Background:Himalayan Griffons(Gyps himalayensis),large scavenging raptors widely distributed in Qinghai-Tibetan Plateau,have evolved a remarkable ability to feed on carcasses without suffering any adverse effects.The ...Background:Himalayan Griffons(Gyps himalayensis),large scavenging raptors widely distributed in Qinghai-Tibetan Plateau,have evolved a remarkable ability to feed on carcasses without suffering any adverse effects.The gut microbiome plays an important role in animal physiological and pathological processes,and has also been found to play a health protective role in the vulture adaptation to scavenging.However,the microbial taxonomic diversity(including nonculturable and culturable microbes),functions,and metabolites related to Himalayan Griffons have not been fully explored.Methods:In the present study,the 28 fecal samples of the Himalayan Griffons and 8 carrion samples were collected and sequenced using high-throughput 16 S rRNA gene sequencing methods to analyze the composition and functional structures of the microbiomes.Twelve fecal samples of the Himalayan Griffons were analyzed using untargeted Liquid Chromatography Mass Spectroscopy(LC-MS)to identify metabolites.We used different culture conditions to grow Himalayan Griffons gut microbes.Inhibitory effects of gut beneficial bacteria on 5 common pathogenic bacteria were also tested using the Oxford cup method.Results:According to the results of the culture-independent method,a high abundance of four major phyla in Himalayan Griffons were identified,including Fusobacteria,Firmicutes,Bacteroidetes,and Proteobacteria.The most abundant genera were Fusobacterium,followed by Clostridium_sensu_stricto_1,Cetobacterium,Epulopiscium,and Bacteroides.The predicted primary functional categories of the Himalayan Griffons'gut microbiome were associated with carbohydrate and amino acid metabolism,replication and repair,and membrane transport.LC-MS metabolomic analysis showed a total of 154 metabolites in all the fecal samples.Cultivation yielded 184 bacterial isolates with Escherichia coli,Enterococcus faecium,Enterococcus hirae,and Paeniclostridium sordellii as most common isolates.Moreover,7 potential beneficial gut bacteria isolated showed certain inhibition to 5 common pathogenic bacteria.Conclusions:Our findings broaden and deepen the understanding of Himalayan Griffons'gut microbiome,and highlighted the importance of gut microbiome-mediated adaptation to scavenging habits.In particular,our results highlighted the protective role of gut beneficial bacteria in the Himalayan Griffons against pathogenic bacteria that appear in rotten food resources.展开更多
This study was carried out based on consistent observations on the activities of scavengers of scrap metal in Obio/Akpor local government Rivers State. The study was carried out to ascertain the profitability of scrap...This study was carried out based on consistent observations on the activities of scavengers of scrap metal in Obio/Akpor local government Rivers State. The study was carried out to ascertain the profitability of scrap metal scavenging and how scrap metal waste can generate wealth to the public and the government. The study made use of primary and secondary data with the former being the main focus. The data were analyzed using the simple percentage, while the hypothesis was tested by means of the chi-square. The study findings revealed that there was a relationship between waste and wealth in relation to scrap metal scavenging. The researches therefore make the following recommendations;that scavengers should form co-operatives so that they can pull their efforts and resources together and bargain collectively. Government and nongovernmental organization should enlighten them through seminars, workshops, etc., on how to carry out their activities in an environmentally safe manner. The state government should encourage scavenging by enacting a law to back the profession and make it attractive for the teaming youths to venture into.展开更多
The effects of an exogenous nitric oxide donor(sodium nitroprusside, SNP), a NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxode(PTIO) and carboxy-PTIO potassium salt(c PTIO) on the embryo germination ...The effects of an exogenous nitric oxide donor(sodium nitroprusside, SNP), a NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxode(PTIO) and carboxy-PTIO potassium salt(c PTIO) on the embryo germination of Sorbus pohuashanensis were studied in a petri dish test. SNP at 0.5–5 mmol L-1 increased germination percentage, mean time to germination, germination index and germination energy compared with the control to different degrees. Treatment with 2 mmol L-1 SNP improved germination most significantly; embryo germination percentage for mother tree 1(91.11%) and mother tree 2(64.44%) were much higher than the control. In addition,excessive SNP levels did not enhance embryo germination.Combined treatment with SNP and an NO scavenger delayed embryo germination. Treatment with c PTIO inhibited embryo germination; germination percentage was 42.22% and was lower than that of the control. These results show that low concentrations of exogenous NO can enhance the embryo germination of S. pohuashanensis,providing a simple, effective way for promoting germination of S. pohuashanensis.展开更多
Namibia’s Etosha National Park(ENP)is home to many different animals such as lions,jackals,hyenas,zebras,elephants,etc.Each year,grazing animals are infected and die from anthrax caused by the bacteria Bacillus anthr...Namibia’s Etosha National Park(ENP)is home to many different animals such as lions,jackals,hyenas,zebras,elephants,etc.Each year,grazing animals are infected and die from anthrax caused by the bacteria Bacillus anthracis.This increases the number of carcasses in the park,which serve as food for scavengers such as jackals.This study investigates the interplay between anthrax transmission in zebras and the scavenging of zebra carcasses in ENP,using a deterministic mathematical model to describe the population dynamics.We strive to answer the following research questions:Under what conditions can the presence of scavengers control anthrax outbreaks in zebra populations=Does carcass production by anthrax help or hurt scavengers in the long term?Standard qualitative analysis techniques distinguished outcomes(stable equilibria)using reproduction numbers as threshold quantities.We found that,when scavengers feed on anthrax-laden carcasses,the scavengers help the zebras,by eliminating potential infection zones for the zebras.In this way they reduce anthrax’s spread by orders of magnitude.We also identify conditions under which the presence of anthrax benefits the scavengers,in terms of death-to-birth ratios for zebras,scavengers and anthrax.展开更多
Inflammatory skin disorders can cause chronic scarring and functional impairments,posing a significant burden on patients and the healthcare system.Conventional therapies,such as corticosteroids and nonsteroidal anti-...Inflammatory skin disorders can cause chronic scarring and functional impairments,posing a significant burden on patients and the healthcare system.Conventional therapies,such as corticosteroids and nonsteroidal anti-inflammatory drugs,are limited in efficacy and associated with adverse effects.Recently,nanozyme(NZ)-based hydrogels have shown great promise in addressing these challenges.NZ-based hydrogels possess unique therapeutic abilities by combining the therapeutic benefits of redox nanomaterials with enzymatic activity and the water-retaining capacity of hydrogels.The multifaceted therapeutic effects of these hydrogels include scavenging reactive oxygen species and other inflammatory mediators modulating immune responses toward a pro-regenerative environment and enhancing regenerative potential by triggering cell migration and differentiation.This review highlights the current state of the art in NZ-engineered hydrogels(NZ@hydrogels)for anti-inflammatory and skin regeneration applications.It also discusses the underlying chemo-mechano-biological mechanisms behind their effectiveness.Additionally,the challenges and future directions in this ground,particularly their clinical translation,are addressed.The insights provided in this review can aid in the design and engineering of novel NZ-based hydrogels,offering new possibilities for targeted and personalized skin-care therapies.展开更多
