A CMOS Dynamic Comparator for Pipelined ADCs with Improved Speed/Power Ratio

This paper presents a fully-differential CMOS dynamic comparator for use in high-speed pipelined ADCs with low stage resolution. Because the architecture is based on the coupled current sources and differential input pairs, this comparator＇s threshold voltage can be adjusted to a desired level. Compared with traditional comparators, this one shows significant improvement in area,power,and speed. Fabricated in 0.35μm CMOS technology,it occupies only 30μm × 70μm. Simulation and measurement results indicate the comparator has a sampling frequency up to 1GHz with 2Vpp differential input signal range and only 181μW power consumption under a 3.3V supply. The speed/power ratio reaches up to 5524GS/J.

A Time-Domain Comparator Based Skipping-Window SAR ADC

This paper presents an energy efficient successive-approximation register(SAR)analog-to-digital converter(ADC)for low-power applications.To improve the overall energy-efficiency,a skipping-window technique is used to bypass corresponding conversion steps when the input falls in a window indicated by a time-domain comparator,which can provide not only the polarity of the input,but also the amount information of the input.The timedomain comparator,which is based on the edge pursing principle,consists of delay cells,two NAND gates,two D-flip-flop register-based phase detectors and a counter.The digital characteristic of the comparator makes the design more flexible,and the comparator can achieve noise and power optimization automatically by simply adjusting the delay cell number.An energy efficient digital-to-analog converter(DAC)control scheme suitable for the skipping window technique is also developed to reduce the switching energy during SAR conversion.Together with the skipping-window technique,the linearity and the power consumption of the SAR ADC are improved.The impact of different window sizes on comparison cycles,DAC switching energy and the overall energy efficiency is analyzed.Simulation results show that the proposed skipping-window technique can improve the overall energy-efficiency of the SAR ADC,as well as the linearity,and the optimized window size for the overall energy efficiency will vary with the DAC switching energy.

THE DESIGN OF THE HIGH SPEED AND HIGH PRECISION LATCHING VOLTAGE COMPARATOR ZJ03

The design of a new type of latching voltage comparator ZJ03 is described.Thecommon voltage comparators consist of multistage DC amplifiers,for which it is difficult to realizehigh speed and high precision.The ZJ03 comparator contains a controlled positive feedbackamplifier.Therefore,it is capable of realizing high speed and high precision.For improving theperformance and producibility,the tolerance extension,design centering and potential adaptingtechniques are used in the design of comparator ZJ03.

A Novel Power Optimization Method by Minimum Comparator Number Algorithm for Pipeline ADCs

The effects of stage numbers on power dissipation of pipeline analog-to-digital converter （ADC） are studied and a novel design method aiming for power optimization is presented. In this method, a minimum comparator number algorithm （MCNA） is first introduced, and then the optimum distribution of resolutions through pipeline ADC stages is deduced by MCNA. Based on the optimum stage-resolution distribution, an optimization method is established, which examines the precise function between ADC power and stage resolutions with a parameter of power ratio （Rp）. For 10-bit pipeline ADC with scaling down technology, the simulation results by using MATLAB CAD tools show that an eight-stage topology with 1-bit RSD correction achieves the power optimization indicated by the power reduction ratio.

Novel Design of Low-power Multiplex Differential Voltage Comparators

A novel design of multiplex differential voltage comparators(MDVC) is presented for reducing current and power dissipation. According to the special properties of relational operation and logical operation, parts of the comparators are redundant in some instances, and thus can be turned off. By selecting and switching the current routes, several effective differential pairs are biased by a single tail current stage-by-stage and the redundant comparators are turned off by cutting their tail currents. As a result, the quiescent current and power consumption are greatly decreased. The switching of current is achieved by the input differential pair transistors themselves and hence no extra switches are required. When a MDVC is used in a flash analog-to-digital converter(ADC), its current dissipation is much lower than that of the conventional comparators. This architecture can also be used in window-comparators, maximum or minimum comparators, and comparators for logical operations. The power dissipation in all these cases could be reduced significantly.

