed amphipathic Janus particles can be transported to the appropriate positions by the water since the hydrophilic regimes still remain a strong particle-water interaction. We also note that most natural subsurface rocks are not completely hydrophobic or hydrophilic but have complex surfaces with inhomogeneous wetting property. Our work therefore provides a detailed molecular level understanding of the formation of underground strata as well as the new insight for constructing the artificial hydrophobic channels for various applications, such as the design of proppants to enhance the recovery of the unconventional oil/gas.
基金supported by the Fundamental Research Funds for the Central Universities(No.2232019A3-02)DHU Distinguished Young Professor Program(No.LZB2019002)+1 种基金Young Elite Scientists Sponsorship Program by CAST(No.2017QNRC001)J.L.acknowledges funding provided by the Donghua University Doctoral Innovation Fund Program(Nos.17D310606,106-06-0019058).
文摘The development of lightweight,flexible,and stretchable energy storage systems is essential for state-of-the-art electronic devices.We propose a new and broad strategy to fabricate a stretchable and conductive GO/CNTs-TPU fiber electrode by direct wet spinning,from which a flexible fibrous supercapacitor is fabricated.The fibrous electrode exhibits a high strength of 11.68 MPa,high conductivity of 342 S/cm,and high specific capacitances(21.8 mF/cm,36.45 F/cm^3,and 95 F/g).The specific capacitance of the assembled all-solid-state hybrid fiber-shaped supercapacitor reaches 14.3 F/cm^3.After 5000 charge-discharge cycles,97%of the capacitance of the hybrid supercapacitor is maintained.These high-strength electrochemical electrode materials could be potential candidates for applications in practical and large-scale energy storage systems and textile clothes.
基金supported by the Natural Science Foundation of China(21978325,21776312,22078364)Key research and development plan of Shandong Province(2019RKE28003,2018GGX107005)Fundamental Research Funds for the Central Universities(18CX02014A).
文摘Engineering unique electronic structure of catalyst to boost catalytic performance is of prime scientific and industrial importance.Herein,the identification of intrinsic electronic sensitivity for direct propene epoxidation was first achieved over highly stable Au/wormhole-like TS-1 catalyst.Results show that the electron transfer of Au species can be regulated by manipulating the dynamic evolutions and contents of Au valence states,thus resulting in different catalytic performance in 100 h time-on-stream.By DFT calculations,kinetic analysis and multicharacterizations,it is found that the Au^(0) species with higher electronic population can easily transfer more electrons to activate surface O_(2) compared with Au^(1+) and Au^(3+) species.Moreover,there is a positive correlation between Au^(0) content and activity.Based on this correlation,a facile strategy is further proposed to boost Au^(0) percentage,resulting in the reported highest PO formation rate without adding promoters.This work harbors tremendous guiding significance to the design of highly efficient Au/Ti-containing catalyst for propene epoxidation with H_(2) and O_(2).
基金supported by the Natural Science Foundation of China(21978325,21776312,22078364)Postgraduate Innovation Engineering(YCX2020044).
文摘The advocacy of green chemical industry has led to the development of highly efficient catalysts for direct gas-phase propene epoxidation with green,sustainable and simple essence.The S-1/TS-1@dendritic-SiO_(2) material with three-layer core–shell structure was developed and used as the support for Au catalysts,which showed simultaneously fantastic PO formation rate,PO selectivity and stability(over 100 h)for propene epoxidation with H_(2) and O_(2).It is found that silicalite-1(S-1)core and the middle thin layer of TS-1 offer great mass transfer ability,which could be responsible for the excellent stability.The designed dendritic SiO_(2) shell covers part of the acid sites on the external surface of TS-1,inhibiting the side reactions and improving the PO selectivity.Furthermore,three kinds of SiO_(2) shell morphologies(i.e.,dendritic,net,mesoporous shell)were designed,and relationship between shell morphology and catalytic performance was elucidated.The results in this paper harbour tremendous guiding significance for the design of highly efficient epoxidation catalysts.
