Anisotropy correction is necessary during the processing of converted PS- wave seismic data to achieve accurate structural imaging, reservoir prediction, and fracture detection. To effectively eliminate the adverse ef...Anisotropy correction is necessary during the processing of converted PS- wave seismic data to achieve accurate structural imaging, reservoir prediction, and fracture detection. To effectively eliminate the adverse effects of S-wave splitting and to improve PS- wave imaging quality, we tested methods for pre-stack migration imaging and anisotropic correction of PS-wave data. We based this on the propagation rules of seismic waves in a horizontal transverse isotropy medium, which is a fractured medium model that reflects likely subsurface conditions in the field. We used the radial （R） and transverse （T） components of PS-wave data to separate the fast and slow S-wave components, after which their propagation moveout was effectively extracted. Meanwhile, corrections for the energies and propagation moveouts of the R and T components were implemented using mathematical rotation. The PS-wave imaging quality was distinctly improved, and we demonstrated the reliability of our methods through numerical simulations. Applying our methods to three-dimensional and three-component seismic field data from the Xinchang-Hexingchang region of the Western Sichuan Depression in China, we obtained high-quality seismic imaging with continuous reflection wave groups, distinct structural features, and specific stratigraphic contact relationships. This study provides an effective and reliable approach for data processing that will improve the exploration of complex, hidden lithologic gas reservoirs.展开更多
The published article titled“MicroRNA-133b Inhibits Proliferation,Cellular Migration,and Invasion via Targeting LASP1 in Hepatocarcinoma Cells”has been retracted from Oncology Research,Vol.25,No.8,2017,pp.1269–1282.
Adult neurogenesis continuously produces new neurons critical for cognitive plasticity in adult rodents.While it is known transforming growth factor-βsignaling is important in embryonic neurogenesis,its role in postn...Adult neurogenesis continuously produces new neurons critical for cognitive plasticity in adult rodents.While it is known transforming growth factor-βsignaling is important in embryonic neurogenesis,its role in postnatal neurogenesis remains unclear.In this study,to define the precise role of transforming growth factor-βsignaling in postnatal neurogenesis at distinct stages of the neurogenic cascade both in vitro and in vivo,we developed two novel inducible and cell type-specific mouse models to specifically silence transforming growth factor-βsignaling in neural stem cells in(mGFAPcre-ALK5fl/fl-Ai9)or immature neuroblasts in(DCXcreERT2-ALK5fl/fl-Ai9).Our data showed that exogenous transforming growth factor-βtreatment led to inhibition of the proliferation of primary neural stem cells while stimulating their migration.These effects were abolished in activin-like kinase 5(ALK5)knockout primary neural stem cells.Consistent with this,inhibition of transforming growth factor-βsignaling with SB-431542 in wild-type neural stem cells stimulated proliferation while inhibited the migration of neural stem cells.Interestingly,deletion of transforming growth factor-βreceptor in neural stem cells in vivo inhibited the migration of postnatal born neurons in mGFAPcre-ALK5fl/fl-Ai9 mice,while abolishment of transforming growth factor-βsignaling in immature neuroblasts in DCXcreERT2-ALK5fl/fl-Ai9 mice did not affect the migration of these cells in the hippocampus.In summary,our data supports a dual role of transforming growth factor-βsignaling in the proliferation and migration of neural stem cells in vitro.Moreover,our data provides novel insights on cell type-specific-dependent requirements of transforming growth factor-βsignaling on neural stem cell proliferation and migration in vivo.展开更多
In wave-equation migration and demigration,the cross-correlation imaging/forwarding step implicitly injects an additional copy of the source wavelet,so that the amplitude spectrum of the wavelet is applied redundantly...In wave-equation migration and demigration,the cross-correlation imaging/forwarding step implicitly injects an additional copy of the source wavelet,so that the amplitude spectrum of the wavelet is applied redundantly(effectively imposing a wavelet-spectrum weighting,often akin to an amplitude-squared bias).This redundancy degrades structural fidelity and amplitude balance yet is frequently overlooked.We(i)formalize the mechanism by which cross-correlation duplicates the source-wavelet amplitude effect in both migration and demigration,and(ii)introduce a source-equalized operator that removes the redundancy by deconvolving(or dividing by)the wavelet amplitude spectrum in the imaging condition and its demigration counterpart,while leaving phase/kinematics intact.Using a band-limited Ricker wavelet on a two-layer model and on Marmousi,we show that,if unmanaged,the redundant wavelet spectrum broadens main lobes,introduces ringing,and suppresses vertical resolution in migrated images,and inflates spectrum mismatches between demigrated and observed data even when peak times agree.With our correction,images recover observed-data-consistent bandwidth and sharpened interfaces,and demigrated data also exhibit improved spectrum conformity and reduced amplitude misfit.The results clarify when source amplitudes matter,why cross-correlation makes them redundantly matter,and how a lightweight spectral correction restores physically meaningful amplitude behavior in wave-equation migration/demigration.展开更多
Peripheral nerve defect repair is a complex process that involves multiple cell types;perineurial cells play a pivotal role.Hair follicle neural crest stem cells promote perineurial cell proliferation and migration vi...Peripheral nerve defect repair is a complex process that involves multiple cell types;perineurial cells play a pivotal role.Hair follicle neural crest stem cells promote perineurial cell proliferation and migration via paracrine signaling;however,their clinical applications are limited by potential risks such as tumorigenesis and xenogeneic immune rejection,which are similar to the risks associated with other stem cell transplantations.The present study therefore focuses on small extracellular vesicles derived from hair follicle neural crest stem cells,which preserve the bioactive properties of the parent cells while avoiding the transplantation-associated risks.In vitro,small extracellular vesicles derived from hair follicle neural crest stem cells significantly enhanced the proliferation,migration,tube formation,and barrier function of perineurial cells,and subsequently upregulated the expression of tight junction proteins.Furthermore,in a rat model of sciatic nerve defects bridged with silicon tubes,treatment with small extracellular vesicles derived from hair follicle neural crest stem cells resulted in higher tight junction protein expression in perineurial cells,thus facilitating neural tissue regeneration.At 10 weeks post-surgery,rats treated with small extracellular vesicles derived from hair follicle neural crest stem cells exhibited improved nerve function recovery and reduced muscle atrophy.Transcriptomic and micro RNA analyses revealed that small extracellular vesicles derived from hair follicle neural crest stem cells deliver mi R-21-5p,which inhibits mothers against decapentaplegic homolog 7 expression,thereby activating the transforming growth factor-β/mothers against decapentaplegic homolog signaling pathway and upregulating hyaluronan synthase 2 expression,and further enhancing tight junction protein expression.Together,our findings indicate that small extracellular vesicles derived from hair follicle neural crest stem cells promote the proliferation,migration,and tight junction protein formation of perineurial cells.These results provide new insights into peripheral nerve regeneration from the perspective of perineurial cells,and present a novel approach for the clinical treatment of peripheral nerve defects.展开更多
Engineering seismic exploration aims at shallow imaging which is confused by statics if the surface is uneven. Direct pre-stack depth migration （DPDM） is based on accurate elevations of sources and receivers, by whi...Engineering seismic exploration aims at shallow imaging which is confused by statics if the surface is uneven. Direct pre-stack depth migration （DPDM） is based on accurate elevations of sources and receivers, by which static correction is completely abandoned before migration and surely the imaging quality is remarkably improved. To obtain some artificial shot gathers, high-order staggered-grid finite-difference （FD） method is adapted to model acoustic wave propagation. Since the shot gathers are always disturbed by regular interferences, the statics still must be applied to supporting the interference elimination by apparent velocity filtering method. Then all the shot gathers should be removed back to their original positions by reverse statics. Finally, they are migrated by pre-stack reverse-time depth migration and imaged. The numerical experiments show that the DPDM can ideally avoid the mistakes caused by statics and increase imaging precision.展开更多