Comparative transcriptome analysis between rhesus macaques(Macaca mulatta) and crab-eating macaques(M. fascicularis)

Understanding gene expression variations between species is pivotal for deciphering the evolutionary diversity in phenotypes. Rhesus macaques(Macaca mulatta, MMU)and crab-eating macaques(M. fascicularis, MFA) serve as crucial nonhuman primate biomedical models with different phenotypes. To date, however, large-scale comparative transcriptome research between these two species has not yet been fully explored. Here, we conducted systematic comparisons utilizing newly sequenced RNA-seq data from84 samples(41 MFA samples and 43 MMU samples)encompassing 14 common tissues. Our findings revealed a small fraction of genes(3.7%) with differential expression between the two species, as well as 36.5% of genes with tissue-specific expression in both macaques. Comparison of gene expression between macaques and humans indicated that 22.6% of orthologous genes displayed differential expression in at least two tissues. Moreover,19.41% of genes that overlapped with macaque-specific structural variants showed differential expression between humans and macaques. Of these, the FAM220A gene exhibited elevated expression in humans compared to macaques due to lineage-specific duplication. In summary,this study presents a large-scale transcriptomic comparison between MMU and MFA and between macaques and humans. The discovery of gene expression variations not only enhances the biomedical utility of macaque models but also contributes to the wider field of primate genomics.

A 0.5-V, 1.2-GS/s, 6-Bit Flash ADC Using Temporarily-Boosted Comparator

A low-voltage, high-speed flash ADC is designed. The bottleneck of the operation speed in the low-voltage region is the delay time increase of the comparator. The temporarily boosted comparator is proposed to address this problem. The proposed circuit only boosts the supply voltage in the comparison phase, and therefore, can reduce the delay time while keeping the power overhead to a minimum. Moreover, the body bias control calibration is combined with the temporarily boosted technique. This helps to create a low-power and high-precision comparator. A 0.5-V, 6-bit flash ADC was designed by using 65-nm CMOS technology to demonstrate the effectiveness of the proposed technique. The simulation results showed a high sampling frequency of 1.2 GHz, a low power consumption of 1.4 mW, and an FOM of 28 fJ/conv.-step even at a low supply voltage of 0.5 V.

A Two-Dimension Time-Domain Comparator for Low Power SAR ADCs

This paper presents a two-dimension time-domain comparator suitable for low power successive-approximation register(SAR)analog-to-digital converters(ADCs).The proposed two-dimension time-domain comparator consists of a ring oscillator collapse-based comparator and a counter.The propagation delay of a voltage controlled ring oscillator depends on the input.Thus,the comparator can automatically change the comparison time according to its input difference,which can adjust the power consumption of the comparator dynamically without any control logic.And a counter is utilized to count the cycle needed to finish a comparison when the input difference is small.Thus,the proposed comparator can not only provide the polarity of the input,but also the amount information of the input,which helps to skip most of the SAR cycles when the initial input is small.Thus,most energy can be saved when the initial input is small.The proposed time-domain comparator is designed in 0.18μm CMOS technology.Simulation results demonstrate that the comparator can not only save power consumption,but also give the design flexibility,and the current is only nA level when the supply voltage is 0.6 V.

Design of Low Power Comparator Using DG Gate

In recent studies, reversible logic has emerged as a great scene of research, having applications in low power CMOS circuits, optical computing, quantum computing and nanotechnology. The classical logic gates such as AND, OR, EXOR and EXNOR are not reversible. In the existing literature, reversible sequential circuits designs are offered that are improved for the number of the garbage outputs and reversible gates. Minimizing the number of garbage is very noticeable. In the present paper, we show a design of the reversible comparator based on the quantum gates implementation of the reversible DG gate. The reversible DG gate is designed by using 3 × 3 quantum gates such as NOT, CNOT, Controlled-V and Controlled-V+ gates. Also, we have used the TR gate and various types of quantum gates in the implementation results. Low power three-bit comparator is designed using DG Gate, New Gate and Fredkin Gate. In order to evaluate the benefit of using the DG gate proposed in this paper, one-bit comparator is constructed. The design is useful for the future computing techniques like quantum computers. The proposed designs are implemented using VHDL and functionally investigated using Quartus II simulator.