基金supported by the National Basic Research Program of China (973No.2013CB945004)the National Natural Science Foundation of China (No.21477127)
文摘Phthalates are a large family of ubiquitous environmental pollutants suspected of being endocrine disruptors. Epidemiological studies have associated phthalate metabolites with decreased reproductive parameters and linked phthalate exposure with the level of urinary 5-methyl-2′-deoxycytidine（5mdC, a product of methylated DNA）. In this study, adult male mice were exposed to 450 mg di-isobutyl phthalate（DiBP）/（kg·day） via dietary exposure for 28 days. Mono-isobutyl phthalate（Mi BP, the urinary metabolite） and reproductive function parameters were determined. The levels of 5mdC and 5-hydroxymethyl-2′-deoxycytidine（5hmdC） were measured in urine to evaluate if their contents were also altered by DiBP exposure in this animal model. Results showed that DiBP exposure led to a significant increase in the urinary 5mdC level and significant decreases in sperm concentration and motility in the epididymis, accompanied with reduced testosterone levels and downregulation of the P450 cholesterol side-chain cleavage enzyme（P450scc） gene in the mice testes. Our findings indicated that exposure to DiBP increased the urinary 5mdC levels,which supported our recent epidemiological study about the associations of urinary 5mdC with phthalate exposure in the male human population. In addition, DiBP exposure impaired male reproductive function, possibly by disturbing testosterone levels; P450scc might be a major steroidogenic enzyme targeted by DiBP or other phthalates.
基金supported by the National Natural Science Foundation of China(31300551)the Anhui Outstanding Young Talent Support Program(gxfx2017059)
文摘A new species of the genus Tipulodina Enderlein, 1912, Tipulodina simianshanensis Men sp. nov.(South China: Chongqing) is described and illustrated. A key to known species of the genus in China is provided. The new species represents the first record of Tipulodina species from Chongqing, China.
基金the National Natural Science Foundation of China under Grant Nos.U1632135,U1832170,11862003,11474299,11574339,U1932123,and 11722548the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(Nos.QYZDJ-SSW-SLH053 and QYZDJ-SSW-SLH019)the Key Research Program of the Chinese Academy of Sciences(No.KJZDEW-M03)。
文摘Recently,there are great efforts that have been taken to suppressing/controlling the coffee ring effect,but it is of challenge to achieve inexpensive and efficient control with less disturbance,suitable for scalable production and highly enhancing the printing/dyeing color fastness.By only adding trace amounts of salt into the suspensions,here we experimentally achieve the facile and highly efficient control of the coffee ring effect of suspended matter on substrates of graphene,natural graphite,and polyethylene terephthalate surfaces.Notably,friction force measurements show that ion-controlled uniform patterns also greatly enhance color fastness.Molecular dynamics simulations reveal that,due to strong hydrated cation-π interactions between hydrated cations and aromatic rings in the substrate surface,the suspended matters are adsorbed on the surfaces mediated by cations so that the suspended matters are uniformly distributed.These findings will open new avenues for fabricating functional patterns on graphene substrates and will benefit practical applications including printing,coating,and dyeing.
基金supported by the National Natural Science Foundation of China(52173287,52373296,51873117)Med-X Innovation Programme of Med-X Center for Materials,Sichuan University(MCMGD202304)the State Key Laboratory of Polymer Materials Engineering(sklpme2022-2-07).
文摘Mechanical adaptation of tissue engineering scaffolds is critically important since natural tissue regeneration is highly regulated by mechanical signals.Herein,we report a facile and convenient strategy to tune the modulus of waterborne biodegradable polyurethanes(WBPU)via cross-linking manipulation of phase separation and water infiltration for constructing mechanically adaptable tissue engineering scaffolds.Amorphous aliphatic polycarbonate and trifunctional trimethylolpropane were introduced to polycaprolactone-based WBPUs to interrupt interchain hydrogen bonds in the polymer segments and suppress microphase separation,inhibiting the crystallization process and enhancing covalent cross-linking.Intriguingly,as the crosslinking density of WBPU increases and the extent of microphase separation decreases,the material exhibits a surprisingly soft modulus and enhanced water infiltration.Based on this strategy,we constructed WBPU scaffolds with a tunable modulus to adapt various cells for tissue regeneration and regulate the immune response.As a representative application of brain tissue regeneration model in vivo,it was demonstrated that the mechanically adaptable WBPU scaffolds can guide the migration and differentiation of endogenous neural progenitor cells into mature neurons and neuronal neurites and regulate immunostimulation with low inflammation.Therefore,the proposed strategy of tuning the modulus of WBPU can inspire the development of novel mechanically adaptable biomaterials,which has very broad application value.
基金supported by the National Natural Science Foundation of China(Grant Nos.10825520,11422542,11175230,and 11290164)the Key Research Program of the Chinese Academy of Sciences(Grant No.KJZD-EW-M03)Deepcomp7000 and ScGrid of the Supercomputing Center,the Computer Network Information Center of the Chinese Academy of Sciences, and the Shanghai Supercomputer Center of China
文摘Using molecular dynamics simulations,we show that an asymmetrically shaped nanoparticle in dilute solution possesses a spontaneously curved trajectory within a finite time interval,instead of the generally expected random walk.This unexpected dynamic behavior has a similarity to that of active matters,such as swimming bacteria,cells,or even fish,but is of a different physical origin.The key to the curved trajectory lies in the non-zero resultant force originated from the imbalance of the collision forces acted by surrounding solvent molecules on the asymmetrically shaped nanoparticle during its orientation regulation.Theoretical formulae based on microscopic observations have been derived to describe this non-zero force and the resulting motion of the asymmetrically shaped nanoparticle.
