The efficiency of plant cytidine base-editing systems is limited, and unwanted mutations frequently occur in transgenic plants. We increased the cytidine editing frequency and fidelity of the plant base editor 3(BE3) ...The efficiency of plant cytidine base-editing systems is limited, and unwanted mutations frequently occur in transgenic plants. We increased the cytidine editing frequency and fidelity of the plant base editor 3(BE3) and targeted activation-induced cytidine deaminase(CDA)(target-AID) systems by coexpressing three copies of free uracil–DNA glycosylase(UDG) inhibitor(UGI). The editing efficiency of the improved BE3 and CDA systems reached as high as 88.9% and 85.7%, respectively, in regenerated rice plants, with a very low frequency of unwanted mutations. The low editing frequency of the BE3 system in the GC context could be overcome by the modified CDA system. These results provide a highfidelity and high-efficiency solution for rice genomic base editing.展开更多
The paper presents detailed comparisons between CRM (critical conduction mode) and CCM (continuous conduction mode) control schemes used for Boost PFC converter. The two schemes are analyzed and compared under the chi...The paper presents detailed comparisons between CRM (critical conduction mode) and CCM (continuous conduction mode) control schemes used for Boost PFC converter. The two schemes are analyzed and compared under the chips of L6561 and UC 3854 which are commonly used for CRM and CCM respectively. Both schemes are based on multiplier;however, the CCM is more complex and needs more periphery components which increase the cost. The Boost PFC under CRM is easier to be implemented. Nevertheless, the variable switch frequency makes the system (including the power-stage inductor and capacitor) hard to design. It seems that the CRM PFC is more attractive in low power applications which only need to meet IEC61000-3-2 D standard. Some experiment results are also presented for the comparison.展开更多
The present study observed hemodynamic changes in 26 patients with cerebral arteriosclerosis using a cerebral circulation dynamics detector and transcranial Doppler. In patients with cerebral arteriosclerosis the bloo...The present study observed hemodynamic changes in 26 patients with cerebral arteriosclerosis using a cerebral circulation dynamics detector and transcranial Doppler. In patients with cerebral arteriosclerosis the blood supply and flow rate in the bilateral carotid arteries and the blood flow rate in the anterior cerebral and middle cerebral arteries were similar to normal controls, but the cerebral vascular resistance, critical pressure and pulsatility index were increased, and cerebral arterial elasticity and cerebral blood flow autoregulation were decreased. Compared with the lesioned hemisphere of patients with cerebral infarction, the total blood supply and blood flow rate of patients with cerebral arteriosclerosis were higher. Compared with normal subjects, patients with cerebral arteriosclerosis exhibited cognitive disturbances, mainly in short-term memory, attention, abstract capability, and spatial and executive dysfunction. Results showed that cerebral arteriosclerosis does not directly affect the blood supply of a cerebral hemisphere, but affects cognitive function. The increased cerebral vascular resistance and reduced autoregulation of cerebral blood vessels may be important hemodynamic mechanisms of arteriosclerosis-induced cerebral infarction.展开更多
The Buck converter with LC input filter operating in discontinuous output current mode has a high power factor with a constant duty cycle. A Buck converter in this operation mode can reduce the reverse recovery loss o...The Buck converter with LC input filter operating in discontinuous output current mode has a high power factor with a constant duty cycle. A Buck converter in this operation mode can reduce the reverse recovery loss of the freewheeling diode thus increase the efficiency. The operation, power factor analysis and modeling of the converter are studied in this paper. Experimental results are presented to verify the theoretical predictions.展开更多
