As a promising signaling transduction approach, fluorescence polarization(FP)/fluorescence anisotropy(FA), provides a powerful quantitative tool for the rotational motion of fluorescently labeled molecules in chemical...As a promising signaling transduction approach, fluorescence polarization(FP)/fluorescence anisotropy(FA), provides a powerful quantitative tool for the rotational motion of fluorescently labeled molecules in chemical or biological homogeneous systems. Unlike fluorescence intensity, FP/FA is almost independent the concentration or quantum of fluorophores, but they are highly dependent on the size or molecular weight of the molecules or materials attached to fluorophores. Recently, significant progress in FP/FA was made, due to the introduction of some nanomaterials as FP/FA enhancers. The detection sensitivity is thus greatly improved by using nanomaterials as FP/FA enhancers, and nanomaterial-based FP/FA is currently used successfully in immunoassay, and analysis of protein, nucleic acid, small molecule and metal ion.Nanomaterial-based FP/FA provides a new kind of strategy to design fluorescent sensors and establishes innovative analytical methods. In this review, we summarize the scientific publications in the field of FP/FA sensor in recent five years, and first introduce the recent progress of FP/FA sensor based on nanomaterial. Subsequently, the various analytical applications of FP/FA based on nanomaterial are discussed. Finally, we provide perspectives on the current challenges and future prospects in this promising field.展开更多
Several N-alkyl/aryl-Se-alkyl/（aryl）selenocarbamates were prepared from various isocyanates and diselenides by reductive cleavage of Se-Se bond with the Zn/AIC]3 system in dry acetonitrile at 80 ℃.
Combustion within small motors is key in the application-specific development of nanothermite-based micro-energetic systems. This study evaluates the performance of nanothermite mixtures in a converging-diverging nozz...Combustion within small motors is key in the application-specific development of nanothermite-based micro-energetic systems. This study evaluates the performance of nanothermite mixtures in a converging-diverging nozzle and an open tube. Mixtures were prepared using nano-aluminum(n-Al),potassium perchlorate(KClO_(4)), and different carbon nanomaterials(CNMs) including graphene-oxide(GO), reduced GO, carbon nanotubes(CNTs) and nanofibers(CNFs). The mixtures were packed at different densities and ignited by laser beam. Performance was measured using thrust measurement,high-speed imaging, and computational fluid dynamics modeling, respectively. Thrust, specific impulse(ISP), volumetric impulse(ISV), as well as normalized energy were found to increase notably with CNM content. Two distinctive reaction regimes(fast and slow) were observed in combustion of low and high packing densities(20% and 55%TMD), respectively. Total impulse(IFT) and ISPwere maximized in the 5%GO/Al/KClO_4 mixture, producing 7.95 m N·s and 135.20 s respectively at 20%TMD, an improvement of 57%compared to a GO-free sample(5.05 m N·s and 85.88 s). CFD analysis of the motors over predicts the thrust generated but trends in nozzle layout and packing density agree with those observed experimentally;peak force was maximized by reducing packing density and using an open tube. The numerical force profiles fit better for the nozzle cases than the open tube scenarios due to the rapid nature of combustion. This study reveals the potential of GO in improving oxygenated salt-based nanothermites,and further demonstrates their applicability for micro-propulsion and micro-energetic applications.展开更多
For many decades,Alzheimer's disease research has primarily focused on impairments within cortical and hippocampal regions,which are thought to be related to cognitive dysfunctions such as memory and language defi...For many decades,Alzheimer's disease research has primarily focused on impairments within cortical and hippocampal regions,which are thought to be related to cognitive dysfunctions such as memory and language deficits.The exact cause of Alzheimer's disease is still under debate,making it challenging to establish an effective therapy or early diagnosis.It is widely accepted that the accumulation of amyloid-beta peptide in the brain parenchyma leads to synaptic dysfunction,a critical step in Alzheimer's disease development.The traditional amyloid cascade model is initiated by accumulating extracellular amyloid-beta in brain areas essential for memory and language.However,while it is possible to reduce the presence of amyloid-beta plaques in the brain with newer immunotherapies,cognitive symptoms do not necessarily improve.Interestingly,recent studies support the notion that early alterations in subcortical brain regions also contribute to brain damage and precognitive decline in Alzheimer's disease.A body of recent evidence suggests that early Alzheimer's disease is associated with alterations(e.g.,motivation,anxiety,and motor impairment)in subcortical areas,such as the striatum and amygdala,in both human and animal models.Also,recent data indicate that intracellular amyloid-beta appears early in subcortical regions such as the nucleus accumbens,locus coeruleus,and raphe nucleus,even without extracellular amyloid plaques.The reported effects are mainly excitatory,increasing glutamatergic transmission and neuronal excitability.In agreement,data in Alzheimer's disease patients and animal models show an increase in neuronal synchronization that leads to electroencephalogram disturbances and epilepsy.The data indicate that early subcortical brain dysfunctions might be associated with non-cognitive symptoms such as anxiety,irritability,and motivation deficits,which precede memory loss and language alterations.Overall,the evidence reviewed suggests that subcortical brain regions could explain early dysfunctions and perhaps be targets for therapies to slow disease progression.Future research should focus on these non-traditional brain regions to reveal early pathological alterations and underlying mechanisms to advance our understanding of Alzheimer's disease beyond the traditionally studied hippocampal and cortical circuits.展开更多
As underground mining advances to greater depths,cemented paste backfill(CPB)is increasingly subjected to complex thermo-mechanical loading conditions,including multiaxial stress states and elevated temperatures.This ...As underground mining advances to greater depths,cemented paste backfill(CPB)is increasingly subjected to complex thermo-mechanical loading conditions,including multiaxial stress states and elevated temperatures.This study investigates the coupled effects of field-representative vertical self-weight and horizontal rockwall closure stresses,along with in-situ temperatures,on the mechanical behavior and pore water pressure(PWP)evolution of CPB.Experiments were conducted using a novel apparatus capable of controlling multiaxial stress and temperature during curing,replicating in-situ stress paths and thermal profiles typical of deep mine environments.Results show that multiaxial stress enhances CPB strength and stiffness by promoting denser particle packing,reducing porosity,and increasing frictional resistance.Elevated temperatures independently accelerate early-age cement hydration,further improving bond strength and stiffness.When combined,multiaxial stress and elevated temperature produce a synergistic enhancement in unconfined compressive strength(UCS)and elastic modulus,as confirmed by two-way ANOVA and synergy index analysis.PWP responses were also highly sensitive to thermo-mechanical conditions.The evolution of positive and negative PWP was governed by the interplay of thermal expansion,hydration-induced desaturation,and mechanical compaction.Multiaxial stress amplified early positive PWP and delayed its dissipation,whereas elevated temperature accelerated hydration and reduced pore pressure,leading to enhanced suction at later ages.A transient“stress-induced resaturation”effect was observed under late-stage excessive horizontal stress but was mitigated by elevated temperatures.These findings provide critical insights into the coupled mechanical and hydraulic behavior of CPB under realistic field conditions and offer guidance for optimizing backfill design,binder content,and barricade stability in deep mining applications.展开更多
