This study aimed to investigate the interaction between maltodextrin/starch of different molecular weight distributions and soy protein isolate (SPI)–wheat gluten (WG) matrix during high-moisture extrusion.Two maltod...This study aimed to investigate the interaction between maltodextrin/starch of different molecular weight distributions and soy protein isolate (SPI)–wheat gluten (WG) matrix during high-moisture extrusion.Two maltodextrins (dextrose equivalent (DE):10 and 20) and wheat starch were extruded with SPI–WG blend in a system of 65,70,and 75%moisture to investigate their effects on texture and thermal stability.Incorporating 5%maltodextrin (DE10) in the SPI–WG matrix improved the fiber structure and thermal stability.When wheat starch was thoroughly gelatinized during subsequent sterilization,the fiber structure and thermal stability were also improved.It was found that the plasticization caused by small-molecular weight saccharides and enhanced phase separation caused by large-molecular weight saccharides changed the melting temperature of blends and significantly improved the texture and thermal stability of extrudates.展开更多
A rapid and continuous method for production of LiFePO4/C nanoparticles in super heated water is described, wherein soluble starch was used as carbon precursor. The effects of pH, flow rate, temperature, and pressure ...A rapid and continuous method for production of LiFePO4/C nanoparticles in super heated water is described, wherein soluble starch was used as carbon precursor. The effects of pH, flow rate, temperature, and pressure on the formation of LiFePO4/C particles were investigated. Results showed that the pH value was the key factot on the formation of phase pure LiFePO4, which only formed at pH = 7; the LiFePO4/C-occurred as particles with about 70-200 nm size and LiFePO4 was covered by a thin carbon layer; higher flow rate, higher pressure, and lower temperature led to smaller particles of LiFePO4/C.展开更多
Reported in this paper are the Nd isotopic compositions of the pre-Sinian and Sinian-Cambrian sedimentary rocks in the Xiushui area,Jiangxi Province.Significant differences are noticed between them in their Nd isotopi...Reported in this paper are the Nd isotopic compositions of the pre-Sinian and Sinian-Cambrian sedimentary rocks in the Xiushui area,Jiangxi Province.Significant differences are noticed between them in their Nd isotopic dompositions.As for the pre-Sinian lightly metmorphozed sedimentary rocks,^143Nd/^144Nd=0.512000-0.512214,CNd(T)=-8.04-9.99,and TDM=18332426Ma are suggested for the Sinian-Cambrian sedimentary rocks .These differences would reflect the diversity of material source for the sedimentary rocks deposited before and after the Sinian period.Mantle material ap-pears to have been involved in the formation of the pre-Sinian sedimentary rocks while the post-Sinian sedimentary rocks are composed mainly of recycled detritus from the continental crust.展开更多
Na-ion batteries(NIBs)have attracted considerable attention in recent years owing to the high abundance and low cost of Na.It is well known that S doping can improve the electrochemical performance of carbon materials...Na-ion batteries(NIBs)have attracted considerable attention in recent years owing to the high abundance and low cost of Na.It is well known that S doping can improve the electrochemical performance of carbon materials for NIBs.However,the current methods for S doping in carbons normally involve toxic precursors or rigorous conditions.In this work,we report a creative and facile strategy for preparing S-doped porous carbons(SCs)via the pyrolysis of conjugated microporous polymers(CMPs).Briefly,thiophene-based CMPs served as the precursors and doping sources simultaneously.Simple direct carbonization of CMPs produced S-doped carbon materials with highly porous structures.When used as an anode for NIBs,the SCs exhibited a high reversible capacity of 440 mAh g?1 at 50 mA g?1 after 100 cycles,superior rate capability,and excellent cycling stability(297 mAh g?1 after 1000 cycles at 500 mA g?1),outperforming most S-doped carbon materials reported thus far.The excellent performance of the SCs is attributed to the expanded lattice distance after S doping.Furthermore,we employed ex situ X-ray photoelectron spectroscopy to investigate the electrochemical reaction mechanism of the SCs during sodiation-desodiation,which can highlight the role of doped S for Na-ion storage.展开更多
Three-dimensional quantitative structure activity relationship (3D-QSAR) and docking studies of a series of arylthioindole derivatives as tubulin inhibitors against human breast cancer cell line MCF-7 have been carr...Three-dimensional quantitative structure activity relationship (3D-QSAR) and docking studies of a series of arylthioindole derivatives as tubulin inhibitors against human breast cancer cell line MCF-7 have been carried out. An optimal 3D-QSAR model from the comparative molecular field analysis (CoMFA) for training set with significant statistical quality (R2=0.898) and predictive ability (q2=0.654) was established. The same model was further applied to predict pIC50 values of the compounds in test set, and the resulting predictive correlation coefficient R2(pred) reaches 0.816, further showing that this CoMFA model has high predictive ability. Moreover, the appropriate binding orientations and conformations of these compounds interacting with tubulin are located by docking study, and it is very interesting to find the consistency between the CoMFA field distribution and the 3D topology structure of active site of tubulin. Based on CoMFA along with docking results, some important factors improving the activities of these compounds were discussed in detail and were summarized as follows: the substituents R3-R5 (on the phenyl ring) with higher electronegativity, the substituent R6 with higher eleetropositivity and bigger bulk, the substituent R7 with smaller bulk, and so on. In addition, five new compounds with higher activities have been designed. Such results can offer useful theoretical references for experimental works.展开更多