Difunctionalization of unsaturated hydrocarbons is a pivotal synthetic strategy enabling the conversion of alkenes and alkynes into high value-added compounds.It allows for the introduction of two functional groups in...Difunctionalization of unsaturated hydrocarbons is a pivotal synthetic strategy enabling the conversion of alkenes and alkynes into high value-added compounds.It allows for the introduction of two functional groups into the unsaturated bond in a single step,facilitating the efficient construction of complex molecular architectures,which has been widely utilized in material chemistry,pharmaceutical and fine chemical synthesis.Recently,significant progress has been made via free radical-mediated difunctionalization due to the extensive application of photocatalysis.However,highly selective difunc-tionalization reactions still remain challenging.The research progress of selective difunctionalization of unsaturated hydro-carbons using a free radical addition/functional group migration strategy over the past decade is summarized,and synthetic strategies and key reaction steps are systematically elaborated.展开更多
Objective:Ovarian cancer(OC)ranks among the leading causes of mortality among the female cancers worldwide.Numerous studies have explored the development and progression of OC at multiple genetic regulatory levels.How...Objective:Ovarian cancer(OC)ranks among the leading causes of mortality among the female cancers worldwide.Numerous studies have explored the development and progression of OC at multiple genetic regulatory levels.However,relatively few studies have explored the impact of post-translational modifications(PTM)on OC progression,which is essential for uncovering new therapeutic targets.This study aimed to systematically identify the key PTM types involved in OCprogression,and to explore and evaluate their translational potential as therapeutic targets.Methods:First,we utilized multiple general PTM antibodies to compare gross PTM levels between normal ovarian and OC tissues from clinical females.After identifying lactylation as the PTM with the most significant differences,we selected representative samples for label-free mass spectrometry to identify specific lactylation sites.Next,we transfected A2780(OC)cells with either wild-type(WT)or mutant(K192A[Q])poly(ADP-ribose)polymerase 1(PARP1)conjugated to enhanced green fluorescent protein(EGFP)with a StrepⅡpeptide tag and assessed various cellular indexes related to cell proliferation(clonogenicity assay),migration(scratch wound healing assay),and reactive oxygen species levels.Results:Pan-lactylation was significantly upregulated in clinical OC samples,with PARP1 lactylation at K192 being one of the most common modifications.The growth and migration of A2780 cells were markedly suppressed by overexpressing PARP1-WT but not mutant PARP1.Overexpressing PARP1 significantly downregulated the phosphorylation of extracellular signal-regulated kinases 1/2(ERK1/2).Conclusion:This study uncovered a novel PTM of PARP1 in OC,lactylation,and demonstrated that lactylation at K192 is crucial in regulating OC cell growth and migration via the ERK1/2 pathway.Further investigations are required to elucidate the broader functional implications of PARP1 lactylation and its therapeutic potential.展开更多
This study aims to explore the unconscious motivations underlying migration in Niger, with an emphasis on understanding the phenomenon of pathological travel. Its aim is to identify the unconscious factors of patholog...This study aims to explore the unconscious motivations underlying migration in Niger, with an emphasis on understanding the phenomenon of pathological travel. Its aim is to identify the unconscious factors of pathological travel among migrants. Pathological travel, as discussed in the scientific literature on psychopathology, is characterised by movements initiated under the influence of delusions, hallucinations or other serious psychiatric disorders. The aim of this research is to contribute to our understanding of how these unconscious factors influence migration decisions. Using a retrospective analysis of five cases, this study examines the psychological and psychiatric dimensions of migration, particularly among patients referred to the psychiatry department of the Niamey National Hospital between 2017 and 2018. The five cases analysed, representing 12% of a cohort of 40 migrant patients, suffered from chronic psychotic disorders, including schizophrenia and chronic hallucinatory psychosis. By means of diagnostic interviews and categorical sorting, three main unconscious motivations were identified: the delusional state with themes of filiation and persecution, the hallucinations that dictated the travel behaviour, and the dissociative states manifested by depersonalisation and derealisation. It also emerges from this analysis that pathological travel often involves prolonged journeys on foot and without purpose. Thus, untreated mental illness plays a significant role in shaping and influencing individual and social behaviour. The results of this study have important implications for public health and migration policy. They highlight the need to integrate health assessments into migration management systems, particularly in regions serving as transit hubs for migrants. The research also highlights the need for culturally sensitive psychiatric interventions to address the interaction between pre-existing mental disorders and migration. This study contributes to a better understanding of the psychological dimensions of migration by highlighting the importance of addressing mental health as an integral part of humanitarian action. The knowledge gained paves the way for future research to explore this understudied aspect of migration on a broader scale.展开更多
Seismic forward-prospecting in tunnels is an important step to ensure excavation safety. Nowadays, most advanced imaging techniques in seismic exploration involve calculating the solution of elastic wave equation in a...Seismic forward-prospecting in tunnels is an important step to ensure excavation safety. Nowadays, most advanced imaging techniques in seismic exploration involve calculating the solution of elastic wave equation in a certain coordinate system. However, considering the cylindrical geometry of common tunnel body, Cartesian coordinate system seemingly has limited applicability in tunnel seismic forwardprospecting. To accurately simulate the seismic signal received in tunnels, previous imaging method using decoupled non-conversion elastic wave equation is extended from Cartesian coordinates to cylindrical coordinates. The proposed method preserves the general finite-difference time-domain(FDTD)scheme in Cartesian coordinates, except for a novel wavefield calculation strategy addressing the singularity issue inherited at the cylindrical axis. Moreover, the procedure of cylindrical elastic reverse time migration(CERTM) in tunnels is introduced based on the decoupled non-conversion elastic wavefield. Its imaging effect is further validated via numerical experiments on typical tunnel models. As indicated in the synthetic examples, both the PP-and SS-images could clearly show the geological structure in front of the tunnel face without obvious crosstalk artifacts. Migration imaging using PP-waves can present satisfactory results with higher resolution information supplemented by the SS-images. The potential of applying the proposed method in real-world cases is demonstrated in a water diversion tunnel. In the end, we share our insights regarding the singularity treatment and further improvement of the proposed method.展开更多
Ecological barriers present significant challenges to bird migration by limiting the availability of stopover sites and shelters. The Qinghai-Tibet Plateau, a major migratory barrier located in higher latitude Central...Ecological barriers present significant challenges to bird migration by limiting the availability of stopover sites and shelters. The Qinghai-Tibet Plateau, a major migratory barrier located in higher latitude Central Asia, exerts a substantial influence on avian migration patterns. Species traversing such ecological barriers may adopt multiple optimal routes, which can contribute to the formation of migratory divides. From 2018 to 2021, the migration routes of 13 adult Common Cuckoos (Cuculus canorus) breeding in the north of the Qinghai-Tibet Plateau were tracked using satellite transmitters. We found Common Cuckoos have two primary migration routes: western and eastern, respectively following western and eastern edges of the Qinghai-Tibet plateau. The eastern and western routes are likely the optimal routes for the Central Asian Common Cuckoos population to navigate the Qinghai-Tibet Plateau. Furthermore, two individuals exhibited intermediate migration routes, suggesting attempted traverses of the Qinghai-Tibet Plateau, although neither completed the migration. These intermediate routes may indicate migratory behavior influenced by hybridization between eastern and western populations or migratory flexibility. Common Cuckoos exhibit significantly faster migration speed, flight speed, and shorter stopover durations during spring compared to autumn. The observed seasonal differences in migration behavior support birds following time-minimization strategies during spring migration. These results revealed the diverse migration routes of Common Cuckoos shaped by the Qinghai-Tibet Plateau and seasonal variation in migration patterns.展开更多
