The design and implementation of a novel ADC architecture called ring-ADC for digital voltage regulator module controllers are presented. Based on the principle of voltage-controlled oscillators＇ transform from volta...The design and implementation of a novel ADC architecture called ring-ADC for digital voltage regulator module controllers are presented. Based on the principle of voltage-controlled oscillators＇ transform from voltage to frequency,the A/D conversion of ring-ADC achieves good linearity and precise calibration against process variations compared with the delay-line ADC. A differential pulse counting discriminator also helps decrease the power consumption of the ring-ADC. It is fabricated with a Chartered 0.35μm CMOS process, and the measurement results of the integral and differential nonlinearity performance are 0.92LSB and 1.2LSB respectively. The maximum gain error measured in ten sample chips is ± 3.85%. With sampling rate of 500kHz and when the voltage regulator module （VRM） works in steady state, the ring-ADC＇s average power consumption is 2.56mW. The ring-ADC is verified to meet the requirements for digital VRM controller application.展开更多
Wintersweet(Chimonanthus praecox),a well-known fragrant flowering shrub,is extensively planted for ornamental purpose and production of floral essential oil.Although the tepal color of wintersweet varieties exhibits t...Wintersweet(Chimonanthus praecox),a well-known fragrant flowering shrub,is extensively planted for ornamental purpose and production of floral essential oil.Although the tepal color of wintersweet varieties exhibits the most remarkable diversity,variations in the floral scent traits are also noticeable across different cultivars.In this study,the floral volatile organic compounds(VOCs)in three wintersweet cultivars,‘Yanlingsuxin’,‘Yuxiang’,and‘Hongyun’were detected via GC-MS coupled with OAV.The distinct floral aromas of the three cultivars were primarily attributed to benzyl alcohol(abundant in‘Yuxiang’),linalool(abundant in‘Yanlingsuxin’),(-)-γ-cadinene and eugenol(abundant in‘Hongyun’).Integrated analyses of metabolome and transcriptome showed that an R2R3-MYB transcription factor gene,CpODO1,potentially have a crucial regulatory function in controlling the production of multiple aroma compounds.Overexpression of CpODO1 can enhance the production of benzyl alcohol in transgenic tobacco flowers.Analysis of DAP-seq data,EMSA and dual-luciferase assay revealed that CpODO1 predominantly regulate the expression of CpCYP71,a cytochrome P450 gene encoding a key enzyme in the production of benzyl alcohol,and the transcriptional regulation of CpODO1 is driven by CpEOBII.The identification of polymorphisms in the MYB binding cis-motifs of CpCYP71 and CpODO1 promoters revealed the regulatory mechanism underlying the varied synthesis of benzyl alcohol in three wintersweet cultivars.This study provides new anchor points for floral scent quality improvement breeding of wintersweet,and the profusion of wintersweet germplasm can serve as a material basis for developing various aroma products.展开更多
A new approach for the design and implementation of a programmable voltage reference based on an improved current mode bandgap voltage reference is presented. The circuit is simulated and fabricated with Chartered 0....A new approach for the design and implementation of a programmable voltage reference based on an improved current mode bandgap voltage reference is presented. The circuit is simulated and fabricated with Chartered 0. 35μm mixed-signal technology. Measurements demonstrate that the temperature coefficient is ± 36. 3ppm/℃ from 0 to 100℃ when the VID inputs are 11110.As the supply voltage is varied from 2.7 to 5V, the voltage reference varies by about 5mV. The maximum glitch of the transient response is about 20mV at 125kHz. Depending on the state of the five VID inputs,an output voltage between 1.1 and 1.85V is programmed in increments of 25mV.展开更多
Cystic fibrosis(CF)is an autosomal recessive disorder caused by mutations in the CF transmembrane conductance regulator gene.CF liver disease develops in 5%-10%of patients with CF and is the third leading cause of dea...Cystic fibrosis(CF)is an autosomal recessive disorder caused by mutations in the CF transmembrane conductance regulator gene.CF liver disease develops in 5%-10%of patients with CF and is the third leading cause of death among patients with CF after pulmonary disease or lung transplant complications.We review the pathogenesis,clinical presentations,complications,diagnostic evaluation,effect of medical therapies especially CF transmembrane conductance regulator modulators and liver transplantation in CF associated liver disease.展开更多
BACKGROUND Hepatic steatosis is a common form of cystic fibrosis associated liver disease(CFLD)seen in an estimated 15%-60%of patients with cystic fibrosis(CF).The pathophysiology and health implications of hepatic st...BACKGROUND Hepatic steatosis is a common form of cystic fibrosis associated liver disease(CFLD)seen in an estimated 15%-60%of patients with cystic fibrosis(CF).The pathophysiology and health implications of hepatic steatosis in cystic fibrosis remain largely unknown.In the general population,hepatic steatosis is strongly associated with insulin resistance and type 2 diabetes.Cystic fibrosis related diabetes(CFRD)impacts 40%-50%of CF adults and is characterized by both insulin insufficiency and insulin resistance.We hypothesized that patients with CFRD would have higher levels of hepatic steatosis than cystic fibrosis patients without diabetes.AIM To determine whether CFRD is associated with hepatic steatosis and to explore the impact of lumacaftor/ivacaftor therapy on hepatic steatosis in CF.METHODS Thirty patients with CF were recruited