The practical engineering applications of powder metallurgy (PM) Ti alloys produced through cold compaction and pressure-less sintering are impeded by poor sintering densification, embrittlement caused by excessive O ...The practical engineering applications of powder metallurgy (PM) Ti alloys produced through cold compaction and pressure-less sintering are impeded by poor sintering densification, embrittlement caused by excessive O impurities, and severe sintering deforma-tion resulting from the use of heterogeneous powder mixtures. This review presents a summary of our previous work on addressing the above challenges. Initially, we proposed a novel strategy using reaction-induced liquid phases to enhance sintering densification. Near- complete density (relative density exceeding 99%) was achieved by applying the above strategy and newly developed sintering aids. By focusing on the O-induced embrittlement issue, we determined the onset dissolution temperature of oxide films in the Ti matrix. On the basis of this finding, we established a design criterion for effective O scavengers that require reaction with oxide films before their dissol-ution. Consequently, a ductile PM Ti alloy was successfully obtained by introducing 0.3wt% NdB6 as the O scavenger. Lastly, a powder- coating strategy was adopted to address the sintering deformation issue. The ultrafine size and shell-like distribution characteristics of coating particles ensured rapid dissolution and homogeneity in the Ti matrix, thereby facilitating linear shrinkage during sintering. As a result, geometrically complex Ti alloy parts with high dimensional accuracy were fabricated by using the coated powder. Our fundament-al findings and related technical achievements enabled the development of an integrated production technology for the high-performance and accurate shaping of low-cost PM Ti alloys. Additionally, the primary engineering applications and progress in the industrialization practice of our developed technology are introduced in this review.展开更多
Low temperature causes rice yield losses of up to 30%–40%,therefore increasing its cold tolerance is a breeding target.Few genes in rice are reported to confer cold tolerance at both the vegetative and reproductive s...Low temperature causes rice yield losses of up to 30%–40%,therefore increasing its cold tolerance is a breeding target.Few genes in rice are reported to confer cold tolerance at both the vegetative and reproductive stages.This study revealed a rice-specific 24-nt miRNA,miR1868,whose accumulation was suppressed by cold stress.Knockdown of MIR1868 increased seedling survival,pollen fertility,seed setting,and grain yield under cold stress,whereas its overexpression conferred the opposite phenotype.Knockdown of MIR1868 increased reactive oxygen species(ROS)scavenging and soluble sugar content under cold stress by increasing the expression of peroxidase genes and sugar metabolism genes,and its overexpression produced the opposite effect.Thus,MIR1868 negatively regulated rice cold tolerance via ROS scavenging and sugar accumulation.展开更多
The gut microbiota significantly influences host physiology and provides essential ecosystem services.While diet can affect the composition of the gut microbiota,the gut microbiota can also help the host adapt to spec...The gut microbiota significantly influences host physiology and provides essential ecosystem services.While diet can affect the composition of the gut microbiota,the gut microbiota can also help the host adapt to specific dietary habits.The carrion crow(Corvus corone),an urban facultative scavenger bird,hosts an abundance of pathogens due to its scavenging behavior.Despite this,carrion crows infrequently exhibit illness,a phenomenon related to their unique physiological adaptability.At present,however,the role of the gut microbiota remains incompletely understood.In this study,we performed a comparative analysis using 16S rRNA amplicon sequencing technology to assess colonic content in carrion crows and 16 other bird species with different diets in Beijing,China.Our findings revealed that the dominant gut microbiota in carrion crows was primarily composed of Proteobacteria(75.51%)and Firmicutes(22.37%).Significant differences were observed in the relative abundance of Enterococcus faecalis among groups,highlighting its potential as a biomarker of facultative scavenging behavior in carrion crows.Subsequently,E.faecalis isolated from carrion crows was transplanted into model mice to explore the protective effects of this bacterial community against Salmonella enterica infection.Results showed that E.faecalis down-regulated the expression of pro-inflammatory cytokines tumor necrosis factor alpha(TNF-α),interferon gamma(IFN-γ),and interleukin 6(IL-6),prevented S.enterica colonization,and regulated the composition of gut microbiota in mice,thereby modulating the host’s immune regulatory capacity.Therefore,E.faecalis exerts immunoregulatory and anti-pathogenic functions in carrion crows engaged in scavenging behavior,offering a representative case of how the gut microbiota contributes to the protection of hosts with specialized diets.展开更多
[Objectives]To study the optimum conditions of solid fermentation of natto with antioxidant function as an index.[Methods]Single factor experiment and orthogonal experiment were designed to study the effects of temper...[Objectives]To study the optimum conditions of solid fermentation of natto with antioxidant function as an index.[Methods]Single factor experiment and orthogonal experiment were designed to study the effects of temperature,time,initial pH and inoculum amount on the antioxidant activity of natto solid fermentation.The optimum conditions of natto solid fermentation were determined and the antioxidant ac-tivity of natto extract was compared.[Results]The optimal fermentation conditions were as follows:temperature 32℃,initial pH 7.0,inocu-lation amount 8%,fermentation time 32 h.The hydroxyl radical scavenging rate of natto solid fermentation crude extract was the highest,which was 82.7%.The optimized nato fermentation extract showed stronger scavenging ability for-OH and O,:,and showed obvious dose-effect relationship.ICso was 3.63 and 4.24 mg/mL,respectively,and the scavenging efficiency was 1.3 and 1.9 times higher than that of the unoptimized fermentation extract,respectively.[Conclusions]Natto is rich in nattokinase and other functional factors,and its antioxidant ac-tivity can be improved by optimizing fermentation technology,so that natto products can be widely used,including cosmetic raw materials,nat-to skin care soap,health food and medicine,etc.,and have a broader development prospect.展开更多
Saharan dust represents more than 50%of the total desert dust emitted around the globe and its radiative effect significantly affects the atmospheric circulation at a continental scale.Previous studies on dust vertica...Saharan dust represents more than 50%of the total desert dust emitted around the globe and its radiative effect significantly affects the atmospheric circulation at a continental scale.Previous studies on dust vertical distribution and the Saharan Air Layer(SAL)showed some shortcomings that could be attributed to imperfect representation of the effects of deep convection and scavenging.The authors investigate here the role of deep convective transport and scavenging on the vertical distribution of mineral dust over Western Africa.Using multi-year(2006-2010)simulations performed with the variable-resolution(zoomed)version of the LMDZ climate model.Simulations are compared with aerosol amounts recorded by the Aerosol Robotic Network(AERONET)and with vertical profiles of the Cloud-Aerosol Lidar with Orthogonal Polarization(CALIOP)measurements.LMDZ allows a thorough examination of the respective roles of deep convective transport,convective and stratiform scavenging,boundary layer transport,and advection processes on the vertical mineral dust distribution over Western Africa.The comparison of simulated dust Aerosol Optical Depth(AOD)and distribution with measurements suggest that scavenging in deep convection and subsequent re-evaporation of dusty rainfall in the lower troposphere are critical processes for explaining the vertical distribution of desert dust.These processes play a key role in maintaining a well-defined dust layer with a sharp transition at the top of the SAL and in establishing the seasonal cycle of dust distribution.This vertical distribution is further reshaped offshore in the Inter-Tropical Convergence Zone(ITCZ)over the Atlantic Ocean by marine boundary layer turbulent and convective transport and wet deposition at the surface.展开更多
Although tremendous efforts have been devoted to the structural and functional tailoring of natural polyphenol-functionalized nan oparticles,preparing ultrasmall sized(<6 nm)particles with precisely-defined structu...Although tremendous efforts have been devoted to the structural and functional tailoring of natural polyphenol-functionalized nan oparticles,preparing ultrasmall sized(<6 nm)particles with precisely-defined structures has remained a grand challenge.In this work,we reported the preparation of ultra-small and precisely structured polyhedral oligomeric silsesquioxanes(POSS)-based polyphenol nanopartides(T8^-,T10^-,and T12^-GAPOSS)by accurately functionalizing the POSS surface with plant polyphenol gallic acid units via thiol-Michael"click"reactions.Those polyphenol nanoparticles exhibited strong free radical scavenging capacity,good biocompatibility and ability to resist cell oxidative damage,which dem on strated great potentials in inhibiting oxidative stress in duced pathologies.展开更多
