The effects of three different typical resistivity models(Spitzer, Z&L and M&G) on the performance of pulsed inductive acceleration plasma are studied. Numerical results show that their influences decrease with th...The effects of three different typical resistivity models(Spitzer, Z&L and M&G) on the performance of pulsed inductive acceleration plasma are studied. Numerical results show that their influences decrease with the increase of the plasma temperature. The significant discriminations among them appear at the plasma temperature lower than 2.5 eV, and the maximum gap of the pulsed inductive plasma accelerated efficiency is approximately 2.5%.Moreover, the pulsed inductive plasma accelerated efficiency is absolutely related to the dynamic impedance parameters, such as voltage, inductance, capacitance and flow rate. However, the distribution of the efficiency as a function of plasma temperature with three resistivity models has nothing to do with the dynamic impedance parameter.展开更多
Efficient photogenerated carrier migration/separation plays a critical role in increasing the photocatalytic performance of g-C_(3)N_(4).Herein,sulfonic acid group-functionalized g-C_(3)N_(4)(SACN)was synthesized and ...Efficient photogenerated carrier migration/separation plays a critical role in increasing the photocatalytic performance of g-C_(3)N_(4).Herein,sulfonic acid group-functionalized g-C_(3)N_(4)(SACN)was synthesized and then synchronously strengthened by a facile-solid-state thermal reaction of g-C_(3)N_(4)and sulfamic acid.As a solid strong acid,sulfamic acid can be used to achieve acid etching on the surface of g-C_(3)N_(4)with the assistance of thermal treatment,leading to an enlarged specific surface area and increased surface catalytic reaction sites.More importantly,our experiments and density functional theory calculations indicate that the driving force generated by the negative inductive effect of sulfonic acid groups significantly improves the charge transfer dynamics and effectively inhibits their recombination.Moreover,the negative inductive effect can induce charge redistribution,which reduces the conduction band potential of g-C_(3)N_(4)to enhance the reduction ability of photo-induced electrons.As a result,the SACN-400 sample showed excellent photocatalytic performance in H2 generation with an apparent quantum efficiency of 11.03%at 420±15 nm,as well as an efficient photodegradation rate for organic pollutants.展开更多
Contradiction between ultrafast nucleation and deposition rates of lithium(Li)crystals at high rate and heterogeneity of Li^(+)flux resulting from concentration polarization has compromised the performance of Li metal...Contradiction between ultrafast nucleation and deposition rates of lithium(Li)crystals at high rate and heterogeneity of Li^(+)flux resulting from concentration polarization has compromised the performance of Li metal anodes especially at high areal capacity and current density.Here,multifunctional protective layer consisting of MoO_(3) nanobelt films(MoO_(3)-NF)is introduced on the surface of Li by a simple rolling method.The strong binding energy between Li and MoO_(3) guides the homogeneous nucleation and deposition of Li,while the nanobelt networks provide effective ion channels for uniform distribution of the Li+flux.Because of the novel multifunctional protective layer,the MoO_(3)-NF@Li anodes demonstrate a remarkable stability for 800 h with ultralow overpotential of 159 mV at extreme harsh conditions of 60 mA·h/cm^(2) and 60 mA/cm^(2).MoO_(3)-NF@Li||LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2) full-cells can run 100 cycles with a superior capacity retention of 84.2%under practical test conditions,demonstrating great potential for high output and energy-density metal batteries.展开更多
A stable Sc phase is formed through hydrogen bonding between side-chain aromatic acid groups of polysiloxane: Bending of polysiloxane with N-Acetyl Latimic acid (NAA) gives a chiral S c * phase; The influence of polym...A stable Sc phase is formed through hydrogen bonding between side-chain aromatic acid groups of polysiloxane: Bending of polysiloxane with N-Acetyl Latimic acid (NAA) gives a chiral S c * phase; The influence of polymerism and hydrogen bond induction effect over mesophase is discussed. The influence of NAA over mesophase is studied.展开更多
