Potential therapeutic role of spermine via Rac1 in osteoporosis:Insights from zebrafish and mice

Osteoporosis(OP)is a prevalent metabolic bone disease.While drug therapy is essential to prevent bone loss in osteoporotic patients,current treatments are limited by side effects and high costs,necessitating the development of more effective and safer targeted therapies.Utilizing a zebrafish(Danio rerio)larval model of osteoporosis,we explored the influence of the metabolite spermine on bone homeostasis.Results showed that spermine exhibited dual activity in osteoporotic zebrafish larvae by increasing bone formation and decreasing bone resorption.Spermine not only demonstrated excellent biosafety but also mitigated prednisolone-induced embryonic neurotoxicity and cardiotoxicity.Notably,spermine showcased protective attributes in the nervous systems of both zebrafish embryos and larvae.At the molecular level,Rac1 was identified as playing a pivotal role in mediating the antiosteoporotic effects of spermine,with P53 potentially acting downstream of Rac1.These findings were confirmed using mouse(Mus musculus)models,in which spermine not only ameliorated osteoporosis but also promoted bone formation and mineralization under healthy conditions,suggesting strong potential as a bonestrengthening agent.This study underscores the beneficial role of spermine in osteoporotic bone homeostasis and skeletal system development,highlighting pivotal molecular mediators.Given their efficacy and safety,human endogenous metabolites like spermine are promising candidates for new anti-osteoporotic drug development and daily bone-fortifying agents.

Single atom doping induced charge-specific distribution of Cu1-TiO_(2) for selective aniline oxidation via a new mechanism

Utilizing single atom sites doping into metal oxides to modulate their intrinsic active sites,achieving precise selectivity control in complex organic reactions,is a highly desirable yet challenging endeavor.Meanwhile,identifying the active site also represents a significant obstacle,primarily due to the intricate electronic environment of single atom site doped metal oxide.Herein,a single atom Cu doped TiO_(2)catalyst(Cu_(1)-TiO_(2)) is prepared via a simple“colloid-acid treatment”strategy,which switches aniline oxidation selectivity of TiO_(2) from azoxybenzene to nitrosobenzene,without using additives or changing solvent,while other metal or nonmetal doped TiO_(2) did not possess.Comprehensive mechanistic investigations and DFT calculations unveil that Ti-O active site is responsible for triggering the aniline to form a new PhNOH intermediate,two PhNOH condense to azoxybenzene over TiO_(2) catalyst.As for Cu_(1)-TiO_(2),the charge-specific distribution between the isolated Cu and TiO_(2) generates unique Cu_(1)-O-Ti hybridization structure with nine catalytic active sites,eight of them make PhNOH take place spontaneous dissociation to produce nitrosobenzene.This work not only unveils a new mechanistic pathway featuring the PhNOH intermediate in aniline oxidation for the first time but also presents a novel approach for constructing single-atom doped metal oxides and exploring their intricate active sites.

Transfer Behavior of Carbendazim from Dried Yingshan Yunwu Tea Leaves into Tea Infusions

Tea infusion is the main route of human exposure to pollutants in tea,and it is vital to investigate the transfer rate of pollutants from tea leaves to infusion.Carbendazim is a commonly used systemic fungicide,the transfer behavior of which in Yingshan Yunwu tea is not clear.Hence,this study firstly established the analytical method for determination of carbendazim with great accuracy and precision via modified QuEChERS method and ultra-performance liquid chromatography-fluorescence detection(UPLC-FLD).Then,the transfer behavior of carbendazim from tea leaves and infusion was systematically investigated.Results indicated that water temperature and proportion of tea to water ration would obviously increase the transfer rate of carbendazim,but times of infusion repetition showed negative correlation with the transfer rate of carbendazim.In addition,brewing time seemed to have lesser impact on the transfer rate.This study will be helpful for the risk assessment of carbendazim residue and provide the guidance for tea brewing.