Melanin is a ubiquitous but poorly understood polymeric,dark brown to black pigment biomaterial found both in nature and by organic synthesis.Its structural heterogeneity and disordered covalent/noncovalent interactio...Melanin is a ubiquitous but poorly understood polymeric,dark brown to black pigment biomaterial found both in nature and by organic synthesis.Its structural heterogeneity and disordered covalent/noncovalent interactions make it a grand challenge to tune and improve the physical and biological properties of both melanin sources.Herein,we report a facile one-pot fabrication approach for synthetic melanins with controlled size and composition via copolymerization of dopamine and basic amino acid such as arginine in an aqueous solution.The resulting arginine-doped polydopamine melanin-like nanoparticles possess less ordered nonplanar microstructures within the particles,whereas the conventional polydopamine-based melanins contain a variety of compactπ-stacked microstructures.The assembly of these distinct polymeric microstructures could lead the preceding ones for greater accessibility to free radicals,with resultant stronger free-radical scavenging effect,and thus,exhibit superior antioxidant performance toward cellular oxidative stress.This work has inspired us to continue to fabricate new synthetic melanin pigments with tunable and improved functions by rational structural tailoring.展开更多
The antibacterial activity of copper is well-known from an ancient civilization, however, its biocidal mechanism has not been necessarily elucidated. Notwithstanding up to now, mainly 4 processes have been proposed. A...The antibacterial activity of copper is well-known from an ancient civilization, however, its biocidal mechanism has not been necessarily elucidated. Notwithstanding up to now, mainly 4 processes have been proposed. Among them, it is cleared that 4 kinds of reactive oxygen species (ROS): hydroxyl radical ·OH, hydrogen per oxide H<sub>2</sub>O<sub>2</sub>, superoxide anion ·O<sup>-</sup>2</sub></sub> and singlet oxygen <sup>1</sup>O<sub>2</sub>, play an important role for contact-killing of bacteria, viruses and fungi. In this paper, generation of ROS on the surfaces of copper plates heated from room temperature to 673 K for 4.2 × 10<sup>2</sup> s in air, was investigated using the chemiluminescence. ROS have been evaluated by selecting the most suitable scavengers, such as 2-propanol for ·OH, sodium pyruvate for H<sub>2</sub>O<sub>2</sub>, nitro blue tetrazolium for ·O<sup>-</sup>2</sub></sub>, and sodium azide NaN<sub>3</sub> for <sup>1</sup>O<sub>2</sub>. At the same time the outermost surface of copper, on which thin film of cuprous oxide Cu<sub>2</sub>O was first formed and then cupric oxide CuO was laminated on Cu<sub>2</sub>O, was examined by thin-film XRD and TEM analysis to estimate the amounts and kinds of copper oxides. It was found that the most amounts of ROS were obtained for the 573 K-heated Cu plate and they were composed of ·OH, H<sub>2</sub>O<sub>2</sub>, and ·O<sup>-</sup>2.</sub></sub>.展开更多
[Objectives]To explore the extraction and in vitro antioxidant effects of astragalus polysaccharides(APS)and Ganoderma lucidum mycelia polysaccharides(GLMPS).[Methods]By studying the polysaccharides of the herbal medi...[Objectives]To explore the extraction and in vitro antioxidant effects of astragalus polysaccharides(APS)and Ganoderma lucidum mycelia polysaccharides(GLMPS).[Methods]By studying the polysaccharides of the herbal medicinal material Astragalus membranaceus and the fungal medicinal material Ganoderma lucidum mycelia,two polysaccharides were mixed according to different proportions and concentrations by using the principle of traditional Chinese medicine compound combination.The effect of polysaccharides on the scavenging ability of hydroxyl radical system was determined by salicylic acid method.[Results]When the compound ratios of GLMPS and APS were 1∶1,1∶4,1∶5,4∶1,and 5∶1,the scavenging effect of compound polysaccharides was better than that of single-component polysaccharides,and with the increase of concentration,the scavenging effect increased.When the ratio of GLMPS and APS was 5∶1,the hydroxyl radical scavenging rate of the compound polysaccharide reached 59.77%,which was 18.72%higher than that of single GLMPS and 28.58%higher than that of single APS.The scavenging effect of compound polysaccharide is closely related to the compound ratio and concentration.[Conclusions]APS and GLMPS can obtain better hydroxyl radical scavenging ability than single-component polysaccharides through compounding in appropriate proportions.In addition,within a suitable concentration range,as the concentration increases,the scavenging ability also increases.展开更多
Vultures are the only obligate scavengers among extant vertebrates.They provide valuable ecological services in ecosystems through removing carcasses,thus preventing the growth of other scavenger populations and the s...Vultures are the only obligate scavengers among extant vertebrates.They provide valuable ecological services in ecosystems through removing carcasses,thus preventing the growth of other scavenger populations and the spread of pathogens.Moreover,their specific diets expose them to various deadly pathogens,which makes them potential candidates for studying molecular adaptations required to survive this extremely specialized scavenging habit.In this review,we summarize the morphological characteristics and behavioral habits,origin and phylogeny,and molecular adaptations to scavenging in both Old and New World vultures.The two groups of vultures share a similar appearance,indicative of convergent evolution.Vultures have experienced different degrees of specialization in their sensory organs;Old World vultures depend on sight,while New World ones depend on both smell and sight.Combined fossil records and molecular data suggest that vultures evolved independently,with distinct phylogenetic positions.We also explored their adaptation to scavenging in facial and intestinal microbiomes,gastric acid secretion and immunity.Compared with the facial microbiome,the intestinal microbiome had a lower diversity,dominated by Fusobacteria and Clostridia.The phages and single invertebrate species Adineta vaga,which feeds on dead bacteria and protozoa,present in the gut suggest a possible alternative defense mechanism.Several genes involved in gastric acidic secretion(including ATP4B,SLC26A7 and SST)and immunity(including BCL6,STING,and TLRs) undergoing positive selection likely have essential roles in eliminating invasive pathogens and initiating an innate immune response.Taken together,this review presents the current research status of vultures and highlights the use of vultures as a model for exploring molecular adaptations of dietary specialization in birds.It also provides a theoretical basis for the study of the genetic mechanisms of vultures to scavenging,and contributes to the formulation of vulture conservation strategies.展开更多
Large scavengers are strongly dependent on environmental conditions and carrion distribution and abundance,so season and breeding-related factors may influence the spatial ecology of species such as the Cinereous Vult...Large scavengers are strongly dependent on environmental conditions and carrion distribution and abundance,so season and breeding-related factors may influence the spatial ecology of species such as the Cinereous Vulture(Aegypius monachus),the largest European raptor.Iberia holds one of the biggest populations worldwide,but some aspects of the spatial ecology of the species in this region remain unknown.In this study,17 adult Cinereous Vultures were GPS-tracked in order to study their spatial ecology during the adult phase.The average monthly home ranges(95%Kernel Density Estimation,KDE)and core areas(50%KDE)were 6543±19,935 km^(2)and 1174±4004 km^(2),respectively.The average monthly home range fidelity ranged between 50 and 73%.Differences in movement-related variables between the seasonal periods(incubation,chick-rearing and non-breeding)were found.During the chick-rearing period,the monthly accumulated distance was higher than during the other periods:3316±1108(chick-rearing)vs.1621±622(incubation)vs.1726±1159 km per month(nonbreeding).Additionally,large home range sizes were more frequent during the chick-rearing period.There are two likely causes for these seasonal differences.Firstly,chick-rearing entails a higher energetic expenditure by the parental individuals in foraging activities,so larger movements and foraging areas are expected during this period.Secondly,the flight is favoured during spring and summer due to environmental conditions.Matching chick-rearing and warm months is a great evolutionary advantage for soaring-gliding raptors,as it allows them to cover larger areas with low energy expenditure.Furthermore,six individuals tagged as nestlings highlight the philopatric behaviour of the species:vultures settle their breeding areas 54±51 km from their natal nest(range=9–138 km).展开更多