This paper aims to elucidate the seismic characteristics of the Three Gorges Reservoir area after impoundment and investigate the seismic source migration.Based on the seismic data analysis from the Badong segment in ...This paper aims to elucidate the seismic characteristics of the Three Gorges Reservoir area after impoundment and investigate the seismic source migration.Based on the seismic data analysis from the Badong segment in the Three Gorges Reservoir area,we assessed the local temporal and spatial variations in the frequent earthquakes.Correlation analysis was conducted to investigate the relationship between changes in reservoir water levels and the occurrence of reservoir-induced earthquakes.Additionally,we examined the regularity of earthquake occurrences at the exact location during different periods.Based on the fault mechanics principles,a formula was derived to estimate the length of open and wing-shaped rupture at the hypocenter under the influence of pore or excess pore water pressure.The results reveal that reservoir-induced seismicity demonstrates short-term cycles characterized by alternating"active periods"and"quiet periods,"as well as long-term cycles with the combined periods.The probability of earthquakes occurring within one year at the epicentre is relatively high and decreases after four years.The derived formula can be utilized to estimate the seismic migration distance at the epicentre in the short term.These research findings provide valuable insights for analyzing the regularity of reservoir-induced earthquake activities and understanding the mechanism of seismic source migration.展开更多
What does the impact of migration mean in a social context?This article aims to see migrants by taking their stories into account.Through the individual stories,the readers can see the way in which a bigger picture is...What does the impact of migration mean in a social context?This article aims to see migrants by taking their stories into account.Through the individual stories,the readers can see the way in which a bigger picture is emerged in terms of community,society and nation.By doing so,the authors want to show the way in which migrants integrate into a society,including both migrants having a residence permit and those who are undocumented,as these two groups of people do differ greatly.The cultural clash does mean the inner struggle and the outer struggle that a society has to confront with.展开更多
The authors regret to report the following error made in“Spatiotemporal dynamics of neuron differentiation and migration in the developing human spinal cord;52(2025)-101283-1295;Doi:https://doi.org/10.1016/j.jgg.2025...The authors regret to report the following error made in“Spatiotemporal dynamics of neuron differentiation and migration in the developing human spinal cord;52(2025)-101283-1295;Doi:https://doi.org/10.1016/j.jgg.2025.08.004”.In Tables S1 and S2 in the supplementary materials of this paper,some items were written in Chinese.The corresponding pictures and tables were not uploaded in time.展开更多
BACKGROUND Ventriculoperitoneal shunt(VPS)catheter insertion is one of the most widely accepted surgical procedures for hydrocephalus.Migration of the end of the distal VPS catheter into the scrotum is one of the rare...BACKGROUND Ventriculoperitoneal shunt(VPS)catheter insertion is one of the most widely accepted surgical procedures for hydrocephalus.Migration of the end of the distal VPS catheter into the scrotum is one of the rare complications of VPS catheter insertion.METHODS This is a systematic review of the published cases,and the literature search was performed from 1974 to June 30,2024,to retrieve the relevant manuscripts.The cases were grouped into two.Group A included cases of migration of the distal VPS catheter into the scrotum,detected in children.Group B included the cases of migration of the distal VPS catheter into the scrotum,which was detected in adults and older people.RESULTS One hundred-twenty cases of migration of the distal end of VPS catheter into the scrotum were included in this study,a systematic literature review.Group A included n=112 cases,and group B included n=8 cases only.Three-fourths of the cases involved the right scrotum.Bilateral involvement was rare.The indication for initial VPS insertion was congenital hydrocephalus in four-fifths of the group A cases.The majority were infants at the time of initial shunt insertion.Four-fifths of the group A cases were 24 months-old or younger at the time of clinical diagnosis and treatment was provided for migration of the distal VPS catheter into the scrotum.In children,the interval from VPS insertion or shunt revision if any,to the diagnosis of the complication mentioned above was 12 months or less in four-fifths of the cases.The repositioning of migrated distal VPS catheter into the peritoneal cavity and herniotomy was preferred for the surgical procedure,and it was performed for two-thirds of group A cases.CONCLUSION Migration of the distal part of the VPS catheter into the scrotum is a rare complication of cerebrospinal fluid diversion via VPS catheter insertion.It was most frequent in children,and the right side of the scrotum was most often involved.展开更多
Migratory insect pests tend to suddenly immigrate into new habitats over a short period to simultaneously lay eggs in clusters,resulting in gregarious larvae that cause severe damage to crops.These aggregated larvae c...Migratory insect pests tend to suddenly immigrate into new habitats over a short period to simultaneously lay eggs in clusters,resulting in gregarious larvae that cause severe damage to crops.These aggregated larvae can adapt well to various natural enemies and pathogens in their new habitats,but how their resistance might be enhanced and its immunological significance remain unknown.Here,we examined how infection by a pathogen and a parasitic fly affect the immune response and migratory behavior in two phases of the oriental armyworm,Mythimna separata,which differ dramatically in their flight capacity and fecundity.The gregarious larvae displayed greater resistance than solitary larvae to the challenges of both the entomopathogenic fungus Metarhizium anisopliae and the parasitoid Exorista civilis.In response to a challenge by M.anisopliae,gregarious larvae exhibited more pronounced increases in phenoloxidase(PO)activity and lysozyme activity than solitary larvae.Furthermore,in addition to the greater PO and lysozyme activities,the levels of dopamine and 5-hydroxytryptamine(5-HT)were also greater in challenged gregarious and solitary larvae.Injection of dopamine(or 5-HT)significantly enhanced PO activity,lysozyme activity,antibacterial activity and larval survival.Subsequently,there was a significant increase in the flight capacity of adults derived from gregarious larvae challenged by M.anisopliae;while no significant variation was observed in the adults from challenged solitary larvae.The preoviposition period,oviposition period and fecundity were not significantly affected by M.anisopliae,regardless of whether the larvae were gregarious or solitary.These results provide new insights into the relationship between migration and immunity in insects,and their behavior after immunization.展开更多
The gas-liquid countercurrent flow pattern is complex and the bubble migration velocity is difficult to predict in the process of bullheading well killing.The experiment on bubble migration in gas-liquid countercurren...The gas-liquid countercurrent flow pattern is complex and the bubble migration velocity is difficult to predict in the process of bullheading well killing.The experiment on bubble migration in gas-liquid countercurrent flow in annulus is carried out under different working conditions to reveal how the wellbore inclination angle,liquid phase property and countercurrent liquid velocity affect the bubble deformation and bubble migration trajectory/velocity,and to establish a bubble migration velocity prediction model.The bubbles in the countercurrent flow mainly migrate in two modes:free rising of isolated bubbles,and interactive rising of multiple bubbles.The bubbles migrate by an S-shaped trajectory in the countercurrent flow.With the increase of countercurrent liquid velocity,the lateral oscillation of bubbles is intensified.The increases of wellbore inclination angle,liquid density and liquid viscosity make the bubble migration trajectory gradually to be linear.The bubble is generally ellipsoidal during its rising.The wellbore inclination angle has little effect on the degree of bubble deformation.The bubbles are ellipsoidal during rising,with little influence of wellbore inclination angle on bubble deformation.With the increase of liquid viscosity and density,the aspect ratio of the bubble decreases.As the wellbore inclination angle increases,the bubble migration velocity gradually decreases.As the liquid viscosity increases,the bubble migration velocity decreases.As the liquid density increases,the bubble migration velocity increases slightly.The established bubble migration velocity prediction model yields errors within±15%,and demonstrates broad applicability across a wide range of operating conditions.展开更多
