水分解是一种利用可再生能源驱动的绿色制氢方法,零碳排放特性使其成为解决氢能源生产的重要途径.在电化学水分解中,制备高活性和稳定性的催化剂至关重要.高熵合金(HEAs)由于独特的结构和性能使其成为理想的催化剂材料,其多元成分和可...水分解是一种利用可再生能源驱动的绿色制氢方法,零碳排放特性使其成为解决氢能源生产的重要途径.在电化学水分解中,制备高活性和稳定性的催化剂至关重要.高熵合金(HEAs)由于独特的结构和性能使其成为理想的催化剂材料,其多元成分和可调组成提供了丰富的表面活性位点和灵活的催化特性,有望提高水分解的效率并降低成本.然而,简易高效地制备HEAs仍面临挑战,且目前对HEA催化剂的结构-活性关系的了解存在不足.因此,探索一种简便有效的方法用以制备高性能HEAs催化剂,并深入理解其在水分解反应中的作用机制和结构演变,能够为未来绿色制氢技术的发展提供重要的科学基础和技术支持.本文采用了电化学测量、CuK-边和PtL3-边的原位同步辐射X射线吸收光谱(XAS)测试以及密度泛函理论(DFT)计算相结合的方法,系统地研究了高熵合金电催化剂PtPdRhRuCu/C的析氢反应(HER)活性、反应机制以及结构演变规律.PtPdRhRuCu HEAs纳米颗粒由简便的一步溶剂热法制备,直径约为6.7±0.6 nm,其合金结构和元素分布通过多种表征手段(扫描透射电子显微镜、X射线衍射和能量色散X射线光谱等)得到确认.XAS对Cu K-边和PtL3-边的分析结果显示,HEAs纳米颗粒表面的少量铜氧化物在HER过程中被还原至金属态.扩展X射线吸收精细结构的拟合结果表明,HEAs在工况HER中保持了金属态和无序的原子排列,没有新的分离相形成.电化学测试结果表明,得益于多金属活性位点,PtPdRhRuCu/C催化剂在酸性和碱性条件下均表现出较好的HER活性和耐久性.在10 m Acm^(-2)的电流密度下,该催化剂在1molL^(-1)KOH中具有23.3 m V的极低过电位,优于商业Pt/C催化剂(50.3 m V),其质量活性是Pt/C的7.9倍,达到3.0 Amg^(-1)Pt.PtPdRhRuCu的高熵效应显著提升了催化剂在HER中的长期稳定性,在稳定性测试中,PtPdRhRuCu/C催化剂在10000次循环伏安测试后�展开更多
Obesity is a major global health problem determined by heredity and environment,and its incidence is increasing yearly.In recent years,increasing evidence linking obesity to the gut microbiota has been reported.Gut mi...Obesity is a major global health problem determined by heredity and environment,and its incidence is increasing yearly.In recent years,increasing evidence linking obesity to the gut microbiota has been reported.Gut microbiota management has become a new method of obesity treatment.However,the complex interactions among genetics,environment,the gut microbiota,and obesity remain poorly understood.In this review,we summarize the characteristics of the gut microbiota in obesity,the mechanism of obesity induced by the gut microbiota,and the influence of genetic and environmental factors on the gut microbiota and obesity to provide support for understanding the complex relationship between obesity and microbiota.At the same time,the prospect of obesity research related to the gut microbiota is proposed.展开更多
Theoretical analysis and wind tunnel tests were carried out to study wind-induced intemal pressure response for the structure with single windward opening and background leakage. Its goveming differential equation was...Theoretical analysis and wind tunnel tests were carried out to study wind-induced intemal pressure response for the structure with single windward opening and background leakage. Its goveming differential equation was derived by the Bemoulli equation in an unsteady-isentropic form. Numerical examples were provided to study the additive damping caused by background leakage in laminar and turbulent flow, and the influence of background leakage on fluctuating internal pressure response was quantized. A series of models for low-rise building with various opening ratios and background leakage were designed and wind tunnel tests were conducted. It is shown that the fluctuating intemal pressure reduces when the background leakage are considered and that the effect of background leakage can be predicted accurately by the governing differential equation deduced in this paper.展开更多
Objective To investigate the effects of simple hypobaric hypoxia on parameters of hematology and blood rheology in order to establish a rat model of simulated high altitude polycythemia(HAPC) for the study of pathophy...Objective To investigate the effects of simple hypobaric hypoxia on parameters of hematology and blood rheology in order to establish a rat model of simulated high altitude polycythemia(HAPC) for the study of pathophysiologic mechanisms and medical prevention and treatment of HAPC.Methods Fortyeight male Wistar rats were randomly divided into three normal control groups and three hypoxia model groups.Normal control group rats were bred in normoxia conditions,and hypoxia group rats were subjected to hypoxic exposure for 8 hours per day at simulated 5 500 m high altitude in a hypobaric chamber.After hypoxic exposure for 2,4,12 weeks,one group of normal control and hypoxia model rats were killed and blood was collected,respectively.Then parameters of erythrocyte and blood rheology were examined.Results Mucous membrane of hypoxia model rats showed obviously cyanosis after 2 weeks hypoxic exposure.Hemoglobin concentration of hypoxia model rats were beyond 210 g/L after 2 weeks,4 weeks and 12 weeks hypoxia exposure and significantly increased than that of normal control rats respectively.Besides,RBC counts,hematocrit,whole blood viscosity,erythrocyte aggregation index of hypoxia model rats were all notably higher than those of normal control rats respectively.Conclusion A rat model of high altitude polycythemia can be rapidly established by hypobaric hypoxia exposure at simulated 5 500 m high altitude for 8 hours daily.展开更多