Objective:This study aims to investigate the effects of hydralazine on inflammation induced by spinal cord injury(SCI)in the central nervous system(CNS)and its mechanism in promoting the structural and functional reco...Objective:This study aims to investigate the effects of hydralazine on inflammation induced by spinal cord injury(SCI)in the central nervous system(CNS)and its mechanism in promoting the structural and functional recovery of the injured CNS.Methods:A compressive SCI mouse model was utilized for this investigation.Immunofluorescence and quantitative real-time polymerase chain reaction were employed to examine the levels of acrolein,acrolein-induced inflammation-related factors,and macrophages at the injury site and within the CNS.Western blotting was used to evaluate the activity of the phosphoinositide 3-kinase(PI3K)/AKT pathway to study macrophage regulation.The neuropathic pain and motor function recovery were evaluated by glutamic acid decarboxylase 65/67(GAD65/67),vesicular glutamate transporter 1(VGLUT1),paw withdrawal response,and Basso Mouse Scale score.Nissl staining and Luxol Fast Blue(LFB)staining were performed to investigate the structural recovery of the injured CNS.Results:Hydralazine downregulated the levels of acrolein,IL-1β,and TNF-αin the spinal cord.The downregulation of acrolein induced by hydralazine promoted the activation of the PI3K/AKT pathway,leading to M2 macrophage polarization,which protected neurons against SCI-induced inflammation.Additionally,hydralazine promoted the structural recovery of the injured spinal cord area.Mitigating inflammation and oxidative stress by hydralazine in the animal model alleviated neuropathic pain and altered neurotransmitter expression.Furthermore,hydralazine facilitated motor function recovery following SCI.Nissl staining and LFB staining indicated that hydralazine promoted the structural recovery of the injured CNS.Conclusion:Hydralazine,an acrolein scavenger,significantly mitigated SCI-induced inflammation and oxidative stress in vivo,modulated macrophage activation,and consequently promoted the structural and functional recovery of the injured CNS.展开更多
The objective in this study is to investigate the adsorption-degradation of the methylene blue(MB)dye using a fabricated heterojunction Ag@TiO_(2)nanocomposite.The batch factors used in photo catalytic reactions were ...The objective in this study is to investigate the adsorption-degradation of the methylene blue(MB)dye using a fabricated heterojunction Ag@TiO_(2)nanocomposite.The batch factors used in photo catalytic reactions were pH,UV-irradiation time,temperature,catalytic dosage,and concentration of MB.The results showed that 0.2×10^(3) g·ml^(-1))of the catalytic dose caused the Ag@TiO_(2)adsorption to degrade by 96.67%with darks and UV exposure.Using the Langmuir-Hinshelwood model to determine the kinetic,the Ag@TiO_(2)displays a greater kinetic rate than TiO_(2)and silver nanoparticle(AgNPs).The photocatalytic degradation of MB,which is an endothermic reaction involving all catalysts,is shown by the thermodynamic parameter to have the positive value of enthalpy(ΔH°).The enthalpies observed were Ag@TiO_(2)(126.80 kJ·mol^(-1))<AgNPs(354.47 kJ·mol^(-1))<TiO_(2)(430.04 kJ·mol^(-1)).Ascorbic acid(·OH scavenger),2-propanol(·O_(2)scavenger),and ammonium oxalate(AO)(hole h+scavenger)were employed to conduct the scavenger effects.The Ag@TiO_(2)demonstrated a reduction in MB degradation when combined with 2-propanol,and this clearly demonstrated that,in contrast to hydroxyl radicals(·OH)and holeh scavengers,superoxide radical anion(O_(2)scavenger)plays a significant role in MB degradation.Utilizing density functional theory(DFT)to elucidate the mechanism and B3LYP/6-311+G(d,p)level optimization,the degradation-adsorption process was explained.When the N-N,C-N or C-C bonds were severed,the Fukui faction was demonstrated for nucleophilic,electrophilic,and radical attack.展开更多
Objective:To examine the effects of hydroalcoholic extract and fractions of Hordeum vulgare Linn.(H.vulgare,Da Mai)on streptozotocin(STZ)-induced diabetic nephropathy in Sprague-Dawley rat models.Methods:The study inv...Objective:To examine the effects of hydroalcoholic extract and fractions of Hordeum vulgare Linn.(H.vulgare,Da Mai)on streptozotocin(STZ)-induced diabetic nephropathy in Sprague-Dawley rat models.Methods:The study involved preliminary phytochemical screening of extract and fractions,estimation of secondary metabolites,chromatographic studies using high performance liquid chromatography(HPLC),antioxidant potential using 1,1-diphenyl-2-picrylhydrazyl(DPPH),nitric oxide radical scavenging and reducing power methods along with the determination of potential against diabetic nephropathy in STZ-induced rat models.Results:The phytochemical evaluation of the hydroalcoholic extract of H.vulgare and fractions revealed the presence of various phytoconstituents such as alkaloids,saponins,tannins,flavonoids,and glycosides.The chromatographic analysis indicated the peak complementing marker compound epicatechin and significant antioxidant activity in the extract and aqueous fraction.STZ-induced rats showed abnormal levels of serum albumin,creatinine,total cholesterol,blood urea nitrogen(BUN),and triglycerides,and urine albumin and creatinine,which returned to normal after 8 weeks of treatment with hydroalcoholic extract(400 mg/kg)and aqueous fraction(50 mg/kg)of H.vulgare.Conclusion:Hydroalcoholic extract(400 mg/kg)and aqueous fraction(50 mg/kg)of H.vulgare have significant antioxidant potential and positive effects on diabetic nephropathy.The fractionation and optimization increase the concentration of polyphenols in aqueous extract,causing a decrease in the dose required for effects against diabetic nephropathy.展开更多
Senescence is the last developmental process in plant,which has an important impact on crop yield and quality.In this study,a stable hereditary early-senescence line BC64 was isolated from the high-generation recombin...Senescence is the last developmental process in plant,which has an important impact on crop yield and quality.In this study,a stable hereditary early-senescence line BC64 was isolated from the high-generation recombinant inbred lines of 93-11 and Wuyunjing7(W7).Genetic analysis showed that the premature aging phenotype was controlled by a dominant gene derived from 93-11.By linkage analysis,the gene was primarily mapped in the region between marker B4 and B5 near the centromere of chromosome 4,described as ES(4).Through multiple backcrossing with W7,the near-isogenic line of ES(4)(NIL-ES(4))was obtained.Compared with wild-type W7,NIL-ES(4)plants showed more sever senescence phenotype in both nature and dark conditions.In NIL plants,leaves turned yellow at the fully tillering stage;photosynthetic rate,pollen fertility and seed setting rate were decreased.Moreover,the malondialdehyde,proline content and relative conductivity in NIL-ES(4)were significantly higher than those in W7;both transcript level and activities of reactive oxygen species scavenging enzymes were repressed;H2O2 and O^(2−)were significantly accumulated.This study provides a basis for further cloning and function identification of ES(4).展开更多
基金funded by the National Natural Science Foundation of China(Grant No.31960277)the National Natural Science Foundation of China and Russian Foundation for Basic Research Cooperative Exchange Project(Grant Nos.32111530018,21-54-53031)+1 种基金the Natural Science Foundation of Qinghai Province of China(Grant No.2018-ZJ-932Q)supported by“1000 Talent”programs of Qinghai Province。
文摘Background:Himalayan Griffons(Gyps himalayensis),large scavenging raptors widely distributed in Qinghai-Tibetan Plateau,have evolved a remarkable ability to feed on carcasses without suffering any adverse effects.The gut microbiome plays an important role in animal physiological and pathological processes,and has also been found to play a health protective role in the vulture adaptation to scavenging.However,the microbial taxonomic diversity(including nonculturable and culturable microbes),functions,and metabolites related to Himalayan Griffons have not been fully explored.Methods:In the present study,the 28 fecal samples of the Himalayan Griffons and 8 carrion samples were collected and sequenced using high-throughput 16 S rRNA gene sequencing methods to analyze the composition and functional structures of the microbiomes.Twelve fecal samples of the Himalayan Griffons were analyzed using untargeted Liquid Chromatography Mass Spectroscopy(LC-MS)to identify metabolites.We used different culture conditions to grow Himalayan Griffons gut microbes.Inhibitory effects of gut beneficial bacteria on 5 common pathogenic bacteria were also tested using the Oxford cup method.Results:According to the results of the culture-independent method,a high abundance of four major phyla in Himalayan Griffons were identified,including Fusobacteria,Firmicutes,Bacteroidetes,and Proteobacteria.The most abundant genera were Fusobacterium,followed by Clostridium_sensu_stricto_1,Cetobacterium,Epulopiscium,and Bacteroides.The predicted primary functional categories of the Himalayan Griffons'gut microbiome were associated with carbohydrate and amino acid metabolism,replication and repair,and membrane transport.LC-MS metabolomic analysis showed a total of 154 metabolites in all the fecal samples.Cultivation yielded 184 bacterial isolates with Escherichia coli,Enterococcus faecium,Enterococcus hirae,and Paeniclostridium sordellii as most common isolates.Moreover,7 potential beneficial gut bacteria isolated showed certain inhibition to 5 common pathogenic bacteria.Conclusions:Our findings broaden and deepen the understanding of Himalayan Griffons'gut microbiome,and highlighted the importance of gut microbiome-mediated adaptation to scavenging habits.In particular,our results highlighted the protective role of gut beneficial bacteria in the Himalayan Griffons against pathogenic bacteria that appear in rotten food resources.