The dry powder inhalation of antibiotics for the treatment of lung infections has attracted drastically increasing attention as it offers rapid local therapy at lower doses and minimal side effects.In this study,aztre...The dry powder inhalation of antibiotics for the treatment of lung infections has attracted drastically increasing attention as it offers rapid local therapy at lower doses and minimal side effects.In this study,aztreonam(AZT)was used as the model antibiotic and spraydried to prepare powders for inhalation.Amino acids of glycine(GLY),histidine(HIS)and leucine(LEU)were used as excipients to modify the spray-dried particles.It was demonstrated that the GLY-AZT spray-dried powders formed huge agglomerates with the size of 144.51μm,which made it very difficult to be delivered to the lungs(FPF:0.29%w/w only).In comparison with the AZT spray-dried powders,HIS-modified spray-dried powders showed increased compressibility,indicating larger distance and less cohesion between particles;while the LEU-modified spray-dried particles showed a hollow structure with significantly decreased densities.The fine particle fraction for HIS-and LEU-modified powders was 51.4%w/w and 61.7%w/w,respectively,and both were significantly increased(one-way ANOVA,Duncan’s test,P<0.05)compared to that of AZT spray-dried powders(45.4%w/w),showing a great potential to be applied in clinic.展开更多
In response to new European Union regulations,studies are underway to mitigate accumulation of toxic cadmium(Cd)in cacao(Theobroma cacao,Tc).This study advances such research with Cd isotope analyses of 19 genetically...In response to new European Union regulations,studies are underway to mitigate accumulation of toxic cadmium(Cd)in cacao(Theobroma cacao,Tc).This study advances such research with Cd isotope analyses of 19 genetically diverse cacao clones and yeast transformed to express cacao natural resistance-associated macrophage protein(NRAMP5)and heavy metal ATPases(HMAs).The plants were enriched in light Cd isotopes relative to the hydroponic solution withΔ^(114/110)Cd_(tot-sol)=−0.22±0.08‰.Leaves show a systematic enrichment of isotopically heavy Cd relative to total plants,in accord with closed-system isotope fractionation ofΔ^(114/110)C_(dseq-mob)=−0.13‰,by sequestering isotopically light Cd in roots/stems and mobilisation of remaining Cd to leaves.The findings demonstrate that(i)transfer of Cd between roots and leaves is primarily unidirectional;(ii)different clones utilise similar pathways for Cd sequestration,which differ from those of other studied plants;(iii)clones differ in their efficiency of Cd sequestration.Transgenic yeast that expresses TcNRAMP5(T.cacao natural resistance-associated macrophage gene)had isotopically lighter Cd than did cacao.This suggests that NRAMP5 transporters constitute an important pathway for uptake of Cd by cacao.Cd isotope signatures of transgenic yeast expressing HMA-family proteins suggest that they may contribute to Cd sequestration.The data are the first to record isotope fractionation induced by transporter proteins in vivo.展开更多
Objective:To study the relationship between plasma treatment time acrylic resin denture material in the size of 2 mm × 10 mm × 10 mm. and efficacy. Methods:Test specimens were prepared from an Plasma treat...Objective:To study the relationship between plasma treatment time acrylic resin denture material in the size of 2 mm × 10 mm × 10 mm. and efficacy. Methods:Test specimens were prepared from an Plasma treatment was carried out on the surface of Polymethyl methacrylate(PMMA) at different time. XPS studies, IR spectra studies and measurement of wetting angle were performed. Results: XPS showed the peak corresponding to C-O getting higher as the treatment proceeded, however at 120 seconds, the peak did not increase any longer and partly crossed with the peak at the duration of 60 seconds. IR spectra showed the wave corresponding to C-H was reduced as O2-plasma treatment proceeded, and then changed little, Wetting angle initially decreased dramatically, however, as the reaction proceeded, wetting angle increased slightly. Conclusion:Equilibrium was reached for introducing oxygen-containing groups and changing of C-H. As the treatment proceeded, wetting angle increased slightly.展开更多
Crystal defects,disorder,phase by high resolution such as grain boundary.dislocation,stacking boundary and surface of granule were examined electron microscope(HREM)in superconducting Tl_(2)Ba_(2)Ca_(2)Cu_(3)O_(x).Som...Crystal defects,disorder,phase by high resolution such as grain boundary.dislocation,stacking boundary and surface of granule were examined electron microscope(HREM)in superconducting Tl_(2)Ba_(2)Ca_(2)Cu_(3)O_(x).Some possible effects of the defects on the sample's properties viz.,Jc and Tc are discussed.展开更多
Two linked models have been developed to explore the relationship between the amount of porosity arising in service from both radiolytic oxidation and fast neutron damage that influences both the strength and the forc...Two linked models have been developed to explore the relationship between the amount of porosity arising in service from both radiolytic oxidation and fast neutron damage that influences both the strength and the force-displacement(load-displacement)behaviour and crack propagation in pile grade A graphite used as a nuclear reactor moderator material.Firstly models of the microstructure of the porous graphite for both unirradiated and irradiated graphite are created.These form the input for the second stage,simulating fracture in lattice-type finite element models,which predicts force(load)-displacement and crack propagation paths.Microstructures comprising aligned filler particles,typical of needle coke,in a porous matrix have been explored.The purpose was to isolate the contributions of filler particles and porosity to fracture strength and crack paths and consider their implications for the overall failure of reactor core graphite.展开更多