Resveratrol, as a natural polyphenolic compound, has a wide range of beneficial effects, which includes anti-tumor, cardiovascular protection, anti-oxidant and estrogen-like effects, and so on. Its various physiologic...Resveratrol, as a natural polyphenolic compound, has a wide range of beneficial effects, which includes anti-tumor, cardiovascular protection, anti-oxidant and estrogen-like effects, and so on. Its various physiological properties are closely related to the therapeutic principle for prevention and treatment of high altitude hypoxia injury. Resveratrol may play an important role in relieving or curing high altitude diseases, especially high altitude polycythemia(HAPC). However, the literature about study and application of resveratrol in plateau medicine field is rarely reported up to now. In this review, we summarized the physiological effects of resveratrol, discussed the possible main principle of resveratrol for HAPC therapy, and looked forward to resveratrol's perspective or potential application in high altitude medicine.展开更多
Lithium-sulfur batteries are a promising candidate for next-generation energy storage due to their high theoretical energy density.However,S insulation and the lithium polysulfide intermediate’s shuttle effect greatl...Lithium-sulfur batteries are a promising candidate for next-generation energy storage due to their high theoretical energy density.However,S insulation and the lithium polysulfide intermediate’s shuttle effect greatly hinder its practical application.In this paper,a three-dimensional porous graphene oxide(GO)/MXene(Ti_(3)C_(2)T_(x))(GM)aerogel is designed and applied to a lithium-sulfur battery to settle the problem mentioned.In this strategy,two-dimensional(2D)GO sheets and highly conductive MXene nanosheets are integrated to form a 3D porous aerogel structure,creating a 3D conductive network and large polar surfaces,which can simultaneously achieve fast Li-ion/electron transport,strong chemical anchoring sulfur,and promot redox reactions between poly sulfides.Therefore,the cathode shows excellent sulfur utilization and cycle stability.The prepared GM electrode battery has been tested for nearly nine months at 0.1C,providing the high initial capacity of 1255.62 mAh·g^(-1)and maintaining615.7 mAh·g^(-1)after 450 cycles.展开更多
Attentions have been increasingly paid to the influence of the corrosion on the ultimate strength of ship structures. In consideration of the random characteristics of the corrosion of ship structures, the method for ...Attentions have been increasingly paid to the influence of the corrosion on the ultimate strength of ship structures. In consideration of the random characteristics of the corrosion of ship structures, the method for the ultimate strength analysis of the ship stiffened panel structure subjected to random corrosion degradation is presented. According to the measured corrosion data of the bulk carriers, the distribution characteristics of the corrosion data for the stiffened panel on the midship deck are analyzed, and a random corrosion model is established. The ultimate strength of the corroded stiffened panel is calculated by lhe nonlinear finite element analysis. The statistical descriptions of the ultimate strength of the corroded stiffened panel are defined through the Monte Carlo simulations. A formula is proposed on the ultimate strength reduction of the stiffened panel as a function of the corrosion volume. The reliability analysis of the ultimate strength of the corroded deck stiffened panel is performed. It shows that both the corrosion data of the deck stiffened panel and the ultimate strength of the random corroded deck stiffened panel follow the log-normal distribution. The ultimate stress ratio of the stiffened panel is inversely proportional to the corrosion volume ratio.展开更多
