This paper presents an analytical model for calculating the Earth discontinuous coverage of satellite constellation with repeating ground tracks by integrating and extending the application of coverage region and rout...This paper presents an analytical model for calculating the Earth discontinuous coverage of satellite constellation with repeating ground tracks by integrating and extending the application of coverage region and route theory.Specifically,the visibility condition for a ground point is represented as a coverage region in the two-dimension map of visibility properties,and the trajectories of satellites with circular orbits and repeating ground tracks are converted to several inclined lines in the map.By analyzing the intersections of the lines and the edge of the coverage region,the coverage durations for the ground point can be calculated.Based on the point coverage,the variations of coverage characteristics along the parallel are analyzed,and the regional or global coverage characteristics of constellations can be obtained.Numerical examples show that the proposed method can accurately and rapidly calculate the coverage characteristics,e.g.revisit time and coverage time.The calculated results are extremely close to those of the Satellite Tool Kit(STK)and are also superior to the existing research results.The proposed analytical model can be a useful tool for constellation design and coverage performance analysis.展开更多
Regionalized location accuracy of the China National Seismograph Network was estimated using the results obtained by studying “repeating earthquakes" or “doublets" in and around China by Schaff and Richard...Regionalized location accuracy of the China National Seismograph Network was estimated using the results obtained by studying “repeating earthquakes" or “doublets" in and around China by Schaff and Richards (2004). It is assumed that the “repeating events" or “doublets" are separated by no more than 1km, and the network measured apparent distance X of “doublets" indicates the order of magnitudes of the location error. It is observed that the average location accuracy of the China National Seismograph Network, as represented by average X value, is in the order of magnitudes of 10km, and is larger in the Qinghai-Xizang (Tibet) Plateau, western and northern Xinjiang, and eastern Inner Mongolia.展开更多
A novel strategy to enhance the expression efficiency of cloned target gene in Escherichia coli was developed. The whole expression cartridge , consisting of promoter. SD sequence , target gene and transcription termi...A novel strategy to enhance the expression efficiency of cloned target gene in Escherichia coli was developed. The whole expression cartridge , consisting of promoter. SD sequence , target gene and transcription terminator, was tandem repeatedly engineered into a expression plasmid. Consequently, the copy number of specific gene was increased substantially, leading to the improvement of expression efficiency.Using this approach, a recombinant plasmid , designed as PLYD, was constructed and transformated into the Escherichia coli strain DH5α. Upon induction , the desired protein was synthesized in a considerable level and accumulated up to 63% of the total cell proteins. The present study revealed that tandem repeating of expression cartridge provided a convenient means to improve expression level efficiently.展开更多
"Repeating earthquakes",identified by cross-correlation of seismic waveforms,are found to be much more abundant in the nature than conventionally expected. In recent years, with the development of digital se..."Repeating earthquakes",identified by cross-correlation of seismic waveforms,are found to be much more abundant in the nature than conventionally expected. In recent years, with the development of digital seismic networks, waveform cross correlation and "repeating earthquakes"have caused much attention to the measuring the variation of crustal medium properties and estimation of location accuracy and fault slip rate at depth or earthquake recurrence intervals. Moreover, as a useful tool, the "repeating earthquake" approach has also been used in the assessment of the accuracy of seismic phase picking,hypocenter location,fault structure and physics of earthquake sources,as well as the study of earthquake prediction. In this paper, we summarized the latest research and applications of "repeating earthquakes".展开更多
The Haicheng-Xiuyan region is an earthquake-prone area in Liaoning Province where earthquake sequences frequently occur and is regarded as the regional seismic window. In this area we found many earthquake events with...The Haicheng-Xiuyan region is an earthquake-prone area in Liaoning Province where earthquake sequences frequently occur and is regarded as the regional seismic window. In this area we found many earthquake events with the highest waveform similarity in the records of the same station from some remarkable seismic sequences,namely repeating earthquake sequences. In principle,rupture areas of the repeating events overlap with each other and are most closely located. Therefore these events may reflect the seismic process near the earthquake fault. In this paper, we identified four remarkable earthquake sequences of Haicheng-Xiuyan by waveform cross-correlation. The result shows that the cumulative slip of repeating earthquakes is related to moderately strong earthquakes,among which the Xiuyan M_S5. 4 foreshock sequence has the strongest and most apparent pre-shock accelerating-like slip behavior.展开更多
Fast radio bursts(FRBs)are extremely energetic,millisecond-duration flashes of radio waves that represent one of the most intriguing phenomena in astronomy.Their cosmological distances,immense energy outputs,and poten...Fast radio bursts(FRBs)are extremely energetic,millisecond-duration flashes of radio waves that represent one of the most intriguing phenomena in astronomy.Their cosmological distances,immense energy outputs,and potential links to other high-energy astrophysical events make them particularly valuable for probing a wide range of fundamental physics(e.g.,ref.[1]).展开更多
Plastome variation,including single spontaneous nucleotide substitutions and single insertions/deletions,is the major source of leaf variegation in plants.Additionally,one recent study has showed that a simple plastom...Plastome variation,including single spontaneous nucleotide substitutions and single insertions/deletions,is the major source of leaf variegation in plants.Additionally,one recent study has showed that a simple plastome structural variation,which is induced by one pair of small inverted repeats,can also result in leaf variegation.Here we show a complex plastome structural variation caused by intermolecular and intramolecular recombination across three pairs of small inverted repeats accounts for leaf variegation in a widely cultivated shrub Heptapleurum ellipticum(Araliaceae).This plastome structural variation contains two deletions and two duplications,resulting in dramatic expansion of IRs,substantial contraction of LSC and loss of 11 genes that essential for photosynthesis.Plastome heteroplasmy was detected in both green and albino sectors of variegated leaves.Relative to green sectors,albino sectors in the variegated leaves exhibit significantly reduced expression for the 11 genes lost in the mutated plastome as well as 26 other genes,but significantly increased expression for one gene related to translation apparatus.Optical and transmission electron microscopy observations showed that mesophyll cells of albino sectors possess plastids lacking grana lamellae,which likely carry the mutated plastome and contribute to albinism.In both sectors,the first layer of spongy mesophyll cells beneath the lower epidermis contains normal chloroplasts,suggesting periclinal division of the lower epidermis during development.Our study demonstrates that multiple small repeats can collectively mediate intra-and inter-molecular recombination in plastome and offers a new mechanism accounting for leaf variegation in plants.展开更多