Being a patient in a strange and unknown environment is sometimes very stressful. Research has shown that a healthpromoting environment can reduce anxiety and enhance wellbeing and views of nature can support this. Th...Being a patient in a strange and unknown environment is sometimes very stressful. Research has shown that a healthpromoting environment can reduce anxiety and enhance wellbeing and views of nature can support this. This low-cost intervention wasperformed at a heart surgery intensive care unit.The aim was to use a simple method to improve the health care environment and tomonitor the experiences of patients and staf~ Two patients share the same room at the 1CU. The beds can be separated by roller shadesthat are plain grey and neutral. These were changed to new ones with nature motives. Questionnaires with fixed and open questionswere used for evaluation among patients and staff. Patients treated in an ICU seem to be aware of the surrounding environment even ifthey are severely ill. Both patients and staff stated that the roller shades with motive affected wellbeing in a positive way. An estheticalpleasing environment can contribute to wellbeing even if the effort is small and insignificant. Roller shades with nature motive might bean easy way to improve and strengthen a health promoting environment.展开更多
Objective: Cerebral venous sinus thrombosis (CVST) is a life-threatening cerebrovascular disease which has high prevalence and mortality rate in Iran. Thrombophilia caused by gene mutation is a common cause of CVST. T...Objective: Cerebral venous sinus thrombosis (CVST) is a life-threatening cerebrovascular disease which has high prevalence and mortality rate in Iran. Thrombophilia caused by gene mutation is a common cause of CVST. The present study aimed at assessing the prevalence of thrombophilic gene mutations in Iranian CVST patients and then comparing it with normal population. Materials and methods: In a case-control study, polymerase chain reaction-restriction fragment length polymorphism (PCR_RFLP) and amplification-refractory mutation system (ARMS-PCR) were carried out to detect common thrombophilic mutations in 70 CVST patients. Next, it was compared with 82 sex- and age-matched healthy controls. Results: Factor-V-Leiden, Factor-V-Leiden HR2, Factor prothrombin II, MTHFR (667C/T) and MTHFR (1298A/C) prevalence were significantly high in cases of CVST as compared to the controls (P values: 0.012, 0.019, 0.007 and 0.036, respectively). However, there was no significant difference between the two groups in plasminogen activator inhibitor (PAI), angiotensin-converting enzyme (ACE), beta-fibrinogen (FGB), Factor VIII, Factor XIII, and tissue plasminogen activator (tPA) mutations. Conclusion: The findings of the present study suggest that Factor V-Leiden, Factor-V-Leiden HR2, prothrombin II (G20210A), and MTHFR (667C/T & 1298A/C) mutations are more frequent in CVST. Detection of these mutations may help clinicians to decide on the duration of treatment and referral to genetic counseling for valuable prevention.展开更多
Lithium-sulfur battery is one of the most promising battery systems for industrialization due to its high theoretical specific capacity and high energy density.Nonetheless,the"shuttle effect"has restrained t...Lithium-sulfur battery is one of the most promising battery systems for industrialization due to its high theoretical specific capacity and high energy density.Nonetheless,the"shuttle effect"has restrained the advancement of lithium-sulfur batteries.In this work,a gradient-structured nanofiber membrane with pure gelatin on one side and Super P-MoO_(2)/MoS_(2)-gelatin on the other side was created using a multi-step electrostatic spinning technique,which was applied for multi-functional separator for lithium-sulfur batteries.The pure gelatin layer facing the anode side primarily homogenizes the lithium flux,whereas the Super P-MoO_(2)/MoS_(2)-gelatin layer facing the cathode side primarily adsorbs polysulfides by physical and chemical adsorption and enhancing polysulfide conversion efficiency.The findings demonstrate that even after 150 cycles at 0.2C,the lithium-sulfur battery can still sustain a discharge-specific capacity of 572.3 mAh·g^(-1).When used with Li||Li symmetric batteries,it has a cycle life of more than 1200 h.The commercialization of lithium-sulfur batteries is given a fresh idea by this straightforward preparation technique.展开更多
To explore the influence of the meso-mechanical behaviors of the wet coal dust layers on the contact stiffness of mechanical bonding surfaces,a three-body contact model incorporating an interface with wet coal dust wa...To explore the influence of the meso-mechanical behaviors of the wet coal dust layers on the contact stiffness of mechanical bonding surfaces,a three-body contact model incorporating an interface with wet coal dust was constructed based on breakage theory.The model considered the mechanical surface morphology and contact characteristics of the wet coal dust.The force chain evolution laws of the wet coal dust layer were elucidated under the effects of gap filling and the cover layer,and the bearing characteristics of the three-body contact bonding surfaces were revealed by quantitative analyses of the number,length,collimation coefficient,and coordination number of the force chains within the wet coal dust layer.Finally,the three-body normal contact stiffness under various preload forces was computed and experimentally validated.The results demonstrate that the external load transfer path of the three-body contact bonding surfaces was from mechanical surface(macroscopic stress)to wet coal dust layer(mesoscopic force chains)and then to mechanical surface(peaks and valleys).The interactions among these three elements contributed to transforming the distributions of the macroscopic stresses and mesoscopic force chains to the locations at the peaks and valleys of the mechanical surface.Among them,the proportion of short force chains in the wet coal dust layer increased from approximately 0.8%–91%,while the proportion of long force chains exhibited an opposite changing trend.The force chain collimation coefficient initially increased and subsequently stabilized,reaching a maximum value of 0.93.A large number of broken,small particles in the wet coal dust layer mainly served to fill the gaps among large particles.The maximum relative error between the experimental and simulated values on the three-body contact stiffness is 7.26%,indicating that the simulation results can be an approximate substitute for the experimental results with a certain degree of accuracy and practicality.The research results are of great significance for understanding the contact characteristics of mechanical surfaces containing particulate media.展开更多