Nuclear deformations are fundamentally important in nuclear physics.We recently developed a multidimensionally constrained relativistic Hartree-Bogoliubov(MDCRHB)model,in which all multipole deformations respecting th...Nuclear deformations are fundamentally important in nuclear physics.We recently developed a multidimensionally constrained relativistic Hartree-Bogoliubov(MDCRHB)model,in which all multipole deformations respecting the V_(4) symmetry can be considered self-consistently.In this work we extend this model by incorporating the angular momentum projection and parity projection to restore the rotational and parity symmetries broken in the mean-field level.This projected MDCRHB(p-MDCRHB)model enables us to connect certain nuclear spectra to exotic intrinsic shapes such as triangles or tetrahedrons.We present the details of the method and an exemplary calculation for ^(12)C.We develop a triangular moment constraint to generate the triangular configurations consisting of three α clusters arranged as an equilateral triangle.The resulting ^(12)C spectra are consistent with that from a triangular rigid rotor for large separations between the α clusters.We also calculate the B(E2)and B(E3)values for low-lying states and find good agreement with the experiments.展开更多
A faeilo monofluorination of α,ω-dihaloporfluoroalkanes was achieved by the reaction of them with antimony trifluoride and chlorine in anhydrous antimony pentachloride when mono- fluorinated products wero removed im...A faeilo monofluorination of α,ω-dihaloporfluoroalkanes was achieved by the reaction of them with antimony trifluoride and chlorine in anhydrous antimony pentachloride when mono- fluorinated products wero removed immediately after their formation from the reaction mixture by fractionation.The reaction conditions were also investigated.展开更多
To improve the efficacy of traditional chemotherapy and radiotherapy and reduce their serious side effects,further efforts need to be exerted to identify better cancer therapeutic options that are effective,affordable...To improve the efficacy of traditional chemotherapy and radiotherapy and reduce their serious side effects,further efforts need to be exerted to identify better cancer therapeutic options that are effective,affordable,and acceptable to patients.In this study,a novel theranostic agent was produced to perform synergetic cancer immunotherapy and phototherapy.The theranostic agent,named natural killer(NK)cells carrying indocyanine green loaded liposomes was synthesized NK cells with ICG nanoparticles to serve as the agent for a newly-established cancer treatment.It is expected that the developed synergistic therapy can pave a new avenue for improved efficacy of cancer theranostics.展开更多
Objective:To elucidate the mechanisms of 4 effective components from a Chinese medicine formula,namely Qingre Huoxue Jiedu Formula(QHJ heat-and toxin-clearing and blood-activating formula),in the treatment of nerve gr...Objective:To elucidate the mechanisms of 4 effective components from a Chinese medicine formula,namely Qingre Huoxue Jiedu Formula(QHJ heat-and toxin-clearing and blood-activating formula),in the treatment of nerve growth factor(NGF)-induced psoriasis.Methods:Keratinocyte proliferation and T cell proliferation models were developed using NGF.An NGF solution(NGF+DMEM,100 ng/mL)was added to all induced groups and treated groups and were cultured for 24 h,while a solution with NTRK1 antagonist(K252 a+DEME,300 nmol/L)was added and cultured for 1 h.The models were used to evaluate the effects of the treatment with each of the 4 components of QHJ,namely shikonin,paeonol,astilbin and ursolic acid.Cell apoptosis and proliferation were measured by flow cytometry analysis and CCK8 assay,respectively.The mRNA expression levels of Bax,Bcl-xl,and NGF receptor(NGFR)were assessed by quantitative real-time PCR(qRT-PCR)and Western blot analysis,respectively.Results:(1)All QHJ-treated groups showed significantly increased cell apoptosis and inhibition of cell proliferation compared with the NGF-induced groups(P<0.05).In addition,treatment with QHJ plus NTRK1 significantly enhanced cell apoptosis and inhibition of cell proliferation compared with cells treated with QHJ only(P<0.05),particularly in cells treated with ursolic acid.