BACKGROUND Glioblastoma multiforme(GBM)is the most aggressive and prevalent primary malignant brain tumor in adults,marked by poor prognosis and high invasiveness.Traditional GBM invasion assays,such as those involvin...BACKGROUND Glioblastoma multiforme(GBM)is the most aggressive and prevalent primary malignant brain tumor in adults,marked by poor prognosis and high invasiveness.Traditional GBM invasion assays,such as those involving mouse brain xenografts,are often time-consuming and limited in efficiency.In this context,stem cell-derived neural organoids(NOs)have emerged as advanced,threedimensional,human-relevant platforms that mimic the cellular architecture and microenvironment of the human brain.These models provide novel opportunities to investigate glioblastoma stem cell invasion,a critical driver of tumor progression and therapeutic resistance.AIM To evaluate studies using stem cell-derived NOs to model glioblastoma migration/invasion,focusing on methodologies,applications and therapeutic implications.METHODS We conducted a systematic review following PRISMA guidelines,searching PubMed and Scopus for studies published between March 2019 and March 2025 that investigated NOs in the context of glioblastoma invasion/migration.After screening 377 articles based on predefined inclusion and exclusion criteria,10 original research articles were selected for analysis.Extracted data were categorized into four analytical domains:(1)Tumor model formation;(2)NO characteristics;(3)NO differentiation protocols;and(4)Invasion/migration assessment methodologies.RESULTS The included studies exhibit significant methodological heterogeneity GBM model development,particularly regarding model type,cell source and culture conditions.Most studies(70%)used suspension cell models,while 30%employed spheroids,with most research focusing on patient-derived glioblastoma stem cells.NOs were predominantly generated from human induced pluripotent stem cells using both guided and unguided differentiation protocols.Confocal fluorescence microscopy was the primary method used for assessing invasion,revealing invasion depths of up to 300μm.Organoid maturity and co-culture duration influenced results,while key factors for model optimization included tumor cell density,organoid age and extracellular matrix composition.Some studies also tested therapeutic strategies such as Zika virus and microRNA modulation.Collectively,findings support the utility of NOs as effective tools for studying GBM behavior and therapeutic responses in a humanized three-dimensional context.CONCLUSION Human NOs represent promising platforms for modeling glioblastoma invasion in a humanized three-dimensional environment.However,a limited number of studies and methodological heterogeneity hinder reproducibility.Protocol standardization is essential to enhance the translational application of these models.展开更多
The attenuation and anisotropy characteristics of real earth media give rise to amplitude loss and phase dispersion during seismic wave propagation.To address these effects on seismic imaging,viscoacoustic anisotropic...The attenuation and anisotropy characteristics of real earth media give rise to amplitude loss and phase dispersion during seismic wave propagation.To address these effects on seismic imaging,viscoacoustic anisotropic wave equations expressed by the fractional Laplacian have been derived.However,the huge computational expense associated with multiple Fast Fourier transforms for solving these wave equations makes them unsuitable for industrial applications,especially in three dimensions.Therefore,we first derived a cost-effective pure-viscoacoustic wave equation expressed by the memory-variable in tilted transversely isotropic(TTI)media,based on the standard linear solid model.The newly derived wave equation featuring decoupled amplitude dissipation and phase dispersion terms,can be easily solved using the finite-difference method(FDM).Computational efficiency analyses demonstrate that wavefields simulated by our newly derived wave equation are more efficient compared to the previous pure-viscoacoustic TTI wave equations.The decoupling characteristics of the phase dispersion and amplitude dissipation of the proposed wave equation are illustrated in numerical tests.Additionally,we extend the newly derived wave equation to implement Q-compensated reverse time migration(RTM)in attenuating TTI media.Synthetic examples and field data test demonstrate that the proposed Qcompensated TTI RTM effectively migrate the effects of anisotropy and attenuation,providing highquality imaging results.展开更多
Amplitude dissipation and phase dispersion occur when seismic waves propagate in attenuated anisotropic media,affecting the quality of migration imaging.To compensate and correct for these effects,the fractional Lapla...Amplitude dissipation and phase dispersion occur when seismic waves propagate in attenuated anisotropic media,affecting the quality of migration imaging.To compensate and correct for these effects,the fractional Laplacian pure viscoacoustic wave equation capable of producing stable and noise-free wavefields has been proposed and implemented in the Q-compensated reverse time migration(RTM).In addition,the second-order Taylor series expansion is usually adopted in the hybrid finite-difference/pseudo-spectral(HFDPS)strategy to solve spatially variable fractional Laplacian.However,during forward modeling and Q-compensated RTM,this HFDPS strategy requires 11 and 17 fast Fourier transforms(FFTs)per time step,respectively,leading to computational inefficiency.To improve computational efficiency,we introduce two high-efficiency HFDPS numerical modeling strategies based on asymptotic approximation and algebraic methods.Through the two strategies,the number of FFTs decreased from 11 to 6 and 5 per time step during forward modeling,respectively.Numerical examples demonstrate that wavefields simulated using the new numerical modeling strategies are accurate and highly efficient.Finally,these strategies are employed for implementing high-efficiency and stable Q-compensated RTM techniques in tilted transversely isotropic media,reducing the number of FFTs from 17 to 9 and 8 per time step,respectively,significantly improving computational efficiency.Synthetic data examples illustrate the effectiveness of the proposed Q-compensated RTM scheme in compensating amplitude dissipation and correcting phase distortion.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.41574099)the National Key Science and Technology Special Projects(grant No.2016ZX05002004-005)
文摘Anisotropy correction is necessary during the processing of converted PS- wave seismic data to achieve accurate structural imaging, reservoir prediction, and fracture detection. To effectively eliminate the adverse effects of S-wave splitting and to improve PS- wave imaging quality, we tested methods for pre-stack migration imaging and anisotropic correction of PS-wave data. We based this on the propagation rules of seismic waves in a horizontal transverse isotropy medium, which is a fractured medium model that reflects likely subsurface conditions in the field. We used the radial （R） and transverse （T） components of PS-wave data to separate the fast and slow S-wave components, after which their propagation moveout was effectively extracted. Meanwhile, corrections for the energies and propagation moveouts of the R and T components were implemented using mathematical rotation. The PS-wave imaging quality was distinctly improved, and we demonstrated the reliability of our methods through numerical simulations. Applying our methods to three-dimensional and three-component seismic field data from the Xinchang-Hexingchang region of the Western Sichuan Depression in China, we obtained high-quality seismic imaging with continuous reflection wave groups, distinct structural features, and specific stratigraphic contact relationships. This study provides an effective and reliable approach for data processing that will improve the exploration of complex, hidden lithologic gas reservoirs.