By adding a suitable LC filter to the input of a Buck converter, a high-power-factor buck converter is proposed. The converter can operate in the discontinuous-output-current mode operation. A Buck converter in this o...By adding a suitable LC filter to the input of a Buck converter, a high-power-factor buck converter is proposed. The converter can operate in the discontinuous-output-current mode operation. A Buck converter in this operation mode features simple control as the constant duty cycle PWM used. The operation condition of the converter is studied. The validity of analysis is verified by Simulation and Experimental results.展开更多
A novel high-power-factor Buck type converter with average current control based on UC 3854 is proposed. The input current is directly controlled by average current control scheme to deliver sinusoidal input current a...A novel high-power-factor Buck type converter with average current control based on UC 3854 is proposed. The input current is directly controlled by average current control scheme to deliver sinusoidal input current and to gain a high power factor. The practical results, which illustrate the proposed control philosophy, were obtained from a 120 W AC/DC Buck type converter. The power factor can reach 0.97.展开更多
This paper first introduces the overview of real estate appraisal theory,the basic situation of real estate appraisal,the basic principles and characteristics of real estate appraisal,and three main appraisal methods....This paper first introduces the overview of real estate appraisal theory,the basic situation of real estate appraisal,the basic principles and characteristics of real estate appraisal,and three main appraisal methods.On this basis,the specific use scope of each method,the meaning of each parameter,and the influencing factors are analyzed.Then,based on the in-depth study of various existing appraisal theories and methods,a new appraisal method is proposed:the appraisal analysis method based on fuzzy analytic hierarchy process.展开更多
Natural killer(NK)cells act as a first line of defense in innate immune system against new malignant transformed cells without prior exposure to tumor antigens.The activity of NK cells is tightly controlled by a balan...Natural killer(NK)cells act as a first line of defense in innate immune system against new malignant transformed cells without prior exposure to tumor antigens.The activity of NK cells is tightly controlled by a balance between inhibitory receptors and activating receptors,and when activation signals outweigh inhibitory signals,NK cells can mediate a response to eliminate the targeted cells.As a bridge between the innate and adaptive immune responses to enhance destruction of tumors,NK cells kill their tumor targets through a variety of mechanisms,including receptor-mediated cytotoxicity,antibody-dependent cell-mediated cytotoxicity(ADCC),death receptor Fas/FasL signaling pathway-mediated cancer apoptosis.However,the efficacy of using NK cells for tumor immunotherapy has been limited by a lack of antigen specificity.To overcome this limitation,Vallera and colleagues developed a bispecific killer cell engager(BiKE),which is comprised of a first ScFv that recognizes a tumor antigen and a second ScFv against CD16(expressed on NK cells)to trigger ADCC.To overcome the poor expansion of NK cells in vivo,a novel trispecific killer cell engager(TriKE)was evolved from the BiKE by the same team.In this molecule,IL-15 was integrated to promote NK cell expansion,thereby eliciting superior NK cytotoxicity and NK cell persistence in vivo compared to BiKE.In order to simultaneously target drug-refractory cancer stem cells(CSC)and cancer cells,a novel tetraspecific killer engager(TetraKE)comprising anti-CD133,EpCAM,CD16 ScFvs and a sustaining IL-15 signal cross-linker was recently developed.Compared to BiKE or TriKE,TetraKE1615EpCAM133 was highly specific against EpCAM-and CD133-bearing cells,leading to enhanced NK cell proliferation,prolonged survival and a limited cytokine response.This TetraKE represents a promising new modality for immunotherapy.展开更多