(2)QHJ-treated groups showed higher protein expression levels of Bax,Bcl-xl compared with other groups(P<0.05).Additionally,treatment with QHJ plus NTRK1 significantly increased the protein expression levels of Bax,Bcl-xl and NGFR compared with those treated with QHJ only(all P<0.05),especially in those treated with shikonin.Conclusion:The action mechanism of QHJ on psoriasis might be through enhancing cell apoptosis and inhibition of cell proliferation,and upregulating the expression level of Bax,Bcl-xl and NGFR.展开更多
The human body is one of the most sophisticated material systems.It is still a considerable challenge to biomimic the“life-design”process to construct a part of“life”in vivo.Herein,we mimicked the natural fibronec...The human body is one of the most sophisticated material systems.It is still a considerable challenge to biomimic the“life-design”process to construct a part of“life”in vivo.Herein,we mimicked the natural fibronectin(FN)fibrillogenesis system using ligand–receptor interaction-induced self-assembly to construct in situ artificial fibrous FN in vivo,based on exogenous FN mimic peptide(FNMP).We performed the in vivo study with a tumor-bearing mouse model,to which the particle formulated FNMP raw materials were delivered with high efficiency to the tumor site through intravenous(iv)administration.In the tumor,the presence of overexpressed integrin receptors on the cell surface induced the self-assembly of the FNMP into fibrous structures,thereby,creating an artificial fibrous FN.However,the FNMP-based artificial fibrous FN showed different biological functionality from the natural fibrous FN,inhibiting the growth and migration of cells,making our constructed FN able to inhibit tumor growth,invasion,and metastasis.Thus,this study opens an avenue for the precise construction of biomimetic materials for in vivo biomedical applications.展开更多
Objective:To develop a model to predict the risk of postpartum hemorrhage(PPH)following cesarean delivery in women with a scarred uterus.Methods:A total of 4,637 pregnant women with scarred uterus who underwent a cesa...Objective:To develop a model to predict the risk of postpartum hemorrhage(PPH)following cesarean delivery in women with a scarred uterus.Methods:A total of 4,637 pregnant women with scarred uterus who underwent a cesarean delivery at a large hospital between January 2014 and December 2017 were enrolled.The women were divided into PPH(n=287)and non-PPH(n=4,350)groups.A model to predict PPH(blood loss≥1,000 mL within 24 h following cesarean delivery)was developed using multivariate logistic regression analysis.Receiver operating characteristic curve was drawn,and the area under curve(AUC)was calculated.Results:The incidence of PPH was 6.19%(287 of 4,637 women).Seven independent risk factors were associated with PPH:maternal age(odds ratio[OR]=1.42,95%confidence interval[CI]:1.02-1.97),previous gravidity(OR=1.24,95%CI:1.01-1.50),placental location(posterior wall of uterus,OR=0.69,95%CI:0.47-1.02;other locations,OR=1.21,95%CI:0.81-1.80),placenta previa(incomplete placenta previa,OR=10.51,95%CI:5.99-18.42;complete placenta previa,OR=31.65,95%CI:21.07-47.54),placenta accreta(OR=6.39,95%CI:4.02-10.16),hypertensive disorders of pregnancy(OR=2.27,95%CI:1.40-3.68),and fetal position(breech position,OR=2.07,95%CI:1.19-3.60;transverse position,OR=1.07,95%CI:0.48-2.41).A predictive model with AUC of 0.89 was developed(95%CI:0.86-0.91,P<0.001).Conclusions:A model was developed to predict PPH following cesarean delivery in women with a scarred uterus.展开更多
A simulation of unsteady separating flow in an expanding flume is presented in this paper.The numerical modeling is based on a general horizontal 2-D mathematical model of unsteady flow.It is verified that the flow pa...A simulation of unsteady separating flow in an expanding flume is presented in this paper.The numerical modeling is based on a general horizontal 2-D mathematical model of unsteady flow.It is verified that the flow pattern,whirlpool length and maximum reversal velocity reasonably agree with the data from flume tests and this result could be an additional proof for the validity of the earlier developed mathematical model.展开更多