The flotation of kaolinite using a series of tertiary amines (N,N-dimethyl-dodecyl amine (DRN), N,N-diethyl-dodecyl amine (DEN), N,N-dipropyl-dodecyl amine (DPN) and N,N-dibenzyl-bodecyl amine (DBN)) was inv...The flotation of kaolinite using a series of tertiary amines (N,N-dimethyl-dodecyl amine (DRN), N,N-diethyl-dodecyl amine (DEN), N,N-dipropyl-dodecyl amine (DPN) and N,N-dibenzyl-bodecyl amine (DBN)) was investigated. The results show that the maximum recoveries of kaolinite for DEN, DPN and DRN are 93%, 88% and 84%, respectively, but that of DBN is very low. On the basis of zeta potential and FT-IR spectra, the ionization of surface hydroxyl and isomorphic exchange of surface ions account for the charging mechanisms of kaolinite surface. The adsorption mechanism of tertiary amines on kaolinite surface is mainly electrostatic. The isoelectric point (IEP) of kaolinite increases from 3.4 to some more positive points after the interaction of kaolinite with the four tertiary amines. The FT-IR spectra of kaolinite change with the presence of some new sharp shapes belonging to the tertiary amines. The inductive electronic effects and space-steric effects of -CH3, -C2H5, -C3H7 and -C7H7 bonding to N atom result in different collecting power of the four tertiary amines.展开更多
In this study;the effect of the electron density over the Br atoms raising with increasing number of CH_2 group using the results of the K X-ray cross-sections and average fluorescence yields of bromine in quaternary-...In this study;the effect of the electron density over the Br atoms raising with increasing number of CH_2 group using the results of the K X-ray cross-sections and average fluorescence yields of bromine in quaternary-imidazole ring.In the experimental set-up,50 mCi ^(241) Am source and a collimated Ultra-LEGe detector were used.The electron density on the Br atoms raises according to the number of the CH_2 groups on the contrary of the inductive effect.The decreasing of the X-ray fluorescence parameters is interested with the increasing the electron density of Br atoms.展开更多
Experiments showed the agglutinin activity in the hemolymph of both spring wild parents and autumncultured individuals of the shrimp Penaeus chinensis Osbeck with the body length of 12 - 16 cm as all 32. Thehemolymph ...Experiments showed the agglutinin activity in the hemolymph of both spring wild parents and autumncultured individuals of the shrimp Penaeus chinensis Osbeck with the body length of 12 - 16 cm as all 32. Thehemolymph of the above shrimps showed agglutinant reaction to all A-, B- and O-type human erythrocytes, with thereaction titer equal to that of rabbit blood cells. However, the agglutinin activity level was enhanced after being in-duced by Vibro, which was 128 after 24 h of induction and reached the peak value 256 after 48 h of induction, thendecreased gradually.展开更多
Lithium metal batteries are considered as high energy density battery systems with very promising prospects and have bee n widely studied.However,The uncon trollable plating/strippi ng behavior,infinite volume change ...Lithium metal batteries are considered as high energy density battery systems with very promising prospects and have bee n widely studied.However,The uncon trollable plating/strippi ng behavior,infinite volume change and den drites formation of lithium metal anode restrict the applicati on.The unc on trolled n ucleati on of lithium caused by the non uniform multi-physical field distributions,can lead to the undesirable lithium deposition.Herein,a graphene composite uniformly loaded with Ag nano-particles(Ag NPs)is prepared through a facile Gamma ray irradiation method and assembled into self-supported film with layered structure(Ag-rGO film).Whe n such film is used as a lithium metal an ode host,the uncontrolled deposition is converted into a highly nucleation-induced process.On one hand,the Ag NPs distributed between the in terlayers of graphe ne can preferentially induce lithium nu cleati on and en able uniform deposition morphology of lithium between interlayers.On the other hand,the stable layered graphene structure can accommodate volume change,stabilize the interface between anode and electrolyte and inhibit dendrites formation.Therefore,the layered Ag-rGO film as anode host can reach a high Coulombic efficiency over 93.3% for 200 cycle(786 h)at a current density of 1 mA cm^(-2) for 2 mAh cm^(-2) in carbonate-based electrolyte.This work proposes a facile Gamma ray irradiation method to prepare metal/3D-skeleton structure as lithium anode host and demonstrates the potential to regulate the lithium metal deposition behaviors via manipulating the distribution of lithiophilic metal(e.g.Ag)in 3D frameworks.This may offer a practicable thinking for the subsequent design of the lithium metal anode.展开更多