The disability,mortality and costs due to ionizing radiation(IR)-induced osteoporotic bone fractures are sub-stantial and no effective therapy exists.Ionizing radiation increases cellular oxidative damage,causing an i...The disability,mortality and costs due to ionizing radiation(IR)-induced osteoporotic bone fractures are sub-stantial and no effective therapy exists.Ionizing radiation increases cellular oxidative damage,causing an imbalance in bone turnover that is primarily driven via heightened activity of the bone-resorbing osteoclast.We demonstrate that rats exposed to sublethal levels of IR develop fragile,osteoporotic bone.At reactive surface sites,cerium ions have the ability to easily undergo redox cycling:drastically adjusting their electronic con-figurations and versatile catalytic activities.These properties make cerium oxide nanomaterials fascinating.We show that an engineered artificial nanozyme composed of cerium oxide,and designed to possess a higher fraction of trivalent(Ce^(3+))surface sites,mitigates the IR-induced loss in bone area,bone architecture,and strength.These investigations also demonstrate that our nanozyme furnishes several mechanistic avenues of protection and selectively targets highly damaging reactive oxygen species,protecting the rats against IR-induced DNA damage,cellular senescence,and elevated osteoclastic activity in vitro and in vivo.Further,we reveal that our nanozyme is a previously unreported key regulator of osteoclast formation derived from macrophages while also directly targeting bone progenitor cells,favoring new bone formation despite its exposure to harmful levels of IR in vitro.These findings open a new approach for the specific prevention of IR-induced bone loss using synthesis-mediated designer multifunctional nanomaterials.展开更多
Magnetic Fe_3O_4@PANI@Au nanocomposites are fabricated through electrostatic self-assembly and seed growth methods.The rate constant K_(app) is calculated to be 8.63×10^(-3) s^(-1) at room temperature for the red...Magnetic Fe_3O_4@PANI@Au nanocomposites are fabricated through electrostatic self-assembly and seed growth methods.The rate constant K_(app) is calculated to be 8.63×10^(-3) s^(-1) at room temperature for the reduction of 4-nitrophenol to 4-aminophenol with an excessive amount of NaBH_4 as a model system showing outstanding catalytic efficiency and stability.For recyclable performance,the catalyst exhibits slight loss in catalytic performance on the conversion of 4-nitrophenol after running for more than 10 cycles.Besides,the smaller and simpler the structure,the easier the molecular structure can be degraded,and the faster the cationic dyes can be degraded than the anionic dyes,which can reveal the selectivity.For practical application,Congo red as a pollutant of the lake water is degraded rapidly after Fe_3O_4@PANI@Au is added to the solution in a few minutes.It has been demonstrated that magnetic Fe_3O_4@PANI@Au nanoparticle composite is a promising catalyst for environment sewage.展开更多
A simple and efficient microwave-assisted procedure for synthesis of L-cysteine-capped nickel nanoparticles(cyst-Ni NPs) in ethylene glycol solvent was demonstrated. The as-synthesised NPs were characterised by ultrav...A simple and efficient microwave-assisted procedure for synthesis of L-cysteine-capped nickel nanoparticles(cyst-Ni NPs) in ethylene glycol solvent was demonstrated. The as-synthesised NPs were characterised by ultraviolet–visible(UV–Vis) spectrophotometer, Fourier transform infrared(FTIR) spectroscopy, transmission electron microscopy(TEM) and X-ray diffractometry(XRD). The cyst-Ni NPs are proved to be excellent heterogeneous catalysts for the 100% reduction of 4-nitrophenol(4-NPh) in the presence of reductant(Na BH4)within reaction time of 40 s. In contrast, Raney nickel in similar sample environments shows only 25.5% reduction.The kinetic and energetic behaviours of cyst-Ni NPs were also studied, and the reduction reaction is determined to follow pseudo-first-order kinetics with a rate constant value of 0.115 s-1 and activation energy of 36.1 kJ·mol-1. In addition to its high catalytic competence, cyst-Ni NPs catalyst exhibits excellent recyclability with negligible catalytic poisoning.展开更多
基金financially supported by the National Natural Science Foundation of China (32202081)the National Key Research and Development Plan of China (2021YFC2101402)。
文摘This study aimed to investigate the interaction between maltodextrin/starch of different molecular weight distributions and soy protein isolate (SPI)–wheat gluten (WG) matrix during high-moisture extrusion.Two maltodextrins (dextrose equivalent (DE):10 and 20) and wheat starch were extruded with SPI–WG blend in a system of 65,70,and 75%moisture to investigate their effects on texture and thermal stability.Incorporating 5%maltodextrin (DE10) in the SPI–WG matrix improved the fiber structure and thermal stability.When wheat starch was thoroughly gelatinized during subsequent sterilization,the fiber structure and thermal stability were also improved.It was found that the plasticization caused by small-molecular weight saccharides and enhanced phase separation caused by large-molecular weight saccharides changed the melting temperature of blends and significantly improved the texture and thermal stability of extrudates.