Radical addition of polyfluoroalkyl iodides to the C=C double bond of diethyl allylphos- phonate was carried out in CH_2Cl_2-H_2O two-phase medium in the presence of sodium dithionite to give dicthyl 3-polyfluoroalkyl...Radical addition of polyfluoroalkyl iodides to the C=C double bond of diethyl allylphos- phonate was carried out in CH_2Cl_2-H_2O two-phase medium in the presence of sodium dithionite to give dicthyl 3-polyfluoroalkyl-2-iodopropylphosphonates(3)in excellent yields.Compounds 3 were then converted to diethyl polyfluoroalkanephosphonates(4)by zinc-reduction,Thus a facile method for preparing polyfluoroalkanephosphonates is realized.展开更多
Polyfluoroalkyl iodides reacted with olefins in aqueous DMF solution of sodium disulfite under mild conditions to give the corresponding 1:1 adducts in good yields,providing a convenient polyfluoroalkylation method.Th...Polyfluoroalkyl iodides reacted with olefins in aqueous DMF solution of sodium disulfite under mild conditions to give the corresponding 1:1 adducts in good yields,providing a convenient polyfluoroalkylation method.This indicated that R_F radicals were formed in the reaction of polyfluoroalkyl iodides and sodium disulfite.A SET mechanism is proposed for the sulfinatodehalogenation reaction of sodium disulfite.展开更多
文摘水分解是一种利用可再生能源驱动的绿色制氢方法,零碳排放特性使其成为解决氢能源生产的重要途径.在电化学水分解中,制备高活性和稳定性的催化剂至关重要.高熵合金(HEAs)由于独特的结构和性能使其成为理想的催化剂材料,其多元成分和可调组成提供了丰富的表面活性位点和灵活的催化特性,有望提高水分解的效率并降低成本.然而,简易高效地制备HEAs仍面临挑战,且目前对HEA催化剂的结构-活性关系的了解存在不足.因此,探索一种简便有效的方法用以制备高性能HEAs催化剂,并深入理解其在水分解反应中的作用机制和结构演变,能够为未来绿色制氢技术的发展提供重要的科学基础和技术支持.本文采用了电化学测量、CuK-边和PtL3-边的原位同步辐射X射线吸收光谱(XAS)测试以及密度泛函理论(DFT)计算相结合的方法,系统地研究了高熵合金电催化剂PtPdRhRuCu/C的析氢反应(HER)活性、反应机制以及结构演变规律.PtPdRhRuCu HEAs纳米颗粒由简便的一步溶剂热法制备,直径约为6.7±0.6 nm,其合金结构和元素分布通过多种表征手段(扫描透射电子显微镜、X射线衍射和能量色散X射线光谱等)得到确认.XAS对Cu K-边和PtL3-边的分析结果显示,HEAs纳米颗粒表面的少量铜氧化物在HER过程中被还原至金属态.扩展X射线吸收精细结构的拟合结果表明,HEAs在工况HER中保持了金属态和无序的原子排列,没有新的分离相形成.电化学测试结果表明,得益于多金属活性位点,PtPdRhRuCu/C催化剂在酸性和碱性条件下均表现出较好的HER活性和耐久性.在10 m Acm^(-2)的电流密度下,该催化剂在1molL^(-1)KOH中具有23.3 m V的极低过电位,优于商业Pt/C催化剂(50.3 m V),其质量活性是Pt/C的7.9倍,达到3.0 Amg^(-1)Pt.PtPdRhRuCu的高熵效应显著提升了催化剂在HER中的长期稳定性,在稳定性测试中,PtPdRhRuCu/C催化剂在10000次循环伏安测试后�
基金Supported by The Dalian Science and Technology Bureau,No.2019RQ099and the Department of Education of Liaoning Province,No.J2020097.
文摘Obesity is a major global health problem determined by heredity and environment,and its incidence is increasing yearly.In recent years,increasing evidence linking obesity to the gut microbiota has been reported.Gut microbiota management has become a new method of obesity treatment.However,the complex interactions among genetics,environment,the gut microbiota,and obesity remain poorly understood.In this review,we summarize the characteristics of the gut microbiota in obesity,the mechanism of obesity induced by the gut microbiota,and the influence of genetic and environmental factors on the gut microbiota and obesity to provide support for understanding the complex relationship between obesity and microbiota.At the same time,the prospect of obesity research related to the gut microbiota is proposed.
基金Project (No. 50578144) supported by the National Natural ScienceFoundation of China
文摘Theoretical analysis and wind tunnel tests were carried out to study wind-induced intemal pressure response for the structure with single windward opening and background leakage. Its goveming differential equation was derived by the Bemoulli equation in an unsteady-isentropic form. Numerical examples were provided to study the additive damping caused by background leakage in laminar and turbulent flow, and the influence of background leakage on fluctuating internal pressure response was quantized. A series of models for low-rise building with various opening ratios and background leakage were designed and wind tunnel tests were conducted. It is shown that the fluctuating intemal pressure reduces when the background leakage are considered and that the effect of background leakage can be predicted accurately by the governing differential equation deduced in this paper.