from a tertiary care medical center for this cross-sectional study.Only pancreatic insufficient patients with CFRD or normal glucose tolerance(NGT)were included.Patients with established CFLD,end stage lung disease,or persistently elevated liver enzymes were excluded.Mean magnetic resonance imaging(MRI)proton density fat fraction(PDFF)was obtained for all participants.Clinical characteristics[age,sex,body mass index,percent predicted forced expiratory volume at 1 s(FEV1),lumacaftor/ivacaftor use]and blood chemistries were assessed for possible association with hepatic steatosis.Hepatic steatosis was defined as a mean MRI PDFF>5%.Patients were grouped by diabetes status(CFRD,NGT)and cystic fibrosis transmembrane conductance regulator(CFTR)modulator use(lumacaftor/ivacaftor,no lumacaftor/ivacaftor)to determine between group differences.Continuous variables were analyzed with a Wilcoxon rank sum test and discrete variables with a Chi square test or Fisher’s exact test.RESULTS Twenty subjects were included in the final analysis.The median age was 22.3 years(11.3-39.0)and median FEV1 was 77%(33%-105%).Twelve subjects had CFRD and 8 had NGT.Nine subjects were receiving lumacaftor/ivacaftor.The median PDFF was 3.0%(0.0%-21.0%).Six subjects(30%)had hepatic steatosis defined as PDFF>5%.Hepatic fat fraction was significantly lower in patients receiving lumacaftor/ivacaftor(median,range)(2.0%,0.0%-6.4%)than in patients not receiving lumacaftor/ivacaftor(4.1%,2.7-21.0%),P=0.002.Though patients with CFRD had lower PDFF(2.2%,0.0%-14.5%)than patients with NGT(4.9%,2.4-21.0%)this did not reach statistical significance,P=0.06.No other clinical characteristic was strongly associated with hepatic steatosis.CONCLUSION Use of the CFTR modulator lumacaftor/ivacaftor was associated with significantly lower hepatic steatosis.No association between CFRD and hepatic steatosis was found in this cohort.展开更多
Fluid flow is a ubiquitous aspect of microfluidic systems.Gravity-driven flow is one microfluidic flow initiation and maintenance mechanism that is appealing because it is simple,requires no external power source,and ...Fluid flow is a ubiquitous aspect of microfluidic systems.Gravity-driven flow is one microfluidic flow initiation and maintenance mechanism that is appealing because it is simple,requires no external power source,and is easy to use.However,the driving forces created by hydraulic head differences gradually decrease during operation,resulting in decreasing flow rates that are undesirable in many microfluidic applications such as perfusion culture,droplet microfluidics,etc.Existing methods to maintain a constant gravity-driven flow either require additional control equipment,involve complex fabrication or operation,are incompatible with miniaturization,or introduce interfaces that lack robustness.Here we tackled those problems by introducing a 3D-printed compact hydraulic head auto-regulating module that automatically maintains a constant fluid level at the microfluidic inlet port without human intervention.Our module successfully maintained a constant hydraulic head for more than 24 h,with the operation time solely limited by the reservoir capacity.A comparison with the conventional gravity-driven flow demonstrated our device’s capability to produce a more stable flow over the perfusion period.Overall,our module creates a simple,robust solution to produce a stable flow rate in gravity-driven flow systems.The compactness of the design allows easy parallelization and compatibility with high-throughput applications,and the biocompatibility of the materials enables the device’s use with life science applications.展开更多
A method was developed to solve the combined system of the current field and the circuit. The ＂super-node＂ was used to transform the matrix for conventional nodal analyses of a circuit system from non-positive defin...A method was developed to solve the combined system of the current field and the circuit. The ＂super-node＂ was used to transform the matrix for conventional nodal analyses of a circuit system from non-positive definite to positive definite. Then, a positive definite matrix for the overall system was obtained by combining the matrix from the circuit nodal analysis method and the matrix resulted from finite element method （FEM） formulation to solve the FEM fields. This approach has been successfully applied to simulate the electrical potential and current distributions on each metal layer of printed circuit boards （PCBs） and integrated circuit （IC） packages for a given power supply. The simulation results can then be used to analyze the properties of the PCBs and IC packages such as the port resistances and IR drops. The results can also be used to optimize PCB and IC package designs, such as by adjusting the power/ground distribution networks.展开更多
文摘The design and implementation of a novel ADC architecture called ring-ADC for digital voltage regulator module controllers are presented. Based on the principle of voltage-controlled oscillators＇ transform from voltage to frequency,the A/D conversion of ring-ADC achieves good linearity and precise calibration against process variations compared with the delay-line ADC. A differential pulse counting discriminator also helps decrease the power consumption of the ring-ADC. It is fabricated with a Chartered 0.35μm CMOS process, and the measurement results of the integral and differential nonlinearity performance are 0.92LSB and 1.2LSB respectively. The maximum gain error measured in ten sample chips is ± 3.85%. With sampling rate of 500kHz and when the voltage regulator module （VRM） works in steady state, the ring-ADC＇s average power consumption is 2.56mW. The ring-ADC is verified to meet the requirements for digital VRM controller application.