Mosl of anticancer drugs are mutagenic. A possible exeeption is diallyl .trisulfide(DAT ), a component of garlic. It is an antimutagenic anticunccr chemical although it ismainly uscd as antibiotic. Its modifying eff...Mosl of anticancer drugs are mutagenic. A possible exeeption is diallyl .trisulfide(DAT ), a component of garlic. It is an antimutagenic anticunccr chemical although it ismainly uscd as antibiotic. Its modifying effeci on induction of UDS by mutagenicmitomycin C (MMC), cyclophosphamide (CP) and cis-diamine dichloroplatin (DDP) was invcstigiltcd with the UDS assay in the primary cultures of Wistar rat hepatocytes (hpc)using the autoradiographic technique. Resultsshowed that 1.0-4.0 nmol/ml of DAT didnot inducc UDS and that MMC, CP and DDP resulted in a significant induction ofdosc-dependent UDS. DAT enhanced induction of UDS by these drugs. A dose-effectrclationship was observed betwecn dose of DAT and enhancement of induction of UDS.Howcvcr, thc mcchanism of the enhancement is not clear.展开更多
Antibiotic wastewater contains a variety of pollutant stressors that can induce and promote antibiotic resistance(AR)when released into the environment.Although these substances are mostly in concentrations lower than...Antibiotic wastewater contains a variety of pollutant stressors that can induce and promote antibiotic resistance(AR)when released into the environment.Although these substances are mostly in concentrations lower than those known to induce AR individually,it is possible that antibiotic wastewater discharge might still promote the AR transmission risk via additive or synergistic effects.However,the comprehensive effect of antibiotic wastewater on AR development has rarely been evaluated,and its treatment efficiency remains unknown.Here,samples were collected from different stages of a cephalosporin production wastewater treatment plant,and the potential AR induction effect of their chemical mixtures was explored through the exposure of the antibiotic-sensitive Escherichia coli K12 strain.Incubation with raw cephalosporin production wastewater significantly promoted mutation rates(3.6×10^(3)-9.3×10^(3)-fold)and minimum inhibition concentrations(6.0-6.7-fold)of E.coli against ampicillin and chloramphenicol.This may be attributed to the inhibition effect and oxidative stress of cephalosporin wastewater on E.coli.The AR induction effect of cephalosporin wastewater decreased after the coagulation sedimentation treatment and was completely removed after the full treatment process.A Pearson correlation analysis revealed that the reduction in the AR induction effect had a strong positive correlation with the removal of organics and biological toxicity.This indicates that the antibiotic wastewater treatment had a collaborative processing effect of conventional pollutants,toxicity,and the AR induction effect.This study illustrates the potential AR transmission risk of antibiotic wastewater and highlights the need for its adequate treatment.展开更多
The induction generator effect(IGE)and the openloop modal proximity(OLMP)are two different reasons why subsynchronous oscillations(SSOs)in a series-compensated power system(SCPS)may occur.The IGE attributes the growin...The induction generator effect(IGE)and the openloop modal proximity(OLMP)are two different reasons why subsynchronous oscillations(SSOs)in a series-compensated power system(SCPS)may occur.The IGE attributes the growing SSOs to negative resistance,while the OLMP explains the SSO mechanism from the standpoint of modal conditions.In this paper,we investigate the connections between the IGE and the OLMP through equivalent RLC circuit and open-loop modal analysis.Our investigation is conducted for two types of seriescompensated power systems where either a synchronous generator or a DFIG is connected at the sending end.The investigation reveals the conditions,in which the IGE and the OLMP may jointly cause the growing SSOs,i.e.,both the IGE and the OLMP can explain why the growing SSOs occur.Furthermore,the investigation indicates that the IGE and the OLMP may be totally irrelevant and lead to growing SSOs separately.This implies that it is possible that in a SCPS,the growing SSOs are only due to the IGE,and the OLMP is non-existent,and vice versa.Hence,when the growing SSOs occurs in a SCPS,examination based on both the IGE and the OLMP should be carefully conducted in order to find if the oscillatory instability is due to the IGE,or the OLMP,or both of them.展开更多