文摘The published article titled“MicroRNA-133b Inhibits Proliferation,Cellular Migration,and Invasion via Targeting LASP1 in Hepatocarcinoma Cells”has been retracted from Oncology Research,Vol.25,No.8,2017,pp.1269–1282.
基金supported by NIH grants,Nos.R01NS125074,R01AG083164,R01NS107365,and R21NS127177(to YL),1F31NS129204-01A1(to KW)and Albert Ryan Fellowship(to KW).
文摘Adult neurogenesis continuously produces new neurons critical for cognitive plasticity in adult rodents.While it is known transforming growth factor-βsignaling is important in embryonic neurogenesis,its role in postnatal neurogenesis remains unclear.In this study,to define the precise role of transforming growth factor-βsignaling in postnatal neurogenesis at distinct stages of the neurogenic cascade both in vitro and in vivo,we developed two novel inducible and cell type-specific mouse models to specifically silence transforming growth factor-βsignaling in neural stem cells in(mGFAPcre-ALK5fl/fl-Ai9)or immature neuroblasts in(DCXcreERT2-ALK5fl/fl-Ai9).Our data showed that exogenous transforming growth factor-βtreatment led to inhibition of the proliferation of primary neural stem cells while stimulating their migration.These effects were abolished in activin-like kinase 5(ALK5)knockout primary neural stem cells.Consistent with this,inhibition of transforming growth factor-βsignaling with SB-431542 in wild-type neural stem cells stimulated proliferation while inhibited the migration of neural stem cells.Interestingly,deletion of transforming growth factor-βreceptor in neural stem cells in vivo inhibited the migration of postnatal born neurons in mGFAPcre-ALK5fl/fl-Ai9 mice,while abolishment of transforming growth factor-βsignaling in immature neuroblasts in DCXcreERT2-ALK5fl/fl-Ai9 mice did not affect the migration of these cells in the hippocampus.In summary,our data supports a dual role of transforming growth factor-βsignaling in the proliferation and migration of neural stem cells in vitro.Moreover,our data provides novel insights on cell type-specific-dependent requirements of transforming growth factor-βsignaling on neural stem cell proliferation and migration in vivo.
基金supported by the National Natural Science Foundation of China(42430303)Strategy Priority Research Program(Category B)of the Chinese Academy of Sciences(XDB0710000)+2 种基金National Natural Science Foundation of China(42288201)the National Key R&D Program of China(2023YFF0803203)the IGGCAS start-up funding(Grant No.E251510101).
文摘In wave-equation migration and demigration,the cross-correlation imaging/forwarding step implicitly injects an additional copy of the source wavelet,so that the amplitude spectrum of the wavelet is applied redundantly(effectively imposing a wavelet-spectrum weighting,often akin to an amplitude-squared bias).This redundancy degrades structural fidelity and amplitude balance yet is frequently overlooked.We(i)formalize the mechanism by which cross-correlation duplicates the source-wavelet amplitude effect in both migration and demigration,and(ii)introduce a source-equalized operator that removes the redundancy by deconvolving(or dividing by)the wavelet amplitude spectrum in the imaging condition and its demigration counterpart,while leaving phase/kinematics intact.Using a band-limited Ricker wavelet on a two-layer model and on Marmousi,we show that,if unmanaged,the redundant wavelet spectrum broadens main lobes,introduces ringing,and suppresses vertical resolution in migrated images,and inflates spectrum mismatches between demigrated and observed data even when peak times agree.With our correction,images recover observed-data-consistent bandwidth and sharpened interfaces,and demigrated data also exhibit improved spectrum conformity and reduced amplitude misfit.The results clarify when source amplitudes matter,why cross-correlation makes them redundantly matter,and how a lightweight spectral correction restores physically meaningful amplitude behavior in wave-equation migration/demigration.
基金supported by the National Natural Science Foundation of China,No.81571211(to FL)the Natural Science Foundation of Shanghai,No.22ZR1476800(to CH)。
文摘Peripheral nerve defect repair is a complex process that involves multiple cell types;perineurial cells play a pivotal role.Hair follicle neural crest stem cells promote perineurial cell proliferation and migration via paracrine signaling;however,their clinical applications are limited by potential risks such as tumorigenesis and xenogeneic immune rejection,which are similar to the risks associated with other stem cell transplantations.The present study therefore focuses on small extracellular vesicles derived from hair follicle neural crest stem cells,which preserve the bioactive properties of the parent cells while avoiding the transplantation-associated risks.In vitro,small extracellular vesicles derived from hair follicle neural crest stem cells significantly enhanced the proliferation,migration,tube formation,and barrier function of perineurial cells,and subsequently upregulated the expression of tight junction proteins.Furthermore,in a rat model of sciatic nerve defects bridged with silicon tubes,treatment with small extracellular vesicles derived from hair follicle neural crest stem cells resulted in higher tight junction protein expression in perineurial cells,thus facilitating neural tissue regeneration.At 10 weeks post-surgery,rats treated with small extracellular vesicles derived from hair follicle neural crest stem cells exhibited improved nerve function recovery and reduced muscle atrophy.Transcriptomic and micro RNA analyses revealed that small extracellular vesicles derived from hair follicle neural crest stem cells deliver mi R-21-5p,which inhibits mothers against decapentaplegic homolog 7 expression,thereby activating the transforming growth factor-β/mothers against decapentaplegic homolog signaling pathway and upregulating hyaluronan synthase 2 expression,and further enhancing tight junction protein expression.Together,our findings indicate that small extracellular vesicles derived from hair follicle neural crest stem cells promote the proliferation,migration,and tight junction protein formation of perineurial cells.These results provide new insights into peripheral nerve regeneration from the perspective of perineurial cells,and present a novel approach for the clinical treatment of peripheral nerve defects.
