Ionic liquids(ILs)are an emerging class of media of fundamental importance for chemical engineering,especially due to their interaction with solid surfaces.Here,we explore the growth phenomenon of surface-confined ILs...Ionic liquids(ILs)are an emerging class of media of fundamental importance for chemical engineering,especially due to their interaction with solid surfaces.Here,we explore the growth phenomenon of surface-confined ILs and reveal a peculiar structural transition behavior from order to disorder above a threshold thickness.This behavior can be explained by the variation of interfacial forces with increasing distance from the solid surface.Direct structural observation of different ILs highlights the influence of the ionic structure on the growth process.Notably,the length of the alkyl chain in the cation is found to be a determining factor for the ordering trend.Also,the thermal stability of surface-confined ILs is investigated in depth by controlling annealing treatments.It is found that the ordered monolayer ILs exhibit high robustness against high temperatures.Our findings provide new perspectives on the properties of surface-confined ILs and open up potential avenues for manipulating the structures of nanometer-thick IL films for various applications.展开更多
To date,the primary industrial carbon capture approach is still absorption using aqueous solutions of alkanolamines.Here,to pursue a substitute for the amine-based approach to improve the CO_(2) capture efficiency and...To date,the primary industrial carbon capture approach is still absorption using aqueous solutions of alkanolamines.Here,to pursue a substitute for the amine-based approach to improve the CO_(2) capture efficiency and decrease the energy cost further,we report a new carbon capture approach using a 2-methylimidazole(mIm)aqueous solution.The properties and sorption behaviors of this approach have been experimentally investigated.The results show that the mIm solution has higher CO_(2) absorption capacity under relatively higher equilibrium pressure(>130 kPa)and lower desorption heat than the methyldiethanolamine solution.91.6%sorption capacity of mIm solution can be recovered at 353.15 K and 80 kPa.The selectivity for CO_(2)/N_(2) and CO_(2)/CH_(4) can reach an exceptional 7609 and 4324,respectively.Furthermore,the pilot-scale tests were also performed,and the results demonstrate that more than 98%of CO_(2) in the feed gas could be removed and cyclic absorption capacity can reach 1 mol·L^(-1).This work indicates that mIm is an excellent alternative to alkanolamines for carbon capture in the industry.展开更多
Due to the many types of distributed denial-of-service attacks(DDoS)attacks and the large amount of data generated,it becomes a chal-lenge to manage and apply the malicious behavior knowledge generated by DDoS attacks...Due to the many types of distributed denial-of-service attacks(DDoS)attacks and the large amount of data generated,it becomes a chal-lenge to manage and apply the malicious behavior knowledge generated by DDoS attacks.We propose a malicious behavior knowledge base framework for DDoS attacks,which completes the construction and application of a multi-domain malicious behavior knowledge base.First,we collected mali-cious behavior traffic generated by five mainstream DDoS attacks.At the same time,we completed the knowledge collection mechanism through data pre-processing and dataset design.Then,we designed a malicious behavior category graph and malicious behavior structure graph for the characteristic information and spatial structure of DDoS attacks and completed the knowl-edge learning mechanism using a graph neural network model.To protect the data privacy of multiple multi-domain malicious behavior knowledge bases,we implement the knowledge-sharing mechanism based on federated learning.Finally,we store the constructed knowledge graphs,graph neural network model,and Federated model into the malicious behavior knowledge base to complete the knowledge management mechanism.The experimental results show that our proposed system architecture can effectively construct and apply the malicious behavior knowledge base,and the detection capability of multiple DDoS attacks occurring in the network reaches above 0.95,while there exists a certain anti-interference capability for data poisoning cases.展开更多
This paper provides insight into the application of electron-beam welding in pellet mold preparation,highlighting the importance of the combination of electron-beam welding and pellet mold preparation in the fields of...This paper provides insight into the application of electron-beam welding in pellet mold preparation,highlighting the importance of the combination of electron-beam welding and pellet mold preparation in the fields of microstructure joining and micro-and nanostructure preparation.Precise material joining and microstructure fabrication can be achieved by the precise control of electron-beam welding and the shape adjustment of pellet molds.These applications hold significant potential in the modern industrial field,providing robust support for the development of new materials and the growth of the petrochemical industry.This paper asserts that in the future,the ongoing development of electron-beam welding and pelletizing template technology will unlock new possibilities in the field of petrochemicals,fostering progress in science and technology.展开更多
The structure of liquid water is primarily composed of three-dimensional networks of water clusters formed by hydrogen bonds,and dis-solved oxygen is one of the most important indicators for assessing water qual-ity.I...The structure of liquid water is primarily composed of three-dimensional networks of water clusters formed by hydrogen bonds,and dis-solved oxygen is one of the most important indicators for assessing water qual-ity.In this work,distilled water with different concentration of dissolved oxygen were prepared,and a clear negative correlation between the size of water clus-ters and dissolved oxygen concentration was observed.Besides,a phenomenon of rapid absorption and release of oxygen at the water interfaces was unveiled,suggesting that oxygen molecules predominantly exist at the interfaces of water clusters.Oxygen molecules can move rapidly through the interfaces among water clusters,allowing dissolved oxygen to quickly reach a saturation level at certain partial pressure of oxygen and temperature.Further exploration into the mechanism by molecular dynamics simulations of oxygen and water clusters found that oxygen molecules can only exist stably at the interfaces among water clusters.A semi-empirical formula relating the average number of water molecules in a cluster(n)to ^(17)O NMR half-peak width(W)was summarized:n=0.1 W+0.85.These findings provide a foundation for exploring the structure and properties of water.展开更多