Objective To investigate the effects of arotinoid acid (Ro13 7410) on the morphological and functional alterations of leukemia HL 60 cell line and compared with those of RA Methods Differentiation of HL 60 ce...Objective To investigate the effects of arotinoid acid (Ro13 7410) on the morphological and functional alterations of leukemia HL 60 cell line and compared with those of RA Methods Differentiation of HL 60 cells was assessed by morphology and by NBT reduction Trypan blue exclusion was used to determine viability Apoptosis was assessed by changes in cell morphology and by measurement of fragmented DNA using the PCD assay kit Telomerase PCR ELISA kit tested telomerase activity The cell cycle was analyzed by flow cytometry Results Incubation of the HL 60 cells with 10 -6 10 -8 ?mol/L Ro13 7410 resulted in suppression of cell growth Apoptotic cells were detected following exposure to 10 -6 ?mol/LRo13 7410 for 3 hours by measurement of the “in situ” enzymatic labeling of DNA breaks with biotinylated dUTP Ultrastructural examination of Ro13 7410 treated samples showed cells with chromatin compaction and cytoplasm condensation and the presence of “apoptotic bodies” Cells induced into apoptosis were accompanied by Department of Hematology, the First Affiliated Hospital, Chongqing University of Medical Sciences, Chongqing 400016, China (Liu XS, Lou LS, Zeng SR and Tang ZH) Department of Clinical Biochemistry, Chongqing University of Medical Sciences, Chongqing 400046, China (Jiang JK, Zhang Y, Xu XG, Liu BZ, He YJ and Kang GF) increase of intracellular free Ca 2+ Percentage of HL 60 cells reduced NBT following incubation with Ro13 7410 was lower than with all trans retinoic acid (RA) (27% vas 85%) Telomerase PCR ELISA assay showed that HL 60 cells cultured in the absence of inducing agents had significant telomerase activity Telomerase activity declined gradually after 10 -6 ?mol/L Ro13 7410 treatment, and changes becoming evident at 1 day The inhibition of telomerase activity at day 5 of treatment with Ro13 7410 was less effective than with RA DNA flow cytofluorimetric analysis revealed that Ro13 7410 caused partial cell arrest in the G 2/M phase after a 2 day treatment and the percentage of cells arrested in the G 2/M phase increased after 4 days treatment With RA treated cells, a reduction in the percentage of cells in the G 2/M phase was observed after 2 day of treatment Conclusion Our study shows that Ro13 7410 suppresses HL 60 cells growth mainly via the induction of apoptosis and is less effective than RA in induction differentiation Ro13 7410 dramatically inhibits telomerase activity during the course of induction and results in G 2/M arrest within 2 days These findings suggest that Ro13 7410 is worthy of further study for its effects on leukemic cells展开更多
With more and more wind power generation integrated into power grids to replace the conventional turbine-generator (T-G) units,how the subsynchronous resonance (SSR) of conventional T-G units is affected becomes an im...With more and more wind power generation integrated into power grids to replace the conventional turbine-generator (T-G) units,how the subsynchronous resonance (SSR) of conventional T-G units is affected becomes an important technical issue.In this paper,a group of T-G units are interconnected with a series compensated transmission line,and some units are substituted by a nearby DFIG-based wind farm (WF).Under such circumstances,the SSR of power systems would change accordingly.This paper establishes the mathematical model to analyze the torsional interaction (TI) and the induction generator effect of the T-G units.Both eigenvalue analysis and time domain simulations demonstrate the impact of DFIG-based WF on SSR of power systems and how the control parameters of wind farms can affect the SSR.展开更多
Wrinkling and buckling of nano-films on the compliant substrate are always induced due to thermal deformation mismatch.This paper proposes effective means to control the surface wrinkling of thin film on the compliant...Wrinkling and buckling of nano-films on the compliant substrate are always induced due to thermal deformation mismatch.This paper proposes effective means to control the surface wrinkling of thin film on the compliant substrate,which exploits the curvatures of the curve cracks designed on the stiff film.The procedures of the method are summarized as:1)curve patterns are fabricated on the surface of PDMS(Polydimethylsiloxane)substrate and then the aluminum film with the thickness of several hundred nano-meters is deposited on the substrate;2)the curve patterns are transferred onto the aluminum film and lead to cracking of the film along the curves.The cracking redistributes the stress in the compressed film on the substrate;3)on the concave side of the curve,the wrinkling of the film surface is suppressed to be identified as shielding effect and on the convex side the wrinkling of the film surface is induced to be identified as inductive effect.The shielding and inductive effects make the dis-ordered wrinkling and buckling controllable.This phenomenon provides a potential application in the fabrication of flexible electronic devices.