文摘This study was carried out based on consistent observations on the activities of scavengers of scrap metal in Obio/Akpor local government Rivers State. The study was carried out to ascertain the profitability of scrap metal scavenging and how scrap metal waste can generate wealth to the public and the government. The study made use of primary and secondary data with the former being the main focus. The data were analyzed using the simple percentage, while the hypothesis was tested by means of the chi-square. The study findings revealed that there was a relationship between waste and wealth in relation to scrap metal scavenging. The researches therefore make the following recommendations;that scavengers should form co-operatives so that they can pull their efforts and resources together and bargain collectively. Government and nongovernmental organization should enlighten them through seminars, workshops, etc., on how to carry out their activities in an environmentally safe manner. The state government should encourage scavenging by enacting a law to back the profession and make it attractive for the teaming youths to venture into.
基金supported by the Science Foundation of Heilongjiang Province of China(C201407)the National Natural Science Foundation of China(No.31400535)
文摘The effects of an exogenous nitric oxide donor(sodium nitroprusside, SNP), a NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxode(PTIO) and carboxy-PTIO potassium salt(c PTIO) on the embryo germination of Sorbus pohuashanensis were studied in a petri dish test. SNP at 0.5–5 mmol L-1 increased germination percentage, mean time to germination, germination index and germination energy compared with the control to different degrees. Treatment with 2 mmol L-1 SNP improved germination most significantly; embryo germination percentage for mother tree 1(91.11%) and mother tree 2(64.44%) were much higher than the control. In addition,excessive SNP levels did not enhance embryo germination.Combined treatment with SNP and an NO scavenger delayed embryo germination. Treatment with c PTIO inhibited embryo germination; germination percentage was 42.22% and was lower than that of the control. These results show that low concentrations of exogenous NO can enhance the embryo germination of S. pohuashanensis,providing a simple, effective way for promoting germination of S. pohuashanensis.
文摘Namibia’s Etosha National Park(ENP)is home to many different animals such as lions,jackals,hyenas,zebras,elephants,etc.Each year,grazing animals are infected and die from anthrax caused by the bacteria Bacillus anthracis.This increases the number of carcasses in the park,which serve as food for scavengers such as jackals.This study investigates the interplay between anthrax transmission in zebras and the scavenging of zebra carcasses in ENP,using a deterministic mathematical model to describe the population dynamics.We strive to answer the following research questions:Under what conditions can the presence of scavengers control anthrax outbreaks in zebra populations=Does carcass production by anthrax help or hurt scavengers in the long term?Standard qualitative analysis techniques distinguished outcomes(stable equilibria)using reproduction numbers as threshold quantities.We found that,when scavengers feed on anthrax-laden carcasses,the scavengers help the zebras,by eliminating potential infection zones for the zebras.In this way they reduce anthrax’s spread by orders of magnitude.We also identify conditions under which the presence of anthrax benefits the scavengers,in terms of death-to-birth ratios for zebras,scavengers and anthrax.
基金supported by the grants from National Research Foundation(NRF,#2021R1A5A2022318,#RS-2023-00220408,#RS-2023-00247485),Republic of Korea.
文摘Inflammatory skin disorders can cause chronic scarring and functional impairments,posing a significant burden on patients and the healthcare system.Conventional therapies,such as corticosteroids and nonsteroidal anti-inflammatory drugs,are limited in efficacy and associated with adverse effects.Recently,nanozyme(NZ)-based hydrogels have shown great promise in addressing these challenges.NZ-based hydrogels possess unique therapeutic abilities by combining the therapeutic benefits of redox nanomaterials with enzymatic activity and the water-retaining capacity of hydrogels.The multifaceted therapeutic effects of these hydrogels include scavenging reactive oxygen species and other inflammatory mediators modulating immune responses toward a pro-regenerative environment and enhancing regenerative potential by triggering cell migration and differentiation.This review highlights the current state of the art in NZ-engineered hydrogels(NZ@hydrogels)for anti-inflammatory and skin regeneration applications.It also discusses the underlying chemo-mechano-biological mechanisms behind their effectiveness.Additionally,the challenges and future directions in this ground,particularly their clinical translation,are addressed.The insights provided in this review can aid in the design and engineering of novel NZ-based hydrogels,offering new possibilities for targeted and personalized skin-care therapies.
基金supported by the National Natural Science Foundation of China (Nos.52074254 and 52174349)the CAS Project for Young Scientists in Basic Research,China (No.YSBR-025)+3 种基金the Shandong Provincial Science and Technology Innovation Project,China (No.2019JZZY010363)the Key Projects of International Cooperation,China (No.122111KYSB20200034)the Project of Key Laboratory of Science and Technology on Particle Materials,China (No.CXJJ-22S043)Chinese Academy of Sciences.This work was also financially supported by the Selection of Best Candidates to Undertake Key Research Projects,China (No.211110230200).
文摘The practical engineering applications of powder metallurgy (PM) Ti alloys produced through cold compaction and pressure-less sintering are impeded by poor sintering densification, embrittlement caused by excessive O impurities, and severe sintering deforma-tion resulting from the use of heterogeneous powder mixtures. This review presents a summary of our previous work on addressing the above challenges. Initially, we proposed a novel strategy using reaction-induced liquid phases to enhance sintering densification. Near- complete density (relative density exceeding 99%) was achieved by applying the above strategy and newly developed sintering aids. By focusing on the O-induced embrittlement issue, we determined the onset dissolution temperature of oxide films in the Ti matrix. On the basis of this finding, we established a design criterion for effective O scavengers that require reaction with oxide films before their dissol-ution. Consequently, a ductile PM Ti alloy was successfully obtained by introducing 0.3wt% NdB6 as the O scavenger. Lastly, a powder- coating strategy was adopted to address the sintering deformation issue. The ultrafine size and shell-like distribution characteristics of coating particles ensured rapid dissolution and homogeneity in the Ti matrix, thereby facilitating linear shrinkage during sintering. As a result, geometrically complex Ti alloy parts with high dimensional accuracy were fabricated by using the coated powder. Our fundament-al findings and related technical achievements enabled the development of an integrated production technology for the high-performance and accurate shaping of low-cost PM Ti alloys. Additionally, the primary engineering applications and progress in the industrialization practice of our developed technology are introduced in this review.