Low-cost photovoltaic materials are essential for realizing large-scale commercial applications of organic solar cells(OSCs).However,highly efficient OSCs based on low-cost photovoltaic materials are scarce due to a d...Low-cost photovoltaic materials are essential for realizing large-scale commercial applications of organic solar cells(OSCs).However,highly efficient OSCs based on low-cost photovoltaic materials are scarce due to a deficiency in understanding the structure-property relationship.Herein,we investigated two low-cost terthiophene-based electron acceptors,namely,3TC8 and 3TEH,with 3,4-bis(octan-3-yloxy)thiophene,differing only in the alkylated thiophene-bridges.Both acceptors exhibit low optical gaps(∼1.43 eV)and possess deep highest occupied molecular orbital(HOMO)levels(∼−5.8 eV).Notably,the single-crystal structure of 3TEH demonstrates highly planar conjugated backbone and strongπ-πstacking between intermolecular terminal groups,attributed to the presence of the bulky alkylated noncovalently conformational locks.Upon utilizing both acceptors to fabricate OSCs,the 3TC8-based device exhibited a power conversion efficiency(PCE)of 11.1%,while the 3TEH-based OSC demonstrated an excellent PCE of 14.4%.This PCE is the highest among OSCs based on terthiophene-containing electron acceptors.These results offer a new strategy for designing low-cost electron acceptors for highly efficient OSCs.展开更多
A multitracer-gas method was proposed to study the secondary air(SA)mixing along the bed height in a circulating fluidized bed(CFB)using carbon monoxide(CO),oxygen(O_(2)),and carbon dioxide(CO_(2))as tracer gases.Expe...A multitracer-gas method was proposed to study the secondary air(SA)mixing along the bed height in a circulating fluidized bed(CFB)using carbon monoxide(CO),oxygen(O_(2)),and carbon dioxide(CO_(2))as tracer gases.Experiments were carried out on a cold CFB test rig with a cross-section of 0.42 m×0.73 m and a height of 5.50 m.The effects of superficial velocity,SA ratio,bed inventory,and particle diameter on the SA mixing were investigated.The results indicate that there are some differences in the measurement results obtained using different tracer gases,wherein the deviation between CO and CO_(2) ranges from 42%to 66%and that between O_(2) and CO_(2) ranges from 45%to 71%in the lower part of the fluidized bed.However,these differences became less pronounced as the bed height increased.Besides,the high solid concentration and fine particle diameter in the CFB may weaken the difference.The measurement results of different tracer gases show the same trends under the variation of operating parameters.Increasing superficial velocity and SA ratio and decreasing particle diameter result in better mixing of the SA.The effect of bed inventory on SA mixing is not monotonic.展开更多
While KRAS mutation is the leading cause of low survival rates in lung cancer bone metastasis patients,effective treatments are still lacking.Here,we identified homeobox C10(HOXC10)as a lynchpin in pan-KRAS-mutant lun...While KRAS mutation is the leading cause of low survival rates in lung cancer bone metastasis patients,effective treatments are still lacking.Here,we identified homeobox C10(HOXC10)as a lynchpin in pan-KRAS-mutant lung cancer bone metastasis.展开更多
Dear Editor,An adaptive consensus control algorithm for uncertain multi-agent systems(MAS),capable of guaranteeing unified prescribed performance,is presented in this letter.Unlike many existing prescribed performance...Dear Editor,An adaptive consensus control algorithm for uncertain multi-agent systems(MAS),capable of guaranteeing unified prescribed performance,is presented in this letter.Unlike many existing prescribed performance related works,the developed control exhibits some features.Firstly,a distributed prescribed time observer is introduced so that not only each follower is able to estimate the leader’s signal within a predetermined time,but also the control design for each agent is independent with its neighbors.展开更多
Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis m...Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis method,and their antibacterial activities were evaluated by three strains of spoilage bacteria,Escherichia coli,Pseudomonas aeruginosa and Shewanella putrefaciens,and the relationship of their antibacterial activities and structures was also investigated.Uv-vis spectrophotometry was used to determine the growth curves of three kinds of active indicator bacteria.Minimum inhibitory concentration(MIC)was determined by micro broth dilution method.The results showed that 2-methyl-3-(methylthio)pyrazine had significant antibacterial activity against three strains of the bacteria,and its MIC was 1.25%.It indicates 2-methyl-3-(methylthio)pyrazine has the potential to be developed as a kind of preservative in future.展开更多
Objective:To compare the efficacy of platinum-and non-platinum-based regimens as first-line treatment for advanced triple-negative breast cancer(TNBC)and analyze the relationship between their efficacy and BRCA gene s...Objective:To compare the efficacy of platinum-and non-platinum-based regimens as first-line treatment for advanced triple-negative breast cancer(TNBC)and analyze the relationship between their efficacy and BRCA gene status.Methods:Retrospectively analyze clinical data of 220 patients diagnosed pathologically with advanced TNBC and treated at the Department of Breast Oncology,Peking University Cancer Hospital from 2013 to 2018 and evaluate the efficacy of chemotherapy.A total of 114 patients had BRCA1/2 gene tested by next generation sequencing(NGS)using peripheral blood,and we analyzed the correlation between their efficacy and BRCA1/2 gene status.Results:Non-platinum-based chemotherapy(NPCT)was administered to 129 and platinum-based