Male sterility is an important trait in rice for hybrid rice(Oryza sativa)breeding.However,the factors involved in dominant male sterility are largely unknown.Here,we identified a gene from Sanming dominant genic male...Male sterility is an important trait in rice for hybrid rice(Oryza sativa)breeding.However,the factors involved in dominant male sterility are largely unknown.Here,we identified a gene from Sanming dominant genic male sterile rice,named Sanming dominant male sterility(SMS),and reported that an epi-allele of this locus contributes to male sterility.Segregation analysis attributed dominant male sterility to a single locus,SMS,which we characterized using a male-sterile near isogenic line(NIL)of rice cultivar 93-11.The SMS locus was heterozygous in the male-sterile 93-11 NIL,containing an epi-allele identical to that in 93-11,and an epi-allele identical to that in rice cultivar Nipponbare,which we refer to as SMS9 and SMSN,respectively.SMS9is silent and hyper-methylated,whereas SMSNis expressed and hypo-methylated in the 93-11 NIL.Overexpressing SMSNled to male sterility.Mutations in SMS rescued the male sterility of the 93-11 NIL.Interestingly,we observed the duplication of SMSN in Nipponbare,but did not observe the duplication of SMS9in 93-11.Together,these findings suggest that the reduced methylation and enhanced expression of the SMSNepi-allele in the 93-11 NIL is responsible for its role in conferring dominant male sterility.展开更多
Most of the important agronomic traits in crop plants, such as yield, quality and stress response, are quantitative and jointly controlled by many genomic loci or major genes. Improving these complex traits depends on...Most of the important agronomic traits in crop plants, such as yield, quality and stress response, are quantitative and jointly controlled by many genomic loci or major genes. Improving these complex traits depends on the combination of beneficial alleles at the quantitative trait loci (QTLs). However, the conventional cross breeding method is extremely time-consuming and laborious for pyramiding multiple QTLs. In certain cases, this approach might be technically difficult because of close linkage between genes separately responsible for desirable and undesirable traits.展开更多
Three novel polycyclic polyprenyled acylphloroglucinols,Hyperscabins A-C,were obtained from the aerial parts of Hypericum scabrum.They featured an unprecedented 5,5-spiro ketal subunit with the loss of C-2’carbonyl i...Three novel polycyclic polyprenyled acylphloroglucinols,Hyperscabins A-C,were obtained from the aerial parts of Hypericum scabrum.They featured an unprecedented 5,5-spiro ketal subunit with the loss of C-2’carbonyl in the phloroglucinol ring.Their structures were characterized by extensive spectroscopic analyses,NMR calculations with DP4+analysis,calculated electronic circular dichroism(ECD)spectra and the application of modified Mosher’s methods.In the assay of[^(3)H]-5-HT and[^(3)H]-NE reuptake inhibition,compounds 1 and 2 showed good inhibito ry activity(81.8%and 83.2%)in 10μmol/L.In addition,compound 1 significantly increased cell viability in the experiment of oxygen and glucose deprivation/deoxygenation.展开更多
This study reports an investigation of the chemical constituents of Balanophora polyandra Griff.Fifteen compounds were isolated by column chromatography on silica gel,Toyo-pearl HW-40C,Sephadex LH-20 and by HPLC.Their...This study reports an investigation of the chemical constituents of Balanophora polyandra Griff.Fifteen compounds were isolated by column chromatography on silica gel,Toyo-pearl HW-40C,Sephadex LH-20 and by HPLC.Their structures were elucidated as 1,4-di-O galloy-2-O-[(E)-p-coumaroyl]-β-D-glucopyranose(1),1-O-galloyl-β-D-pyranglucose(2),1-p-coumaryl-β-D-pyranglu-cose(3),1-O-(E)-caffeoyl-β-D-pyranglucose(4),1,3-di-O-galloyl-β-D-pyranglucose(5),1,6-di-O-galloyl-β-D-pyranglucose(6),1-O-(E)-caffeoyl-4-O-galloyl-β-D-pyranglucose(7),1-O-(E)-caffeoy1-6-O galloyl-β-D-pyranglucose(8),1-0-(E)-caffeoy1-4,6-di-O-galloyl-β-D-pyranglucose(9),1-O-(E)-caffeoyl-4,6-(S)-HHDP-B-D-pyranglucose(10),1,23,6-tetra-O-galloyl-β-D-pyranglucose(11),4,6-(S)-hexahydroxydi-phenoyl-(α/β)-D-glucose(12),1-O-(E)-caffeoyl-4,6-[1′,1″-3′,3″,4′,4″-tetrahydroxydibenzofurandicar-boxyl)]-β-D glucopyranose(13),flavogallonic acid(14),and phloretin-4′-O-β-D-glucoside(15)on the basis of spectral analysis.Compound 1 was a new hydrolyzable tannin,9 was obtained from this genus for the first time,and compounds 5,6 and 11-14 were isolated from this plant for the first time.展开更多