基金Supported by Shanghai Special Foundation on Nanomaterials (0243nm305)
文摘A rapid and continuous method for production of LiFePO4/C nanoparticles in super heated water is described, wherein soluble starch was used as carbon precursor. The effects of pH, flow rate, temperature, and pressure on the formation of LiFePO4/C particles were investigated. Results showed that the pH value was the key factot on the formation of phase pure LiFePO4, which only formed at pH = 7; the LiFePO4/C-occurred as particles with about 70-200 nm size and LiFePO4 was covered by a thin carbon layer; higher flow rate, higher pressure, and lower temperature led to smaller particles of LiFePO4/C.
基金This project was financially supported by the National Natural Science Foundation of China.
文摘Reported in this paper are the Nd isotopic compositions of the pre-Sinian and Sinian-Cambrian sedimentary rocks in the Xiushui area,Jiangxi Province.Significant differences are noticed between them in their Nd isotopic dompositions.As for the pre-Sinian lightly metmorphozed sedimentary rocks,^143Nd/^144Nd=0.512000-0.512214,CNd(T)=-8.04-9.99,and TDM=18332426Ma are suggested for the Sinian-Cambrian sedimentary rocks .These differences would reflect the diversity of material source for the sedimentary rocks deposited before and after the Sinian period.Mantle material ap-pears to have been involved in the formation of the pre-Sinian sedimentary rocks while the post-Sinian sedimentary rocks are composed mainly of recycled detritus from the continental crust.
基金Financial support from National Natural Science Foundation of China(Nos.51702056 and 51772135)the Ministry of Education of China(6141A02022516)China Postdoctoral Science Foundation(2017M622902 and 2019T120790).
文摘Na-ion batteries(NIBs)have attracted considerable attention in recent years owing to the high abundance and low cost of Na.It is well known that S doping can improve the electrochemical performance of carbon materials for NIBs.However,the current methods for S doping in carbons normally involve toxic precursors or rigorous conditions.In this work,we report a creative and facile strategy for preparing S-doped porous carbons(SCs)via the pyrolysis of conjugated microporous polymers(CMPs).Briefly,thiophene-based CMPs served as the precursors and doping sources simultaneously.Simple direct carbonization of CMPs produced S-doped carbon materials with highly porous structures.When used as an anode for NIBs,the SCs exhibited a high reversible capacity of 440 mAh g?1 at 50 mA g?1 after 100 cycles,superior rate capability,and excellent cycling stability(297 mAh g?1 after 1000 cycles at 500 mA g?1),outperforming most S-doped carbon materials reported thus far.The excellent performance of the SCs is attributed to the expanded lattice distance after S doping.Furthermore,we employed ex situ X-ray photoelectron spectroscopy to investigate the electrochemical reaction mechanism of the SCs during sodiation-desodiation,which can highlight the role of doped S for Na-ion storage.
基金This work was supported by the National Natural Science Foundation of China (No.20673148). We heartily thank the Molecular Discovery Ltd. for giving us the Dock 6.0 program as a freeware and the College of Life Sciences, Sun Yat-Sen University for the SYBYL 6.9 computation environment support.
文摘Three-dimensional quantitative structure activity relationship (3D-QSAR) and docking studies of a series of arylthioindole derivatives as tubulin inhibitors against human breast cancer cell line MCF-7 have been carried out. An optimal 3D-QSAR model from the comparative molecular field analysis (CoMFA) for training set with significant statistical quality (R2=0.898) and predictive ability (q2=0.654) was established. The same model was further applied to predict pIC50 values of the compounds in test set, and the resulting predictive correlation coefficient R2(pred) reaches 0.816, further showing that this CoMFA model has high predictive ability. Moreover, the appropriate binding orientations and conformations of these compounds interacting with tubulin are located by docking study, and it is very interesting to find the consistency between the CoMFA field distribution and the 3D topology structure of active site of tubulin. Based on CoMFA along with docking results, some important factors improving the activities of these compounds were discussed in detail and were summarized as follows: the substituents R3-R5 (on the phenyl ring) with higher electronegativity, the substituent R6 with higher eleetropositivity and bigger bulk, the substituent R7 with smaller bulk, and so on. In addition, five new compounds with higher activities have been designed. Such results can offer useful theoretical references for experimental works.