展开更多
基金Supported by the Fund of Science and Technology on Vacuum Technology and Physics Laboratory of Lanzhou Institute of Physics under Grant No YSC0715the National Natural Science Foundation of China under Grant No 62601210the Civil Aerospace Technology Research Project under Grant No D010509
文摘The effects of three different typical resistivity models(Spitzer, Z&L and M&G) on the performance of pulsed inductive acceleration plasma are studied. Numerical results show that their influences decrease with the increase of the plasma temperature. The significant discriminations among them appear at the plasma temperature lower than 2.5 eV, and the maximum gap of the pulsed inductive plasma accelerated efficiency is approximately 2.5%.Moreover, the pulsed inductive plasma accelerated efficiency is absolutely related to the dynamic impedance parameters, such as voltage, inductance, capacitance and flow rate. However, the distribution of the efficiency as a function of plasma temperature with three resistivity models has nothing to do with the dynamic impedance parameter.
文摘Efficient photogenerated carrier migration/separation plays a critical role in increasing the photocatalytic performance of g-C_(3)N_(4).Herein,sulfonic acid group-functionalized g-C_(3)N_(4)(SACN)was synthesized and then synchronously strengthened by a facile-solid-state thermal reaction of g-C_(3)N_(4)and sulfamic acid.As a solid strong acid,sulfamic acid can be used to achieve acid etching on the surface of g-C_(3)N_(4)with the assistance of thermal treatment,leading to an enlarged specific surface area and increased surface catalytic reaction sites.More importantly,our experiments and density functional theory calculations indicate that the driving force generated by the negative inductive effect of sulfonic acid groups significantly improves the charge transfer dynamics and effectively inhibits their recombination.Moreover,the negative inductive effect can induce charge redistribution,which reduces the conduction band potential of g-C_(3)N_(4)to enhance the reduction ability of photo-induced electrons.As a result,the SACN-400 sample showed excellent photocatalytic performance in H2 generation with an apparent quantum efficiency of 11.03%at 420±15 nm,as well as an efficient photodegradation rate for organic pollutants.
基金This work was supported by the National Natural Science Foundation of China(51602277 and 21671167)Open Project of Jiangsu Provincial Key Laboratory of Eco-Environmental Materials,Shanghai Local Capacity Building Program(23010500700)+1 种基金Project of Shanghai Municipal Science and Technology Commission(22DZ2291100)the Open Project Program(PEBM202106)of Key Laboratory for Photonic and Electric Bandgap Materials,Ministry of Education.
文摘Contradiction between ultrafast nucleation and deposition rates of lithium(Li)crystals at high rate and heterogeneity of Li^(+)flux resulting from concentration polarization has compromised the performance of Li metal anodes especially at high areal capacity and current density.Here,multifunctional protective layer consisting of MoO_(3) nanobelt films(MoO_(3)-NF)is introduced on the surface of Li by a simple rolling method.The strong binding energy between Li and MoO_(3) guides the homogeneous nucleation and deposition of Li,while the nanobelt networks provide effective ion channels for uniform distribution of the Li+flux.Because of the novel multifunctional protective layer,the MoO_(3)-NF@Li anodes demonstrate a remarkable stability for 800 h with ultralow overpotential of 159 mV at extreme harsh conditions of 60 mA·h/cm^(2) and 60 mA/cm^(2).MoO_(3)-NF@Li||LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2) full-cells can run 100 cycles with a superior capacity retention of 84.2%under practical test conditions,demonstrating great potential for high output and energy-density metal batteries.