Background:Tandem gene repeats naturally occur as important genomic features and determine many traits in living organisms,like human diseases and microbial productivities of target bioproducts.Methods:Here,we develop...Background:Tandem gene repeats naturally occur as important genomic features and determine many traits in living organisms,like human diseases and microbial productivities of target bioproducts.Methods:Here,we developed a bacterial type-II toxin-antitoxin-mediated method to manipulate genomic integration of tandem gene repeats in Saccharomyces cerevisiae and further visualised the evolutionary trajectories of gene repeats.We designed a tri-vector system to introduce toxin-antitoxin-driven gene amplification modules.Results:This system delivered multi-copy gene integration in the form of tandem gene repeats spontaneously and independently from toxin-antitoxin-mediated selection.Inducing the toxin(RelE)expressing via a copper(II)-inducible CUP1 promoter successfully drove the in-situ gene amplification of the antitoxin(RelB)module,resulting in~40 copies of a green fluorescence reporter gene per copy of genome.Copy-number changes,copy-number increase and copy-number decrease,and stable maintenance were visualised using the green fluorescence protein and blue chromoprotein AeBlue as reporters.Copy-number increases happened spontaneously and independent on a selection pressure.Increased copy number was quickly enriched through toxin-antitoxin-mediated selection.Conclusion:In summary,the bacterial toxin-antitoxin systems provide a flexible mechanism to manipulate gene copy number in eukaryotic cells and can be exploited for synthetic biology and metabolic engineering applications.展开更多
This study investigates the genetic variability and environmental adaptability of Acacia hybrid clones across three distinct ecological regions,providing insights into growth characteristics and stem quality for futur...This study investigates the genetic variability and environmental adaptability of Acacia hybrid clones across three distinct ecological regions,providing insights into growth characteristics and stem quality for future breeding strategies.42 natural hybrid clones were evaluated over a five-year period in three clonal trials in northern,central and southern Vietnam for height(HT),diameter at breast height(DBH),volume(VOL),trunk straightness(STR),branch size(BRA)and survival.Significant clonal differences were found in all traits across all three regions.From age 2-5,the clone repeatability(H_(C)^(2))for growth traits improved from 0.19 to 0.59,indicating substantial genetic control.Genotypic coefficients of variation(CVG)for volume ranged from 21%to 34%,suggesting significant potential for genetic improvement.Site-to-site genotypic correlations ranged from 0.53 to 0.78,pointing to the existence of genotype-environment interactions.Clones derived from Acacia mangium material demonstrated enhanced growth,while the hybrid clones exhibited superior stem quality,particularly in terms of straightness.The findings emphasize the importance of selecting clones that are adapted to specific environmental conditions,with both growth and quality traits considered in breeding programs.展开更多
Objective This study aimed to determine the temporal trends in sleep duration among Chinese adults.Methods In this series of repeated nationally representative cross-sectional surveys(China Chronic Disease and Risk Fa...Objective This study aimed to determine the temporal trends in sleep duration among Chinese adults.Methods In this series of repeated nationally representative cross-sectional surveys(China Chronic Disease and Risk Factors Surveillance)conducted between 2010 and 2018,a total of 645,420 adult participants(97,741 in 2010;175,749 in 2013;187,777 in 2015;and 184,153 in 2018)were included in the trend analysis.Linear and logistic regression models were utilized to assess trends in sleep duration.Results In 2018,the estimated overall mean sleep duration among the Chinese adult population was7.58(SD,1.45)hours per day,with no significant trend from 2010.A significant increase in short sleep duration(≤6 hours)was observed in the total population,from 15.3%(95%CI:14.1%–16.5%)in 2010 to18.5%(95%CI:17.7%–19.3%)in 2018(P<0.001).Similarly,the trend in long sleep duration(>9 hours)was also significant,increasing in weighted prevalence from 7.2%(95%CI:6.3%–8.1%)in 2010 to 9.0%(95%CI:8.2%–9.9%)in 2018(P<0.001).Conclusion The prevalence of both short and long sleep durations significantly increased among Chinese adults from 2010 to 2018,highlighting the urgency of health initiatives to promote optimal sleep duration in China.展开更多
BACKGROUND Repeated application of the Pringle maneuver is a key obstacle to safe minimally invasive repeat liver resection(MISRLR).However,limited technical guidance is available.AIM To study the utility of newly dev...BACKGROUND Repeated application of the Pringle maneuver is a key obstacle to safe minimally invasive repeat liver resection(MISRLR).However,limited technical guidance is available.AIM To study the utility of newly developed Pringle taping method guided by liver surface in MISRLR.METHODS We retrospectively reviewed 72 cases of MISRLR performed by a single surgeon at two centers from August 2015 to July 2024.Beginning in October 2019,a liver surface-guided encirclement of hepatoduodenal ligament(LSEH)was used for repeat Pringle taping.Perioperative outcomes including Pringle taping success,operative time,blood loss,conversion rate,morbidity,and mortality were assessed.RESULTS Laparoscopic and robotic approaches were used in 63 patients and 9 patients,respectively.The median operative time,blood loss,and hospital stay were 331.5 minutes,70 mL,and 8 days,respectively.Open conversion occurred in two cases(2.8%)due to severe adhesions and right renal vein injury.Clavien-Dindo grade≥III complications occurred in 5.6%of cases with no mortality.Anti-adhesion barriers were used in 54 patients(75.0%).LSEH was attempted in 57 cases,improving Pringle taping success from 33.0%to 91.4%(P<0.001).LSEH succeeded in all patients with prior open liver resection(n=11).Among 6 patients in whom LSEH failed,3 patients(50.0%)had undergone a third liver resection,and 1 patient had a history of distal gastrectomy with choledochoduodenostomy.CONCLUSION The newly developed LSEH technique for Pringle taping in MISRLR was feasible,enhancing safety and reproducibility even in patients with a history of open liver resection.展开更多
Learning a foreign language like English needs patience and right methods.Grammar,which helps us form correct and clear sentences,is a basic part we can't ignore.We can review grammar rules through textbook exerci...Learning a foreign language like English needs patience and right methods.Grammar,which helps us form correct and clear sentences,is a basic part we can't ignore.We can review grammar rules through textbook exercises.To improve pronunciation,listening to native speakers'conversations on English podcasts and repeating after them works well.展开更多