基金support from Natural Science Foundation of Jiangsu Province(BK2011295)Youth Fund of Soochow University(SDY2011A21)。
文摘The dry powder inhalation of antibiotics for the treatment of lung infections has attracted drastically increasing attention as it offers rapid local therapy at lower doses and minimal side effects.In this study,aztreonam(AZT)was used as the model antibiotic and spraydried to prepare powders for inhalation.Amino acids of glycine(GLY),histidine(HIS)and leucine(LEU)were used as excipients to modify the spray-dried particles.It was demonstrated that the GLY-AZT spray-dried powders formed huge agglomerates with the size of 144.51μm,which made it very difficult to be delivered to the lungs(FPF:0.29%w/w only).In comparison with the AZT spray-dried powders,HIS-modified spray-dried powders showed increased compressibility,indicating larger distance and less cohesion between particles;while the LEU-modified spray-dried particles showed a hollow structure with significantly decreased densities.The fine particle fraction for HIS-and LEU-modified powders was 51.4%w/w and 61.7%w/w,respectively,and both were significantly increased(one-way ANOVA,Duncan’s test,P<0.05)compared to that of AZT spray-dried powders(45.4%w/w),showing a great potential to be applied in clinic.
基金supported by grants from the GCRF programmes of STFC(grants ST/P003257/1,4070200262)and UKRI(grant EP/S515875/1)to M.R.as well as funding from Mars Wrigley Confectionery to J.M.D.and M.R.and Cocoa Research UK to J.M.D.V.H.d.O.was supported by CAPES(Coordination for the Improvement of Higher Education Personnel—Brazil)[project:13462-13-0].
文摘In response to new European Union regulations,studies are underway to mitigate accumulation of toxic cadmium(Cd)in cacao(Theobroma cacao,Tc).This study advances such research with Cd isotope analyses of 19 genetically diverse cacao clones and yeast transformed to express cacao natural resistance-associated macrophage protein(NRAMP5)and heavy metal ATPases(HMAs).The plants were enriched in light Cd isotopes relative to the hydroponic solution withΔ^(114/110)Cd_(tot-sol)=−0.22±0.08‰.Leaves show a systematic enrichment of isotopically heavy Cd relative to total plants,in accord with closed-system isotope fractionation ofΔ^(114/110)C_(dseq-mob)=−0.13‰,by sequestering isotopically light Cd in roots/stems and mobilisation of remaining Cd to leaves.The findings demonstrate that(i)transfer of Cd between roots and leaves is primarily unidirectional;(ii)different clones utilise similar pathways for Cd sequestration,which differ from those of other studied plants;(iii)clones differ in their efficiency of Cd sequestration.Transgenic yeast that expresses TcNRAMP5(T.cacao natural resistance-associated macrophage gene)had isotopically lighter Cd than did cacao.This suggests that NRAMP5 transporters constitute an important pathway for uptake of Cd by cacao.Cd isotope signatures of transgenic yeast expressing HMA-family proteins suggest that they may contribute to Cd sequestration.The data are the first to record isotope fractionation induced by transporter proteins in vivo.
基金This work was supported by Science Fund of Department of Education of Jiangsu Province(06KJD320125)
文摘Objective:To study the relationship between plasma treatment time acrylic resin denture material in the size of 2 mm × 10 mm × 10 mm. and efficacy. Methods:Test specimens were prepared from an Plasma treatment was carried out on the surface of Polymethyl methacrylate(PMMA) at different time. XPS studies, IR spectra studies and measurement of wetting angle were performed. Results: XPS showed the peak corresponding to C-O getting higher as the treatment proceeded, however at 120 seconds, the peak did not increase any longer and partly crossed with the peak at the duration of 60 seconds. IR spectra showed the wave corresponding to C-H was reduced as O2-plasma treatment proceeded, and then changed little, Wetting angle initially decreased dramatically, however, as the reaction proceeded, wetting angle increased slightly. Conclusion:Equilibrium was reached for introducing oxygen-containing groups and changing of C-H. As the treatment proceeded, wetting angle increased slightly.
文摘Crystal defects,disorder,phase by high resolution such as grain boundary.dislocation,stacking boundary and surface of granule were examined electron microscope(HREM)in superconducting Tl_(2)Ba_(2)Ca_(2)Cu_(3)O_(x).Some possible effects of the defects on the sample's properties viz.,Jc and Tc are discussed.
文摘Two linked models have been developed to explore the relationship between the amount of porosity arising in service from both radiolytic oxidation and fast neutron damage that influences both the strength and the force-displacement(load-displacement)behaviour and crack propagation in pile grade A graphite used as a nuclear reactor moderator material.Firstly models of the microstructure of the porous graphite for both unirradiated and irradiated graphite are created.These form the input for the second stage,simulating fracture in lattice-type finite element models,which predicts force(load)-displacement and crack propagation paths.Microstructures comprising aligned filler particles,typical of needle coke,in a porous matrix have been explored.The purpose was to isolate the contributions of filler particles and porosity to fracture strength and crack paths and consider their implications for the overall failure of reactor core graphite.
文摘Being a patient in a strange and unknown environment is sometimes very stressful. Research has shown that a healthpromoting environment can reduce anxiety and enhance wellbeing and views of nature can support this. This low-cost intervention wasperformed at a heart surgery intensive care unit.The aim was to use a simple method to improve the health care environment and tomonitor the experiences of patients and staf~ Two patients share the same room at the 1CU. The beds can be separated by roller shadesthat are plain grey and neutral. These were changed to new ones with nature motives. Questionnaires with fixed and open questionswere used for evaluation among patients and staff. Patients treated in an ICU seem to be aware of the surrounding environment even ifthey are severely ill. Both patients and staff stated that the roller shades with motive affected wellbeing in a positive way. An estheticalpleasing environment can contribute to wellbeing even if the effort is small and insignificant. Roller shades with nature motive might bean easy way to improve and strengthen a health promoting environment.