基金supported by grants from National New Drug Research and Development of Key Project (2011ZXJ09105-05B)the National Natural Science Foundation(81171870,81471812)
文摘Objective To investigate the effects of simple hypobaric hypoxia on parameters of hematology and blood rheology in order to establish a rat model of simulated high altitude polycythemia(HAPC) for the study of pathophysiologic mechanisms and medical prevention and treatment of HAPC.Methods Fortyeight male Wistar rats were randomly divided into three normal control groups and three hypoxia model groups.Normal control group rats were bred in normoxia conditions,and hypoxia group rats were subjected to hypoxic exposure for 8 hours per day at simulated 5 500 m high altitude in a hypobaric chamber.After hypoxic exposure for 2,4,12 weeks,one group of normal control and hypoxia model rats were killed and blood was collected,respectively.Then parameters of erythrocyte and blood rheology were examined.Results Mucous membrane of hypoxia model rats showed obviously cyanosis after 2 weeks hypoxic exposure.Hemoglobin concentration of hypoxia model rats were beyond 210 g/L after 2 weeks,4 weeks and 12 weeks hypoxia exposure and significantly increased than that of normal control rats respectively.Besides,RBC counts,hematocrit,whole blood viscosity,erythrocyte aggregation index of hypoxia model rats were all notably higher than those of normal control rats respectively.Conclusion A rat model of high altitude polycythemia can be rapidly established by hypobaric hypoxia exposure at simulated 5 500 m high altitude for 8 hours daily.
基金supported by grants from the National Natural Science Foundation of China(81471812)National New Drug Research and Development of Key Project(2011ZXJ09202-0212011ZXJ09105-05B)
文摘Resveratrol, as a natural polyphenolic compound, has a wide range of beneficial effects, which includes anti-tumor, cardiovascular protection, anti-oxidant and estrogen-like effects, and so on. Its various physiological properties are closely related to the therapeutic principle for prevention and treatment of high altitude hypoxia injury. Resveratrol may play an important role in relieving or curing high altitude diseases, especially high altitude polycythemia(HAPC). However, the literature about study and application of resveratrol in plateau medicine field is rarely reported up to now. In this review, we summarized the physiological effects of resveratrol, discussed the possible main principle of resveratrol for HAPC therapy, and looked forward to resveratrol's perspective or potential application in high altitude medicine.
基金financially supported by the National Natural Science Foundation of Yunnan Province(Nos.202101AW070006 and 202001AU070079)。
文摘Lithium-sulfur batteries are a promising candidate for next-generation energy storage due to their high theoretical energy density.However,S insulation and the lithium polysulfide intermediate’s shuttle effect greatly hinder its practical application.In this paper,a three-dimensional porous graphene oxide(GO)/MXene(Ti_(3)C_(2)T_(x))(GM)aerogel is designed and applied to a lithium-sulfur battery to settle the problem mentioned.In this strategy,two-dimensional(2D)GO sheets and highly conductive MXene nanosheets are integrated to form a 3D porous aerogel structure,creating a 3D conductive network and large polar surfaces,which can simultaneously achieve fast Li-ion/electron transport,strong chemical anchoring sulfur,and promot redox reactions between poly sulfides.Therefore,the cathode shows excellent sulfur utilization and cycle stability.The prepared GM electrode battery has been tested for nearly nine months at 0.1C,providing the high initial capacity of 1255.62 mAh·g^(-1)and maintaining615.7 mAh·g^(-1)after 450 cycles.
基金partially supported by the National Natural Science Foundation of China(Grant No.51279034)
文摘Attentions have been increasingly paid to the influence of the corrosion on the ultimate strength of ship structures. In consideration of the random characteristics of the corrosion of ship structures, the method for the ultimate strength analysis of the ship stiffened panel structure subjected to random corrosion degradation is presented. According to the measured corrosion data of the bulk carriers, the distribution characteristics of the corrosion data for the stiffened panel on the midship deck are analyzed, and a random corrosion model is established. The ultimate strength of the corroded stiffened panel is calculated by lhe nonlinear finite element analysis. The statistical descriptions of the ultimate strength of the corroded stiffened panel are defined through the Monte Carlo simulations. A formula is proposed on the ultimate strength reduction of the stiffened panel as a function of the corrosion volume. The reliability analysis of the ultimate strength of the corroded deck stiffened panel is performed. It shows that both the corrosion data of the deck stiffened panel and the ultimate strength of the random corroded deck stiffened panel follow the log-normal distribution. The ultimate stress ratio of the stiffened panel is inversely proportional to the corrosion volume ratio.
基金This work has been supported by NSAF(Grant No.U1930403)the National Key R&D Program of China(Grant No.2018YFA0404402)+2 种基金the National Natural Science Foundation of China(Grant No.11525524,No.12070131001,No.12047503,and No.11961141004)the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(Grant No.QYZDB-SSWSYS013)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB34010000 and No.XDPB15).