Neurodegenerative diseases cause great medical and economic burdens for both patients and society;however, the complex molecular mechanisms thereof are not yet well understood. With the development of high-coverage se...Neurodegenerative diseases cause great medical and economic burdens for both patients and society;however, the complex molecular mechanisms thereof are not yet well understood. With the development of high-coverage sequencing technology, researchers have started to notice that genomic repeat regions, previously neglected in search of disease culprits, are active contributors to multiple neurodegenerative diseases. In this review, we describe the association between repeat element variants and multiple degenerative diseases through genome-wide association studies and targeted sequencing. We discuss the identification of disease-relevant repeat element variants, further powered by the advancement of long-read sequencing technologies and their related tools, and summarize recent findings in the molecular mechanisms of repeat element variants in brain degeneration, such as those causing transcriptional silencing or RNA-mediated gain of toxic function. Furthermore, we describe how in silico predictions using innovative computational models, such as deep learning language models, could enhance and accelerate our understanding of the functional impact of repeat element variants. Finally, we discuss future directions to advance current findings for a better understanding of neurodegenerative diseases and the clinical applications of genomic repeat elements.展开更多
The leucine-rich repeat(LRR)protein family is involved in a variety of fundamental metabolic and signaling processes in plants,including growth and defense responses.LRR proteins can be divided into two categories:tho...The leucine-rich repeat(LRR)protein family is involved in a variety of fundamental metabolic and signaling processes in plants,including growth and defense responses.LRR proteins can be divided into two categories:those containing LRR domains along with other structural elements,which are further subdivided into five groups,LRR receptor-like kinases,LRR receptor-like proteins,nucleotide-binding site LRR proteins,LRR-extensin proteins,and polygalacturonase-inhibiting proteins,and those containing only LRR domains.Functionally,various LRR proteins are primarily involved in plant development and responses to environmental stress.Notably,the LRR protein family plays a central role in signal transduction pathways related to stress adaptation.In this review,we classify and analyze the functions of LRR proteins in plants.While extensive research has been conducted on the roles of LRR proteins in disease resistance signaling,these proteins also play important roles in abiotic stress responses.This review highlights recent advances in understanding how LRR proteins mediate responses to biotic and abiotic stresses.Building upon these insights,further exploration of the roles of LRR proteins in abiotic stress resistance may aid efforts to develop rice varieties with enhanced stress and disease tolerance.展开更多
When microdissection testicular sperm extraction(micro-TESE)fails,a redo procedure may be the only option for patients who want a biological child.However,there are many gaps of knowledge surrounding the procedure,whi...When microdissection testicular sperm extraction(micro-TESE)fails,a redo procedure may be the only option for patients who want a biological child.However,there are many gaps of knowledge surrounding the procedure,which need to be addressed to help clinicians and patients make informed decisions.This review explores redo micro-TESE in the context of nonobstructive azoospermia(NOA).Literature was searched using Google Scholar,Medline,and PubMed.Search terms were“NOA”AND“second microdissection testicular sperm extractions”AND“redo microdissection testicles sperm extraction”AND“repeat microdissection testicular sperm extractions”AND“failed microdissection testicular sperm extractions”AND“salvage microdissection testicular sperm extractions”.Only original articles in English were included.A total of nine articles were included,consisting of four retrospective and five prospective studies.The time gap between the first and second micro-TESE varied from 6 months to 24 months.Most of the included studies reported successful surgical sperm retrieval(SSR)in the second micro-TESE in the range of 10%–21%,except in one study where it reached 42%.It has not been presented any definitive information about the use of hormonal treatment or the benefit of varicocelectomy prior to the second micro-TESE.Patients with hypospermatogenesis and Klinefelter syndrome(KS)had the highest chance of success in redo surgery.In conclusion,redo micro-TESE following a negative procedure can lead to sperm recovery in 10%–21%.Patients with hypospermatogenesis and KS have a higher chance of success.There is no enough evidence to conclude which is the best hormonal stimulation if any before a redo surgery.展开更多
Objective Current autosomal short tandem repeat(STR)assays can analyze the zygotic composition by comparing the allelic genes at each locus of complete hydatidiform moles(CHM),with a maternal genotype serving as an es...Objective Current autosomal short tandem repeat(STR)assays can analyze the zygotic composition by comparing the allelic genes at each locus of complete hydatidiform moles(CHM),with a maternal genotype serving as an essential reference for comparative analysis.However,their application in pathology represents a challenge because of deficiency or contamination of maternal-origin tissues.This study aimed to develop a novel STR genotyping method for identifying CHM genotypes without a maternal component.Methods Samples with the pathologic description of molar pregnancy were collected.Routine hematoxylin–eosin(HE)staining and p57 immunohistochemistry staining were conducted in accordance with standard guidelines.A novel 26-plex system was explored to classify CHM and diploid pregnancies.The system combined 22 STRs on chromosomes 21/18/13/X,3 sex loci,and 1 quality control marker(TAF9L),enabling molecular diagnosis in the absence of maternal tissue.At last,traditional DNA typing based on villi and decidua(maternal component)of each case was used for result consistency analysis.Results CHM and nonmolar abortus could not be distinguished by the basic HE staining with no fetal evidence or other prominent features.DNA typing was successfully processed for all cases according to the novel 26-plex and traditional system.CHM(46XX)diagnosis required single A-STR/X-STR peaks and absent Y-chromosome markers,excluding chromosomal abnormalities via TAF9L analysis.When the villous tissue analysis revealed single peaks at X-STR/SRY loci,a 1:1 amelogenin ratio,and a 2:1 TAF9L peak ratio,these results overlapped with those of 46XY hydropic abortus or CHM.Notably,p57 immunohistochemical staining resolved the ambiguity.Consistency with traditional DNA genotyping confirmed system accuracy.This multiplex assay enhanced reliability in mole diagnosis,supporting clinical differentiation and genetic counseling.Conclusion This study presents a rapid and cost-effective assay for the genotypic identification of CHM without the need for a maternal component.The method combined the characteristics of STR loci distributed across different chromosomes and developed the clinic application of forensic biomarkers.展开更多