文摘A stable Sc phase is formed through hydrogen bonding between side-chain aromatic acid groups of polysiloxane: Bending of polysiloxane with N-Acetyl Latimic acid (NAA) gives a chiral S c * phase; The influence of polymerism and hydrogen bond induction effect over mesophase is discussed. The influence of NAA over mesophase is studied.
基金Project(2005CB623701) supported by the National Basic Research Program of China
文摘The flotation of kaolinite using a series of tertiary amines (N,N-dimethyl-dodecyl amine (DRN), N,N-diethyl-dodecyl amine (DEN), N,N-dipropyl-dodecyl amine (DPN) and N,N-dibenzyl-bodecyl amine (DBN)) was investigated. The results show that the maximum recoveries of kaolinite for DEN, DPN and DRN are 93%, 88% and 84%, respectively, but that of DBN is very low. On the basis of zeta potential and FT-IR spectra, the ionization of surface hydroxyl and isomorphic exchange of surface ions account for the charging mechanisms of kaolinite surface. The adsorption mechanism of tertiary amines on kaolinite surface is mainly electrostatic. The isoelectric point (IEP) of kaolinite increases from 3.4 to some more positive points after the interaction of kaolinite with the four tertiary amines. The FT-IR spectra of kaolinite change with the presence of some new sharp shapes belonging to the tertiary amines. The inductive electronic effects and space-steric effects of -CH3, -C2H5, -C3H7 and -C7H7 bonding to N atom result in different collecting power of the four tertiary amines.
文摘In this study;the effect of the electron density over the Br atoms raising with increasing number of CH_2 group using the results of the K X-ray cross-sections and average fluorescence yields of bromine in quaternary-imidazole ring.In the experimental set-up,50 mCi ^(241) Am source and a collimated Ultra-LEGe detector were used.The electron density on the Br atoms raises according to the number of the CH_2 groups on the contrary of the inductive effect.The decreasing of the X-ray fluorescence parameters is interested with the increasing the electron density of Br atoms.
文摘Experiments showed the agglutinin activity in the hemolymph of both spring wild parents and autumncultured individuals of the shrimp Penaeus chinensis Osbeck with the body length of 12 - 16 cm as all 32. Thehemolymph of the above shrimps showed agglutinant reaction to all A-, B- and O-type human erythrocytes, with thereaction titer equal to that of rabbit blood cells. However, the agglutinin activity level was enhanced after being in-duced by Vibro, which was 128 after 24 h of induction and reached the peak value 256 after 48 h of induction, thendecreased gradually.
基金support from the National Natural Science Foundation of China(Grant No.21875195,21875198 and 22005257)the Fundamental Research Funds for the Central Universities(20720190040).
文摘Lithium metal batteries are considered as high energy density battery systems with very promising prospects and have bee n widely studied.However,The uncon trollable plating/strippi ng behavior,infinite volume change and den drites formation of lithium metal anode restrict the applicati on.The unc on trolled n ucleati on of lithium caused by the non uniform multi-physical field distributions,can lead to the undesirable lithium deposition.Herein,a graphene composite uniformly loaded with Ag nano-particles(Ag NPs)is prepared through a facile Gamma ray irradiation method and assembled into self-supported film with layered structure(Ag-rGO film).Whe n such film is used as a lithium metal an ode host,the uncontrolled deposition is converted into a highly nucleation-induced process.On one hand,the Ag NPs distributed between the in terlayers of graphe ne can preferentially induce lithium nu cleati on and en able uniform deposition morphology of lithium between interlayers.On the other hand,the stable layered graphene structure can accommodate volume change,stabilize the interface between anode and electrolyte and inhibit dendrites formation.Therefore,the layered Ag-rGO film as anode host can reach a high Coulombic efficiency over 93.3% for 200 cycle(786 h)at a current density of 1 mA cm^(-2) for 2 mAh cm^(-2) in carbonate-based electrolyte.This work proposes a facile Gamma ray irradiation method to prepare metal/3D-skeleton structure as lithium anode host and demonstrates the potential to regulate the lithium metal deposition behaviors via manipulating the distribution of lithiophilic metal(e.g.Ag)in 3D frameworks.This may offer a practicable thinking for the subsequent design of the lithium metal anode.