chemotherapy(PBCT)to 91 study patients.The clinical benefit rate(CBR)and median progression-free survival(PFS)were not statistically different between NPCT and PBCT groups.The median overall survival(OS)was 30.0 and 22.5 months for PBCT and NPCT group,respectively[P=0.090,hazard ratios(HR)=0.703].BRCA status was assessed in 114 patients,14 of whom had deleterious germline BRCA1/2(g BRCA)mutations(seven in each group).In PBCT group,the CBR was 85.7%and 35.1%for patients with and without deleterious g BRCA mutations,respectively(P=0.039).The median PFS were 14.9 and 5.3 months and median OS were 26.5 and 15.5 months for patients with and without deleterious g BRCA mutations,respectively(P=0.001,P=0.161,respectively).Patients in PBCT group had significantly greater rates of grade 3-4 anemia(5.5%vs.0%)and thrombocytopenia(8.8%vs.0%),whereas palmar-plantar erythrodysesthesia(12.4%vs.0%)and peripheral neuropathy(8.6%vs.1.1%)occurred more frequently in NPCT group.Conclusions:Platinum-based regimens are more effective in patients with deleterious g BRCA mutations,but no difference in patients without BRCA gene mutations,so non-platinum is an option in patients without BRCA gene mutations considering the toxicity and side effect.And we recommend that patients with advanced TNBC should have BRCA gene test.展开更多
To investigate the effect of solidification parameters on the solidification path and microstructure evolution of Ti-45Al-5Nb(at.%) alloy, Bridgman-type directional solidification and thermodynamics calculations were ...To investigate the effect of solidification parameters on the solidification path and microstructure evolution of Ti-45Al-5Nb(at.%) alloy, Bridgman-type directional solidification and thermodynamics calculations were performed on the alloy. The microstructures, micro-segregation and solidification path were investigated.The results show that the β phase is the primary phase of the alloy at growth rates of 5-20 μm·s^(-1) under the temperature gradients of 15-20 K·mm^(-1), and the primary phase is transformed into an α phase at relatively higher growth rates(V >20 μm·s^(-1)). The mainly S-segregation and β-segregation can be observed in Ti-45Al-5Nb alloy at a growth rate of 10 μm·s^(-1) under a temperature gradient of 15 K·mm^(-1). The increase of temperature gradient to 20 K·mm^(-1) can eliminate β-segregation, but has no obvious effect on S-segregation. The results also show that 5 at.% Nb addition can expand the β phase region, increase the melting point of the alloy and induce the solidification path to become complicated. The equilibrium solidification path of Ti-45Al-5Nb alloy can be described as L L→β L+β L+β→αα+β_R β→ααα→γα+γα→α_2+γγ_R+(α_2+γ), in which β_R and γ_R mean the residual β and展开更多
AIM: To examine the correlation of phosphatidylinositol 3-kinase (PIK3) CB expression with preoperative radiotherapy response in patients with stage II/III rectal adenocarcinoma.
AIM To investigate the anti-inflammatory effect and the possible mechanisms of an agonist of cannabinoid(CB) receptors, WIN55-212-2(WIN55), in mice with experimental colitis, so as to supply experimental evidence for ...AIM To investigate the anti-inflammatory effect and the possible mechanisms of an agonist of cannabinoid(CB) receptors, WIN55-212-2(WIN55), in mice with experimental colitis, so as to supply experimental evidence for its clinical use in future. METHODS We established the colitis model in C57BL/6 mice by replacing the animals' water supply with 4% dextran sulfate sodium(DSS) for 7 consecutive days. A colitis scoring system was used to evaluate the severity of colon local lesion. The plasma levels of proinflammatory cytokines, such as tumor necrosis factor-alpha(TNF-α) and interleukin-6(IL-6), and the myeloperoxidase(MPO) activity in colon tissue were measured. The expressions of cannabinoid receptors, claudin-1 protein, p38 mitogen-activated protein kinase(p38MAPK) and its phosphorylated form(p-p38) in colon tissue were determined by immunohistochemistry and Western blot. In addition, the effect of SB203580(SB), an inhibitor of p38, was investigated in parallel experiments, andthe data were compared with those from intervention groups of WIN55 and SB alone or used together. RESULTS The results demonstrated that WIN55 or SB treatment alone or together improved the pathological changes in mice with DSS colitis, decreased the plasma levels of TNF-α, and IL-6, and MPO activity in colon. The enhanced expression of claudin-1 and the inhibited expression of p-p38 in colon tissues were found in the WIN55-treated group. Besides, the expression of CB1 and CB2 receptors was enhanced in the colon after the induction of DSS colitis, but reduced when p38 MAPK was inhibited. CONCLUSION These results confirmed the anti-inflammatory effect and protective role of WIN55 on the mice with experimental colitis, and revealed that this agent exercises its action at least partially by inhibiting p38 MAPK. Furthermore, the results showed that SB203580, affected the expression of CB1 and CB2 receptors in the mouse colon, suggesting a close linkage and cross-talk between the p38 MAPK signaling pathway and the endogenous CB system.展开更多
Objective: To evaluate the tolerance limit of rats tonormothermic hepatic inflow occlusion under portalblood bypass.Methods: A new rat model of normothermic hepaticinflow occlusion under portal blood bypass was estab-...Objective: To evaluate the tolerance limit of rats tonormothermic hepatic inflow occlusion under portalblood bypass.Methods: A new rat model of normothermic hepaticinflow occlusion under portal blood bypass was estab-lished by clamping temporarily the pedicles of all liverlobes while the caudal lobe was kept as a passage ofthe portal blood flow. After hepatic blood flow re-stored, the caudal lobe was cut off. On the 7th postop-erative day, survival rate, hepatic morphological changes,and the severity and reversibility of the injured energymetabolism of the liver were investigated.Results: All rats that had been subjected to 30, 60 and90 minutes of hepatic inflow occlusion under portalblood bypass survived on the 7th postoperativeday. Ischemia-reperfusion injury of the liver was re-versible and compensatory in rats with hepatic inflowocclusion within 90minutes. However, the survivalrates of rats with 100, 110 and 120 minutes of hepaticinflow occlusion were 50%, 30% and 20% respective-ly. Liver injury of rats with 120 minutes of hepatic in-flow occlusion was severe and irreversible.Conclusions: The tolerance limit of rats to normother-mic hepatic inflow occlusion is enhanced significantlyunder portal blood bypass and the upper limit is 90minutes.展开更多