Nonperiodic interrupted sampling repeater jamming(ISRJ)against inverse synthetic aperture radar(ISAR)can obtain two-dimensional blanket jamming performance by joint fast and slow time domain interrupted modulation,whi...Nonperiodic interrupted sampling repeater jamming(ISRJ)against inverse synthetic aperture radar(ISAR)can obtain two-dimensional blanket jamming performance by joint fast and slow time domain interrupted modulation,which is obviously dif-ferent from the conventional multi-false-target deception jam-ming.In this paper,a suppression method against this kind of novel jamming is proposed based on inter-pulse energy function and compressed sensing theory.By utilizing the discontinuous property of the jamming in slow time domain,the unjammed pulse is separated using the intra-pulse energy function diffe-rence.Based on this,the two-dimensional orthogonal matching pursuit(2D-OMP)algorithm is proposed.Further,it is proposed to reconstruct the ISAR image with the obtained unjammed pulse sequence.The validity of the proposed method is demon-strated via the Yake-42 plane data simulations.展开更多
The emission of anomalous X-ray pulsars(AXPs)and soft gamma-ray repeaters(SGRs)is believed to be powered by the dissipation of their strong magnetic fields,which coined the name“magnetar”.By combining timing and ene...The emission of anomalous X-ray pulsars(AXPs)and soft gamma-ray repeaters(SGRs)is believed to be powered by the dissipation of their strong magnetic fields,which coined the name“magnetar”.By combining timing and energy observational results,the magnetar model can be easily appreciated.From a timing perspective,the magnetic field strengths of AXPs and SGRs,which are calculated under the assumption of dipole radiation,are extremely strong.From an energy perspective,the X-ray/soft gamma-ray luminosities of AXPs and SGRs are larger than their rotational energy loss rates(i.e.,L_(x>E_(rot)).It is thus reasonable to assume that the high-energy radiation comes from magnetic energy decay,and the magnetar model has been extensively discussed(or accepted).However,we argue that:(ⅰ)Calculating magnetic fields by assuming that rotational energy loss is dominated by dipole radiation(i.e.,E_(rot)■E_(μ))may be controversial,and we suggest that the energies carried by outflowing particles should also be considered.(ⅱ)The fact that X-ray luminosity is greater than the rotational energy loss rate does not necessarily mean that the emission energy comes from the magnetic field decaying,which requires further observational testing.Furthermore,some observational facts conflict with the“magnetar”model,such as observations of anti-magnetars,high magnetic field pulsars,and radio and X-ray observations of AXPs/SGRs.Therefore,we propose a crusted strange star model as an alternative,which can explain many more observational facts of AXPs/SGRs.展开更多
Objective Junctophilin-2(JPH2)is an essential structural protein that maintains junctional membrane complexes(JMCs)in cardiomyocytes by tethering the plasma membrane to the sarcoplasmic reticulum,thereby facilitating ...Objective Junctophilin-2(JPH2)is an essential structural protein that maintains junctional membrane complexes(JMCs)in cardiomyocytes by tethering the plasma membrane to the sarcoplasmic reticulum,thereby facilitating excitationcontraction(E-C)coupling.Mutations in JPH2 have been associated with hypertrophic cardiomyopathy(HCM),but the molecular mechanisms governing its membrane-binding properties and the functional relevance of its membrane occupation and recognition nexus(MORN)repeat motifs remain incompletely understood.This study aimed to elucidate the structural basis of JPH2 membrane association and its implications for HCM pathogenesis.Methods A recombinant N-terminal fragment of mouse JPH2(residues 1-440),encompassing the MORN repeats and an adjacent helical region,was purified under near-physiological buffer conditions.X-ray crystallography was employed to determine the structure of the JPH2 MORN-Helix domain.Sequence conservation analysis across species and junctophilin isoforms was performed to assess the evolutionary conservation of key structural features.Functional membrane-binding assays were conducted using liposome co-sedimentation and cell-based localization studies in COS7 and HeLa cells.In addition,site-directed mutagenesis targeting positively charged residues and known HCM-associated mutations,including R347C,was used to evaluate their effects on membrane interaction and subcellular localization.Results The crystal structure of the mouse JPH2 MORN-Helix domain was resolved at 2.6Å,revealing a compact,elongated architecture consisting of multiple tandem MORN motifs arranged in a curved configuration,forming a continuous hydrophobic core stabilized by alternating aromatic residues.A C-terminalα-helix further reinforced structural integrity.Conservation analysis identified the inner groove of the MORN array as a highly conserved surface,suggesting its role as a protein-binding interface.A flexible linker segment enriched in positively charged residues,located adjacent to the MORN motifs,was found to mediate direct electrostatic interactions with negatively charged phospholipid membranes.Functional assays demonstrated that mutation of these basic residues impaired membrane association,while the HCM-linked R347C mutation completely abolished membrane localization in cellular assays,despite preserving the overall MORN-Helix fold in structural modeling.Conclusion This study provides structural insight into the membrane-binding mechanism of the cardiomyocyte-specific protein JPH2,highlighting the dual roles of its MORN-Helix domain in membrane anchoring and protein interactions.The findings clarify the structural basis for membrane targeting via a positively charged linker and demonstrate that disruption of this interaction—such as that caused by the R347C mutation—likely contributes to HCM pathogenesis.These results not only enhance current understanding of JPH2 function in cardiac E-C coupling but also offer a structural framework for future investigations into the assembly and regulation of JMCs in both physiological and disease contexts.展开更多
基金the National Natural Science Foundation of China (No. 12072365)the Hunan Provincial Natural Science Foundation of China (No. 2020JJ4657)
文摘This paper presents an analytical model for calculating the Earth discontinuous coverage of satellite constellation with repeating ground tracks by integrating and extending the application of coverage region and route theory.Specifically,the visibility condition for a ground point is represented as a coverage region in the two-dimension map of visibility properties,and the trajectories of satellites with circular orbits and repeating ground tracks are converted to several inclined lines in the map.By analyzing the intersections of the lines and the edge of the coverage region,the coverage durations for the ground point can be calculated.Based on the point coverage,the variations of coverage characteristics along the parallel are analyzed,and the regional or global coverage characteristics of constellations can be obtained.Numerical examples show that the proposed method can accurately and rapidly calculate the coverage characteristics,e.g.revisit time and coverage time.The calculated results are extremely close to those of the Satellite Tool Kit(STK)and are also superior to the existing research results.The proposed analytical model can be a useful tool for constellation design and coverage performance analysis.