Acalypha gaumeri(Euphorbiaceae)is the only endemic species of the genus in the Yucatan Peninsula.It is dioecious and has antifungal properties against various phytopathogens.In the present study,molecular identificati...Acalypha gaumeri(Euphorbiaceae)is the only endemic species of the genus in the Yucatan Peninsula.It is dioecious and has antifungal properties against various phytopathogens.In the present study,molecular identification of A.gaumeri was performed using the rbcL region,confirming its belonging to the Acalypha genus.Its genetic diversity was evaluated using 10 SPAR markers(ISSR and DAMD)from 60 individuals collected from female and male plants of the Kiuic,Tinum and Yaxcaba ex-situ populations.The results showed a high level of genetic polymorphism(PIC=0.980)and significant differences among the populations.Ethanol and aqueous extracts from leaves,stems,and roots of both genders and three populations were evaluated against three phytopathogenic fungi.Only the ethanol extracts of the roots showed inhibitory antifungal activity,whereas Kiuic and Tinum,both male and female individuals,showed inhibitory effects at 1000μg/mL against the three pathogens.The ethanol extract of the female flowering plant of Kiuic showed activity at minimum inhibitory concentrations of 250μg/mL against Alternaria chrysanthemi CICY004 and 500μg/mL against Colletotrichum gloeosporioides CICY002 and Penicillium oxalicum ITC25.Chromatographic profile of the ethanol extracts confirmed the presence of alkaloidal components in the ex-situ cultivated plants,which were analyzed by HPLC.The results revealed that the peaks at T_(R) of 7.60,7.88,and 8.49 min were the most abundant components(9.95%-21.93%),with differences between female and male plants of the three populations.This research confirms that A.gaumeri cultivated and genetically characterized is a potential raw material to develop an eco-friendly product for the control of fungal diseases in crops.展开更多
Earthquakes are highly destructive spatio-temporal phenomena whose analysis is essential for disaster preparedness and risk mitigation.Modern seismological research produces vast volumes of heterogeneous data from sei...Earthquakes are highly destructive spatio-temporal phenomena whose analysis is essential for disaster preparedness and risk mitigation.Modern seismological research produces vast volumes of heterogeneous data from seismic networks,satellite observations,and geospatial repositories,creating the need for scalable infrastructures capable of integrating and analyzing such data to support intelligent decision-making.Data warehousing technologies provide a robust foundation for this purpose;however,existing earthquake-oriented data warehouses remain limited,often relying on simplified schemas,domain-specific analytics,or cataloguing efforts.This paper presents the design and implementation of a spatio-temporal data warehouse for seismic activity.The framework integrates spatial and temporal dimensions in a unified schema and introduces a novel array-based approach for managing many-to-many relationships between facts and dimensions without intermediate bridge tables.A comparative evaluation against a conventional bridge-table schema demonstrates that the array-based design improves fact-centric query performance,while the bridge-table schema remains advantageous for dimension-centric queries.To reconcile these trade-offs,a hybrid schema is proposed that retains both representations,ensuring balanced efficiency across heterogeneous workloads.The proposed framework demonstrates how spatio-temporal data warehousing can address schema complexity,improve query performance,and support multidimensional visualization.In doing so,it provides a foundation for integrating seismic analysis into broader big data-driven intelligent decision systems for disaster resilience,risk mitigation,and emergency management.展开更多
The malicious dissemination of hate speech via compromised accounts,automated bot networks and malware-driven social media campaigns has become a growing cybersecurity concern.Automatically detecting such content in S...The malicious dissemination of hate speech via compromised accounts,automated bot networks and malware-driven social media campaigns has become a growing cybersecurity concern.Automatically detecting such content in Spanish is challenging due to linguistic complexity and the scarcity of annotated resources.In this paper,we compare two predominant AI-based approaches for the forensic detection of malicious hate speech:(1)finetuning encoder-only models that have been trained in Spanish and(2)In-Context Learning techniques(Zero-and Few-Shot Learning)with large-scale language models.Our approach goes beyond binary classification,proposing a comprehensive,multidimensional evaluation that labels each text by:(1)type of speech,(2)recipient,(3)level of intensity(ordinal)and(4)targeted group(multi-label).Performance is evaluated using an annotated Spanish corpus,standard metrics such as precision,recall and F1-score and stability-oriented metrics to evaluate the stability of the transition from zero-shot to few-shot prompting(Zero-to-Few Shot Retention and Zero-to-Few Shot Gain)are applied.The results indicate that fine-tuned encoder-only models(notably MarIA and BETO variants)consistently deliver the strongest and most reliable performance:in our experiments their macro F1-scores lie roughly in the range of approximately 46%–66%depending on the task.Zero-shot approaches are much less stable and typically yield substantially lower performance(observed F1-scores range approximately 0%–39%),often producing invalid outputs in practice.Few-shot prompting(e.g.,Qwen 38B,Mistral 7B)generally improves stability and recall relative to pure zero-shot,bringing F1-scores into a moderate range of approximately 20%–51%but still falling short of fully fine-tuned models.These findings highlight the importance of supervised adaptation and discuss the potential of both paradigms as components in AI-powered cybersecurity and malware forensics systems designed to identify and mitigate coordinated online hate campaigns.展开更多
We thank Power et al.1 for their interest in our review2 and for contributing to this important scientific discussion.We welcome their commentary and acknowledge the merit of continuing to scrutinize and refine interp...We thank Power et al.1 for their interest in our review2 and for contributing to this important scientific discussion.We welcome their commentary and acknowledge the merit of continuing to scrutinize and refine interpretations in this evolving field.Given that much research time and financial investment is being given to the study of the effects of eccentric training in both athletic and clinical contexts,it is incumbent on our field to demonstrate whether eccentric contractions are a key(or the key)stimulus for sarcomerogenesis(increases in serial sarcomere number(SSN)).展开更多
Cannabidiol(CBD),the second most significant phytocannabinoid in the plant Cannabis sativa,which lacks potential as a drug of abuse(Viudez-Martinez et al.,2019),has gained widespread attention due to its anti-inflamma...Cannabidiol(CBD),the second most significant phytocannabinoid in the plant Cannabis sativa,which lacks potential as a drug of abuse(Viudez-Martinez et al.,2019),has gained widespread attention due to its anti-inflammatory,antioxidant,and antidepressant properties(Garci a-Gutierrez et al.,2020).Additionally,CBD exhibits neuroprotective properties,preserving neuronal viability and function by preventing or limiting cellular damage.Our team has demonstrated that CBD produces rapid antidepressant-like effects in a murine model of chronic mild stress,restoring hippocampal expression of brain-derived neurotrophic factor(BDNF).展开更多