Protamines are a group of highly basic proteins first discovered in spermatozoon that allow for denser packaging of DNA than histones and will result in down-regulation of gene transcription^l~. It is well recognized ...Protamines are a group of highly basic proteins first discovered in spermatozoon that allow for denser packaging of DNA than histones and will result in down-regulation of gene transcription^l~. It is well recognized that the Autographa californica multicapsid nucleopolyhedrovirus （AcMNPV） encodes P6.9, a protamine-like protein that forms the viral subnucleosome through binding to the viral genome[29]. Previous research demonstrates that P6.9 is essential for viral nucleocapsid assembly, while it has no influence on viral genome replication1311. In the present study, the role of P6.9 in viral gene transcription regulation is characterized. In contrast to protamines or other protamine-like proteins that usually down-regulate gene transcription, P6.9 appears to up-regulate viral gene transcription at 12-24 hours post infection （hpi）, whereas it is non-essential for the basal level of viral gene transcription. Fluorescence microscopy reveals the P6.9＇s co-localization with DNA is temporally and spatially synchronized with P6.9＇s impact on viral gene transcription, indicating the P6.9-DNA association contributes to transcription regulation. Chromatin fractionation assay further reveals an unexpected co-existence of P6.9 and host RNA polymerase II in the same transcriptionally active chromatin fraction at 24 hpi, which may probably contribute to viral gene transcription up-regulation in the late infection phase.展开更多
Frequency-dependent amplitude versus offset(FAVO)inversion is a popular method to estimate the frequency-dependent elastic parameters by using amplitude and frequency information of pre-stack seismic data to guide flu...Frequency-dependent amplitude versus offset(FAVO)inversion is a popular method to estimate the frequency-dependent elastic parameters by using amplitude and frequency information of pre-stack seismic data to guide fluid identification.Current frequency-dependent AVO inversion methods are mainly based on elastic theory without the consideration of the viscoelasticity of oil/gas.A fluid discrimination approach is proposed in this study by incorporating the viscoelasticity and relevant FAVO inversion.Based on viscoelastic and rock physics theories,a frequency-dependent viscoelastic solid-liquid decoupling fluid factor is initially constructed,and its sensitivity in fluid discrimination is compared with other conventional fluid factors.Furthermore,a novel reflectivity equation is derived in terms of the viscoelastic solid-liquid decoupling fluid factor.Due to the introduction of viscoelastic theory,the proposed reflectivity is related to frequency,which is more widely applicable than the traditional elastic reflectivity equation directly derived from the elastic reflectivity equation on frequency.Finally,a pragmatic frequency-dependent inversion method is introduced to verify the feasibility of the equation for frequency-dependent viscoelastic solid-liquid decoupling fluid factor prediction.Synthetic and field data examples demonstrate the feasibility and stability of the proposed approach in fluid discrimination.展开更多
A reliable,efficient anther culture system,the dominant technique for generating haploid plants in breeding programs,that can be used for generating transgenic poplar plants has been needed.In the present study,theref...A reliable,efficient anther culture system,the dominant technique for generating haploid plants in breeding programs,that can be used for generating transgenic poplar plants has been needed.In the present study,therefore,an anther culture system was developed using isolated mid-and late-uninucleate anthers of poplar(Populus simonii x P.nigra).From a combination of SSR and ploidy analyses,six double haploid and two haploid lines were characterized from 86 plants grown from 16 regenerated anther cultured lines.After 48 months of development,two plant lines from the regenerated plants maintained their haploid level in vitro for over 2 years.A number of haploid plants from the different lines weretransferred to soil.The leaves of these transplants were then used as explants for transformation with the APETALA1(AP1) gene using Agrobacterium tumefaciens.Overexpression of AP1 in haploid poplar induced early flowering with obvious petals when ectopically expressed.To our knowledge,this is the first report on changes in flowering time in AP1-trangenic poplar,which is important for elucidating the regulatory mechanism of tree flower development.展开更多
基金supported by the National Key Research and Development Program of China(2021YFB3802600)the National Natural Science Foundation of China(22278396,22378392,22178344)+1 种基金the Youth Innovation Promotion Association CAS(Y2021022)the Open Research Fund of State Key Laboratory of Mesoscience and Engineering(MESO-23-D17)。
文摘Ionic liquids(ILs)are an emerging class of media of fundamental importance for chemical engineering,especially due to their interaction with solid surfaces.Here,we explore the growth phenomenon of surface-confined ILs and reveal a peculiar structural transition behavior from order to disorder above a threshold thickness.This behavior can be explained by the variation of interfacial forces with increasing distance from the solid surface.Direct structural observation of different ILs highlights the influence of the ionic structure on the growth process.Notably,the length of the alkyl chain in the cation is found to be a determining factor for the ordering trend.Also,the thermal stability of surface-confined ILs is investigated in depth by controlling annealing treatments.It is found that the ordered monolayer ILs exhibit high robustness against high temperatures.Our findings provide new perspectives on the properties of surface-confined ILs and open up potential avenues for manipulating the structures of nanometer-thick IL films for various applications.