文摘Regionalized location accuracy of the China National Seismograph Network was estimated using the results obtained by studying “repeating earthquakes" or “doublets" in and around China by Schaff and Richards (2004). It is assumed that the “repeating events" or “doublets" are separated by no more than 1km, and the network measured apparent distance X of “doublets" indicates the order of magnitudes of the location error. It is observed that the average location accuracy of the China National Seismograph Network, as represented by average X value, is in the order of magnitudes of 10km, and is larger in the Qinghai-Xizang (Tibet) Plateau, western and northern Xinjiang, and eastern Inner Mongolia.
文摘A novel strategy to enhance the expression efficiency of cloned target gene in Escherichia coli was developed. The whole expression cartridge , consisting of promoter. SD sequence , target gene and transcription terminator, was tandem repeatedly engineered into a expression plasmid. Consequently, the copy number of specific gene was increased substantially, leading to the improvement of expression efficiency.Using this approach, a recombinant plasmid , designed as PLYD, was constructed and transformated into the Escherichia coli strain DH5α. Upon induction , the desired protein was synthesized in a considerable level and accumulated up to 63% of the total cell proteins. The present study revealed that tandem repeating of expression cartridge provided a convenient means to improve expression level efficiently.
基金funded by the Spark Program of China Earthquake Administration (XH1006)
文摘"Repeating earthquakes",identified by cross-correlation of seismic waveforms,are found to be much more abundant in the nature than conventionally expected. In recent years, with the development of digital seismic networks, waveform cross correlation and "repeating earthquakes"have caused much attention to the measuring the variation of crustal medium properties and estimation of location accuracy and fault slip rate at depth or earthquake recurrence intervals. Moreover, as a useful tool, the "repeating earthquake" approach has also been used in the assessment of the accuracy of seismic phase picking,hypocenter location,fault structure and physics of earthquake sources,as well as the study of earthquake prediction. In this paper, we summarized the latest research and applications of "repeating earthquakes".
基金sponsored by the“Earthquake Trend Tracing Task of China Earthquake Administration for 2016(2016020106)”
文摘The Haicheng-Xiuyan region is an earthquake-prone area in Liaoning Province where earthquake sequences frequently occur and is regarded as the regional seismic window. In this area we found many earthquake events with the highest waveform similarity in the records of the same station from some remarkable seismic sequences,namely repeating earthquake sequences. In principle,rupture areas of the repeating events overlap with each other and are most closely located. Therefore these events may reflect the seismic process near the earthquake fault. In this paper, we identified four remarkable earthquake sequences of Haicheng-Xiuyan by waveform cross-correlation. The result shows that the cumulative slip of repeating earthquakes is related to moderately strong earthquakes,among which the Xiuyan M_S5. 4 foreshock sequence has the strongest and most apparent pre-shock accelerating-like slip behavior.
文摘Fast radio bursts(FRBs)are extremely energetic,millisecond-duration flashes of radio waves that represent one of the most intriguing phenomena in astronomy.Their cosmological distances,immense energy outputs,and potential links to other high-energy astrophysical events make them particularly valuable for probing a wide range of fundamental physics(e.g.,ref.[1]).
基金supported financially by the National Natural Science Foundation of China(31811530297 and 32170217).
文摘Plastome variation,including single spontaneous nucleotide substitutions and single insertions/deletions,is the major source of leaf variegation in plants.Additionally,one recent study has showed that a simple plastome structural variation,which is induced by one pair of small inverted repeats,can also result in leaf variegation.Here we show a complex plastome structural variation caused by intermolecular and intramolecular recombination across three pairs of small inverted repeats accounts for leaf variegation in a widely cultivated shrub Heptapleurum ellipticum(Araliaceae).This plastome structural variation contains two deletions and two duplications,resulting in dramatic expansion of IRs,substantial contraction of LSC and loss of 11 genes that essential for photosynthesis.Plastome heteroplasmy was detected in both green and albino sectors of variegated leaves.Relative to green sectors,albino sectors in the variegated leaves exhibit significantly reduced expression for the 11 genes lost in the mutated plastome as well as 26 other genes,but significantly increased expression for one gene related to translation apparatus.Optical and transmission electron microscopy observations showed that mesophyll cells of albino sectors possess plastids lacking grana lamellae,which likely carry the mutated plastome and contribute to albinism.In both sectors,the first layer of spongy mesophyll cells beneath the lower epidermis contains normal chloroplasts,suggesting periclinal division of the lower epidermis during development.Our study demonstrates that multiple small repeats can collectively mediate intra-and inter-molecular recombination in plastome and offers a new mechanism accounting for leaf variegation in plants.