文摘Objective: Cerebral venous sinus thrombosis (CVST) is a life-threatening cerebrovascular disease which has high prevalence and mortality rate in Iran. Thrombophilia caused by gene mutation is a common cause of CVST. The present study aimed at assessing the prevalence of thrombophilic gene mutations in Iranian CVST patients and then comparing it with normal population. Materials and methods: In a case-control study, polymerase chain reaction-restriction fragment length polymorphism (PCR_RFLP) and amplification-refractory mutation system (ARMS-PCR) were carried out to detect common thrombophilic mutations in 70 CVST patients. Next, it was compared with 82 sex- and age-matched healthy controls. Results: Factor-V-Leiden, Factor-V-Leiden HR2, Factor prothrombin II, MTHFR (667C/T) and MTHFR (1298A/C) prevalence were significantly high in cases of CVST as compared to the controls (P values: 0.012, 0.019, 0.007 and 0.036, respectively). However, there was no significant difference between the two groups in plasminogen activator inhibitor (PAI), angiotensin-converting enzyme (ACE), beta-fibrinogen (FGB), Factor VIII, Factor XIII, and tissue plasminogen activator (tPA) mutations. Conclusion: The findings of the present study suggest that Factor V-Leiden, Factor-V-Leiden HR2, prothrombin II (G20210A), and MTHFR (667C/T & 1298A/C) mutations are more frequent in CVST. Detection of these mutations may help clinicians to decide on the duration of treatment and referral to genetic counseling for valuable prevention.
基金financially supported by the Anhui Provincial Natural Science Foundation(Nos.2208085ME108,1708085QE98 and 2008085QE27)University Synergy Innovation Program of Anhui Province(No.GXXT-2023-024)+7 种基金Project for Cultivating Academic(or Disciplinary)Leaders(No.DTR2023043)Talent Scientific Research Foundation of Hefei University(No.23RC29)National Natural Science Foundation of China(Nos.21606065 and 51902079)University Natural Science Research Project of Anhui Province(Nos.KJ2021A1016,2022AH051788 and2022AH051792)the Natural Science Research Project of Education Department of Anhui Province(No.2022AH010096)University excellent talent program of Anhui Province(Nos.gxyqZD2021136and qxyq2021228)the Top Discipline Talents Foundation of Anhui Province Educational Committee(No.gxbjZD2021085)the Key Projects of Research and Development Program of Anhui Provence(No.201904b11020040)。
文摘Lithium-sulfur battery is one of the most promising battery systems for industrialization due to its high theoretical specific capacity and high energy density.Nonetheless,the"shuttle effect"has restrained the advancement of lithium-sulfur batteries.In this work,a gradient-structured nanofiber membrane with pure gelatin on one side and Super P-MoO_(2)/MoS_(2)-gelatin on the other side was created using a multi-step electrostatic spinning technique,which was applied for multi-functional separator for lithium-sulfur batteries.The pure gelatin layer facing the anode side primarily homogenizes the lithium flux,whereas the Super P-MoO_(2)/MoS_(2)-gelatin layer facing the cathode side primarily adsorbs polysulfides by physical and chemical adsorption and enhancing polysulfide conversion efficiency.The findings demonstrate that even after 150 cycles at 0.2C,the lithium-sulfur battery can still sustain a discharge-specific capacity of 572.3 mAh·g^(-1).When used with Li||Li symmetric batteries,it has a cycle life of more than 1200 h.The commercialization of lithium-sulfur batteries is given a fresh idea by this straightforward preparation technique.
基金the National Natural Science Foundation of China(grant No.52204214)the China Postdoctoral Science Foundation(grant No.2023M741502)the University-local government scientific and technical cooperation cultivation project of Ordos Institute-LNTU(grant No.YJY-XD-2023-009).
文摘To explore the influence of the meso-mechanical behaviors of the wet coal dust layers on the contact stiffness of mechanical bonding surfaces,a three-body contact model incorporating an interface with wet coal dust was constructed based on breakage theory.The model considered the mechanical surface morphology and contact characteristics of the wet coal dust.The force chain evolution laws of the wet coal dust layer were elucidated under the effects of gap filling and the cover layer,and the bearing characteristics of the three-body contact bonding surfaces were revealed by quantitative analyses of the number,length,collimation coefficient,and coordination number of the force chains within the wet coal dust layer.Finally,the three-body normal contact stiffness under various preload forces was computed and experimentally validated.The results demonstrate that the external load transfer path of the three-body contact bonding surfaces was from mechanical surface(macroscopic stress)to wet coal dust layer(mesoscopic force chains)and then to mechanical surface(peaks and valleys).The interactions among these three elements contributed to transforming the distributions of the macroscopic stresses and mesoscopic force chains to the locations at the peaks and valleys of the mechanical surface.Among them,the proportion of short force chains in the wet coal dust layer increased from approximately 0.8%–91%,while the proportion of long force chains exhibited an opposite changing trend.The force chain collimation coefficient initially increased and subsequently stabilized,reaching a maximum value of 0.93.A large number of broken,small particles in the wet coal dust layer mainly served to fill the gaps among large particles.The maximum relative error between the experimental and simulated values on the three-body contact stiffness is 7.26%,indicating that the simulation results can be an approximate substitute for the experimental results with a certain degree of accuracy and practicality.The research results are of great significance for understanding the contact characteristics of mechanical surfaces containing particulate media.