Low-dimensional(LD)halide perovskites have attracted considerable attention due to their distinctive structures and exceptional optoelectronic properties,including high absorption coefficients,extended charge carrier ...Low-dimensional(LD)halide perovskites have attracted considerable attention due to their distinctive structures and exceptional optoelectronic properties,including high absorption coefficients,extended charge carrier diffusion lengths,suppressed non-radiative recombination rates,and intense photoluminescence.A key advantage of LD perovskites is the tunability of their optical and electronic properties through the precise optimization of their structural arrangements and dimensionality.This review systematically examines recent progress in the synthesis and optoelectronic characterizations of LD perovskites,focusing on their structural,optical,and photophysical properties that underpin their versatility in diverse applications.The review further summarizes advancements in LD perovskite-based devices,including resistive memory,artificial synapses,photodetectors,light-emitting diodes,and solar cells.Finally,the challenges associated with stability,scalability,and integration,as well as future prospects,are discussed,emphasizing the potential of LD perovskites to drive breakthroughs in device efficiency and industrial applicability.展开更多
Background Selenium(Se)is an essential soil mineral that can be incorporated into animal feedstuffs.Because of a lack of soil Se in some regions,organic or inorganic supplementation strategies must be implemented to p...Background Selenium(Se)is an essential soil mineral that can be incorporated into animal feedstuffs.Because of a lack of soil Se in some regions,organic or inorganic supplementation strategies must be implemented to prevent deficiencies and promote optimal ovine health.Therefore,the objectives of this study were to assess how inorganic versus organic Se supplementation influenced ewe Se status and immune function during late gestation and postpartum.Dorset Rideau ewes(n=110)were fed a Se deficient diet from gestation d 110 through postpartum d 49 and received one of four daily oral Se treatments diluted in 5 mL of sugar water:0 mg Se,0.3 mg inorganic Se,0.3 mg organic Se,and 0.6 mg organic Se.Throughout the trial,the ewes received various immune challenges,including intramuscular immunizations with a novel antigen(ovalbumin;OVA)on trial d 0 and 10,an intradermal OVA challenge on d 20,and a lipopolysaccharide(LPS)endotoxin challenge on trial d 49.Results The organic Se treatment groups had higher serum Se concentrations on most trial days compared to the 0.3 mg inorganic and control groups(P<0.05).No significant treatment differences were found for the dermal hypersensitivity response to OVA,anti-OVA antibody response,glutathione peroxidase activity,cytokine response,cortisol response,or rectal temperature(P>0.05).However,4 h post-LPS injection,the serum albumin concentration was significantly lower in the 0.3 mg inorganic group compared to both organic Se groups,potentially indicating a higher degree of inflammation in the ewes supplemented with the inorganic Se.Conclusions The results of this study indicate that organic Se supplementation can promote a higher Se status in ewes over time,but Se supplementation during this study period did not affect tested immunological parameters.This lack of difference in immune responsiveness between groups may be due to an absence of true serum Se deficiencies in the Se-deficient group or the levels of Se supplementation being insufficient to significantly improve immunocompetence.展开更多
This study examines radon emissions as potential proxies for environmental change in tropical Andean ecosystems undergoing rapid glacier retreat due to climate forcing.The research was conducted in the proglacial zone...This study examines radon emissions as potential proxies for environmental change in tropical Andean ecosystems undergoing rapid glacier retreat due to climate forcing.The research was conducted in the proglacial zone of the Yana Ucsha glacier in the Peruvian Andes,where field campaigns between July and November 2023 yielded radon measurements at approximately 28-day intervals across ten monitoring sites(M1-M10).Radon flux was measured using LR115 detectors and complemented by analyses of soil texture and the topographic wetness index(TWI)to assess the influence of environmental variables.Results demonstrate that radon emissions are strongly modulated by soil moisture,which in turn is regulated by regional air temperature and glacier runoff.A significant inverse relationship was identified between radon exhalation and regional air temperature,indicating that warmer periods suppress radon release due to increased soil moisture from enhanced glacier melt.Conversely,the coldest monitoring interval(second period)exhibited markedly higher radon exhalation,reaching up to 0.45 and 0.32 Bq m^(-2)hm^(-1)at sites M1 and M4,respectively-approximately four to five times greater than the baseline range(0-0.10 Bq m^(-2)hm^(-1))observed during other periods.This pronounced temporal anomaly coincided with lower regional air temperatures,reduced glacier runoff,and drier soil conditions,highlighting strong climatic control on radon emissions.These findings suggest that ongoing glacier retreat and climate change may constrain or reduce radon emission rates in Andean proglacial environments,with important implications for environmental monitoring and ecosystem dynamics.Overall,this study provides novel insights into the interactions among cryospheric,atmospheric,and radon dynamics in the tropical Andes.展开更多
To address the longstanding challenge in traditional carborane methodology of rapidly and efficiently constructing carboranyl-based polycyclic frameworks,Pd-catalyzed one-pot reactions between pyridyl-substituted nido...To address the longstanding challenge in traditional carborane methodology of rapidly and efficiently constructing carboranyl-based polycyclic frameworks,Pd-catalyzed one-pot reactions between pyridyl-substituted nidocarboranes and alkynes directly afford two distinct types of 2D-3D fused carboranyl polycyclic compounds:3a-3f,4a-4d.The structures of this series of compounds were characterized by nuclear magnetic resonance spectroscopy,single-crystal X-ray diffraction,and high-resolution mass spectrometry,and a plausible reaction mechanism was proposed.Crystal structures reveal that the multiple rings in such 2D-3D fused carboranyl polycyclic compounds exhibit a certain degree of coplanarity.Furthermore,these compounds exhibited properties distinct from those of conventional 2D polycyclic systems.CCDC:2481988,3c,2481990,3f,2481986,4d.展开更多
Ceratitis capitata(Wiedemann)is a cosmopolitan pest of economic importance.It is controlled by using the Sterile Insect Technique(SIT),which involves rearing and release of sterile males destined to mate with wild fem...Ceratitis capitata(Wiedemann)is a cosmopolitan pest of economic importance.It is controlled by using the Sterile Insect Technique(SIT),which involves rearing and release of sterile males destined to mate with wild females,causing generation-to-generation suppression.Medflies are colonized by microorganisms,primarily the Enterobacteriaceae,with the genera Klebsiella and Enterobacter being the most common.Such microbiota contributes to host fitness.During the SIT,diet with antibiotics and irradiation for sterility of adults alter microbiota.We aimed to determine the role of Medfly microbiota on resistance to abiotic stress conditions,evaluating its function under:(i)starvation,(ii)elevated temperatures,and(iii)dry environments.These conditions simulate challenges Medfly may encounter after release,which differ from controlled rearing environments.We compared adult survival between symbiotic and aposymbiotic individuals,under starvation,two thermal regimes(25 and 30℃)or two humidity regimes(20%-25%and 80%-90%R.H.).Aposymbiotic individuals were obtained after providing them with water containing a mixture of antibiotics and methylparaben.Treatment with antimicrobials effectively reduced the gut microbiota.While starvation had no significant effect on survival,a higher proportion of aposymbiotic individuals died earlier at 30℃ and under dry humidity,with the effect being more pronounced after 48 h.Our results suggest that microbiota plays a role in adaptation of Medfly under environmental stress.We report for the presence of a culturable yeast in the digestive tract of C.capitata,Zygosaccharomyces rouxii.Providing a probiotic adult diet with bacteria and Z.rouxii prior to release could improve SIT outcomes under adverse conditions.展开更多