文摘Mosl of anticancer drugs are mutagenic. A possible exeeption is diallyl .trisulfide(DAT ), a component of garlic. It is an antimutagenic anticunccr chemical although it ismainly uscd as antibiotic. Its modifying effeci on induction of UDS by mutagenicmitomycin C (MMC), cyclophosphamide (CP) and cis-diamine dichloroplatin (DDP) was invcstigiltcd with the UDS assay in the primary cultures of Wistar rat hepatocytes (hpc)using the autoradiographic technique. Resultsshowed that 1.0-4.0 nmol/ml of DAT didnot inducc UDS and that MMC, CP and DDP resulted in a significant induction ofdosc-dependent UDS. DAT enhanced induction of UDS by these drugs. A dose-effectrclationship was observed betwecn dose of DAT and enhancement of induction of UDS.Howcvcr, thc mcchanism of the enhancement is not clear.
基金supported by the National Key Research and Development Program of China(No.2017ZX07103-007)。
文摘Antibiotic wastewater contains a variety of pollutant stressors that can induce and promote antibiotic resistance(AR)when released into the environment.Although these substances are mostly in concentrations lower than those known to induce AR individually,it is possible that antibiotic wastewater discharge might still promote the AR transmission risk via additive or synergistic effects.However,the comprehensive effect of antibiotic wastewater on AR development has rarely been evaluated,and its treatment efficiency remains unknown.Here,samples were collected from different stages of a cephalosporin production wastewater treatment plant,and the potential AR induction effect of their chemical mixtures was explored through the exposure of the antibiotic-sensitive Escherichia coli K12 strain.Incubation with raw cephalosporin production wastewater significantly promoted mutation rates(3.6×10^(3)-9.3×10^(3)-fold)and minimum inhibition concentrations(6.0-6.7-fold)of E.coli against ampicillin and chloramphenicol.This may be attributed to the inhibition effect and oxidative stress of cephalosporin wastewater on E.coli.The AR induction effect of cephalosporin wastewater decreased after the coagulation sedimentation treatment and was completely removed after the full treatment process.A Pearson correlation analysis revealed that the reduction in the AR induction effect had a strong positive correlation with the removal of organics and biological toxicity.This indicates that the antibiotic wastewater treatment had a collaborative processing effect of conventional pollutants,toxicity,and the AR induction effect.This study illustrates the potential AR transmission risk of antibiotic wastewater and highlights the need for its adequate treatment.
基金supported in part by the National Natural Science Foundation of China under Grant 52077144by the Fundamental Research Funds for the Central Universities(YJ201654).
文摘The induction generator effect(IGE)and the openloop modal proximity(OLMP)are two different reasons why subsynchronous oscillations(SSOs)in a series-compensated power system(SCPS)may occur.The IGE attributes the growing SSOs to negative resistance,while the OLMP explains the SSO mechanism from the standpoint of modal conditions.In this paper,we investigate the connections between the IGE and the OLMP through equivalent RLC circuit and open-loop modal analysis.Our investigation is conducted for two types of seriescompensated power systems where either a synchronous generator or a DFIG is connected at the sending end.The investigation reveals the conditions,in which the IGE and the OLMP may jointly cause the growing SSOs,i.e.,both the IGE and the OLMP can explain why the growing SSOs occur.Furthermore,the investigation indicates that the IGE and the OLMP may be totally irrelevant and lead to growing SSOs separately.This implies that it is possible that in a SCPS,the growing SSOs are only due to the IGE,and the OLMP is non-existent,and vice versa.Hence,when the growing SSOs occurs in a SCPS,examination based on both the IGE and the OLMP should be carefully conducted in order to find if the oscillatory instability is due to the IGE,or the OLMP,or both of them.