文摘Engineering seismic exploration aims at shallow imaging which is confused by statics if the surface is uneven. Direct pre-stack depth migration （DPDM） is based on accurate elevations of sources and receivers, by which static correction is completely abandoned before migration and surely the imaging quality is remarkably improved. To obtain some artificial shot gathers, high-order staggered-grid finite-difference （FD） method is adapted to model acoustic wave propagation. Since the shot gathers are always disturbed by regular interferences, the statics still must be applied to supporting the interference elimination by apparent velocity filtering method. Then all the shot gathers should be removed back to their original positions by reverse statics. Finally, they are migrated by pre-stack reverse-time depth migration and imaged. The numerical experiments show that the DPDM can ideally avoid the mistakes caused by statics and increase imaging precision.
文摘Difunctionalization of unsaturated hydrocarbons is a pivotal synthetic strategy enabling the conversion of alkenes and alkynes into high value-added compounds.It allows for the introduction of two functional groups into the unsaturated bond in a single step,facilitating the efficient construction of complex molecular architectures,which has been widely utilized in material chemistry,pharmaceutical and fine chemical synthesis.Recently,significant progress has been made via free radical-mediated difunctionalization due to the extensive application of photocatalysis.However,highly selective difunc-tionalization reactions still remain challenging.The research progress of selective difunctionalization of unsaturated hydro-carbons using a free radical addition/functional group migration strategy over the past decade is summarized,and synthetic strategies and key reaction steps are systematically elaborated.
文摘Objective:Ovarian cancer(OC)ranks among the leading causes of mortality among the female cancers worldwide.Numerous studies have explored the development and progression of OC at multiple genetic regulatory levels.However,relatively few studies have explored the impact of post-translational modifications(PTM)on OC progression,which is essential for uncovering new therapeutic targets.This study aimed to systematically identify the key PTM types involved in OCprogression,and to explore and evaluate their translational potential as therapeutic targets.Methods:First,we utilized multiple general PTM antibodies to compare gross PTM levels between normal ovarian and OC tissues from clinical females.After identifying lactylation as the PTM with the most significant differences,we selected representative samples for label-free mass spectrometry to identify specific lactylation sites.Next,we transfected A2780(OC)cells with either wild-type(WT)or mutant(K192A[Q])poly(ADP-ribose)polymerase 1(PARP1)conjugated to enhanced green fluorescent protein(EGFP)with a StrepⅡpeptide tag and assessed various cellular indexes related to cell proliferation(clonogenicity assay),migration(scratch wound healing assay),and reactive oxygen species levels.Results:Pan-lactylation was significantly upregulated in clinical OC samples,with PARP1 lactylation at K192 being one of the most common modifications.The growth and migration of A2780 cells were markedly suppressed by overexpressing PARP1-WT but not mutant PARP1.Overexpressing PARP1 significantly downregulated the phosphorylation of extracellular signal-regulated kinases 1/2(ERK1/2).Conclusion:This study uncovered a novel PTM of PARP1 in OC,lactylation,and demonstrated that lactylation at K192 is crucial in regulating OC cell growth and migration via the ERK1/2 pathway.Further investigations are required to elucidate the broader functional implications of PARP1 lactylation and its therapeutic potential.
文摘This study aims to explore the unconscious motivations underlying migration in Niger, with an emphasis on understanding the phenomenon of pathological travel. Its aim is to identify the unconscious factors of pathological travel among migrants. Pathological travel, as discussed in the scientific literature on psychopathology, is characterised by movements initiated under the influence of delusions, hallucinations or other serious psychiatric disorders. The aim of this research is to contribute to our understanding of how these unconscious factors influence migration decisions. Using a retrospective analysis of five cases, this study examines the psychological and psychiatric dimensions of migration, particularly among patients referred to the psychiatry department of the Niamey National Hospital between 2017 and 2018. The five cases analysed, representing 12% of a cohort of 40 migrant patients, suffered from chronic psychotic disorders, including schizophrenia and chronic hallucinatory psychosis. By means of diagnostic interviews and categorical sorting, three main unconscious motivations were identified: the delusional state with themes of filiation and persecution, the hallucinations that dictated the travel behaviour, and the dissociative states manifested by depersonalisation and derealisation. It also emerges from this analysis that pathological travel often involves prolonged journeys on foot and without purpose. Thus, untreated mental illness plays a significant role in shaping and influencing individual and social behaviour. The results of this study have important implications for public health and migration policy. They highlight the need to integrate health assessments into migration management systems, particularly in regions serving as transit hubs for migrants. The research also highlights the need for culturally sensitive psychiatric interventions to address the interaction between pre-existing mental disorders and migration. This study contributes to a better understanding of the psychological dimensions of migration by highlighting the importance of addressing mental health as an integral part of humanitarian action. The knowledge gained paves the way for future research to explore this understudied aspect of migration on a broader scale.
基金funded by the National Natural Science Foundation of China (Grant Nos. 52021005 and 51739007)the Key Research and Development Plan of Shandong Province (Grant No. 2020ZLYS01)。
文摘Seismic forward-prospecting in tunnels is an important step to ensure excavation safety. Nowadays, most advanced imaging techniques in seismic exploration involve calculating the solution of elastic wave equation in a certain coordinate system. However, considering the cylindrical geometry of common tunnel body, Cartesian coordinate system seemingly has limited applicability in tunnel seismic forwardprospecting. To accurately simulate the seismic signal received in tunnels, previous imaging method using decoupled non-conversion elastic wave equation is extended from Cartesian coordinates to cylindrical coordinates. The proposed method preserves the general finite-difference time-domain(FDTD)scheme in Cartesian coordinates, except for a novel wavefield calculation strategy addressing the singularity issue inherited at the cylindrical axis. Moreover, the procedure of cylindrical elastic reverse time migration(CERTM) in tunnels is introduced based on the decoupled non-conversion elastic wavefield. Its imaging effect is further validated via numerical experiments on typical tunnel models. As indicated in the synthetic examples, both the PP-and SS-images could clearly show the geological structure in front of the tunnel face without obvious crosstalk artifacts. Migration imaging using PP-waves can present satisfactory results with higher resolution information supplemented by the SS-images. The potential of applying the proposed method in real-world cases is demonstrated in a water diversion tunnel. In the end, we share our insights regarding the singularity treatment and further improvement of the proposed method.
基金supported by the National Natural Science Foundation of China(Grant No.31672296).