Comparative efficacy of proximal femoral nail vs dynamic condylar screw in treating unstable intertrochanteric fractures

BACKGROUND Among the most frequent hip fractures are trochanteric fractures,which usually occur from low-energy trauma like minor falls,especially in older people with osteoporotic bones.AIM To evaluate the treatment efficacy of dynamic condylar screws(DCS)and proximal femoral nails(PFN)for unstable intertrochanteric fractures.METHODS To find pertinent randomized controlled trials and retrospective observational studies comparing PFN with DCS for the management of unstable femoral intertrochanteric fractures,a thorough search was carried out.For research studies published between January 1996 and April 2024,PubMed,EMBASE,Scopus,Web of Science,Cochrane Library,and Google Scholar were all searched.The complete texts of the papers were retrieved,vetted,and independently examined by two investigators.Disputes were settled by consensus,and any disagreements that persisted were arbitrated by a third author.RESULTS This study included six articles,comprising a total of 173 patients.Compared to the DCS,the PFN had a shorter operation time[mean difference(MD):-41.7 min,95%confidence interval(95%CI):-63.04 to-20.35,P=0.0001],higher success rates with closed reduction techniques[risk ratio(RR):34.05,95%CI:11.12-104.31,P<0.00001],and required less intraoperative blood transfusion(MD:-1.4 units,95%CI:-1.80 to-1.00,P<0.00001).Additionally,the PFN showed shorter fracture union time(MD:-6.92 wk,95%CI:-10.27 to-3.57,P<0.0001)and a lower incidence of reoperation(RR:0.37,95%CI:0.17-0.82,P=0.01).However,there was no discernible variation regarding hospital stay,implant-related complications,and infections.CONCLUSION Compared to DCS,PFN offers shorter operative times,reduces the blood transfusions requirements,achieves higher closed reduction success,enables faster fracture healing,and lowers reoperation incidence.

Single-Bit Comparator in Quantum-Dot Cellular Automata (QCA) Technology Using Novel QCAXNOR Gates

To fill the continuous needs for faster processing elements with less power consumption causes large pressure on the complementary metal oxide semiconductor(CMOS)technology developers.The scaling scenario is not an option nowadays and other technologies need to be investigated.The quantum-dot cellular automata(QCA)technology is one of the important emerging nanotechnologies that have attracted much researchers’attention in recent years.This technology has many interesting features,such as high speed,low power consumption,and small size.These features make it an appropriate alternative to the CMOS technique.This paper suggests three novel structures of XNOR gates in the QCA technology.The presented structures do not follow the conventional approaches to the logic gates design but depend on the inherent capabilities of the new technology.The proposed structures are used as the main building blocks for a single-bit comparator.The resulted circuits are simulated for the verification purpose and then compared with existing counterparts in the literature.The comparison results are encouraging to append the proposed structures to the library of QCA gates.

Analysis on the Magnetic Shielding Effectiveness of DC Current Comparator

There are magnetic interference problems in the applications of DC current comparator. Analysis on the magnetic effectiveness which is applied by the external magnetic field is introduced in this paper. The effectiveness is proved by the actual results which are compared with the magnetic- circuit method and the finite element method. In addition, the reference comment is given which can be used in the practical work of DC current comparator shield design.

Descriptive and Comparative Histology of the Urinary System of the Hematophagous Bats Desmodus rotundus and Diphylla ecaudata

Desmodus rotundus and Diphylla ecaudata, both of which are mammals of the order Chiroptera, Desmodontidae family, their diet consisting exclusively of blood. D. rotundus is the main vector and transmitter of the rabies virus, which affects human beings as well as several livestock species so the study of this bat species is of high importance within the fields of animal agriculture and public health. The present study describes and compares the histologic characteristics of the urinary system of two hematophagous bat species. A total of 5 bats from each species were captured in the municipalities of Progreso de Obregón, Hidalgo (D. rotundus), and Huayacocotla, Veracruz (D. ecaudata). Organs belonging to the urinary system were extracted: kidneys, ureters, urinary bladder, and urethra;samples were fixed using 10% formalin and processed by the paraffin embedding technique, obtaining sections of 5 µm thickness, which in turn were stained using hematoxylin-eosin (H-E) and Gomori trichrome (GT) stains. From the obtained histologic preparations, a descriptive and comparative analysis of the structural organography of the urinary system of both species was made, and no noteworthy histological differences between samples were noted. The present research is intended to provide a framework for future studies of these species’ currently understudied microscopic anatomy.