基金supported partially by the Australian Government through the Australian Research Council Centres of Excellence funding scheme(project CE200100029)。
文摘Background:Tandem gene repeats naturally occur as important genomic features and determine many traits in living organisms,like human diseases and microbial productivities of target bioproducts.Methods:Here,we developed a bacterial type-II toxin-antitoxin-mediated method to manipulate genomic integration of tandem gene repeats in Saccharomyces cerevisiae and further visualised the evolutionary trajectories of gene repeats.We designed a tri-vector system to introduce toxin-antitoxin-driven gene amplification modules.Results:This system delivered multi-copy gene integration in the form of tandem gene repeats spontaneously and independently from toxin-antitoxin-mediated selection.Inducing the toxin(RelE)expressing via a copper(II)-inducible CUP1 promoter successfully drove the in-situ gene amplification of the antitoxin(RelB)module,resulting in~40 copies of a green fluorescence reporter gene per copy of genome.Copy-number changes,copy-number increase and copy-number decrease,and stable maintenance were visualised using the green fluorescence protein and blue chromoprotein AeBlue as reporters.Copy-number increases happened spontaneously and independent on a selection pressure.Increased copy number was quickly enriched through toxin-antitoxin-mediated selection.Conclusion:In summary,the bacterial toxin-antitoxin systems provide a flexible mechanism to manipulate gene copy number in eukaryotic cells and can be exploited for synthetic biology and metabolic engineering applications.
基金funded by the project:Breeding and selection of Acacia hybrids and Acacia auriculiformis for large-timber plantation establishment in major ecological zones(000.00.16.G06-230504-0003).
文摘This study investigates the genetic variability and environmental adaptability of Acacia hybrid clones across three distinct ecological regions,providing insights into growth characteristics and stem quality for future breeding strategies.42 natural hybrid clones were evaluated over a five-year period in three clonal trials in northern,central and southern Vietnam for height(HT),diameter at breast height(DBH),volume(VOL),trunk straightness(STR),branch size(BRA)and survival.Significant clonal differences were found in all traits across all three regions.From age 2-5,the clone repeatability(H_(C)^(2))for growth traits improved from 0.19 to 0.59,indicating substantial genetic control.Genotypic coefficients of variation(CVG)for volume ranged from 21%to 34%,suggesting significant potential for genetic improvement.Site-to-site genotypic correlations ranged from 0.53 to 0.78,pointing to the existence of genotype-environment interactions.Clones derived from Acacia mangium material demonstrated enhanced growth,while the hybrid clones exhibited superior stem quality,particularly in terms of straightness.The findings emphasize the importance of selecting clones that are adapted to specific environmental conditions,with both growth and quality traits considered in breeding programs.
基金supported by the National Natural Science Foundation of China(82341245,82371491)the Chinese Central Government(Key Project of Public Health Program)the National Key Research and Development Program of China(2018YFC1311706,2018YFC1311702)。
文摘Objective This study aimed to determine the temporal trends in sleep duration among Chinese adults.Methods In this series of repeated nationally representative cross-sectional surveys(China Chronic Disease and Risk Factors Surveillance)conducted between 2010 and 2018,a total of 645,420 adult participants(97,741 in 2010;175,749 in 2013;187,777 in 2015;and 184,153 in 2018)were included in the trend analysis.Linear and logistic regression models were utilized to assess trends in sleep duration.Results In 2018,the estimated overall mean sleep duration among the Chinese adult population was7.58(SD,1.45)hours per day,with no significant trend from 2010.A significant increase in short sleep duration(≤6 hours)was observed in the total population,from 15.3%(95%CI:14.1%–16.5%)in 2010 to18.5%(95%CI:17.7%–19.3%)in 2018(P<0.001).Similarly,the trend in long sleep duration(>9 hours)was also significant,increasing in weighted prevalence from 7.2%(95%CI:6.3%–8.1%)in 2010 to 9.0%(95%CI:8.2%–9.9%)in 2018(P<0.001).Conclusion The prevalence of both short and long sleep durations significantly increased among Chinese adults from 2010 to 2018,highlighting the urgency of health initiatives to promote optimal sleep duration in China.
文摘BACKGROUND Repeated application of the Pringle maneuver is a key obstacle to safe minimally invasive repeat liver resection(MISRLR).However,limited technical guidance is available.AIM To study the utility of newly developed Pringle taping method guided by liver surface in MISRLR.METHODS We retrospectively reviewed 72 cases of MISRLR performed by a single surgeon at two centers from August 2015 to July 2024.Beginning in October 2019,a liver surface-guided encirclement of hepatoduodenal ligament(LSEH)was used for repeat Pringle taping.Perioperative outcomes including Pringle taping success,operative time,blood loss,conversion rate,morbidity,and mortality were assessed.RESULTS Laparoscopic and robotic approaches were used in 63 patients and 9 patients,respectively.The median operative time,blood loss,and hospital stay were 331.5 minutes,70 mL,and 8 days,respectively.Open conversion occurred in two cases(2.8%)due to severe adhesions and right renal vein injury.Clavien-Dindo grade≥III complications occurred in 5.6%of cases with no mortality.Anti-adhesion barriers were used in 54 patients(75.0%).LSEH was attempted in 57 cases,improving Pringle taping success from 33.0%to 91.4%(P<0.001).LSEH succeeded in all patients with prior open liver resection(n=11).Among 6 patients in whom LSEH failed,3 patients(50.0%)had undergone a third liver resection,and 1 patient had a history of distal gastrectomy with choledochoduodenostomy.CONCLUSION The newly developed LSEH technique for Pringle taping in MISRLR was feasible,enhancing safety and reproducibility even in patients with a history of open liver resection.