Statistical distribution of residual fatigue life(RFL)of railway axles under given loading was computed using the Monte Carlo method by considering random variation of the selected input parameters.Experimental data f...Statistical distribution of residual fatigue life(RFL)of railway axles under given loading was computed using the Monte Carlo method by considering random variation of the selected input parameters.Experimental data for the EA4T railway axle steel,the loading spectrum,the press fit loading and the residual stress induced by surface hardening were considered in the crack propagation simulations.Usually,the material properties measured by tensile tests are considered to be the most informative source of material data.Under fatigue loading,however,the crack growth rates near the threshold are the most critical data.Two important influencing factors on these crack growth rates are presented:first,the air humidity and,second,the near-surface residual stress.The typical variation of these parameters in operation may change the RFL by one or two orders of magnitude.Experimentally obtained crack growth thresholds and residual stress profiles are highly affected by the used methodology.Therefore,the obtained input data may be located anywhere within a large scatter,while the experimenters are completely unaware of it.This can lead to dangerously non-conservative situations,e.g.when the thresholds are measured in a laboratory under humid air conditions and then applied to predictions of RFLs of axles operated in winter in low air humidity.This is significant for the topic of inspection interval optimisation.The results of experiments done on real 1:1 railway axles were close to the most frequent value found in the histogram of the numerically computed RFLs.展开更多
Rapid and accurate visible-light photopolymerization is essential for advancing bioprinted engineered tissues.In this study,we developed a novel three-component photoinitiator system for visible light-induced crosslin...Rapid and accurate visible-light photopolymerization is essential for advancing bioprinted engineered tissues.In this study,we developed a novel three-component photoinitiator system for visible light-induced crosslinking of gelatin methacryloyl(GelMA)hydrogels,designed to improve polymerization kinetics,mechanical strength,and structural integrity.Incorporation of 2-bromoacetophenone(BAP)considerably accelerated photopolymerization,with reaction rates increasing alongside BAP concentration,enabling the rapid fabrication of stable hydrogel scaffolds.Printing experiments confirmed that BAP promoted fast crosslinking of GelMA bioinks under visible light,reducing printing time while preserving high-resolution structural features.Additionally,the incorporation of BAP induced microscale structural transformations in the hydrogels during hydration,as evidenced by scanning electron microscopy imaging and swelling analyses.This unique property enabled the fabrication of multilayer constructs exhibiting time-dependent deformation,demonstrating four-dimensional(4 D)printing ca pabilities.Moreover,biocompatibility evaluations revealed that cells maintained high viability in BAP-containing hydrogels.Overall,the BAP-based photoinitiator system offers a promising strategy for high-speed,high-resolution bioprinting,combining enhanced mechanical performance,reduced fabrication time,and dynamic structural adaptability-features that make it highly suitable for advanced biofabrication and tissue engineering applications.展开更多
This study investigates the impacts of mixing time,execution procedure,cement dosage(α),and total water-to-cement ratio(W_(Total)/C)on the mixing energy(E)of deep soil mixing(DSM)columns and how E influences the stre...This study investigates the impacts of mixing time,execution procedure,cement dosage(α),and total water-to-cement ratio(W_(Total)/C)on the mixing energy(E)of deep soil mixing(DSM)columns and how E influences the strength of treated sand.Columns with a diameter of 7.5 cm were constructed using three mixing times(130,190,and 250 s),two execution procedures(normal and zigzag),threeαvalues(300,400,and 500 kg/m^(3)),and three W_(Total)/C ratios(2.5,3.0,and 3.5).For comparison,equivalent laboratory samples were also examined.Results revealed that increasing the mixing time andα,adopting the zigzag execution procedure,and reducing the W_(Total)/C ratio increase E.Outcomes indicated that an increase in E from 0.49-0.70 kJ to 0.70-0.90 kJ,0.90-1.10 kJ,and 1.10-1.40 kJ improves the unconfined compressive strength(UCS)of columns on average by 66%,124%,and 179%,respectively,and the secant modulus by 61%,110%,and 152%.Average strain at maximum stress also rises from 0.68%to 0.75%,0.81%,and 0.84%,respectively.The study identified a threshold in the direct relationship between E and the strength ratio(λ),beyond whichλdid not increase significantly with further increases in E.Additionally,at low and high E levels,DSM samples mainly failed by crushing and cracking modes,respectively.In DSM columns withα=500 kg/m^(3)and W_(Total)/C=2.5,increasing average E from 0.77 kJ to 0.95 kJ,1.08 kJ,and 1.28 kJ resulted in a reduction of coefficients of variation of UCS from 30.4%to 27.8%,24.5%,and 21.1%,respectively.展开更多
Adult neurogenesis is generally considered to be very limited;however,there is increasing evidence that this phenomenon is conserved across species.Traditionally,research has focused on identifying precursor cells,tho...Adult neurogenesis is generally considered to be very limited;however,there is increasing evidence that this phenomenon is conserved across species.Traditionally,research has focused on identifying precursor cells,those that are actively dividing or have the potential to divide.Direct evidence of adult neurogenesis has been found in rats,mice,songbirds,and nonhuman primates.In humans,while the evidence is indirect,it strongly suggests that neurogenesis also occurs during adulthood.In mammals,this active neurogenesis is preserved by radial glial progenitors,which remain in specific niches in the subventricular zone of the lateral ventricles and in the subgranular zone of the hippocampal dentate gyrus(Kumar et al.,2019).展开更多
Acute cerebral ischemia caused by stroke,traumatic brain injury(TBI),or systemic acute conditions such as hemorrhagic shock,cardiac arrest,or disseminated intravascular coagulation results in an energy crisis in local...Acute cerebral ischemia caused by stroke,traumatic brain injury(TBI),or systemic acute conditions such as hemorrhagic shock,cardiac arrest,or disseminated intravascular coagulation results in an energy crisis in local sites or the whole brain.The disruption of cerebral blood flow deprives the brain cells of oxygen and glucose,the essential substrates for adenosine triphosphate(ATP)synthesis.As a result,oxidative phosphorylation in the mitochondria fails,forcing cells to rely on anaerobic glycolysis(He et al.,2020).Although this compensatory mechanism maintains short-term energy production under hypoxic conditions,overall ATP production is significantly reduced.Neurons,which are highly susceptible to ischemic injury,deplete their ATP stores faster than glial cells(e.g.,astrocytes),which have some energy reserves.展开更多
基金the financial support provided by the National Natural Science Foundation of China (Nos. 21822407, 21405163)the top priority program of “OneThree-Five” Strategic Planning of Lanzhou Institute of Chemical Physics, CAS
文摘As a promising signaling transduction approach, fluorescence polarization(FP)/fluorescence anisotropy(FA), provides a powerful quantitative tool for the rotational motion of fluorescently labeled molecules in chemical or biological homogeneous systems. Unlike fluorescence intensity, FP/FA is almost independent the concentration or quantum of fluorophores, but they are highly dependent on the size or molecular weight of the molecules or materials attached to fluorophores. Recently, significant progress in FP/FA was made, due to the introduction of some nanomaterials as FP/FA enhancers. The detection sensitivity is thus greatly improved by using nanomaterials as FP/FA enhancers, and nanomaterial-based FP/FA is currently used successfully in immunoassay, and analysis of protein, nucleic acid, small molecule and metal ion.Nanomaterial-based FP/FA provides a new kind of strategy to design fluorescent sensors and establishes innovative analytical methods. In this review, we summarize the scientific publications in the field of FP/FA sensor in recent five years, and first introduce the recent progress of FP/FA sensor based on nanomaterial. Subsequently, the various analytical applications of FP/FA based on nanomaterial are discussed. Finally, we provide perspectives on the current challenges and future prospects in this promising field.