Comparative Orotomy of the Archean Superior,North China,and Phanerozoic Altaid Orogenic Systems Architecture

Geological maps encode vast amounts of data about rock types,ages,chemistry,orogenic architecture and deep-time history or different tectonic units,yet these are often difficult to extract because of the way different geologists portray their results at various scales.To understand orogenesis in 4D,it is essential to uniformly integrate map data,together with geophysical data and deep geochemical mapping(Wang et al.,2023).

Rice-wheat comparative genomics:Gains and gaps

Rice and wheat provide nearly 40%of human calorie and protein requirements.They share a common ancestor and belong to the Poaceae(grass)family.Characterizing their genetic homology is crucial for developing new cultivars with enhanced traits.Several wheat genes and gene families have been characterized based on their rice orthologs.Rice–wheat orthology can identify genetic regions that regulate similar traits in both crops.Rice–wheat comparative genomics can identify candidate wheat genes in a genomic region identified by association or QTL mapping,deduce their putative functions and biochemical pathways,and develop molecular markers for marker-assisted breeding.A knowledge of gene homology facilitates the transfer between crops of genes or genomic regions associated with desirable traits by genetic engineering,gene editing,or wide crossing.

Comparative genomic analysis revealed that dietary habits affected the adaptation of Bifidobacterium bifidum to the intestinal tract in different geographic populations

Recent research on the genome of Bifidobacterium bifidum has mainly focused on the isolation sources(intestinal tract niche)recently,but reports on the isolation region are limited.This study analyzed the differences in the genome of B.bifidum isolated from different geographical populations by comparative genomic analysis.Results at the genome level indicated that the GC content of American isolates was significantly higher than that of Chinese and Russian isolates.The phylogenetic tree,based on 919 core genes showed that B.bifidum might be related to the geographical characteristics of isolation region.Furthermore,functional annotation analysis demonstrated that copy numbers of carbohydrate-active enzymes(CAZys)involved in the degradation of polysaccharide from plant and host sources in B.bifidum were high,and 18 CAZys showed significant differences across different geographical populations,indicating that B.bifidum had adapted to the human intestinal environment,especially in the groups with diets rich in fiber.Dietary habits were one of the main reasons for the differences of B.bifidum across different geographical populations.Additionally,B.bifidum exhibited high diversity,evident in glycoside hydrolases,the CRISPR-Cas system,and prophages.This study provides a genetic basis for further research and development of B.bifidum.

Comparative and Phylogenetic Analysis of the Complete Chloroplast Genomes of 19 Species in Rosaceae Family

Rosaceae represents a vast and complex group of species,with its classification being intricate and contentious.The taxonomic placement of many species within this family has been a subject of ongoing debate.The study utilized the Illumina platform to sequence 19 plant species from 10 genera in the Rosaceae.The cp genomes,vary-ing in size from 153,366 to 159,895 bp,followed the typical quadripartite organization consisting of a large single-copy(LSC)region(84,545 to 87,883 bp),a small single-copy(SSC)region(18,174 to 19,259 bp),and a pair of inverted repeat(IR)regions(25,310 to 26,396 bp).These genomes contained 132–138 annotated genes,including 87 to 93 protein-coding genes(PCGs),37 tRNA genes,and 8 rRNA genes using MISA software,52 to 121 simple sequence repeat(SSR)loci were identified.D.arbuscular contained the least of SSRs and did not have hexanotides,A.lineata contained the richest SSRs.Long terminal repeats(LTRs)were primarily composed of palindromic and forward repeat sequences,meanwhile,The richest LTRs were found in Argentina lineata.Except for Argentina lineata,Fragariastrum eriocarpum,and Prunus trichostoma,which varied in gene type and position on both sides of the boundary,the remaining species were found to be mostly conserved according to IR boundary analysis.The examination of the Ka/Ks ratio revealed that only the infA gene had a value greater than 1,indicating that this gene was primarily subjected to positive selection during evolution.Additionally,9 hotspots of variation were identified in the LSC and SSC regions.Phylogenetic analysis confirmed the scientific validity of the genus Prunus L.sensu lato(s.l.)within the Rosaceae family.The separation of the three genera Argentina Hill,Fragariastrum Heist.ex Fabr.and Dasiphora Raf.from Potentilla L.may be a more scientific classification.These results offer fresh perspectives on the taxonomy of the Rosaceae.