基金funded by the Genetically Modified Breeding Major Project(2016ZX08010-002-008)the National Natural Science Foundation of China(31701405)the Natural Science Foundation of Anhui Province,China(1708085QC60)。
文摘The efficiency of plant cytidine base-editing systems is limited, and unwanted mutations frequently occur in transgenic plants. We increased the cytidine editing frequency and fidelity of the plant base editor 3(BE3) and targeted activation-induced cytidine deaminase(CDA)(target-AID) systems by coexpressing three copies of free uracil–DNA glycosylase(UDG) inhibitor(UGI). The editing efficiency of the improved BE3 and CDA systems reached as high as 88.9% and 85.7%, respectively, in regenerated rice plants, with a very low frequency of unwanted mutations. The low editing frequency of the BE3 system in the GC context could be overcome by the modified CDA system. These results provide a highfidelity and high-efficiency solution for rice genomic base editing.
文摘The paper presents detailed comparisons between CRM (critical conduction mode) and CCM (continuous conduction mode) control schemes used for Boost PFC converter. The two schemes are analyzed and compared under the chips of L6561 and UC 3854 which are commonly used for CRM and CCM respectively. Both schemes are based on multiplier;however, the CCM is more complex and needs more periphery components which increase the cost. The Boost PFC under CRM is easier to be implemented. Nevertheless, the variable switch frequency makes the system (including the power-stage inductor and capacitor) hard to design. It seems that the CRM PFC is more attractive in low power applications which only need to meet IEC61000-3-2 D standard. Some experiment results are also presented for the comparison.
基金the Technology Research Program of Shaanxi Province, No. 2009K18-02
文摘The present study observed hemodynamic changes in 26 patients with cerebral arteriosclerosis using a cerebral circulation dynamics detector and transcranial Doppler. In patients with cerebral arteriosclerosis the blood supply and flow rate in the bilateral carotid arteries and the blood flow rate in the anterior cerebral and middle cerebral arteries were similar to normal controls, but the cerebral vascular resistance, critical pressure and pulsatility index were increased, and cerebral arterial elasticity and cerebral blood flow autoregulation were decreased. Compared with the lesioned hemisphere of patients with cerebral infarction, the total blood supply and blood flow rate of patients with cerebral arteriosclerosis were higher. Compared with normal subjects, patients with cerebral arteriosclerosis exhibited cognitive disturbances, mainly in short-term memory, attention, abstract capability, and spatial and executive dysfunction. Results showed that cerebral arteriosclerosis does not directly affect the blood supply of a cerebral hemisphere, but affects cognitive function. The increased cerebral vascular resistance and reduced autoregulation of cerebral blood vessels may be important hemodynamic mechanisms of arteriosclerosis-induced cerebral infarction.
文摘The Buck converter with LC input filter operating in discontinuous output current mode has a high power factor with a constant duty cycle. A Buck converter in this operation mode can reduce the reverse recovery loss of the freewheeling diode thus increase the efficiency. The operation, power factor analysis and modeling of the converter are studied in this paper. Experimental results are presented to verify the theoretical predictions.
文摘By adding a suitable LC filter to the input of a Buck converter, a high-power-factor buck converter is proposed. The converter can operate in the discontinuous-output-current mode operation. A Buck converter in this operation mode features simple control as the constant duty cycle PWM used. The operation condition of the converter is studied. The validity of analysis is verified by Simulation and Experimental results.