基金the K.N.Toosi University of Technology Research Council for financial assistance
文摘Several N-alkyl/aryl-Se-alkyl/（aryl）selenocarbamates were prepared from various isocyanates and diselenides by reductive cleavage of Se-Se bond with the Zn/AIC]3 system in dry acetonitrile at 80 ℃.
基金financial funding from the Egyptian governmentthe financial funding from the NSERC Discovery grant。
文摘Combustion within small motors is key in the application-specific development of nanothermite-based micro-energetic systems. This study evaluates the performance of nanothermite mixtures in a converging-diverging nozzle and an open tube. Mixtures were prepared using nano-aluminum(n-Al),potassium perchlorate(KClO_(4)), and different carbon nanomaterials(CNMs) including graphene-oxide(GO), reduced GO, carbon nanotubes(CNTs) and nanofibers(CNFs). The mixtures were packed at different densities and ignited by laser beam. Performance was measured using thrust measurement,high-speed imaging, and computational fluid dynamics modeling, respectively. Thrust, specific impulse(ISP), volumetric impulse(ISV), as well as normalized energy were found to increase notably with CNM content. Two distinctive reaction regimes(fast and slow) were observed in combustion of low and high packing densities(20% and 55%TMD), respectively. Total impulse(IFT) and ISPwere maximized in the 5%GO/Al/KClO_4 mixture, producing 7.95 m N·s and 135.20 s respectively at 20%TMD, an improvement of 57%compared to a GO-free sample(5.05 m N·s and 85.88 s). CFD analysis of the motors over predicts the thrust generated but trends in nozzle layout and packing density agree with those observed experimentally;peak force was maximized by reducing packing density and using an open tube. The numerical force profiles fit better for the nozzle cases than the open tube scenarios due to the rapid nature of combustion. This study reveals the potential of GO in improving oxygenated salt-based nanothermites,and further demonstrates their applicability for micro-propulsion and micro-energetic applications.
文摘For many decades,Alzheimer's disease research has primarily focused on impairments within cortical and hippocampal regions,which are thought to be related to cognitive dysfunctions such as memory and language deficits.The exact cause of Alzheimer's disease is still under debate,making it challenging to establish an effective therapy or early diagnosis.It is widely accepted that the accumulation of amyloid-beta peptide in the brain parenchyma leads to synaptic dysfunction,a critical step in Alzheimer's disease development.The traditional amyloid cascade model is initiated by accumulating extracellular amyloid-beta in brain areas essential for memory and language.However,while it is possible to reduce the presence of amyloid-beta plaques in the brain with newer immunotherapies,cognitive symptoms do not necessarily improve.Interestingly,recent studies support the notion that early alterations in subcortical brain regions also contribute to brain damage and precognitive decline in Alzheimer's disease.A body of recent evidence suggests that early Alzheimer's disease is associated with alterations(e.g.,motivation,anxiety,and motor impairment)in subcortical areas,such as the striatum and amygdala,in both human and animal models.Also,recent data indicate that intracellular amyloid-beta appears early in subcortical regions such as the nucleus accumbens,locus coeruleus,and raphe nucleus,even without extracellular amyloid plaques.The reported effects are mainly excitatory,increasing glutamatergic transmission and neuronal excitability.In agreement,data in Alzheimer's disease patients and animal models show an increase in neuronal synchronization that leads to electroencephalogram disturbances and epilepsy.The data indicate that early subcortical brain dysfunctions might be associated with non-cognitive symptoms such as anxiety,irritability,and motivation deficits,which precede memory loss and language alterations.Overall,the evidence reviewed suggests that subcortical brain regions could explain early dysfunctions and perhaps be targets for therapies to slow disease progression.Future research should focus on these non-traditional brain regions to reveal early pathological alterations and underlying mechanisms to advance our understanding of Alzheimer's disease beyond the traditionally studied hippocampal and cortical circuits.
基金the University of Ottawa, the China Scholarship Council and the Natural Sciences and Engineering Research Council of Canada (NSERC) for their financial support.
文摘As underground mining advances to greater depths,cemented paste backfill(CPB)is increasingly subjected to complex thermo-mechanical loading conditions,including multiaxial stress states and elevated temperatures.This study investigates the coupled effects of field-representative vertical self-weight and horizontal rockwall closure stresses,along with in-situ temperatures,on the mechanical behavior and pore water pressure(PWP)evolution of CPB.Experiments were conducted using a novel apparatus capable of controlling multiaxial stress and temperature during curing,replicating in-situ stress paths and thermal profiles typical of deep mine environments.Results show that multiaxial stress enhances CPB strength and stiffness by promoting denser particle packing,reducing porosity,and increasing frictional resistance.Elevated temperatures independently accelerate early-age cement hydration,further improving bond strength and stiffness.When combined,multiaxial stress and elevated temperature produce a synergistic enhancement in unconfined compressive strength(UCS)and elastic modulus,as confirmed by two-way ANOVA and synergy index analysis.PWP responses were also highly sensitive to thermo-mechanical conditions.The evolution of positive and negative PWP was governed by the interplay of thermal expansion,hydration-induced desaturation,and mechanical compaction.Multiaxial stress amplified early positive PWP and delayed its dissipation,whereas elevated temperature accelerated hydration and reduced pore pressure,leading to enhanced suction at later ages.A transient“stress-induced resaturation”effect was observed under late-stage excessive horizontal stress but was mitigated by elevated temperatures.These findings provide critical insights into the coupled mechanical and hydraulic behavior of CPB under realistic field conditions and offer guidance for optimizing backfill design,binder content,and barricade stability in deep mining applications.