基金University of Central Florida(ER Award:#25089A06)We would also like to acknowledge the National Science Foundation(NSF)Major Research Instrumentation(MRI)Program(Grant ID:ECCS:1726636)for the XPS measurements presented in this manuscript+6 种基金MM acknowledges the University of Huddersfield(UoH)EPSRC-DTP competition 2018–19(EP/R513234/1)for funding SMVice Chancellor’s Scholarship Scheme for funding KMTAnalysis was performed on the Orion computing facility at the UoH.Calculations were run on the ARCHER and ARCHER2 UK National Supercomputing Services via our membership of the UK HEC Materials Chemistry Consortium(MCCEPSRC EP/L000202,EP/R029431)AA acknowledges NIH NCI(Grant R01CA045424),Research Excellence Fund(REF)Center for Biomedical Research for support.AA also acknowledges the National Science Foundation(NSF)instrumentation award(CHE-1920110)JA’s work was supported by the National Aeronautics and Space Administration[grant No.80NSSC21M0309]issued through the NASA Office of STEM Engagement.
文摘The disability,mortality and costs due to ionizing radiation(IR)-induced osteoporotic bone fractures are sub-stantial and no effective therapy exists.Ionizing radiation increases cellular oxidative damage,causing an imbalance in bone turnover that is primarily driven via heightened activity of the bone-resorbing osteoclast.We demonstrate that rats exposed to sublethal levels of IR develop fragile,osteoporotic bone.At reactive surface sites,cerium ions have the ability to easily undergo redox cycling:drastically adjusting their electronic con-figurations and versatile catalytic activities.These properties make cerium oxide nanomaterials fascinating.We show that an engineered artificial nanozyme composed of cerium oxide,and designed to possess a higher fraction of trivalent(Ce^(3+))surface sites,mitigates the IR-induced loss in bone area,bone architecture,and strength.These investigations also demonstrate that our nanozyme furnishes several mechanistic avenues of protection and selectively targets highly damaging reactive oxygen species,protecting the rats against IR-induced DNA damage,cellular senescence,and elevated osteoclastic activity in vitro and in vivo.Further,we reveal that our nanozyme is a previously unreported key regulator of osteoclast formation derived from macrophages while also directly targeting bone progenitor cells,favoring new bone formation despite its exposure to harmful levels of IR in vitro.These findings open a new approach for the specific prevention of IR-induced bone loss using synthesis-mediated designer multifunctional nanomaterials.
基金supported by the National Natural Science Foundation of China(Grant No.11272232)Science and Technology Supporting Major Project of Tianjin City(Grant No.16YFZCSY00850)
文摘Magnetic Fe_3O_4@PANI@Au nanocomposites are fabricated through electrostatic self-assembly and seed growth methods.The rate constant K_(app) is calculated to be 8.63×10^(-3) s^(-1) at room temperature for the reduction of 4-nitrophenol to 4-aminophenol with an excessive amount of NaBH_4 as a model system showing outstanding catalytic efficiency and stability.For recyclable performance,the catalyst exhibits slight loss in catalytic performance on the conversion of 4-nitrophenol after running for more than 10 cycles.Besides,the smaller and simpler the structure,the easier the molecular structure can be degraded,and the faster the cationic dyes can be degraded than the anionic dyes,which can reveal the selectivity.For practical application,Congo red as a pollutant of the lake water is degraded rapidly after Fe_3O_4@PANI@Au is added to the solution in a few minutes.It has been demonstrated that magnetic Fe_3O_4@PANI@Au nanoparticle composite is a promising catalyst for environment sewage.
基金financially supported by the King Saud University via their Research Project(No.RGP-VPP-236)
文摘A simple and efficient microwave-assisted procedure for synthesis of L-cysteine-capped nickel nanoparticles(cyst-Ni NPs) in ethylene glycol solvent was demonstrated. The as-synthesised NPs were characterised by ultraviolet–visible(UV–Vis) spectrophotometer, Fourier transform infrared(FTIR) spectroscopy, transmission electron microscopy(TEM) and X-ray diffractometry(XRD). The cyst-Ni NPs are proved to be excellent heterogeneous catalysts for the 100% reduction of 4-nitrophenol(4-NPh) in the presence of reductant(Na BH4)within reaction time of 40 s. In contrast, Raney nickel in similar sample environments shows only 25.5% reduction.The kinetic and energetic behaviours of cyst-Ni NPs were also studied, and the reduction reaction is determined to follow pseudo-first-order kinetics with a rate constant value of 0.115 s-1 and activation energy of 36.1 kJ·mol-1. In addition to its high catalytic competence, cyst-Ni NPs catalyst exhibits excellent recyclability with negligible catalytic poisoning.