基金supported by the China National Natural Science Foundation(Grant No.32102417)Henan Key R&D Project,China(Grant No.221111110700)+1 种基金Henan Academy of Agricultural Sciences“Innovation and Utilization of Characteristic Flowers and Trees Germplasm”Team Project(Grant Nos.2023TD35 and2024TD26)Hunan Provincial Natural Science Foundation of China(Grant No.2024JJ6711),Natural Science Foundation of Guangxi(Grant No.2024JJB130300)。
文摘Wintersweet(Chimonanthus praecox),a well-known fragrant flowering shrub,is extensively planted for ornamental purpose and production of floral essential oil.Although the tepal color of wintersweet varieties exhibits the most remarkable diversity,variations in the floral scent traits are also noticeable across different cultivars.In this study,the floral volatile organic compounds(VOCs)in three wintersweet cultivars,‘Yanlingsuxin’,‘Yuxiang’,and‘Hongyun’were detected via GC-MS coupled with OAV.The distinct floral aromas of the three cultivars were primarily attributed to benzyl alcohol(abundant in‘Yuxiang’),linalool(abundant in‘Yanlingsuxin’),(-)-γ-cadinene and eugenol(abundant in‘Hongyun’).Integrated analyses of metabolome and transcriptome showed that an R2R3-MYB transcription factor gene,CpODO1,potentially have a crucial regulatory function in controlling the production of multiple aroma compounds.Overexpression of CpODO1 can enhance the production of benzyl alcohol in transgenic tobacco flowers.Analysis of DAP-seq data,EMSA and dual-luciferase assay revealed that CpODO1 predominantly regulate the expression of CpCYP71,a cytochrome P450 gene encoding a key enzyme in the production of benzyl alcohol,and the transcriptional regulation of CpODO1 is driven by CpEOBII.The identification of polymorphisms in the MYB binding cis-motifs of CpCYP71 and CpODO1 promoters revealed the regulatory mechanism underlying the varied synthesis of benzyl alcohol in three wintersweet cultivars.This study provides new anchor points for floral scent quality improvement breeding of wintersweet,and the profusion of wintersweet germplasm can serve as a material basis for developing various aroma products.
文摘A new approach for the design and implementation of a programmable voltage reference based on an improved current mode bandgap voltage reference is presented. The circuit is simulated and fabricated with Chartered 0. 35μm mixed-signal technology. Measurements demonstrate that the temperature coefficient is ± 36. 3ppm/℃ from 0 to 100℃ when the VID inputs are 11110.As the supply voltage is varied from 2.7 to 5V, the voltage reference varies by about 5mV. The maximum glitch of the transient response is about 20mV at 125kHz. Depending on the state of the five VID inputs,an output voltage between 1.1 and 1.85V is programmed in increments of 25mV.
文摘Cystic fibrosis(CF)is an autosomal recessive disorder caused by mutations in the CF transmembrane conductance regulator gene.CF liver disease develops in 5%-10%of patients with CF and is the third leading cause of death among patients with CF after pulmonary disease or lung transplant complications.We review the pathogenesis,clinical presentations,complications,diagnostic evaluation,effect of medical therapies especially CF transmembrane conductance regulator modulators and liver transplantation in CF associated liver disease.