基金The financial supports received from National Natural Science Foundation of China (U20B6005, 22178378, and 22127812)
文摘To date,the primary industrial carbon capture approach is still absorption using aqueous solutions of alkanolamines.Here,to pursue a substitute for the amine-based approach to improve the CO_(2) capture efficiency and decrease the energy cost further,we report a new carbon capture approach using a 2-methylimidazole(mIm)aqueous solution.The properties and sorption behaviors of this approach have been experimentally investigated.The results show that the mIm solution has higher CO_(2) absorption capacity under relatively higher equilibrium pressure(>130 kPa)and lower desorption heat than the methyldiethanolamine solution.91.6%sorption capacity of mIm solution can be recovered at 353.15 K and 80 kPa.The selectivity for CO_(2)/N_(2) and CO_(2)/CH_(4) can reach an exceptional 7609 and 4324,respectively.Furthermore,the pilot-scale tests were also performed,and the results demonstrate that more than 98%of CO_(2) in the feed gas could be removed and cyclic absorption capacity can reach 1 mol·L^(-1).This work indicates that mIm is an excellent alternative to alkanolamines for carbon capture in the industry.
基金supported by the NationalKeyR&DProgramof China underGrant No.2018YFA0701604.
文摘Due to the many types of distributed denial-of-service attacks(DDoS)attacks and the large amount of data generated,it becomes a chal-lenge to manage and apply the malicious behavior knowledge generated by DDoS attacks.We propose a malicious behavior knowledge base framework for DDoS attacks,which completes the construction and application of a multi-domain malicious behavior knowledge base.First,we collected mali-cious behavior traffic generated by five mainstream DDoS attacks.At the same time,we completed the knowledge collection mechanism through data pre-processing and dataset design.Then,we designed a malicious behavior category graph and malicious behavior structure graph for the characteristic information and spatial structure of DDoS attacks and completed the knowl-edge learning mechanism using a graph neural network model.To protect the data privacy of multiple multi-domain malicious behavior knowledge bases,we implement the knowledge-sharing mechanism based on federated learning.Finally,we store the constructed knowledge graphs,graph neural network model,and Federated model into the malicious behavior knowledge base to complete the knowledge management mechanism.The experimental results show that our proposed system architecture can effectively construct and apply the malicious behavior knowledge base,and the detection capability of multiple DDoS attacks occurring in the network reaches above 0.95,while there exists a certain anti-interference capability for data poisoning cases.
文摘This paper provides insight into the application of electron-beam welding in pellet mold preparation,highlighting the importance of the combination of electron-beam welding and pellet mold preparation in the fields of microstructure joining and micro-and nanostructure preparation.Precise material joining and microstructure fabrication can be achieved by the precise control of electron-beam welding and the shape adjustment of pellet molds.These applications hold significant potential in the modern industrial field,providing robust support for the development of new materials and the growth of the petrochemical industry.This paper asserts that in the future,the ongoing development of electron-beam welding and pelletizing template technology will unlock new possibilities in the field of petrochemicals,fostering progress in science and technology.
基金funding support from National Natural Science Foundation of China(Project No.61574091)Wuxi River and Lake Management and Water Resources Management Center(Project No.JSXXCG2022-004).
文摘The structure of liquid water is primarily composed of three-dimensional networks of water clusters formed by hydrogen bonds,and dis-solved oxygen is one of the most important indicators for assessing water qual-ity.In this work,distilled water with different concentration of dissolved oxygen were prepared,and a clear negative correlation between the size of water clus-ters and dissolved oxygen concentration was observed.Besides,a phenomenon of rapid absorption and release of oxygen at the water interfaces was unveiled,suggesting that oxygen molecules predominantly exist at the interfaces of water clusters.Oxygen molecules can move rapidly through the interfaces among water clusters,allowing dissolved oxygen to quickly reach a saturation level at certain partial pressure of oxygen and temperature.Further exploration into the mechanism by molecular dynamics simulations of oxygen and water clusters found that oxygen molecules can only exist stably at the interfaces among water clusters.A semi-empirical formula relating the average number of water molecules in a cluster(n)to ^(17)O NMR half-peak width(W)was summarized:n=0.1 W+0.85.These findings provide a foundation for exploring the structure and properties of water.
基金supported by the Beijing Natural Science Foundation of China(Z230019,2212005)the National Natural Science Foundation of China(NSFC 22173062,21833005,22090022 and 22275125).