文摘Ecological barriers present significant challenges to bird migration by limiting the availability of stopover sites and shelters. The Qinghai-Tibet Plateau, a major migratory barrier located in higher latitude Central Asia, exerts a substantial influence on avian migration patterns. Species traversing such ecological barriers may adopt multiple optimal routes, which can contribute to the formation of migratory divides. From 2018 to 2021, the migration routes of 13 adult Common Cuckoos (Cuculus canorus) breeding in the north of the Qinghai-Tibet Plateau were tracked using satellite transmitters. We found Common Cuckoos have two primary migration routes: western and eastern, respectively following western and eastern edges of the Qinghai-Tibet plateau. The eastern and western routes are likely the optimal routes for the Central Asian Common Cuckoos population to navigate the Qinghai-Tibet Plateau. Furthermore, two individuals exhibited intermediate migration routes, suggesting attempted traverses of the Qinghai-Tibet Plateau, although neither completed the migration. These intermediate routes may indicate migratory behavior influenced by hybridization between eastern and western populations or migratory flexibility. Common Cuckoos exhibit significantly faster migration speed, flight speed, and shorter stopover durations during spring compared to autumn. The observed seasonal differences in migration behavior support birds following time-minimization strategies during spring migration. These results revealed the diverse migration routes of Common Cuckoos shaped by the Qinghai-Tibet Plateau and seasonal variation in migration patterns.
基金supported by the Open Research Fund of Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of China Three Gorges University,the Ministry of Education(2020KDZ12)the National Natural Science Foundation Joint Funded Project of China(U2034203),the National Natural Science Foundation Joint Funded Project of China(U22A20600)+2 种基金the Hubei Key Laboratory of Disaster Prevention and Mitigation of China Three Gorges University(2022KJZ08)Natural Science Research Program of Yichang City in 2023(A23-2-047)Scientific Research Program of Hubei Provincial Department of Education in 2022(B2022567)。
文摘This paper aims to elucidate the seismic characteristics of the Three Gorges Reservoir area after impoundment and investigate the seismic source migration.Based on the seismic data analysis from the Badong segment in the Three Gorges Reservoir area,we assessed the local temporal and spatial variations in the frequent earthquakes.Correlation analysis was conducted to investigate the relationship between changes in reservoir water levels and the occurrence of reservoir-induced earthquakes.Additionally,we examined the regularity of earthquake occurrences at the exact location during different periods.Based on the fault mechanics principles,a formula was derived to estimate the length of open and wing-shaped rupture at the hypocenter under the influence of pore or excess pore water pressure.The results reveal that reservoir-induced seismicity demonstrates short-term cycles characterized by alternating"active periods"and"quiet periods,"as well as long-term cycles with the combined periods.The probability of earthquakes occurring within one year at the epicentre is relatively high and decreases after four years.The derived formula can be utilized to estimate the seismic migration distance at the epicentre in the short term.These research findings provide valuable insights for analyzing the regularity of reservoir-induced earthquake activities and understanding the mechanism of seismic source migration.
文摘What does the impact of migration mean in a social context?This article aims to see migrants by taking their stories into account.Through the individual stories,the readers can see the way in which a bigger picture is emerged in terms of community,society and nation.By doing so,the authors want to show the way in which migrants integrate into a society,including both migrants having a residence permit and those who are undocumented,as these two groups of people do differ greatly.The cultural clash does mean the inner struggle and the outer struggle that a society has to confront with.
文摘The authors regret to report the following error made in“Spatiotemporal dynamics of neuron differentiation and migration in the developing human spinal cord;52(2025)-101283-1295;Doi:https://doi.org/10.1016/j.jgg.2025.08.004”.In Tables S1 and S2 in the supplementary materials of this paper,some items were written in Chinese.The corresponding pictures and tables were not uploaded in time.
文摘BACKGROUND Ventriculoperitoneal shunt(VPS)catheter insertion is one of the most widely accepted surgical procedures for hydrocephalus.Migration of the end of the distal VPS catheter into the scrotum is one of the rare complications of VPS catheter insertion.METHODS This is a systematic review of the published cases,and the literature search was performed from 1974 to June 30,2024,to retrieve the relevant manuscripts.The cases were grouped into two.Group A included cases of migration of the distal VPS catheter into the scrotum,detected in children.Group B included the cases of migration of the distal VPS catheter into the scrotum,which was detected in adults and older people.RESULTS One hundred-twenty cases of migration of the distal end of VPS catheter into the scrotum were included in this study,a systematic literature review.Group A included n=112 cases,and group B included n=8 cases only.Three-fourths of the cases involved the right scrotum.Bilateral involvement was rare.The indication for initial VPS insertion was congenital hydrocephalus in four-fifths of the group A cases.The majority were infants at the time of initial shunt insertion.Four-fifths of the group A cases were 24 months-old or younger at the time of clinical diagnosis and treatment was provided for migration of the distal VPS catheter into the scrotum.In children,the interval from VPS insertion or shunt revision if any,to the diagnosis of the complication mentioned above was 12 months or less in four-fifths of the cases.The repositioning of migrated distal VPS catheter into the peritoneal cavity and herniotomy was preferred for the surgical procedure,and it was performed for two-thirds of group A cases.CONCLUSION Migration of the distal part of the VPS catheter into the scrotum is a rare complication of cerebrospinal fluid diversion via VPS catheter insertion.It was most frequent in children,and the right side of the scrotum was most often involved.
基金supported by the National Key Research and Development Program of China(2022YFD1400600)the National Natural Science Foundation of China(32172397,32472540,31871951 and 31672019)+1 种基金the China Agriculture Research System of MOF and MARA(CARS-22)the Natural Science Foundation of Beijing,China(6172030)。
文摘Migratory insect pests tend to suddenly immigrate into new habitats over a short period to simultaneously lay eggs in clusters,resulting in gregarious larvae that cause severe damage to crops.These aggregated larvae can adapt well to various natural enemies and pathogens in their new habitats,but how their resistance might be enhanced and its immunological significance remain unknown.Here,we examined how infection by a pathogen and a parasitic fly affect the immune response and migratory behavior in two phases of the oriental armyworm,Mythimna separata,which differ dramatically in their flight capacity and fecundity.The gregarious larvae displayed greater resistance than solitary larvae to the challenges of both the entomopathogenic fungus Metarhizium anisopliae and the parasitoid Exorista civilis.In response to a challenge by M.anisopliae,gregarious larvae exhibited more pronounced increases in phenoloxidase(PO)activity and lysozyme activity than solitary larvae.Furthermore,in addition to the greater PO and lysozyme activities,the levels of dopamine and 5-hydroxytryptamine(5-HT)were also greater in challenged gregarious and solitary larvae.Injection of dopamine(or 5-HT)significantly enhanced PO activity,lysozyme activity,antibacterial activity and larval survival.Subsequently,there was a significant increase in the flight capacity of adults derived from gregarious larvae challenged by M.anisopliae;while no significant variation was observed in the adults from challenged solitary larvae.The preoviposition period,oviposition period and fecundity were not significantly affected by M.anisopliae,regardless of whether the larvae were gregarious or solitary.These results provide new insights into the relationship between migration and immunity in insects,and their behavior after immunization.