文摘Nuclear deformations are fundamentally important in nuclear physics.We recently developed a multidimensionally constrained relativistic Hartree-Bogoliubov(MDCRHB)model,in which all multipole deformations respecting the V_(4) symmetry can be considered self-consistently.In this work we extend this model by incorporating the angular momentum projection and parity projection to restore the rotational and parity symmetries broken in the mean-field level.This projected MDCRHB(p-MDCRHB)model enables us to connect certain nuclear spectra to exotic intrinsic shapes such as triangles or tetrahedrons.We present the details of the method and an exemplary calculation for ^(12)C.We develop a triangular moment constraint to generate the triangular configurations consisting of three α clusters arranged as an equilateral triangle.The resulting ^(12)C spectra are consistent with that from a triangular rigid rotor for large separations between the α clusters.We also calculate the B(E2)and B(E3)values for low-lying states and find good agreement with the experiments.
文摘A faeilo monofluorination of α,ω-dihaloporfluoroalkanes was achieved by the reaction of them with antimony trifluoride and chlorine in anhydrous antimony pentachloride when mono- fluorinated products wero removed immediately after their formation from the reaction mixture by fractionation.The reaction conditions were also investigated.
基金This work was supported by the Science and Technology Development Fund of Macao(FDCT/131/2016/A3,FDCT/0015/2018/A1,FDCT/0011/2018/A1)the Guangzhou Science and Technology Program(No.201807010004)+1 种基金Start-up Research Grant(SRG2016-00082-FHS)the intramural research program of Faculty of Health Sciences,University of Macao,and National Natural Science Foundation of China(No.31440041).First,second,third,fifth and sixth authors contributed equally to this work.
文摘To improve the efficacy of traditional chemotherapy and radiotherapy and reduce their serious side effects,further efforts need to be exerted to identify better cancer therapeutic options that are effective,affordable,and acceptable to patients.In this study,a novel theranostic agent was produced to perform synergetic cancer immunotherapy and phototherapy.The theranostic agent,named natural killer(NK)cells carrying indocyanine green loaded liposomes was synthesized NK cells with ICG nanoparticles to serve as the agent for a newly-established cancer treatment.It is expected that the developed synergistic therapy can pave a new avenue for improved efficacy of cancer theranostics.
基金Supported by the National Natural Science Foundation of China(No.81403398)China Academy of Chinese Medical Sciences Innovation Fund(No.CI2021A02314)the Fundamental Research Funds for the Central Public Welfare Research Institutes(No.ZZ13-YQ-021)。
文摘Objective:To elucidate the mechanisms of 4 effective components from a Chinese medicine formula,namely Qingre Huoxue Jiedu Formula(QHJ heat-and toxin-clearing and blood-activating formula),in the treatment of nerve growth factor(NGF)-induced psoriasis.Methods:Keratinocyte proliferation and T cell proliferation models were developed using NGF.An NGF solution(NGF+DMEM,100 ng/mL)was added to all induced groups and treated groups and were cultured for 24 h,while a solution with NTRK1 antagonist(K252 a+DEME,300 nmol/L)was added and cultured for 1 h.The models were used to evaluate the effects of the treatment with each of the 4 components of QHJ,namely shikonin,paeonol,astilbin and ursolic acid.Cell apoptosis and proliferation were measured by flow cytometry analysis and CCK8 assay,respectively.The mRNA expression levels of Bax,Bcl-xl,and NGF receptor(NGFR)were assessed by quantitative real-time PCR(qRT-PCR)and Western blot analysis,respectively.Results:(1)All QHJ-treated groups showed significantly increased cell apoptosis and inhibition of cell proliferation compared with the NGF-induced groups(P<0.05).In addition,treatment with QHJ plus NTRK1 significantly enhanced cell apoptosis and inhibition of cell proliferation compared with cells treated with QHJ only(P<0.05),particularly in cells treated with ursolic acid.(2)QHJ-treated groups showed higher protein expression levels of Bax,Bcl-xl compared with other groups(P<0.05).Additionally,treatment with QHJ plus NTRK1 significantly increased the protein expression levels of Bax,Bcl-xl and NGFR compared with those treated with QHJ only(all P<0.05),especially in those treated with shikonin.Conclusion:The action mechanism of QHJ on psoriasis might be through enhancing cell apoptosis and inhibition of cell proliferation,and upregulating the expression level of Bax,Bcl-xl and NGFR.