Effects of Househould Cleaning Methods on Carbendazim Residue in Apples

Carbendazim,belonging to fungicides,was commonly used for controlling crop diseases,resulting in frequent residues in fruits and vegetables.Washing was the initial step of household fruit processing for cleaning and reducing pollutant contents.However,the effect of washing on the removal of carbendazim in apples was not systemically studied.Thus,in this study,an analytical method was firstly established for the determination of carbendazim with great accuracy and precision through quick,simple,cheap,effective and safe(QuEChERS)method and ultra-performance liquid chromatography-fluorescence detection(UPLC-FLD).Then,the influencing factors were systematically researched to unveil their effects on the carbendazim residue in apples.The results indicated that water temperature,washing products and washing method could obviously affect the carbendazim content in apples.In addition,the best cleaning scheme for removal of carbendazim was soaking apples for 5 min in a cleaning solution,which was prepared by dissolving 8 g of commercial fruit washing soup with 500 ml of water at 45℃.Under this condition,the removal rate of carbendazim in the washing step reached 73.91%.This study will be helpful for providing guidance for household cleaning methods for controlling pesticide residues.

Study on Gas Explosion Characteristics in Urban Utility Tunnels

In order to study the effects of three factors,namely,premixed gas concentration,number of pressure relief ports and number of obstacles,on the overpressure characteristics of gas explosion and flame structure of gas chambers in utility tunnels,in this paper,a small and narrow experimental platform for gas explosion was constructed to study the evolution mechanism and law of the kinetic characteristics and flame behavior of gas explosion in utility tunnels,with a view to revealing the special influencing mechanism of the overpressure characteristics and flame behavior of gas explosion in utility tunnels.The results show that in the methane concentration of 9.5%when the explosion overpressure reaches its peak,and at the same time by the utility tunnel long and narrow restricted space,the explosion generated by the precursor shock wave along with the flame compression wave were superimposed on both ends of the pipeline back and forth for many times so that the overpressure waveforms are cyclic oscillatory trend,increasing the explosion hazards;compared with the closed conditions,the relief port on the overpressure characteristics of the significant impact of the maximum decrease of 57.7%,when the frequency of overpressure oscillation is reduced,the gas explosion generated by the overpressure damage is reduced;the presence of obstacles significantly affects the flow field,accelerates the flame propagation and leads to greater overpressure peaks and overpressure oscillations.The conclusions of the study can provide a basis for the safety of natural gas in utility tunnels.

Cost effectiveness analysis of population-based serology screening and ^(13)C-Urea breath test for Helicobacter pylori to prevent gastric cancer:A markov model

AIM:To compare the costs and effectiveness of no screening and no eradication therapy, the population- based Helicobacter pylori (H pylori) serology screening with eradication therapy and 13C-Urea breath test (UBT) with eradication therapy. METHODS:A Markov model simulation was carried out in all 237 900 Chinese males with age between 35 and 44 from the perspective of the public healthcare provider in Singapore. The main outcome measures were the costs, number of gastric cancer cases prevented, life years saved, and quality-adjusted life years (QALYs) gained from screening age to death. The uncertainty surrounding the cost-effectiveness ratio was addressed by one-way sensitivity analyses. RESULTS:Compared to no screening, the incremental cost-effectiveness ratio (ICER) was $16 166 per life year saved or $13 571 per QALY gained for the serology screening, and $38 792 per life year saved and $32 525 per QALY gained for the UBT. The ICER was $477 079 per life year saved or $390 337 per QALY gained for the UBT compared to the serology screening. The cost- effectiveness of serology screening over the UBT was robust to most parameters in the model. CONCLUSION:The population-based serologyscreening for H pylori was more cost-effective than the UBT in prevention of gastric cancer in Singapore Chinese males.

Enhanced CNN for image denoising

Owing to the flexible architectures of deep convolutional neural networks(CNNs)are successfully used for image denoising.However,they suffer from the following drawbacks:(i)deep network architecture is very difficult to train.(ii)Deeper networks face the challenge of performance saturation.In this study,the authors propose a novel method called enhanced convolutional neural denoising network(ECNDNet).Specifically,they use residual learning and batch normalisation techniques to address the problem of training difficulties and accelerate the convergence of the network.In addition,dilated convolutions are used in the proposed network to enlarge the context information and reduce the computational cost.Extensive experiments demonstrate that the ECNDNet outperforms the state-of-the-art methods for image denoising.