基金supported by the SECIHTI project PDCPN-2015-266,México.
文摘Acalypha gaumeri(Euphorbiaceae)is the only endemic species of the genus in the Yucatan Peninsula.It is dioecious and has antifungal properties against various phytopathogens.In the present study,molecular identification of A.gaumeri was performed using the rbcL region,confirming its belonging to the Acalypha genus.Its genetic diversity was evaluated using 10 SPAR markers(ISSR and DAMD)from 60 individuals collected from female and male plants of the Kiuic,Tinum and Yaxcaba ex-situ populations.The results showed a high level of genetic polymorphism(PIC=0.980)and significant differences among the populations.Ethanol and aqueous extracts from leaves,stems,and roots of both genders and three populations were evaluated against three phytopathogenic fungi.Only the ethanol extracts of the roots showed inhibitory antifungal activity,whereas Kiuic and Tinum,both male and female individuals,showed inhibitory effects at 1000μg/mL against the three pathogens.The ethanol extract of the female flowering plant of Kiuic showed activity at minimum inhibitory concentrations of 250μg/mL against Alternaria chrysanthemi CICY004 and 500μg/mL against Colletotrichum gloeosporioides CICY002 and Penicillium oxalicum ITC25.Chromatographic profile of the ethanol extracts confirmed the presence of alkaloidal components in the ex-situ cultivated plants,which were analyzed by HPLC.The results revealed that the peaks at T_(R) of 7.60,7.88,and 8.49 min were the most abundant components(9.95%-21.93%),with differences between female and male plants of the three populations.This research confirms that A.gaumeri cultivated and genetically characterized is a potential raw material to develop an eco-friendly product for the control of fungal diseases in crops.
文摘Earthquakes are highly destructive spatio-temporal phenomena whose analysis is essential for disaster preparedness and risk mitigation.Modern seismological research produces vast volumes of heterogeneous data from seismic networks,satellite observations,and geospatial repositories,creating the need for scalable infrastructures capable of integrating and analyzing such data to support intelligent decision-making.Data warehousing technologies provide a robust foundation for this purpose;however,existing earthquake-oriented data warehouses remain limited,often relying on simplified schemas,domain-specific analytics,or cataloguing efforts.This paper presents the design and implementation of a spatio-temporal data warehouse for seismic activity.The framework integrates spatial and temporal dimensions in a unified schema and introduces a novel array-based approach for managing many-to-many relationships between facts and dimensions without intermediate bridge tables.A comparative evaluation against a conventional bridge-table schema demonstrates that the array-based design improves fact-centric query performance,while the bridge-table schema remains advantageous for dimension-centric queries.To reconcile these trade-offs,a hybrid schema is proposed that retains both representations,ensuring balanced efficiency across heterogeneous workloads.The proposed framework demonstrates how spatio-temporal data warehousing can address schema complexity,improve query performance,and support multidimensional visualization.In doing so,it provides a foundation for integrating seismic analysis into broader big data-driven intelligent decision systems for disaster resilience,risk mitigation,and emergency management.
基金the research project LaTe4PoliticES(PID2022-138099OB-I00)funded by MCIN/AEI/10.13039/501100011033 and the European Fund for Regional Development(ERDF)-a way to make Europe.Tomás Bernal-Beltrán is supported by University of Murcia through the predoctoral programme.
文摘The malicious dissemination of hate speech via compromised accounts,automated bot networks and malware-driven social media campaigns has become a growing cybersecurity concern.Automatically detecting such content in Spanish is challenging due to linguistic complexity and the scarcity of annotated resources.In this paper,we compare two predominant AI-based approaches for the forensic detection of malicious hate speech:(1)finetuning encoder-only models that have been trained in Spanish and(2)In-Context Learning techniques(Zero-and Few-Shot Learning)with large-scale language models.Our approach goes beyond binary classification,proposing a comprehensive,multidimensional evaluation that labels each text by:(1)type of speech,(2)recipient,(3)level of intensity(ordinal)and(4)targeted group(multi-label).Performance is evaluated using an annotated Spanish corpus,standard metrics such as precision,recall and F1-score and stability-oriented metrics to evaluate the stability of the transition from zero-shot to few-shot prompting(Zero-to-Few Shot Retention and Zero-to-Few Shot Gain)are applied.The results indicate that fine-tuned encoder-only models(notably MarIA and BETO variants)consistently deliver the strongest and most reliable performance:in our experiments their macro F1-scores lie roughly in the range of approximately 46%–66%depending on the task.Zero-shot approaches are much less stable and typically yield substantially lower performance(observed F1-scores range approximately 0%–39%),often producing invalid outputs in practice.Few-shot prompting(e.g.,Qwen 38B,Mistral 7B)generally improves stability and recall relative to pure zero-shot,bringing F1-scores into a moderate range of approximately 20%–51%but still falling short of fully fine-tuned models.These findings highlight the importance of supervised adaptation and discuss the potential of both paradigms as components in AI-powered cybersecurity and malware forensics systems designed to identify and mitigate coordinated online hate campaigns.
文摘We thank Power et al.1 for their interest in our review2 and for contributing to this important scientific discussion.We welcome their commentary and acknowledge the merit of continuing to scrutinize and refine interpretations in this evolving field.Given that much research time and financial investment is being given to the study of the effects of eccentric training in both athletic and clinical contexts,it is incumbent on our field to demonstrate whether eccentric contractions are a key(or the key)stimulus for sarcomerogenesis(increases in serial sarcomere number(SSN)).
基金supported by Instituto de Salud CarlosⅢ,Spanish Ministry of Science and Innovation,grant number PI18/00576 to MSGG and JMRRed de Investigación en Atención Primaria de Adicciones,Instituto de Salud CarlosⅢ,Spanish Ministry of Science and Innovation,grant number RD21/0009/0008 and RD24/0003/0002+1 种基金Instituto de Investigación Sanitaria y Biomédica de Alicante(ISABIAL)to JMThe Instituto de Neurociencias is a“Centre of Excellence Severo Ochoa”(CEX2021-001165-S).
文摘Cannabidiol(CBD),the second most significant phytocannabinoid in the plant Cannabis sativa,which lacks potential as a drug of abuse(Viudez-Martinez et al.,2019),has gained widespread attention due to its anti-inflammatory,antioxidant,and antidepressant properties(Garci a-Gutierrez et al.,2020).Additionally,CBD exhibits neuroprotective properties,preserving neuronal viability and function by preventing or limiting cellular damage.Our team has demonstrated that CBD produces rapid antidepressant-like effects in a murine model of chronic mild stress,restoring hippocampal expression of brain-derived neurotrophic factor(BDNF).