基金supported by grants from the National Natural Science Foundation of China(U20A2025,32101672,31971826)the National Key Research and Development Plan of China(2021YFF1001100)+2 种基金Natural Science Foundation of Heilongjiang province(YQ2023C035)Double First-class Innovation Achievement Program of Heilongjiang Province(LJGXCG2023-072)the Graduate Student Scientific Research Innovation Projects of Heilongjiang Bayi Agricultural University(YJSCX2022-Z01)。
文摘Low temperature causes rice yield losses of up to 30%–40%,therefore increasing its cold tolerance is a breeding target.Few genes in rice are reported to confer cold tolerance at both the vegetative and reproductive stages.This study revealed a rice-specific 24-nt miRNA,miR1868,whose accumulation was suppressed by cold stress.Knockdown of MIR1868 increased seedling survival,pollen fertility,seed setting,and grain yield under cold stress,whereas its overexpression conferred the opposite phenotype.Knockdown of MIR1868 increased reactive oxygen species(ROS)scavenging and soluble sugar content under cold stress by increasing the expression of peroxidase genes and sugar metabolism genes,and its overexpression produced the opposite effect.Thus,MIR1868 negatively regulated rice cold tolerance via ROS scavenging and sugar accumulation.
基金supported by the National Key Research and Development Program of China(2022YFC2601602)Major Program of National Natural Science Foundation of China(32090023)Beijing Wildlife Rescue Center,China。
文摘The gut microbiota significantly influences host physiology and provides essential ecosystem services.While diet can affect the composition of the gut microbiota,the gut microbiota can also help the host adapt to specific dietary habits.The carrion crow(Corvus corone),an urban facultative scavenger bird,hosts an abundance of pathogens due to its scavenging behavior.Despite this,carrion crows infrequently exhibit illness,a phenomenon related to their unique physiological adaptability.At present,however,the role of the gut microbiota remains incompletely understood.In this study,we performed a comparative analysis using 16S rRNA amplicon sequencing technology to assess colonic content in carrion crows and 16 other bird species with different diets in Beijing,China.Our findings revealed that the dominant gut microbiota in carrion crows was primarily composed of Proteobacteria(75.51%)and Firmicutes(22.37%).Significant differences were observed in the relative abundance of Enterococcus faecalis among groups,highlighting its potential as a biomarker of facultative scavenging behavior in carrion crows.Subsequently,E.faecalis isolated from carrion crows was transplanted into model mice to explore the protective effects of this bacterial community against Salmonella enterica infection.Results showed that E.faecalis down-regulated the expression of pro-inflammatory cytokines tumor necrosis factor alpha(TNF-α),interferon gamma(IFN-γ),and interleukin 6(IL-6),prevented S.enterica colonization,and regulated the composition of gut microbiota in mice,thereby modulating the host’s immune regulatory capacity.Therefore,E.faecalis exerts immunoregulatory and anti-pathogenic functions in carrion crows engaged in scavenging behavior,offering a representative case of how the gut microbiota contributes to the protection of hosts with specialized diets.
基金Supported by 2023 Zhanjiang Non-funded Science and Technology Research Plan(2023B01023)2022 University-level Education and Teaching Reform Project of Lingnan Normal University(LingShiJiaoWu2022154).Junxia SONG,bachelor degree,experimenter,research fields:physical geography.
文摘[Objectives]To study the optimum conditions of solid fermentation of natto with antioxidant function as an index.[Methods]Single factor experiment and orthogonal experiment were designed to study the effects of temperature,time,initial pH and inoculum amount on the antioxidant activity of natto solid fermentation.The optimum conditions of natto solid fermentation were determined and the antioxidant ac-tivity of natto extract was compared.[Results]The optimal fermentation conditions were as follows:temperature 32℃,initial pH 7.0,inocu-lation amount 8%,fermentation time 32 h.The hydroxyl radical scavenging rate of natto solid fermentation crude extract was the highest,which was 82.7%.The optimized nato fermentation extract showed stronger scavenging ability for-OH and O,:,and showed obvious dose-effect relationship.ICso was 3.63 and 4.24 mg/mL,respectively,and the scavenging efficiency was 1.3 and 1.9 times higher than that of the unoptimized fermentation extract,respectively.[Conclusions]Natto is rich in nattokinase and other functional factors,and its antioxidant ac-tivity can be improved by optimizing fermentation technology,so that natto products can be widely used,including cosmetic raw materials,nat-to skin care soap,health food and medicine,etc.,and have a broader development prospect.
基金The authors wish to thank the Ecosystem Approach to the management of fisheries and the marine environment in the West African Waters(AWA)project.They also acknowledge support from the international joint laboratory ECLAIRS.The Laboratoire de Météorologie Dynamique(LMD)and the Global Challenges Research Fund(GCRF)African Science for Weather Information and Techniques(SWIFT)Programme.NASA,CNES,and ICARE are acknowledged for providing access to CALIOP and Sun photometer AERONET data.
文摘Saharan dust represents more than 50%of the total desert dust emitted around the globe and its radiative effect significantly affects the atmospheric circulation at a continental scale.Previous studies on dust vertical distribution and the Saharan Air Layer(SAL)showed some shortcomings that could be attributed to imperfect representation of the effects of deep convection and scavenging.The authors investigate here the role of deep convective transport and scavenging on the vertical distribution of mineral dust over Western Africa.Using multi-year(2006-2010)simulations performed with the variable-resolution(zoomed)version of the LMDZ climate model.Simulations are compared with aerosol amounts recorded by the Aerosol Robotic Network(AERONET)and with vertical profiles of the Cloud-Aerosol Lidar with Orthogonal Polarization(CALIOP)measurements.LMDZ allows a thorough examination of the respective roles of deep convective transport,convective and stratiform scavenging,boundary layer transport,and advection processes on the vertical mineral dust distribution over Western Africa.The comparison of simulated dust Aerosol Optical Depth(AOD)and distribution with measurements suggest that scavenging in deep convection and subsequent re-evaporation of dusty rainfall in the lower troposphere are critical processes for explaining the vertical distribution of desert dust.These processes play a key role in maintaining a well-defined dust layer with a sharp transition at the top of the SAL and in establishing the seasonal cycle of dust distribution.This vertical distribution is further reshaped offshore in the Inter-Tropical Convergence Zone(ITCZ)over the Atlantic Ocean by marine boundary layer turbulent and convective transport and wet deposition at the surface.
基金the National Natural Science Foundation of China(Nos.51603133 and 21774079)National Key R&D Program of China(No.2019YFA0904500)+1 种基金the Program of the Science,Technology Department of Guangzhou,China(No.201803020039)the Fundamental Research Funds for Central Universities.
文摘Although tremendous efforts have been devoted to the structural and functional tailoring of natural polyphenol-functionalized nan oparticles,preparing ultrasmall sized(<6 nm)particles with precisely-defined structures has remained a grand challenge.In this work,we reported the preparation of ultra-small and precisely structured polyhedral oligomeric silsesquioxanes(POSS)-based polyphenol nanopartides(T8^-,T10^-,and T12^-GAPOSS)by accurately functionalizing the POSS surface with plant polyphenol gallic acid units via thiol-Michael"click"reactions.Those polyphenol nanoparticles exhibited strong free radical scavenging capacity,good biocompatibility and ability to resist cell oxidative damage,which dem on strated great potentials in inhibiting oxidative stress in duced pathologies.