基金Supported by the National Natural Science Foundation of China(U21B2069,52274020,52288101,52274022)National Key Research and Development Program of China(2022YFC2806504)。
文摘The gas-liquid countercurrent flow pattern is complex and the bubble migration velocity is difficult to predict in the process of bullheading well killing.The experiment on bubble migration in gas-liquid countercurrent flow in annulus is carried out under different working conditions to reveal how the wellbore inclination angle,liquid phase property and countercurrent liquid velocity affect the bubble deformation and bubble migration trajectory/velocity,and to establish a bubble migration velocity prediction model.The bubbles in the countercurrent flow mainly migrate in two modes:free rising of isolated bubbles,and interactive rising of multiple bubbles.The bubbles migrate by an S-shaped trajectory in the countercurrent flow.With the increase of countercurrent liquid velocity,the lateral oscillation of bubbles is intensified.The increases of wellbore inclination angle,liquid density and liquid viscosity make the bubble migration trajectory gradually to be linear.The bubble is generally ellipsoidal during its rising.The wellbore inclination angle has little effect on the degree of bubble deformation.The bubbles are ellipsoidal during rising,with little influence of wellbore inclination angle on bubble deformation.With the increase of liquid viscosity and density,the aspect ratio of the bubble decreases.As the wellbore inclination angle increases,the bubble migration velocity gradually decreases.As the liquid viscosity increases,the bubble migration velocity decreases.As the liquid density increases,the bubble migration velocity increases slightly.The established bubble migration velocity prediction model yields errors within±15%,and demonstrates broad applicability across a wide range of operating conditions.
基金Supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico,No.307318/2023-0 and No.102035/2024-5Fundação de AmparoàPesquisa do Estado de São Paulo,No.2023/10843-7 and No 2019/21070-3Nanotechnology National Laboratory System 2.0,Ministry of Science,Technology,Innovation and Communication,No.442539/2019-3.
文摘BACKGROUND Glioblastoma multiforme(GBM)is the most aggressive and prevalent primary malignant brain tumor in adults,marked by poor prognosis and high invasiveness.Traditional GBM invasion assays,such as those involving mouse brain xenografts,are often time-consuming and limited in efficiency.In this context,stem cell-derived neural organoids(NOs)have emerged as advanced,threedimensional,human-relevant platforms that mimic the cellular architecture and microenvironment of the human brain.These models provide novel opportunities to investigate glioblastoma stem cell invasion,a critical driver of tumor progression and therapeutic resistance.AIM To evaluate studies using stem cell-derived NOs to model glioblastoma migration/invasion,focusing on methodologies,applications and therapeutic implications.METHODS We conducted a systematic review following PRISMA guidelines,searching PubMed and Scopus for studies published between March 2019 and March 2025 that investigated NOs in the context of glioblastoma invasion/migration.After screening 377 articles based on predefined inclusion and exclusion criteria,10 original research articles were selected for analysis.Extracted data were categorized into four analytical domains:(1)Tumor model formation;(2)NO characteristics;(3)NO differentiation protocols;and(4)Invasion/migration assessment methodologies.RESULTS The included studies exhibit significant methodological heterogeneity GBM model development,particularly regarding model type,cell source and culture conditions.Most studies(70%)used suspension cell models,while 30%employed spheroids,with most research focusing on patient-derived glioblastoma stem cells.NOs were predominantly generated from human induced pluripotent stem cells using both guided and unguided differentiation protocols.Confocal fluorescence microscopy was the primary method used for assessing invasion,revealing invasion depths of up to 300μm.Organoid maturity and co-culture duration influenced results,while key factors for model optimization included tumor cell density,organoid age and extracellular matrix composition.Some studies also tested therapeutic strategies such as Zika virus and microRNA modulation.Collectively,findings support the utility of NOs as effective tools for studying GBM behavior and therapeutic responses in a humanized three-dimensional context.CONCLUSION Human NOs represent promising platforms for modeling glioblastoma invasion in a humanized three-dimensional environment.However,a limited number of studies and methodological heterogeneity hinder reproducibility.Protocol standardization is essential to enhance the translational application of these models.
基金supported by the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2021QNLM020001)the Major Scientificand Technological Projects of Shandong Energy Group(No.SNKJ2022A06-R23)+1 种基金the National Natural Science Foundation of China(No.42374164)the basic theoretical research of seismic wave imaging technology in complex oilfield of Changqing Oilfield Company(No.2023-10502)。
文摘The attenuation and anisotropy characteristics of real earth media give rise to amplitude loss and phase dispersion during seismic wave propagation.To address these effects on seismic imaging,viscoacoustic anisotropic wave equations expressed by the fractional Laplacian have been derived.However,the huge computational expense associated with multiple Fast Fourier transforms for solving these wave equations makes them unsuitable for industrial applications,especially in three dimensions.Therefore,we first derived a cost-effective pure-viscoacoustic wave equation expressed by the memory-variable in tilted transversely isotropic(TTI)media,based on the standard linear solid model.The newly derived wave equation featuring decoupled amplitude dissipation and phase dispersion terms,can be easily solved using the finite-difference method(FDM).Computational efficiency analyses demonstrate that wavefields simulated by our newly derived wave equation are more efficient compared to the previous pure-viscoacoustic TTI wave equations.The decoupling characteristics of the phase dispersion and amplitude dissipation of the proposed wave equation are illustrated in numerical tests.Additionally,we extend the newly derived wave equation to implement Q-compensated reverse time migration(RTM)in attenuating TTI media.Synthetic examples and field data test demonstrate that the proposed Qcompensated TTI RTM effectively migrate the effects of anisotropy and attenuation,providing highquality imaging results.
基金support this research during the 14th Fiveyear Plan period under contract number 2021QNLM020001the Major Scientific and Technological Projects of Shandong Energy Group under contract number SNKJ2022A06-R23+2 种基金the National Natural Science Foundation of China under contract number 42374164the Funds for Creative Research Groups of China under contract number 41821002the basic theoretical research of seismic wave imaging technology in complex oilfield of Changqing Oilfield Company under contract number 2023e10502.
文摘Amplitude dissipation and phase dispersion occur when seismic waves propagate in attenuated anisotropic media,affecting the quality of migration imaging.To compensate and correct for these effects,the fractional Laplacian pure viscoacoustic wave equation capable of producing stable and noise-free wavefields has been proposed and implemented in the Q-compensated reverse time migration(RTM).In addition,the second-order Taylor series expansion is usually adopted in the hybrid finite-difference/pseudo-spectral(HFDPS)strategy to solve spatially variable fractional Laplacian.However,during forward modeling and Q-compensated RTM,this HFDPS strategy requires 11 and 17 fast Fourier transforms(FFTs)per time step,respectively,leading to computational inefficiency.To improve computational efficiency,we introduce two high-efficiency HFDPS numerical modeling strategies based on asymptotic approximation and algebraic methods.Through the two strategies,the number of FFTs decreased from 11 to 6 and 5 per time step during forward modeling,respectively.Numerical examples demonstrate that wavefields simulated using the new numerical modeling strategies are accurate and highly efficient.Finally,these strategies are employed for implementing high-efficiency and stable Q-compensated RTM techniques in tilted transversely isotropic media,reducing the number of FFTs from 17 to 9 and 8 per time step,respectively,significantly improving computational efficiency.Synthetic data examples illustrate the effectiveness of the proposed Q-compensated RTM scheme in compensating amplitude dissipation and correcting phase distortion.