Exploring Nominalization in English Abstracts of Applied Linguistics Research Articles:A Comparative Study Between Chinese and International Journals

Researchers around the world strive to communicate new knowledge,primarily via publication,with the abstract being crucial in conveying core insights.Previous research has generally analyzed the discourse features of abstracts from a macro perspective and often employed either outdated texts,such as those over a decade old,or papers written by authors with lower English academic writing proficiency as research material.In this study,we analyzed forty abstracts from leading journals in applied linguistics,evenly split between Chinese and international journals.It revealed that the use of nominalization in abstracts by Chinese and international scholars showed similarities due to the universal academic requirement for conciseness.However,due to cultural and educational differences,each group differed in their respective language choices and nominalization usage.By analyzing the application of nominalization in different cultural contexts,the results of our study offered practical suggestions for crafting abstracts that effectively convey information,thereby,contributing to the broader academic community.

Comparative proteomics analysis reveals the domesticated Lepista sordida primordium differentiation regulation mechanism and the subsequent different development patterns in the pileus and stipe

The wild Lepista sordida is a kind of precious and rare edible fungus.An excellent strain of it by artificial domestication was obtained,which was high-yield and high in iron content.In this study,high-throughput comparative proteomics was used to reveal the regulatory mechanism of its primordium differentiation in the early fruiting body formation.The mycelium before the primordium differentiation mainly expressed high levels of mitochondrial functional proteins and carbon dioxide concentration regulatory proteins.In young mushrooms,the highly expressed proteins were mainly involved in cell component generation,cell proliferation,nitrogen compound metabolism,nucleotide metabolism,glutathione metabolism,and purine metabolism.The differential regulation patterns of pileus and stipe growth to maturity were also revealed.The highly expressed proteins related to transcription,RNA splicing,the production of various organelles,DNA conformational change,nucleosome organization,protein processing,maturation and transport,and cell detoxification regulated the pileus development and maturity.The proteins related to carbohydrate and energy metabolism,large amounts of obsolete cytoplasmic parts,nutrient deprivation,and external stimuli regulated the stipe development and maturity.Multiple CAZymes regulated nutrient absorption,morphogenesis,spore production,stress response,and other life activities at different growth and development stages.

The relationship between compartment models and their stochastic counterparts:A comparative study with examples of the COVID-19 epidemic modeling

Deterministic compartment models(CMs)and stochastic models,including stochastic CMs and agent-based models,are widely utilized in epidemic modeling.However,the relationship between CMs and their corresponding stochastic models is not well understood.The present study aimed to address this gap by conducting a comparative study using the susceptible,exposed,infectious,and recovered(SEIR)model and its extended CMs from the coronavirus disease 2019 modeling literature.We demonstrated the equivalence of the numerical solution of CMs using the Euler scheme and their stochastic counterparts through theoretical analysis and simulations.Based on this equivalence,we proposed an efficient model calibration method that could replicate the exact solution of CMs in the corresponding stochastic models through parameter adjustment.The advancement in calibration techniques enhanced the accuracy of stochastic modeling in capturing the dynamics of epidemics.However,it should be noted that discrete-time stochastic models cannot perfectly reproduce the exact solution of continuous-time CMs.Additionally,we proposed a new stochastic compartment and agent mixed model as an alternative to agent-based models for large-scale population simulations with a limited number of agents.This model offered a balance between computational efficiency and accuracy.The results of this research contributed to the comparison and unification of deterministic CMs and stochastic models in epidemic modeling.Furthermore,the results had implications for the development of hybrid models that integrated the strengths of both frameworks.Overall,the present study has provided valuable epidemic modeling techniques and their practical applications for understanding and controlling the spread of infectious diseases.