基金funding from FCT(Fundagao para a Ciencia e Tecnologia,I.P.)under the projects LA/P/0037/2020,UIDP/50025/2020 and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures,Nanomodelling and Nanofabrication-i3Nby the projects FlexSolar(PTDC/CTM-REF/1008/2020),and SpaceFlex(2022.01610.PTDC,DOI:10.54499/2022.01610.PTDC)+1 种基金supported by the project M-ECO2-Industrial Cluster for advanced biofuel production,Ref.C644930471-00000041,R2U Technologies and Befunding from the European Union via the project X-STREAM(Horizon EU,ERC CoG,No 101124803)the support of a fellowship from the"la Caixa"Foundation(ID 100010434)。
文摘Low-dimensional(LD)halide perovskites have attracted considerable attention due to their distinctive structures and exceptional optoelectronic properties,including high absorption coefficients,extended charge carrier diffusion lengths,suppressed non-radiative recombination rates,and intense photoluminescence.A key advantage of LD perovskites is the tunability of their optical and electronic properties through the precise optimization of their structural arrangements and dimensionality.This review systematically examines recent progress in the synthesis and optoelectronic characterizations of LD perovskites,focusing on their structural,optical,and photophysical properties that underpin their versatility in diverse applications.The review further summarizes advancements in LD perovskite-based devices,including resistive memory,artificial synapses,photodetectors,light-emitting diodes,and solar cells.Finally,the challenges associated with stability,scalability,and integration,as well as future prospects,are discussed,emphasizing the potential of LD perovskites to drive breakthroughs in device efficiency and industrial applicability.
基金Ontario Ministry of Agriculture,Food and Agribusiness(OMAFA)Natural Sciences and Engineering Research Council of Canada(NSERC)+1 种基金AdisseoOntario Sheep Farmers。
文摘Background Selenium(Se)is an essential soil mineral that can be incorporated into animal feedstuffs.Because of a lack of soil Se in some regions,organic or inorganic supplementation strategies must be implemented to prevent deficiencies and promote optimal ovine health.Therefore,the objectives of this study were to assess how inorganic versus organic Se supplementation influenced ewe Se status and immune function during late gestation and postpartum.Dorset Rideau ewes(n=110)were fed a Se deficient diet from gestation d 110 through postpartum d 49 and received one of four daily oral Se treatments diluted in 5 mL of sugar water:0 mg Se,0.3 mg inorganic Se,0.3 mg organic Se,and 0.6 mg organic Se.Throughout the trial,the ewes received various immune challenges,including intramuscular immunizations with a novel antigen(ovalbumin;OVA)on trial d 0 and 10,an intradermal OVA challenge on d 20,and a lipopolysaccharide(LPS)endotoxin challenge on trial d 49.Results The organic Se treatment groups had higher serum Se concentrations on most trial days compared to the 0.3 mg inorganic and control groups(P<0.05).No significant treatment differences were found for the dermal hypersensitivity response to OVA,anti-OVA antibody response,glutathione peroxidase activity,cytokine response,cortisol response,or rectal temperature(P>0.05).However,4 h post-LPS injection,the serum albumin concentration was significantly lower in the 0.3 mg inorganic group compared to both organic Se groups,potentially indicating a higher degree of inflammation in the ewes supplemented with the inorganic Se.Conclusions The results of this study indicate that organic Se supplementation can promote a higher Se status in ewes over time,but Se supplementation during this study period did not affect tested immunological parameters.This lack of difference in immune responsiveness between groups may be due to an absence of true serum Se deficiencies in the Se-deficient group or the levels of Se supplementation being insufficient to significantly improve immunocompetence.
基金partially funded by the Ministerio de Relaciones Exteriores del Perú,the Vicerectorado de Investigación of PUCPthe Fondo de Apoyo para la Investigación(FAI)2024 of PUCP.
文摘This study examines radon emissions as potential proxies for environmental change in tropical Andean ecosystems undergoing rapid glacier retreat due to climate forcing.The research was conducted in the proglacial zone of the Yana Ucsha glacier in the Peruvian Andes,where field campaigns between July and November 2023 yielded radon measurements at approximately 28-day intervals across ten monitoring sites(M1-M10).Radon flux was measured using LR115 detectors and complemented by analyses of soil texture and the topographic wetness index(TWI)to assess the influence of environmental variables.Results demonstrate that radon emissions are strongly modulated by soil moisture,which in turn is regulated by regional air temperature and glacier runoff.A significant inverse relationship was identified between radon exhalation and regional air temperature,indicating that warmer periods suppress radon release due to increased soil moisture from enhanced glacier melt.Conversely,the coldest monitoring interval(second period)exhibited markedly higher radon exhalation,reaching up to 0.45 and 0.32 Bq m^(-2)hm^(-1)at sites M1 and M4,respectively-approximately four to five times greater than the baseline range(0-0.10 Bq m^(-2)hm^(-1))observed during other periods.This pronounced temporal anomaly coincided with lower regional air temperatures,reduced glacier runoff,and drier soil conditions,highlighting strong climatic control on radon emissions.These findings suggest that ongoing glacier retreat and climate change may constrain or reduce radon emission rates in Andean proglacial environments,with important implications for environmental monitoring and ecosystem dynamics.Overall,this study provides novel insights into the interactions among cryospheric,atmospheric,and radon dynamics in the tropical Andes.
文摘To address the longstanding challenge in traditional carborane methodology of rapidly and efficiently constructing carboranyl-based polycyclic frameworks,Pd-catalyzed one-pot reactions between pyridyl-substituted nidocarboranes and alkynes directly afford two distinct types of 2D-3D fused carboranyl polycyclic compounds:3a-3f,4a-4d.The structures of this series of compounds were characterized by nuclear magnetic resonance spectroscopy,single-crystal X-ray diffraction,and high-resolution mass spectrometry,and a plausible reaction mechanism was proposed.Crystal structures reveal that the multiple rings in such 2D-3D fused carboranyl polycyclic compounds exhibit a certain degree of coplanarity.Furthermore,these compounds exhibited properties distinct from those of conventional 2D polycyclic systems.CCDC:2481988,3c,2481990,3f,2481986,4d.
基金Fund for Scientific and Technological Research of Argentina(FONCyT PICT 2018 number 03521).