文摘Objective To investigate the effects of arotinoid acid (Ro13 7410) on the morphological and functional alterations of leukemia HL 60 cell line and compared with those of RA Methods Differentiation of HL 60 cells was assessed by morphology and by NBT reduction Trypan blue exclusion was used to determine viability Apoptosis was assessed by changes in cell morphology and by measurement of fragmented DNA using the PCD assay kit Telomerase PCR ELISA kit tested telomerase activity The cell cycle was analyzed by flow cytometry Results Incubation of the HL 60 cells with 10 -6 10 -8 ?mol/L Ro13 7410 resulted in suppression of cell growth Apoptotic cells were detected following exposure to 10 -6 ?mol/LRo13 7410 for 3 hours by measurement of the “in situ” enzymatic labeling of DNA breaks with biotinylated dUTP Ultrastructural examination of Ro13 7410 treated samples showed cells with chromatin compaction and cytoplasm condensation and the presence of “apoptotic bodies” Cells induced into apoptosis were accompanied by Department of Hematology, the First Affiliated Hospital, Chongqing University of Medical Sciences, Chongqing 400016, China (Liu XS, Lou LS, Zeng SR and Tang ZH) Department of Clinical Biochemistry, Chongqing University of Medical Sciences, Chongqing 400046, China (Jiang JK, Zhang Y, Xu XG, Liu BZ, He YJ and Kang GF) increase of intracellular free Ca 2+ Percentage of HL 60 cells reduced NBT following incubation with Ro13 7410 was lower than with all trans retinoic acid (RA) (27% vas 85%) Telomerase PCR ELISA assay showed that HL 60 cells cultured in the absence of inducing agents had significant telomerase activity Telomerase activity declined gradually after 10 -6 ?mol/L Ro13 7410 treatment, and changes becoming evident at 1 day The inhibition of telomerase activity at day 5 of treatment with Ro13 7410 was less effective than with RA DNA flow cytofluorimetric analysis revealed that Ro13 7410 caused partial cell arrest in the G 2/M phase after a 2 day treatment and the percentage of cells arrested in the G 2/M phase increased after 4 days treatment With RA treated cells, a reduction in the percentage of cells in the G 2/M phase was observed after 2 day of treatment Conclusion Our study shows that Ro13 7410 suppresses HL 60 cells growth mainly via the induction of apoptosis and is less effective than RA in induction differentiation Ro13 7410 dramatically inhibits telomerase activity during the course of induction and results in G 2/M arrest within 2 days These findings suggest that Ro13 7410 is worthy of further study for its effects on leukemic cells
文摘With more and more wind power generation integrated into power grids to replace the conventional turbine-generator (T-G) units,how the subsynchronous resonance (SSR) of conventional T-G units is affected becomes an important technical issue.In this paper,a group of T-G units are interconnected with a series compensated transmission line,and some units are substituted by a nearby DFIG-based wind farm (WF).Under such circumstances,the SSR of power systems would change accordingly.This paper establishes the mathematical model to analyze the torsional interaction (TI) and the induction generator effect of the T-G units.Both eigenvalue analysis and time domain simulations demonstrate the impact of DFIG-based WF on SSR of power systems and how the control parameters of wind farms can affect the SSR.
基金supported by the National Basic Research Program of China(Grant Nos.2010CB631005 and 2011CB606105)the National Natural Science Foundation of China(Grant Nos.11232008,91216301,11072125 and 11272175)Tsinghua University Initiative Scientific Research Program
文摘Wrinkling and buckling of nano-films on the compliant substrate are always induced due to thermal deformation mismatch.This paper proposes effective means to control the surface wrinkling of thin film on the compliant substrate,which exploits the curvatures of the curve cracks designed on the stiff film.The procedures of the method are summarized as:1)curve patterns are fabricated on the surface of PDMS(Polydimethylsiloxane)substrate and then the aluminum film with the thickness of several hundred nano-meters is deposited on the substrate;2)the curve patterns are transferred onto the aluminum film and lead to cracking of the film along the curves.The cracking redistributes the stress in the compressed film on the substrate;3)on the concave side of the curve,the wrinkling of the film surface is suppressed to be identified as shielding effect and on the convex side the wrinkling of the film surface is induced to be identified as inductive effect.The shielding and inductive effects make the dis-ordered wrinkling and buckling controllable.This phenomenon provides a potential application in the fabrication of flexible electronic devices.