文摘Learning a foreign language like English needs patience and right methods.Grammar,which helps us form correct and clear sentences,is a basic part we can't ignore.We can review grammar rules through textbook exercises.To improve pronunciation,listening to native speakers'conversations on English podcasts and repeating after them works well.
基金supported by the National Natural Science Foundation of China, No.61932008Natural Science Foundation of Shanghai, No.21ZR1403200 (both to JC)。
文摘Neurodegenerative diseases cause great medical and economic burdens for both patients and society;however, the complex molecular mechanisms thereof are not yet well understood. With the development of high-coverage sequencing technology, researchers have started to notice that genomic repeat regions, previously neglected in search of disease culprits, are active contributors to multiple neurodegenerative diseases. In this review, we describe the association between repeat element variants and multiple degenerative diseases through genome-wide association studies and targeted sequencing. We discuss the identification of disease-relevant repeat element variants, further powered by the advancement of long-read sequencing technologies and their related tools, and summarize recent findings in the molecular mechanisms of repeat element variants in brain degeneration, such as those causing transcriptional silencing or RNA-mediated gain of toxic function. Furthermore, we describe how in silico predictions using innovative computational models, such as deep learning language models, could enhance and accelerate our understanding of the functional impact of repeat element variants. Finally, we discuss future directions to advance current findings for a better understanding of neurodegenerative diseases and the clinical applications of genomic repeat elements.
基金supported by the National Natural Science Foundation of China(Grant Nos.32072048 and U2004204)National Key Research and Development Program of China(Grant No.2023YFF1001200)+2 种基金China Rice Research Institute Basal Research Fund(Grant No.CPSIBRF-CNRRI-202404)Academician Workstation of National Nanfan Research Institute(Sanya),Chinese Agricultural Academic Science(CAAS),(Grant Nos.YBXM2422 and YBXM2423)Agricultural Science and Technology Innovation Program of CAAS,China.
文摘The leucine-rich repeat(LRR)protein family is involved in a variety of fundamental metabolic and signaling processes in plants,including growth and defense responses.LRR proteins can be divided into two categories:those containing LRR domains along with other structural elements,which are further subdivided into five groups,LRR receptor-like kinases,LRR receptor-like proteins,nucleotide-binding site LRR proteins,LRR-extensin proteins,and polygalacturonase-inhibiting proteins,and those containing only LRR domains.Functionally,various LRR proteins are primarily involved in plant development and responses to environmental stress.Notably,the LRR protein family plays a central role in signal transduction pathways related to stress adaptation.In this review,we classify and analyze the functions of LRR proteins in plants.While extensive research has been conducted on the roles of LRR proteins in disease resistance signaling,these proteins also play important roles in abiotic stress responses.This review highlights recent advances in understanding how LRR proteins mediate responses to biotic and abiotic stresses.Building upon these insights,further exploration of the roles of LRR proteins in abiotic stress resistance may aid efforts to develop rice varieties with enhanced stress and disease tolerance.
文摘When microdissection testicular sperm extraction(micro-TESE)fails,a redo procedure may be the only option for patients who want a biological child.However,there are many gaps of knowledge surrounding the procedure,which need to be addressed to help clinicians and patients make informed decisions.This review explores redo micro-TESE in the context of nonobstructive azoospermia(NOA).Literature was searched using Google Scholar,Medline,and PubMed.Search terms were“NOA”AND“second microdissection testicular sperm extractions”AND“redo microdissection testicles sperm extraction”AND“repeat microdissection testicular sperm extractions”AND“failed microdissection testicular sperm extractions”AND“salvage microdissection testicular sperm extractions”.Only original articles in English were included.A total of nine articles were included,consisting of four retrospective and five prospective studies.The time gap between the first and second micro-TESE varied from 6 months to 24 months.Most of the included studies reported successful surgical sperm retrieval(SSR)in the second micro-TESE in the range of 10%–21%,except in one study where it reached 42%.It has not been presented any definitive information about the use of hormonal treatment or the benefit of varicocelectomy prior to the second micro-TESE.Patients with hypospermatogenesis and Klinefelter syndrome(KS)had the highest chance of success in redo surgery.In conclusion,redo micro-TESE following a negative procedure can lead to sperm recovery in 10%–21%.Patients with hypospermatogenesis and KS have a higher chance of success.There is no enough evidence to conclude which is the best hormonal stimulation if any before a redo surgery.
基金supported by the Key Research and Development Program of Shaanxi(No.S2024-YF-YB-SF-1359).
文摘Objective Current autosomal short tandem repeat(STR)assays can analyze the zygotic composition by comparing the allelic genes at each locus of complete hydatidiform moles(CHM),with a maternal genotype serving as an essential reference for comparative analysis.However,their application in pathology represents a challenge because of deficiency or contamination of maternal-origin tissues.This study aimed to develop a novel STR genotyping method for identifying CHM genotypes without a maternal component.Methods Samples with the pathologic description of molar pregnancy were collected.Routine hematoxylin–eosin(HE)staining and p57 immunohistochemistry staining were conducted in accordance with standard guidelines.A novel 26-plex system was explored to classify CHM and diploid pregnancies.The system combined 22 STRs on chromosomes 21/18/13/X,3 sex loci,and 1 quality control marker(TAF9L),enabling molecular diagnosis in the absence of maternal tissue.At last,traditional DNA typing based on villi and decidua(maternal component)of each case was used for result consistency analysis.Results CHM and nonmolar abortus could not be distinguished by the basic HE staining with no fetal evidence or other prominent features.DNA typing was successfully processed for all cases according to the novel 26-plex and traditional system.CHM(46XX)diagnosis required single A-STR/X-STR peaks and absent Y-chromosome markers,excluding chromosomal abnormalities via TAF9L analysis.When the villous tissue analysis revealed single peaks at X-STR/SRY loci,a 1:1 amelogenin ratio,and a 2:1 TAF9L peak ratio,these results overlapped with those of 46XY hydropic abortus or CHM.Notably,p57 immunohistochemical staining resolved the ambiguity.Consistency with traditional DNA genotyping confirmed system accuracy.This multiplex assay enhanced reliability in mole diagnosis,supporting clinical differentiation and genetic counseling.Conclusion This study presents a rapid and cost-effective assay for the genotypic identification of CHM without the need for a maternal component.The method combined the characteristics of STR loci distributed across different chromosomes and developed the clinic application of forensic biomarkers.