基金the National Natural Science Foundation of China(nos.21774079,21975167,and 51503129)the National Key R&D Program of China(no.2019YFA0904500)the Fundamental Research Funds for Central Universities.
文摘Melanin is a ubiquitous but poorly understood polymeric,dark brown to black pigment biomaterial found both in nature and by organic synthesis.Its structural heterogeneity and disordered covalent/noncovalent interactions make it a grand challenge to tune and improve the physical and biological properties of both melanin sources.Herein,we report a facile one-pot fabrication approach for synthetic melanins with controlled size and composition via copolymerization of dopamine and basic amino acid such as arginine in an aqueous solution.The resulting arginine-doped polydopamine melanin-like nanoparticles possess less ordered nonplanar microstructures within the particles,whereas the conventional polydopamine-based melanins contain a variety of compactπ-stacked microstructures.The assembly of these distinct polymeric microstructures could lead the preceding ones for greater accessibility to free radicals,with resultant stronger free-radical scavenging effect,and thus,exhibit superior antioxidant performance toward cellular oxidative stress.This work has inspired us to continue to fabricate new synthetic melanin pigments with tunable and improved functions by rational structural tailoring.
文摘The antibacterial activity of copper is well-known from an ancient civilization, however, its biocidal mechanism has not been necessarily elucidated. Notwithstanding up to now, mainly 4 processes have been proposed. Among them, it is cleared that 4 kinds of reactive oxygen species (ROS): hydroxyl radical ·OH, hydrogen per oxide H<sub>2</sub>O<sub>2</sub>, superoxide anion ·O<sup>-</sup>2</sub></sub> and singlet oxygen <sup>1</sup>O<sub>2</sub>, play an important role for contact-killing of bacteria, viruses and fungi. In this paper, generation of ROS on the surfaces of copper plates heated from room temperature to 673 K for 4.2 × 10<sup>2</sup> s in air, was investigated using the chemiluminescence. ROS have been evaluated by selecting the most suitable scavengers, such as 2-propanol for ·OH, sodium pyruvate for H<sub>2</sub>O<sub>2</sub>, nitro blue tetrazolium for ·O<sup>-</sup>2</sub></sub>, and sodium azide NaN<sub>3</sub> for <sup>1</sup>O<sub>2</sub>. At the same time the outermost surface of copper, on which thin film of cuprous oxide Cu<sub>2</sub>O was first formed and then cupric oxide CuO was laminated on Cu<sub>2</sub>O, was examined by thin-film XRD and TEM analysis to estimate the amounts and kinds of copper oxides. It was found that the most amounts of ROS were obtained for the 573 K-heated Cu plate and they were composed of ·OH, H<sub>2</sub>O<sub>2</sub>, and ·O<sup>-</sup>2.</sub></sub>.
基金Supported by the Project of"Striving to Be First-classImproving Weak LinksBuilding Strong Feature"in 2019–Tropical and South China Sea Biological Resources Comprehensive Utilization Program(000301900410)。
文摘[Objectives]To explore the extraction and in vitro antioxidant effects of astragalus polysaccharides(APS)and Ganoderma lucidum mycelia polysaccharides(GLMPS).[Methods]By studying the polysaccharides of the herbal medicinal material Astragalus membranaceus and the fungal medicinal material Ganoderma lucidum mycelia,two polysaccharides were mixed according to different proportions and concentrations by using the principle of traditional Chinese medicine compound combination.The effect of polysaccharides on the scavenging ability of hydroxyl radical system was determined by salicylic acid method.[Results]When the compound ratios of GLMPS and APS were 1∶1,1∶4,1∶5,4∶1,and 5∶1,the scavenging effect of compound polysaccharides was better than that of single-component polysaccharides,and with the increase of concentration,the scavenging effect increased.When the ratio of GLMPS and APS was 5∶1,the hydroxyl radical scavenging rate of the compound polysaccharide reached 59.77%,which was 18.72%higher than that of single GLMPS and 28.58%higher than that of single APS.The scavenging effect of compound polysaccharide is closely related to the compound ratio and concentration.[Conclusions]APS and GLMPS can obtain better hydroxyl radical scavenging ability than single-component polysaccharides through compounding in appropriate proportions.In addition,within a suitable concentration range,as the concentration increases,the scavenging ability also increases.
基金supported in part by the National Natural Science Foundation of China (32201267)Natural Science Foundation of Anhui Province (2208085QC71)+2 种基金the Key University Science Research Project of Anhui Province (KJ2021A0128)supported by the Key University Science Research Project of Anhui Province (KJ2020A0085)supported in part by the Plateau Ecology Youth Innovative Fund of Wuhan University
文摘Vultures are the only obligate scavengers among extant vertebrates.They provide valuable ecological services in ecosystems through removing carcasses,thus preventing the growth of other scavenger populations and the spread of pathogens.Moreover,their specific diets expose them to various deadly pathogens,which makes them potential candidates for studying molecular adaptations required to survive this extremely specialized scavenging habit.In this review,we summarize the morphological characteristics and behavioral habits,origin and phylogeny,and molecular adaptations to scavenging in both Old and New World vultures.The two groups of vultures share a similar appearance,indicative of convergent evolution.Vultures have experienced different degrees of specialization in their sensory organs;Old World vultures depend on sight,while New World ones depend on both smell and sight.Combined fossil records and molecular data suggest that vultures evolved independently,with distinct phylogenetic positions.We also explored their adaptation to scavenging in facial and intestinal microbiomes,gastric acid secretion and immunity.Compared with the facial microbiome,the intestinal microbiome had a lower diversity,dominated by Fusobacteria and Clostridia.The phages and single invertebrate species Adineta vaga,which feeds on dead bacteria and protozoa,present in the gut suggest a possible alternative defense mechanism.Several genes involved in gastric acidic secretion(including ATP4B,SLC26A7 and SST)and immunity(including BCL6,STING,and TLRs) undergoing positive selection likely have essential roles in eliminating invasive pathogens and initiating an innate immune response.Taken together,this review presents the current research status of vultures and highlights the use of vultures as a model for exploring molecular adaptations of dietary specialization in birds.It also provides a theoretical basis for the study of the genetic mechanisms of vultures to scavenging,and contributes to the formulation of vulture conservation strategies.
基金Iberdrola Espana Foundation(MIGRA program of SEO/Bird Life)Asociación Trenca+4 种基金Generalitat de CatalunyaJunta de ExtremaduraGREFA(supported by REDEIA, MITERD, Junta de Castilla y León, Junta de Comunidades de Castilla la Mancha, and Comunidad de Madrid)Cabaneros National ParkSierra de Guadarrama National Park
文摘Large scavengers are strongly dependent on environmental conditions and carrion distribution and abundance,so season and breeding-related factors may influence the spatial ecology of species such as the Cinereous Vulture(Aegypius monachus),the largest European raptor.Iberia holds one of the biggest populations worldwide,but some aspects of the spatial ecology of the species in this region remain unknown.In this study,17 adult Cinereous Vultures were GPS-tracked in order to study their spatial ecology during the adult phase.The average monthly home ranges(95%Kernel Density Estimation,KDE)and core areas(50%KDE)were 6543±19,935 km^(2)and 1174±4004 km^(2),respectively.The average monthly home range fidelity ranged between 50 and 73%.Differences in movement-related variables between the seasonal periods(incubation,chick-rearing and non-breeding)were found.During the chick-rearing period,the monthly accumulated distance was higher than during the other periods:3316±1108(chick-rearing)vs.1621±622(incubation)vs.1726±1159 km per month(nonbreeding).Additionally,large home range sizes were more frequent during the chick-rearing period.There are two likely causes for these seasonal differences.Firstly,chick-rearing entails a higher energetic expenditure by the parental individuals in foraging activities,so larger movements and foraging areas are expected during this period.Secondly,the flight is favoured during spring and summer due to environmental conditions.Matching chick-rearing and warm months is a great evolutionary advantage for soaring-gliding raptors,as it allows them to cover larger areas with low energy expenditure.Furthermore,six individuals tagged as nestlings highlight the philopatric behaviour of the species:vultures settle their breeding areas 54±51 km from their natal nest(range=9–138 km).