文摘Low-cost photovoltaic materials are essential for realizing large-scale commercial applications of organic solar cells(OSCs).However,highly efficient OSCs based on low-cost photovoltaic materials are scarce due to a deficiency in understanding the structure-property relationship.Herein,we investigated two low-cost terthiophene-based electron acceptors,namely,3TC8 and 3TEH,with 3,4-bis(octan-3-yloxy)thiophene,differing only in the alkylated thiophene-bridges.Both acceptors exhibit low optical gaps(∼1.43 eV)and possess deep highest occupied molecular orbital(HOMO)levels(∼−5.8 eV).Notably,the single-crystal structure of 3TEH demonstrates highly planar conjugated backbone and strongπ-πstacking between intermolecular terminal groups,attributed to the presence of the bulky alkylated noncovalently conformational locks.Upon utilizing both acceptors to fabricate OSCs,the 3TC8-based device exhibited a power conversion efficiency(PCE)of 11.1%,while the 3TEH-based OSC demonstrated an excellent PCE of 14.4%.This PCE is the highest among OSCs based on terthiophene-containing electron acceptors.These results offer a new strategy for designing low-cost electron acceptors for highly efficient OSCs.
基金the Key Project of the National Research Program of China(2020YFB0606201)。
文摘A multitracer-gas method was proposed to study the secondary air(SA)mixing along the bed height in a circulating fluidized bed(CFB)using carbon monoxide(CO),oxygen(O_(2)),and carbon dioxide(CO_(2))as tracer gases.Experiments were carried out on a cold CFB test rig with a cross-section of 0.42 m×0.73 m and a height of 5.50 m.The effects of superficial velocity,SA ratio,bed inventory,and particle diameter on the SA mixing were investigated.The results indicate that there are some differences in the measurement results obtained using different tracer gases,wherein the deviation between CO and CO_(2) ranges from 42%to 66%and that between O_(2) and CO_(2) ranges from 45%to 71%in the lower part of the fluidized bed.However,these differences became less pronounced as the bed height increased.Besides,the high solid concentration and fine particle diameter in the CFB may weaken the difference.The measurement results of different tracer gases show the same trends under the variation of operating parameters.Increasing superficial velocity and SA ratio and decreasing particle diameter result in better mixing of the SA.The effect of bed inventory on SA mixing is not monotonic.
基金sponsored by National Natural Science Foundation of China (82303396,82022051,82072972 and 81672883)Science and Technology Commission of Shanghai (22YF1408400)+6 种基金Shanghai Pilot Program for Basic Research (TQ20240208)Natural Science Foundation of Chongqing (CSTB2024NSCQ-JQX0009 and CSTB2024NSCQ-MSX0594)The Postdoctoral Foundation of China (2023T160122)Anti-cancer Association in Shanghai,Joint Foundation from Fudan University Shanghai Cancer Center (YJQN202102)Science&Techenology Department of Sichuan Province (2023NSFSC0705)the Fund of major military joint research project (2019LH 02)Shanghai municipal hospital emerging frontier joint research project (SHDC12024112)。
文摘While KRAS mutation is the leading cause of low survival rates in lung cancer bone metastasis patients,effective treatments are still lacking.Here,we identified homeobox C10(HOXC10)as a lynchpin in pan-KRAS-mutant lung cancer bone metastasis.
基金supported in part by the National Key Research and Development Program of China(2022YFB4701400/4701401)the National Natural Science Foundation of China(61991400,61991403,62250710167,61860206008,61933012,62273064)+1 种基金the Chongqing Outstanding Young Talents Support Program(cstc2024ycjh-bgzxm0085)CAAI-Huawei MindSpore Open Fund。
文摘Dear Editor,An adaptive consensus control algorithm for uncertain multi-agent systems(MAS),capable of guaranteeing unified prescribed performance,is presented in this letter.Unlike many existing prescribed performance related works,the developed control exhibits some features.Firstly,a distributed prescribed time observer is introduced so that not only each follower is able to estimate the leader’s signal within a predetermined time,but also the control design for each agent is independent with its neighbors.
基金Supported by The Tackling-plan Project of Henan Department of Science and Technology (222102310388)Key Scientific Research Plan of Colleges in Henan Province (22B350002)Henan Provincial Medical Science and Technology Research Plan Joint Construction Project (LHGJ20191520).
文摘Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis method,and their antibacterial activities were evaluated by three strains of spoilage bacteria,Escherichia coli,Pseudomonas aeruginosa and Shewanella putrefaciens,and the relationship of their antibacterial activities and structures was also investigated.Uv-vis spectrophotometry was used to determine the growth curves of three kinds of active indicator bacteria.Minimum inhibitory concentration(MIC)was determined by micro broth dilution method.The results showed that 2-methyl-3-(methylthio)pyrazine had significant antibacterial activity against three strains of the bacteria,and its MIC was 1.25%.It indicates 2-methyl-3-(methylthio)pyrazine has the potential to be developed as a kind of preservative in future.