基金supported by the National Natural Science Foundation of China(62001481,61890542,62071475)the Natural Science Foundation of Hunan Province(2022JJ40561)the Research Program of National University of Defense Technology(ZK22-46).
文摘Nonperiodic interrupted sampling repeater jamming(ISRJ)against inverse synthetic aperture radar(ISAR)can obtain two-dimensional blanket jamming performance by joint fast and slow time domain interrupted modulation,which is obviously dif-ferent from the conventional multi-false-target deception jam-ming.In this paper,a suppression method against this kind of novel jamming is proposed based on inter-pulse energy function and compressed sensing theory.By utilizing the discontinuous property of the jamming in slow time domain,the unjammed pulse is separated using the intra-pulse energy function diffe-rence.Based on this,the two-dimensional orthogonal matching pursuit(2D-OMP)algorithm is proposed.Further,it is proposed to reconstruct the ISAR image with the obtained unjammed pulse sequence.The validity of the proposed method is demon-strated via the Yake-42 plane data simulations.
基金supported by the National Natural Science Foundation of China(12273008,12025303,12403046)the National SKA Program of China(2022SKA0130104)+3 种基金the Natural Science and Technology Foundation of Guizhou Province(QiankehejichuMS[2025]266,[2023]024,ZK[2022]304)the Foundation of Guizhou Provincial Education Department(KY(2020)003)the Academic New Seedling Fund Project of Guizhou Normal University([2022]B18)the Major Science and Technology Program of Xinjiang Uygur Autonomous Region(2022A03013-4).
文摘The emission of anomalous X-ray pulsars(AXPs)and soft gamma-ray repeaters(SGRs)is believed to be powered by the dissipation of their strong magnetic fields,which coined the name“magnetar”.By combining timing and energy observational results,the magnetar model can be easily appreciated.From a timing perspective,the magnetic field strengths of AXPs and SGRs,which are calculated under the assumption of dipole radiation,are extremely strong.From an energy perspective,the X-ray/soft gamma-ray luminosities of AXPs and SGRs are larger than their rotational energy loss rates(i.e.,L_(x>E_(rot)).It is thus reasonable to assume that the high-energy radiation comes from magnetic energy decay,and the magnetar model has been extensively discussed(or accepted).However,we argue that:(ⅰ)Calculating magnetic fields by assuming that rotational energy loss is dominated by dipole radiation(i.e.,E_(rot)■E_(μ))may be controversial,and we suggest that the energies carried by outflowing particles should also be considered.(ⅱ)The fact that X-ray luminosity is greater than the rotational energy loss rate does not necessarily mean that the emission energy comes from the magnetic field decaying,which requires further observational testing.Furthermore,some observational facts conflict with the“magnetar”model,such as observations of anti-magnetars,high magnetic field pulsars,and radio and X-ray observations of AXPs/SGRs.Therefore,we propose a crusted strange star model as an alternative,which can explain many more observational facts of AXPs/SGRs.
文摘Objective Junctophilin-2(JPH2)is an essential structural protein that maintains junctional membrane complexes(JMCs)in cardiomyocytes by tethering the plasma membrane to the sarcoplasmic reticulum,thereby facilitating excitationcontraction(E-C)coupling.Mutations in JPH2 have been associated with hypertrophic cardiomyopathy(HCM),but the molecular mechanisms governing its membrane-binding properties and the functional relevance of its membrane occupation and recognition nexus(MORN)repeat motifs remain incompletely understood.This study aimed to elucidate the structural basis of JPH2 membrane association and its implications for HCM pathogenesis.Methods A recombinant N-terminal fragment of mouse JPH2(residues 1-440),encompassing the MORN repeats and an adjacent helical region,was purified under near-physiological buffer conditions.X-ray crystallography was employed to determine the structure of the JPH2 MORN-Helix domain.Sequence conservation analysis across species and junctophilin isoforms was performed to assess the evolutionary conservation of key structural features.Functional membrane-binding assays were conducted using liposome co-sedimentation and cell-based localization studies in COS7 and HeLa cells.In addition,site-directed mutagenesis targeting positively charged residues and known HCM-associated mutations,including R347C,was used to evaluate their effects on membrane interaction and subcellular localization.Results The crystal structure of the mouse JPH2 MORN-Helix domain was resolved at 2.6Å,revealing a compact,elongated architecture consisting of multiple tandem MORN motifs arranged in a curved configuration,forming a continuous hydrophobic core stabilized by alternating aromatic residues.A C-terminalα-helix further reinforced structural integrity.Conservation analysis identified the inner groove of the MORN array as a highly conserved surface,suggesting its role as a protein-binding interface.A flexible linker segment enriched in positively charged residues,located adjacent to the MORN motifs,was found to mediate direct electrostatic interactions with negatively charged phospholipid membranes.Functional assays demonstrated that mutation of these basic residues impaired membrane association,while the HCM-linked R347C mutation completely abolished membrane localization in cellular assays,despite preserving the overall MORN-Helix fold in structural modeling.Conclusion This study provides structural insight into the membrane-binding mechanism of the cardiomyocyte-specific protein JPH2,highlighting the dual roles of its MORN-Helix domain in membrane anchoring and protein interactions.The findings clarify the structural basis for membrane targeting via a positively charged linker and demonstrate that disruption of this interaction—such as that caused by the R347C mutation—likely contributes to HCM pathogenesis.These results not only enhance current understanding of JPH2 function in cardiac E-C coupling but also offer a structural framework for future investigations into the assembly and regulation of JMCs in both physiological and disease contexts.