基金supported by the National Natural Science Foundation of China Young Scientists Fund(No.81801216,No.81802143,No.81901966)the China Postdoctoral Foundation(No.2018M633748).
文摘Objective:This study aims to investigate the effects of hydralazine on inflammation induced by spinal cord injury(SCI)in the central nervous system(CNS)and its mechanism in promoting the structural and functional recovery of the injured CNS.Methods:A compressive SCI mouse model was utilized for this investigation.Immunofluorescence and quantitative real-time polymerase chain reaction were employed to examine the levels of acrolein,acrolein-induced inflammation-related factors,and macrophages at the injury site and within the CNS.Western blotting was used to evaluate the activity of the phosphoinositide 3-kinase(PI3K)/AKT pathway to study macrophage regulation.The neuropathic pain and motor function recovery were evaluated by glutamic acid decarboxylase 65/67(GAD65/67),vesicular glutamate transporter 1(VGLUT1),paw withdrawal response,and Basso Mouse Scale score.Nissl staining and Luxol Fast Blue(LFB)staining were performed to investigate the structural recovery of the injured CNS.Results:Hydralazine downregulated the levels of acrolein,IL-1β,and TNF-αin the spinal cord.The downregulation of acrolein induced by hydralazine promoted the activation of the PI3K/AKT pathway,leading to M2 macrophage polarization,which protected neurons against SCI-induced inflammation.Additionally,hydralazine promoted the structural recovery of the injured spinal cord area.Mitigating inflammation and oxidative stress by hydralazine in the animal model alleviated neuropathic pain and altered neurotransmitter expression.Furthermore,hydralazine facilitated motor function recovery following SCI.Nissl staining and LFB staining indicated that hydralazine promoted the structural recovery of the injured CNS.Conclusion:Hydralazine,an acrolein scavenger,significantly mitigated SCI-induced inflammation and oxidative stress in vivo,modulated macrophage activation,and consequently promoted the structural and functional recovery of the injured CNS.
基金University of Burdwan was for instrumental and financial support from DST-FIST(SR/FST/ESI-141/2015,dt:30.09.2019)Govt.of India and WBDST-BOOST(39/WBBDC/1p-2/2013,dt:25.03.2015),Govt.of West Bengal.
文摘The objective in this study is to investigate the adsorption-degradation of the methylene blue(MB)dye using a fabricated heterojunction Ag@TiO_(2)nanocomposite.The batch factors used in photo catalytic reactions were pH,UV-irradiation time,temperature,catalytic dosage,and concentration of MB.The results showed that 0.2×10^(3) g·ml^(-1))of the catalytic dose caused the Ag@TiO_(2)adsorption to degrade by 96.67%with darks and UV exposure.Using the Langmuir-Hinshelwood model to determine the kinetic,the Ag@TiO_(2)displays a greater kinetic rate than TiO_(2)and silver nanoparticle(AgNPs).The photocatalytic degradation of MB,which is an endothermic reaction involving all catalysts,is shown by the thermodynamic parameter to have the positive value of enthalpy(ΔH°).The enthalpies observed were Ag@TiO_(2)(126.80 kJ·mol^(-1))<AgNPs(354.47 kJ·mol^(-1))<TiO_(2)(430.04 kJ·mol^(-1)).Ascorbic acid(·OH scavenger),2-propanol(·O_(2)scavenger),and ammonium oxalate(AO)(hole h+scavenger)were employed to conduct the scavenger effects.The Ag@TiO_(2)demonstrated a reduction in MB degradation when combined with 2-propanol,and this clearly demonstrated that,in contrast to hydroxyl radicals(·OH)and holeh scavengers,superoxide radical anion(O_(2)scavenger)plays a significant role in MB degradation.Utilizing density functional theory(DFT)to elucidate the mechanism and B3LYP/6-311+G(d,p)level optimization,the degradation-adsorption process was explained.When the N-N,C-N or C-C bonds were severed,the Fukui faction was demonstrated for nucleophilic,electrophilic,and radical attack.
基金supported by Rashtrsant Tukadoji Maharaj Memorial Fellowship from Rashtrasant Tukadoji Maharaj Nagpur University。
文摘Objective:To examine the effects of hydroalcoholic extract and fractions of Hordeum vulgare Linn.(H.vulgare,Da Mai)on streptozotocin(STZ)-induced diabetic nephropathy in Sprague-Dawley rat models.Methods:The study involved preliminary phytochemical screening of extract and fractions,estimation of secondary metabolites,chromatographic studies using high performance liquid chromatography(HPLC),antioxidant potential using 1,1-diphenyl-2-picrylhydrazyl(DPPH),nitric oxide radical scavenging and reducing power methods along with the determination of potential against diabetic nephropathy in STZ-induced rat models.Results:The phytochemical evaluation of the hydroalcoholic extract of H.vulgare and fractions revealed the presence of various phytoconstituents such as alkaloids,saponins,tannins,flavonoids,and glycosides.The chromatographic analysis indicated the peak complementing marker compound epicatechin and significant antioxidant activity in the extract and aqueous fraction.STZ-induced rats showed abnormal levels of serum albumin,creatinine,total cholesterol,blood urea nitrogen(BUN),and triglycerides,and urine albumin and creatinine,which returned to normal after 8 weeks of treatment with hydroalcoholic extract(400 mg/kg)and aqueous fraction(50 mg/kg)of H.vulgare.Conclusion:Hydroalcoholic extract(400 mg/kg)and aqueous fraction(50 mg/kg)of H.vulgare have significant antioxidant potential and positive effects on diabetic nephropathy.The fractionation and optimization increase the concentration of polyphenols in aqueous extract,causing a decrease in the dose required for effects against diabetic nephropathy.
基金supported by grants from the Science Foundation of Jiangxi Province(Grant No.20212ACB215003)the National Natural Science Foundation of China(Grant No.31960403).
文摘Senescence is the last developmental process in plant,which has an important impact on crop yield and quality.In this study,a stable hereditary early-senescence line BC64 was isolated from the high-generation recombinant inbred lines of 93-11 and Wuyunjing7(W7).Genetic analysis showed that the premature aging phenotype was controlled by a dominant gene derived from 93-11.By linkage analysis,the gene was primarily mapped in the region between marker B4 and B5 near the centromere of chromosome 4,described as ES(4).Through multiple backcrossing with W7,the near-isogenic line of ES(4)(NIL-ES(4))was obtained.Compared with wild-type W7,NIL-ES(4)plants showed more sever senescence phenotype in both nature and dark conditions.In NIL plants,leaves turned yellow at the fully tillering stage;photosynthetic rate,pollen fertility and seed setting rate were decreased.Moreover,the malondialdehyde,proline content and relative conductivity in NIL-ES(4)were significantly higher than those in W7;both transcript level and activities of reactive oxygen species scavenging enzymes were repressed;H2O2 and O^(2−)were significantly accumulated.This study provides a basis for further cloning and function identification of ES(4).