文摘A novel high-power-factor Buck type converter with average current control based on UC 3854 is proposed. The input current is directly controlled by average current control scheme to deliver sinusoidal input current and to gain a high power factor. The practical results, which illustrate the proposed control philosophy, were obtained from a 120 W AC/DC Buck type converter. The power factor can reach 0.97.
文摘This paper first introduces the overview of real estate appraisal theory,the basic situation of real estate appraisal,the basic principles and characteristics of real estate appraisal,and three main appraisal methods.On this basis,the specific use scope of each method,the meaning of each parameter,and the influencing factors are analyzed.Then,based on the in-depth study of various existing appraisal theories and methods,a new appraisal method is proposed:the appraisal analysis method based on fuzzy analytic hierarchy process.
文摘Natural killer(NK)cells act as a first line of defense in innate immune system against new malignant transformed cells without prior exposure to tumor antigens.The activity of NK cells is tightly controlled by a balance between inhibitory receptors and activating receptors,and when activation signals outweigh inhibitory signals,NK cells can mediate a response to eliminate the targeted cells.As a bridge between the innate and adaptive immune responses to enhance destruction of tumors,NK cells kill their tumor targets through a variety of mechanisms,including receptor-mediated cytotoxicity,antibody-dependent cell-mediated cytotoxicity(ADCC),death receptor Fas/FasL signaling pathway-mediated cancer apoptosis.However,the efficacy of using NK cells for tumor immunotherapy has been limited by a lack of antigen specificity.To overcome this limitation,Vallera and colleagues developed a bispecific killer cell engager(BiKE),which is comprised of a first ScFv that recognizes a tumor antigen and a second ScFv against CD16(expressed on NK cells)to trigger ADCC.To overcome the poor expansion of NK cells in vivo,a novel trispecific killer cell engager(TriKE)was evolved from the BiKE by the same team.In this molecule,IL-15 was integrated to promote NK cell expansion,thereby eliciting superior NK cytotoxicity and NK cell persistence in vivo compared to BiKE.In order to simultaneously target drug-refractory cancer stem cells(CSC)and cancer cells,a novel tetraspecific killer engager(TetraKE)comprising anti-CD133,EpCAM,CD16 ScFvs and a sustaining IL-15 signal cross-linker was recently developed.Compared to BiKE or TriKE,TetraKE1615EpCAM133 was highly specific against EpCAM-and CD133-bearing cells,leading to enhanced NK cell proliferation,prolonged survival and a limited cytokine response.This TetraKE represents a promising new modality for immunotherapy.
基金supported by the Global Select Project (DJK-LX-2022007)of the Institute of Health and Medicine,Hefei Comprehensive National Science Centerthe Key Research and Development Projects in Anhui Province (2023n06020035,202104b11020008)+3 种基金the University Synergy Innovation Program of Anhui Province (GXXT-2019033)the National Natural Science Foundation of China (U19A2021,32230017)the Anhui Province Major Special Project for Improving Seed Productionthe Strategic Priority Research Program“Molecular Mechanisms of Plant Growth and Development”of the Chinese Academy of Sciences (XDB27030203)。
文摘Male sterility is an important trait in rice for hybrid rice(Oryza sativa)breeding.However,the factors involved in dominant male sterility are largely unknown.Here,we identified a gene from Sanming dominant genic male sterile rice,named Sanming dominant male sterility(SMS),and reported that an epi-allele of this locus contributes to male sterility.Segregation analysis attributed dominant male sterility to a single locus,SMS,which we characterized using a male-sterile near isogenic line(NIL)of rice cultivar 93-11.The SMS locus was heterozygous in the male-sterile 93-11 NIL,containing an epi-allele identical to that in 93-11,and an epi-allele identical to that in rice cultivar Nipponbare,which we refer to as SMS9 and SMSN,respectively.SMS9is silent and hyper-methylated,whereas SMSNis expressed and hypo-methylated in the 93-11 NIL.Overexpressing SMSNled to male sterility.Mutations in SMS rescued the male sterility of the 93-11 NIL.Interestingly,we observed the duplication of SMSN in Nipponbare,but did not observe the duplication of SMS9in 93-11.Together,these findings suggest that the reduced methylation and enhanced expression of the SMSNepi-allele in the 93-11 NIL is responsible for its role in conferring dominant male sterility.