文摘This paper focuses on the study of mechanical design and control measures in smart home systems.First of all,it elaborates on the theoretical foundation of mechatronics technology,including its multidisciplinary integration characteristics,system design principles,and constituent elements.It then reviews the research progress in this field,followed by a detailed analysis of mechatronics design in systems such as smart lighting and smart security,as well as the application of control algorithms and communication protocols in smart homes.Finally,it discusses challenges such as system compatibility and data security risks,proposing corresponding solutions to provide theoretical and practical references for the development of smart home systems.
基金National Natural Science Foundation of China(NSFC,Grant No.12272149,11802104)partly supported by the National Key Research and Development Program(Grant No.2017YFB0309200).
文摘High-performance yarn artificial muscles are highly desirable as miniature actuators,sensors,energy harvesters,and soft robotics.However,achieving a yarn artificial muscle that covers all the properties of excellent actuation performance,mechanical robustness,structural stability,and high scalability by a low-cost strategy is still a great challenge.Herein,a bio-inspired fasciated yarn structure is first reported for creating robust high-performance yarn artificial muscles.Unlike conventional strategies that leverage costly materials or complex processing,the developed yarn artificial muscles are constructed by hierarchically helical and sheath-core assembly design of cost-effective common fibers,such as viscose and polyester.The hierarchically helical sheath structure pushes the theoretical limit of the inserted twist in yarns and endows the yarn muscles with large stroke(5815°cm^(-1))and high work capacity(23.5 J kg^(-1)).Due to the rapid water transfer and efficient energy conversion of inter-sheath-core coupling,the as-prepared yarn muscles possess fast response,high rotation accelerated speed,and low recovery hysteresis.Moreover,the inactive core yarn serves as support for internal tethering and load-bearing,enabling these yarn muscles to maintain a self-stable structure,robust life cycle and mechanics.We show that the yarn muscle fabricated in this method is readily available and highly scalable for achieving high-dimensional actuation deformations,which considerably broadens the application scenarios of artificial muscles.
基金supported by the National Natural Science Foundation of China(Grant Nos.11175230 and 11474299)the Innovation Program of Shanghai Municipality Education Commission,China(Grant No.14ZZ095)
文摘Self-diffusion of water has been investigated by molecular dynamics simulations. It was found that the preference of the direction in self-diffusion of water is orientation dependent in a finite time. For a time of-lO0 ps, there are more possibilities for water molecules moving along the initial dipole orientation than in the opposite direction. This reveals that self-diffusion of water molecules is asymmetric in a finite time. We tested four water models and found that they all show similar asymmetric diffusion, indicating that asymmetric diffusion of water is intrinsic behavior rather than induced by the water model. These results are important for understanding and application of asymmetric diffusion in research fields such as biological water and confined water in small dimensions.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11175230 and 11474299)Innovation Program of the Shanghai Municipality Education Commission, China (Grant No. 14ZZ095)Shanghai Supercomputer Center and Supercomputing Center of the Chinese Academy of Sciences
文摘The directional drifting of particles/molecules with broken symmetry has received increasing attention. Through molecular dynamics simulations, we investigate the effects of various solvents on the time-dependent directional drifting of a particle with broken symmetry. Our simulations show that the distance of directional drift of the asymmetrical particle is reduced while the ratio of the drift to the mean displacement of the particle is enhanced with increasing mass, size, and interaction strength of the solvent atoms in a short time range. Among the parameters considered, solvent atom size is a particularly influential factor for enhancing the directional drift of asymmetrical particles, while the effects of the interaction strength and the mass of the solvent atoms are relatively weaker. These findings are of great importance to the understanding and control of the Brownian motion of particles in various physical, chemical, and biological processes within finite time spans.
基金National Nature Science Foundation of China(81472872)CAMS Innovation Fund for Medical Sciences(CIFMS, 2016-I2M-1-002).
文摘Introduction Pyoderma gangrenosum (PG) is a chronic skin disease characterized by progressive lesions that present as painful suppurative ulcers and tend to recur. The pathogenesis of the disease is incompletely under-stood;however, 50%to 70%of affected persons have an associated concomitant systemic disease such as inflammatory bowel disease (IBD) (1)Any site of the body can be affected;however, involvement of the oropharynx is rare. Here, we present a patient with disseminated PG with oropharyngeal involvement.