文摘Objective:To compare the efficacy of platinum-and non-platinum-based regimens as first-line treatment for advanced triple-negative breast cancer(TNBC)and analyze the relationship between their efficacy and BRCA gene status.Methods:Retrospectively analyze clinical data of 220 patients diagnosed pathologically with advanced TNBC and treated at the Department of Breast Oncology,Peking University Cancer Hospital from 2013 to 2018 and evaluate the efficacy of chemotherapy.A total of 114 patients had BRCA1/2 gene tested by next generation sequencing(NGS)using peripheral blood,and we analyzed the correlation between their efficacy and BRCA1/2 gene status.Results:Non-platinum-based chemotherapy(NPCT)was administered to 129 and platinum-based chemotherapy(PBCT)to 91 study patients.The clinical benefit rate(CBR)and median progression-free survival(PFS)were not statistically different between NPCT and PBCT groups.The median overall survival(OS)was 30.0 and 22.5 months for PBCT and NPCT group,respectively[P=0.090,hazard ratios(HR)=0.703].BRCA status was assessed in 114 patients,14 of whom had deleterious germline BRCA1/2(g BRCA)mutations(seven in each group).In PBCT group,the CBR was 85.7%and 35.1%for patients with and without deleterious g BRCA mutations,respectively(P=0.039).The median PFS were 14.9 and 5.3 months and median OS were 26.5 and 15.5 months for patients with and without deleterious g BRCA mutations,respectively(P=0.001,P=0.161,respectively).Patients in PBCT group had significantly greater rates of grade 3-4 anemia(5.5%vs.0%)and thrombocytopenia(8.8%vs.0%),whereas palmar-plantar erythrodysesthesia(12.4%vs.0%)and peripheral neuropathy(8.6%vs.1.1%)occurred more frequently in NPCT group.Conclusions:Platinum-based regimens are more effective in patients with deleterious g BRCA mutations,but no difference in patients without BRCA gene mutations,so non-platinum is an option in patients without BRCA gene mutations considering the toxicity and side effect.And we recommend that patients with advanced TNBC should have BRCA gene test.
基金financially supported by the National Natural Science Foundation of China(Nos.51331005 and 51425402)
文摘To investigate the effect of solidification parameters on the solidification path and microstructure evolution of Ti-45Al-5Nb(at.%) alloy, Bridgman-type directional solidification and thermodynamics calculations were performed on the alloy. The microstructures, micro-segregation and solidification path were investigated.The results show that the β phase is the primary phase of the alloy at growth rates of 5-20 μm·s^(-1) under the temperature gradients of 15-20 K·mm^(-1), and the primary phase is transformed into an α phase at relatively higher growth rates(V >20 μm·s^(-1)). The mainly S-segregation and β-segregation can be observed in Ti-45Al-5Nb alloy at a growth rate of 10 μm·s^(-1) under a temperature gradient of 15 K·mm^(-1). The increase of temperature gradient to 20 K·mm^(-1) can eliminate β-segregation, but has no obvious effect on S-segregation. The results also show that 5 at.% Nb addition can expand the β phase region, increase the melting point of the alloy and induce the solidification path to become complicated. The equilibrium solidification path of Ti-45Al-5Nb alloy can be described as L L→β L+β L+β→αα+β_R β→ααα→γα+γα→α_2+γγ_R+(α_2+γ), in which β_R and γ_R mean the residual β and
基金Supported by Grants from the National Natural Science Foundation of China No.30872923the Peking University People’s Hospital Research and Development Fund No.RDB2007-47,No.RDK2008-01 and No.RDB2011-25
文摘AIM: To examine the correlation of phosphatidylinositol 3-kinase (PIK3) CB expression with preoperative radiotherapy response in patients with stage II/III rectal adenocarcinoma.
基金Supported by the National Natural Science Foundation of China,No.81400581(to Feng YJ) and No.81270477(to Li YY)
文摘AIM To investigate the anti-inflammatory effect and the possible mechanisms of an agonist of cannabinoid(CB) receptors, WIN55-212-2(WIN55), in mice with experimental colitis, so as to supply experimental evidence for its clinical use in future. METHODS We established the colitis model in C57BL/6 mice by replacing the animals' water supply with 4% dextran sulfate sodium(DSS) for 7 consecutive days. A colitis scoring system was used to evaluate the severity of colon local lesion. The plasma levels of proinflammatory cytokines, such as tumor necrosis factor-alpha(TNF-α) and interleukin-6(IL-6), and the myeloperoxidase(MPO) activity in colon tissue were measured. The expressions of cannabinoid receptors, claudin-1 protein, p38 mitogen-activated protein kinase(p38MAPK) and its phosphorylated form(p-p38) in colon tissue were determined by immunohistochemistry and Western blot. In addition, the effect of SB203580(SB), an inhibitor of p38, was investigated in parallel experiments, andthe data were compared with those from intervention groups of WIN55 and SB alone or used together. RESULTS The results demonstrated that WIN55 or SB treatment alone or together improved the pathological changes in mice with DSS colitis, decreased the plasma levels of TNF-α, and IL-6, and MPO activity in colon. The enhanced expression of claudin-1 and the inhibited expression of p-p38 in colon tissues were found in the WIN55-treated group. Besides, the expression of CB1 and CB2 receptors was enhanced in the colon after the induction of DSS colitis, but reduced when p38 MAPK was inhibited. CONCLUSION These results confirmed the anti-inflammatory effect and protective role of WIN55 on the mice with experimental colitis, and revealed that this agent exercises its action at least partially by inhibiting p38 MAPK. Furthermore, the results showed that SB203580, affected the expression of CB1 and CB2 receptors in the mouse colon, suggesting a close linkage and cross-talk between the p38 MAPK signaling pathway and the endogenous CB system.