基金supported by the National Natural Science Foundation of China(51890891,21807020,51573031,and 51573032)the National Science Fund for Distinguished Young Scholars(51725302)+2 种基金Science Fund for Creative Research Groups of the National Natural Science Foundation of China(11621505)CAS Interdisciplinary Innovation Team,and Jilin Province Key Laboratory of Organic Functional Molecular Design&Synthesis(130028911)Fundamental Research Funds for the Central Universities(CZD19014).
文摘The human body is one of the most sophisticated material systems.It is still a considerable challenge to biomimic the“life-design”process to construct a part of“life”in vivo.Herein,we mimicked the natural fibronectin(FN)fibrillogenesis system using ligand–receptor interaction-induced self-assembly to construct in situ artificial fibrous FN in vivo,based on exogenous FN mimic peptide(FNMP).We performed the in vivo study with a tumor-bearing mouse model,to which the particle formulated FNMP raw materials were delivered with high efficiency to the tumor site through intravenous(iv)administration.In the tumor,the presence of overexpressed integrin receptors on the cell surface induced the self-assembly of the FNMP into fibrous structures,thereby,creating an artificial fibrous FN.However,the FNMP-based artificial fibrous FN showed different biological functionality from the natural fibrous FN,inhibiting the growth and migration of cells,making our constructed FN able to inhibit tumor growth,invasion,and metastasis.Thus,this study opens an avenue for the precise construction of biomimetic materials for in vivo biomedical applications.
基金supported by the National Key R&D Program of China(2016YFC1000404)the National Natural Science Foundation of China(General Program+3 种基金81370735)the National Natural Science Foundation of China(General Program81771610)the Outstanding Scientific Fund of Shengjing Hospital(201706).
文摘Objective:To develop a model to predict the risk of postpartum hemorrhage(PPH)following cesarean delivery in women with a scarred uterus.Methods:A total of 4,637 pregnant women with scarred uterus who underwent a cesarean delivery at a large hospital between January 2014 and December 2017 were enrolled.The women were divided into PPH(n=287)and non-PPH(n=4,350)groups.A model to predict PPH(blood loss≥1,000 mL within 24 h following cesarean delivery)was developed using multivariate logistic regression analysis.Receiver operating characteristic curve was drawn,and the area under curve(AUC)was calculated.Results:The incidence of PPH was 6.19%(287 of 4,637 women).Seven independent risk factors were associated with PPH:maternal age(odds ratio[OR]=1.42,95%confidence interval[CI]:1.02-1.97),previous gravidity(OR=1.24,95%CI:1.01-1.50),placental location(posterior wall of uterus,OR=0.69,95%CI:0.47-1.02;other locations,OR=1.21,95%CI:0.81-1.80),placenta previa(incomplete placenta previa,OR=10.51,95%CI:5.99-18.42;complete placenta previa,OR=31.65,95%CI:21.07-47.54),placenta accreta(OR=6.39,95%CI:4.02-10.16),hypertensive disorders of pregnancy(OR=2.27,95%CI:1.40-3.68),and fetal position(breech position,OR=2.07,95%CI:1.19-3.60;transverse position,OR=1.07,95%CI:0.48-2.41).A predictive model with AUC of 0.89 was developed(95%CI:0.86-0.91,P<0.001).Conclusions:A model was developed to predict PPH following cesarean delivery in women with a scarred uterus.
文摘A simulation of unsteady separating flow in an expanding flume is presented in this paper.The numerical modeling is based on a general horizontal 2-D mathematical model of unsteady flow.It is verified that the flow pattern,whirlpool length and maximum reversal velocity reasonably agree with the data from flume tests and this result could be an additional proof for the validity of the earlier developed mathematical model.
文摘Radical addition of polyfluoroalkyl iodides to the C=C double bond of diethyl allylphos- phonate was carried out in CH_2Cl_2-H_2O two-phase medium in the presence of sodium dithionite to give dicthyl 3-polyfluoroalkyl-2-iodopropylphosphonates(3)in excellent yields.Compounds 3 were then converted to diethyl polyfluoroalkanephosphonates(4)by zinc-reduction,Thus a facile method for preparing polyfluoroalkanephosphonates is realized.
文摘Polyfluoroalkyl iodides reacted with olefins in aqueous DMF solution of sodium disulfite under mild conditions to give the corresponding 1:1 adducts in good yields,providing a convenient polyfluoroalkylation method.This indicated that R_F radicals were formed in the reaction of polyfluoroalkyl iodides and sodium disulfite.A SET mechanism is proposed for the sulfinatodehalogenation reaction of sodium disulfite.