基金supported by Genetically Modified Breeding Major Projects(No.2016ZX08010-002-008)the National Natural Science Foundation of China(Nos.31501239 and 31401454)
文摘Most of the important agronomic traits in crop plants, such as yield, quality and stress response, are quantitative and jointly controlled by many genomic loci or major genes. Improving these complex traits depends on the combination of beneficial alleles at the quantitative trait loci (QTLs). However, the conventional cross breeding method is extremely time-consuming and laborious for pyramiding multiple QTLs. In certain cases, this approach might be technically difficult because of close linkage between genes separately responsible for desirable and undesirable traits.
基金supported by the Beijing Natural Science Foundation(No.7194299)Fundamental Research Funds for the Central Universities(No.3332018089)+1 种基金the CAMS Innovation Fund for Medical Sciences(No.2016-I2M-1-010)the Drug Innovation Major Project(No.2018ZX09711001-002-010,2018ZX09735006)。
文摘Three novel polycyclic polyprenyled acylphloroglucinols,Hyperscabins A-C,were obtained from the aerial parts of Hypericum scabrum.They featured an unprecedented 5,5-spiro ketal subunit with the loss of C-2’carbonyl in the phloroglucinol ring.Their structures were characterized by extensive spectroscopic analyses,NMR calculations with DP4+analysis,calculated electronic circular dichroism(ECD)spectra and the application of modified Mosher’s methods.In the assay of[^(3)H]-5-HT and[^(3)H]-NE reuptake inhibition,compounds 1 and 2 showed good inhibito ry activity(81.8%and 83.2%)in 10μmol/L.In addition,compound 1 significantly increased cell viability in the experiment of oxygen and glucose deprivation/deoxygenation.
基金This research program was supported by the National Natural Science Foundation of China(Grant No.30772709).
文摘This study reports an investigation of the chemical constituents of Balanophora polyandra Griff.Fifteen compounds were isolated by column chromatography on silica gel,Toyo-pearl HW-40C,Sephadex LH-20 and by HPLC.Their structures were elucidated as 1,4-di-O galloy-2-O-[(E)-p-coumaroyl]-β-D-glucopyranose(1),1-O-galloyl-β-D-pyranglucose(2),1-p-coumaryl-β-D-pyranglu-cose(3),1-O-(E)-caffeoyl-β-D-pyranglucose(4),1,3-di-O-galloyl-β-D-pyranglucose(5),1,6-di-O-galloyl-β-D-pyranglucose(6),1-O-(E)-caffeoyl-4-O-galloyl-β-D-pyranglucose(7),1-O-(E)-caffeoy1-6-O galloyl-β-D-pyranglucose(8),1-0-(E)-caffeoy1-4,6-di-O-galloyl-β-D-pyranglucose(9),1-O-(E)-caffeoyl-4,6-(S)-HHDP-B-D-pyranglucose(10),1,23,6-tetra-O-galloyl-β-D-pyranglucose(11),4,6-(S)-hexahydroxydi-phenoyl-(α/β)-D-glucose(12),1-O-(E)-caffeoyl-4,6-[1′,1″-3′,3″,4′,4″-tetrahydroxydibenzofurandicar-boxyl)]-β-D glucopyranose(13),flavogallonic acid(14),and phloretin-4′-O-β-D-glucoside(15)on the basis of spectral analysis.Compound 1 was a new hydrolyzable tannin,9 was obtained from this genus for the first time,and compounds 5,6 and 11-14 were isolated from this plant for the first time.