文摘Objective: To evaluate the tolerance limit of rats tonormothermic hepatic inflow occlusion under portalblood bypass.Methods: A new rat model of normothermic hepaticinflow occlusion under portal blood bypass was estab-lished by clamping temporarily the pedicles of all liverlobes while the caudal lobe was kept as a passage ofthe portal blood flow. After hepatic blood flow re-stored, the caudal lobe was cut off. On the 7th postop-erative day, survival rate, hepatic morphological changes,and the severity and reversibility of the injured energymetabolism of the liver were investigated.Results: All rats that had been subjected to 30, 60 and90 minutes of hepatic inflow occlusion under portalblood bypass survived on the 7th postoperativeday. Ischemia-reperfusion injury of the liver was re-versible and compensatory in rats with hepatic inflowocclusion within 90minutes. However, the survivalrates of rats with 100, 110 and 120 minutes of hepaticinflow occlusion were 50%, 30% and 20% respective-ly. Liver injury of rats with 120 minutes of hepatic in-flow occlusion was severe and irreversible.Conclusions: The tolerance limit of rats to normother-mic hepatic inflow occlusion is enhanced significantlyunder portal blood bypass and the upper limit is 90minutes.
基金the National Nature Science Foundations of China(31030027,30400271),the National Natural Science Foundations of China for Young Scholars(31000081)
文摘Protamines are a group of highly basic proteins first discovered in spermatozoon that allow for denser packaging of DNA than histones and will result in down-regulation of gene transcription^l~. It is well recognized that the Autographa californica multicapsid nucleopolyhedrovirus （AcMNPV） encodes P6.9, a protamine-like protein that forms the viral subnucleosome through binding to the viral genome[29]. Previous research demonstrates that P6.9 is essential for viral nucleocapsid assembly, while it has no influence on viral genome replication1311. In the present study, the role of P6.9 in viral gene transcription regulation is characterized. In contrast to protamines or other protamine-like proteins that usually down-regulate gene transcription, P6.9 appears to up-regulate viral gene transcription at 12-24 hours post infection （hpi）, whereas it is non-essential for the basal level of viral gene transcription. Fluorescence microscopy reveals the P6.9＇s co-localization with DNA is temporally and spatially synchronized with P6.9＇s impact on viral gene transcription, indicating the P6.9-DNA association contributes to transcription regulation. Chromatin fractionation assay further reveals an unexpected co-existence of P6.9 and host RNA polymerase II in the same transcriptionally active chromatin fraction at 24 hpi, which may probably contribute to viral gene transcription up-regulation in the late infection phase.
基金the sponsorship of National Natural Science Foundation of China(41974119,U1762103)Science Foundation from Innovation and Technology Support Program for Young Scientists in Colleges of Shandong province and Ministry of Science and Technology of China(2020RA2C620131)。
文摘Frequency-dependent amplitude versus offset(FAVO)inversion is a popular method to estimate the frequency-dependent elastic parameters by using amplitude and frequency information of pre-stack seismic data to guide fluid identification.Current frequency-dependent AVO inversion methods are mainly based on elastic theory without the consideration of the viscoelasticity of oil/gas.A fluid discrimination approach is proposed in this study by incorporating the viscoelasticity and relevant FAVO inversion.Based on viscoelastic and rock physics theories,a frequency-dependent viscoelastic solid-liquid decoupling fluid factor is initially constructed,and its sensitivity in fluid discrimination is compared with other conventional fluid factors.Furthermore,a novel reflectivity equation is derived in terms of the viscoelastic solid-liquid decoupling fluid factor.Due to the introduction of viscoelastic theory,the proposed reflectivity is related to frequency,which is more widely applicable than the traditional elastic reflectivity equation directly derived from the elastic reflectivity equation on frequency.Finally,a pragmatic frequency-dependent inversion method is introduced to verify the feasibility of the equation for frequency-dependent viscoelastic solid-liquid decoupling fluid factor prediction.Synthetic and field data examples demonstrate the feasibility and stability of the proposed approach in fluid discrimination.
基金supported by The Fundamental Research Funds for the Central Universities(2572015EA01)the Innovation Project of State Key Laboratory of Tree Genetics and Breeding(Northeast Forestry University+1 种基金grant number 2013A04)Natural Science Fund of Heilongjiang Province(No.QC2015035)
文摘A reliable,efficient anther culture system,the dominant technique for generating haploid plants in breeding programs,that can be used for generating transgenic poplar plants has been needed.In the present study,therefore,an anther culture system was developed using isolated mid-and late-uninucleate anthers of poplar(Populus simonii x P.nigra).From a combination of SSR and ploidy analyses,six double haploid and two haploid lines were characterized from 86 plants grown from 16 regenerated anther cultured lines.After 48 months of development,two plant lines from the regenerated plants maintained their haploid level in vitro for over 2 years.A number of haploid plants from the different lines weretransferred to soil.The leaves of these transplants were then used as explants for transformation with the APETALA1(AP1) gene using Agrobacterium tumefaciens.Overexpression of AP1 in haploid poplar induced early flowering with obvious petals when ectopically expressed.To our knowledge,this is the first report on changes in flowering time in AP1-trangenic poplar,which is important for elucidating the regulatory mechanism of tree flower development.