基金Supported by a grant from the University Hospitals Fellowship Research Award Program(FRAP)
文摘BACKGROUND Hepatic steatosis is a common form of cystic fibrosis associated liver disease(CFLD)seen in an estimated 15%-60%of patients with cystic fibrosis(CF).The pathophysiology and health implications of hepatic steatosis in cystic fibrosis remain largely unknown.In the general population,hepatic steatosis is strongly associated with insulin resistance and type 2 diabetes.Cystic fibrosis related diabetes(CFRD)impacts 40%-50%of CF adults and is characterized by both insulin insufficiency and insulin resistance.We hypothesized that patients with CFRD would have higher levels of hepatic steatosis than cystic fibrosis patients without diabetes.AIM To determine whether CFRD is associated with hepatic steatosis and to explore the impact of lumacaftor/ivacaftor therapy on hepatic steatosis in CF.METHODS Thirty patients with CF were recruited from a tertiary care medical center for this cross-sectional study.Only pancreatic insufficient patients with CFRD or normal glucose tolerance(NGT)were included.Patients with established CFLD,end stage lung disease,or persistently elevated liver enzymes were excluded.Mean magnetic resonance imaging(MRI)proton density fat fraction(PDFF)was obtained for all participants.Clinical characteristics[age,sex,body mass index,percent predicted forced expiratory volume at 1 s(FEV1),lumacaftor/ivacaftor use]and blood chemistries were assessed for possible association with hepatic steatosis.Hepatic steatosis was defined as a mean MRI PDFF>5%.Patients were grouped by diabetes status(CFRD,NGT)and cystic fibrosis transmembrane conductance regulator(CFTR)modulator use(lumacaftor/ivacaftor,no lumacaftor/ivacaftor)to determine between group differences.Continuous variables were analyzed with a Wilcoxon rank sum test and discrete variables with a Chi square test or Fisher’s exact test.RESULTS Twenty subjects were included in the final analysis.The median age was 22.3 years(11.3-39.0)and median FEV1 was 77%(33%-105%).Twelve subjects had CFRD and 8 had NGT.Nine subjects were receiving lumacaftor/ivacaftor.The median PDFF was 3.0%(0.0%-21.0%).Six subjects(30%)had hepatic steatosis defined as PDFF>5%.Hepatic fat fraction was significantly lower in patients receiving lumacaftor/ivacaftor(median,range)(2.0%,0.0%-6.4%)than in patients not receiving lumacaftor/ivacaftor(4.1%,2.7-21.0%),P=0.002.Though patients with CFRD had lower PDFF(2.2%,0.0%-14.5%)than patients with NGT(4.9%,2.4-21.0%)this did not reach statistical significance,P=0.06.No other clinical characteristic was strongly associated with hepatic steatosis.CONCLUSION Use of the CFTR modulator lumacaftor/ivacaftor was associated with significantly lower hepatic steatosis.No association between CFRD and hepatic steatosis was found in this cohort.
基金supported by the NIH award 1R21NS120088the MIT School of Engineering Postdoctoral Fellowship Program for Engineering Excellence.
文摘Fluid flow is a ubiquitous aspect of microfluidic systems.Gravity-driven flow is one microfluidic flow initiation and maintenance mechanism that is appealing because it is simple,requires no external power source,and is easy to use.However,the driving forces created by hydraulic head differences gradually decrease during operation,resulting in decreasing flow rates that are undesirable in many microfluidic applications such as perfusion culture,droplet microfluidics,etc.Existing methods to maintain a constant gravity-driven flow either require additional control equipment,involve complex fabrication or operation,are incompatible with miniaturization,or introduce interfaces that lack robustness.Here we tackled those problems by introducing a 3D-printed compact hydraulic head auto-regulating module that automatically maintains a constant fluid level at the microfluidic inlet port without human intervention.Our module successfully maintained a constant hydraulic head for more than 24 h,with the operation time solely limited by the reservoir capacity.A comparison with the conventional gravity-driven flow demonstrated our device’s capability to produce a more stable flow over the perfusion period.Overall,our module creates a simple,robust solution to produce a stable flow rate in gravity-driven flow systems.The compactness of the design allows easy parallelization and compatibility with high-throughput applications,and the biocompatibility of the materials enables the device’s use with life science applications.
文摘A method was developed to solve the combined system of the current field and the circuit. The ＂super-node＂ was used to transform the matrix for conventional nodal analyses of a circuit system from non-positive definite to positive definite. Then, a positive definite matrix for the overall system was obtained by combining the matrix from the circuit nodal analysis method and the matrix resulted from finite element method （FEM） formulation to solve the FEM fields. This approach has been successfully applied to simulate the electrical potential and current distributions on each metal layer of printed circuit boards （PCBs） and integrated circuit （IC） packages for a given power supply. The simulation results can then be used to analyze the properties of the PCBs and IC packages such as the port resistances and IR drops. The results can also be used to optimize PCB and IC package designs, such as by adjusting the power/ground distribution networks.