文摘Ceratitis capitata(Wiedemann)is a cosmopolitan pest of economic importance.It is controlled by using the Sterile Insect Technique(SIT),which involves rearing and release of sterile males destined to mate with wild females,causing generation-to-generation suppression.Medflies are colonized by microorganisms,primarily the Enterobacteriaceae,with the genera Klebsiella and Enterobacter being the most common.Such microbiota contributes to host fitness.During the SIT,diet with antibiotics and irradiation for sterility of adults alter microbiota.We aimed to determine the role of Medfly microbiota on resistance to abiotic stress conditions,evaluating its function under:(i)starvation,(ii)elevated temperatures,and(iii)dry environments.These conditions simulate challenges Medfly may encounter after release,which differ from controlled rearing environments.We compared adult survival between symbiotic and aposymbiotic individuals,under starvation,two thermal regimes(25 and 30℃)or two humidity regimes(20%-25%and 80%-90%R.H.).Aposymbiotic individuals were obtained after providing them with water containing a mixture of antibiotics and methylparaben.Treatment with antimicrobials effectively reduced the gut microbiota.While starvation had no significant effect on survival,a higher proportion of aposymbiotic individuals died earlier at 30℃ and under dry humidity,with the effect being more pronounced after 48 h.Our results suggest that microbiota plays a role in adaptation of Medfly under environmental stress.We report for the presence of a culturable yeast in the digestive tract of C.capitata,Zygosaccharomyces rouxii.Providing a probiotic adult diet with bacteria and Z.rouxii prior to release could improve SIT outcomes under adverse conditions.
基金financially supported by the Czech Science Foundation in the frame of the project No.22-28283Sby the Technology Agency of the Czech Republic through the project No.CK03000060.
文摘Statistical distribution of residual fatigue life(RFL)of railway axles under given loading was computed using the Monte Carlo method by considering random variation of the selected input parameters.Experimental data for the EA4T railway axle steel,the loading spectrum,the press fit loading and the residual stress induced by surface hardening were considered in the crack propagation simulations.Usually,the material properties measured by tensile tests are considered to be the most informative source of material data.Under fatigue loading,however,the crack growth rates near the threshold are the most critical data.Two important influencing factors on these crack growth rates are presented:first,the air humidity and,second,the near-surface residual stress.The typical variation of these parameters in operation may change the RFL by one or two orders of magnitude.Experimentally obtained crack growth thresholds and residual stress profiles are highly affected by the used methodology.Therefore,the obtained input data may be located anywhere within a large scatter,while the experimenters are completely unaware of it.This can lead to dangerously non-conservative situations,e.g.when the thresholds are measured in a laboratory under humid air conditions and then applied to predictions of RFLs of axles operated in winter in low air humidity.This is significant for the topic of inspection interval optimisation.The results of experiments done on real 1:1 railway axles were close to the most frequent value found in the histogram of the numerically computed RFLs.
基金supported by the Natural Sciences and Engineering Research Council of Canada(NSERC)Discovery Grant(No.RGPIN-2020-04559)the Canada Foundation for Innovation John R.Evans Leaders Fund(JELF).
文摘Rapid and accurate visible-light photopolymerization is essential for advancing bioprinted engineered tissues.In this study,we developed a novel three-component photoinitiator system for visible light-induced crosslinking of gelatin methacryloyl(GelMA)hydrogels,designed to improve polymerization kinetics,mechanical strength,and structural integrity.Incorporation of 2-bromoacetophenone(BAP)considerably accelerated photopolymerization,with reaction rates increasing alongside BAP concentration,enabling the rapid fabrication of stable hydrogel scaffolds.Printing experiments confirmed that BAP promoted fast crosslinking of GelMA bioinks under visible light,reducing printing time while preserving high-resolution structural features.Additionally,the incorporation of BAP induced microscale structural transformations in the hydrogels during hydration,as evidenced by scanning electron microscopy imaging and swelling analyses.This unique property enabled the fabrication of multilayer constructs exhibiting time-dependent deformation,demonstrating four-dimensional(4 D)printing ca pabilities.Moreover,biocompatibility evaluations revealed that cells maintained high viability in BAP-containing hydrogels.Overall,the BAP-based photoinitiator system offers a promising strategy for high-speed,high-resolution bioprinting,combining enhanced mechanical performance,reduced fabrication time,and dynamic structural adaptability-features that make it highly suitable for advanced biofabrication and tissue engineering applications.
文摘This study investigates the impacts of mixing time,execution procedure,cement dosage(α),and total water-to-cement ratio(W_(Total)/C)on the mixing energy(E)of deep soil mixing(DSM)columns and how E influences the strength of treated sand.Columns with a diameter of 7.5 cm were constructed using three mixing times(130,190,and 250 s),two execution procedures(normal and zigzag),threeαvalues(300,400,and 500 kg/m^(3)),and three W_(Total)/C ratios(2.5,3.0,and 3.5).For comparison,equivalent laboratory samples were also examined.Results revealed that increasing the mixing time andα,adopting the zigzag execution procedure,and reducing the W_(Total)/C ratio increase E.Outcomes indicated that an increase in E from 0.49-0.70 kJ to 0.70-0.90 kJ,0.90-1.10 kJ,and 1.10-1.40 kJ improves the unconfined compressive strength(UCS)of columns on average by 66%,124%,and 179%,respectively,and the secant modulus by 61%,110%,and 152%.Average strain at maximum stress also rises from 0.68%to 0.75%,0.81%,and 0.84%,respectively.The study identified a threshold in the direct relationship between E and the strength ratio(λ),beyond whichλdid not increase significantly with further increases in E.Additionally,at low and high E levels,DSM samples mainly failed by crushing and cracking modes,respectively.In DSM columns withα=500 kg/m^(3)and W_(Total)/C=2.5,increasing average E from 0.77 kJ to 0.95 kJ,1.08 kJ,and 1.28 kJ resulted in a reduction of coefficients of variation of UCS from 30.4%to 27.8%,24.5%,and 21.1%,respectively.
文摘Adult neurogenesis is generally considered to be very limited;however,there is increasing evidence that this phenomenon is conserved across species.Traditionally,research has focused on identifying precursor cells,those that are actively dividing or have the potential to divide.Direct evidence of adult neurogenesis has been found in rats,mice,songbirds,and nonhuman primates.In humans,while the evidence is indirect,it strongly suggests that neurogenesis also occurs during adulthood.In mammals,this active neurogenesis is preserved by radial glial progenitors,which remain in specific niches in the subventricular zone of the lateral ventricles and in the subgranular zone of the hippocampal dentate gyrus(Kumar et al.,2019).
基金supported by the Russian Science Foundation,grant 24-75-10013(to NVA).
文摘Acute cerebral ischemia caused by stroke,traumatic brain injury(TBI),or systemic acute conditions such as hemorrhagic shock,cardiac arrest,or disseminated intravascular coagulation results in an energy crisis in local sites or the whole brain.The disruption of cerebral blood flow deprives the brain cells of oxygen and glucose,the essential substrates for adenosine triphosphate(ATP)synthesis.As a result,oxidative phosphorylation in the mitochondria fails,forcing cells to rely on anaerobic glycolysis(He et al.,2020).Although this compensatory mechanism maintains short-term energy production under hypoxic conditions,overall ATP production is significantly reduced.Neurons,which are highly susceptible to ischemic injury,deplete their ATP stores faster than glial cells(e.g.,astrocytes),which have some energy reserves.