Glycerol solutions of highly concentrated biomineral counter-ions towards water-responsive mineralization: Demonstration on bacterial cellulose and its application in hard tissue repair

Mineralization has found widespread use in the fabrication of composite biomaterials for hard tissue regeneration.The current mineralization processes are mainly carried out in neutral aqueous solutions of biomineral counter-ions(a pair of cation and anion that form the corresponding minerals at certain conditions),which are stable only at very low concentrations.This typically results in inefficient mineralization and weak control over biomineral formation.Here,we find that,in the organic solvent glycerol,a variety of biomineral counter-ions(e.g.,Ca/PO_(4),Ca/CO_(3),Ca/SO_(4),Mg/PO_(4),or Fe/OH)corresponding to distinct biominerals at significantly high concentrations(up to hundreds-fold greater than those of simulated body fluid(SBF))are able to form translucent and stable solutions(mineralizing solution of highly concentrated counter-ions(MSCIs)),and mineralization can be triggered upon them with external solvents(e.g.,water or ethanol).Furthermore,with pristine bacterial cellulose(BC)membrane as a model,we demonstrate an effective and controllable mineralization performance of MSCIs on organic substrates.This approach not only forms the homogeneous biominerals on the BC fibers and in the interspaces,but also provides regulations over mineralization rate,mineral content,phase,and dopants.The resulting mineralized BC membranes(MBCs)exhibit high cytocompatibility and favor the proliferation of rat bone marrow mesenchymal stem cells(rBMSC).Following this,we prepare a mineralized bone suture(MBS)from MBC for non-weight bearing bone fixation,which then is tested on a rabbit median sternotomy model.It shows firm fixation of the rabbit sternum without causing discernible toxicity or inflammatory response.This study,by extending the mineralization to the organic solution system of highly concentrated counter-ions,develops a promising strategy to design and build targeted mineral-based composites.

Self-Reported Food Allergy Prevalence Among Elementary School Children—Nanchang City, Jiangxi Province, China, 2021

What is already known about this topic?The prevalence of food allergy(FA)among the general population has been increasing in recent decades,and seriously affects the physical and mental health and the quality of life of many people—especially children.What is added by this report?The survey estimated self-reported FA prevalence using a standardized FA questionnaire among school children in Nanchang City,Jiangxi Province,China in 2021.What are the implications for public health practice?Based on the local,epidemiological characteristics of food allergy,public policies on the prevention and management of FA should be developed and preventive practices should be promoted to decrease the overall prevalence of FA.

Low phosphorus promotes NSP1–NSP2 heterodimerization to enhance strigolactone biosynthesis and regulate shoot and root architecture in rice

Phosphorus is an essential macronutrient for plant development and metabolism,and plants have evolved ingenious mechanisms to overcome phosphate(Pi)starvation.However,the molecular mechanisms underlying the regulation of shoot and root architecture by low phosphorus conditions and the coordinated utilization of Pi and nitrogen remain largely unclear.Here,we show that Nodulation Signaling Pathway 1(NSP1)and NSP2 regulate rice tiller number by promoting the biosynthesis of strigolactones(SLs),a class of phytohormones with fundamental effects on plant architecture and environmental responses.We found that NSP1 and NSP2 are induced by Oryza sativa PHOSPHATE STARVATION RESPONSE2(OsPHR2)in response to low-Pi stress and form a complex to directly bind the promoters of SL biosynthesis genes,thus markedly increasing SL biosynthesis in rice.Interestingly,the NSP1/2–SL signaling module represses the expression of CROWN ROOTLESS 1(CRL1),a newly identified early SL-responsive gene in roots,to restrain lateral root density under Pi deficiency.We also demonstrated that GR24^(4DO) treatment under normal conditions inhibits the expression of OsNRTs and OsAMTs to suppress nitrogen absorption but enhances the expression of OsPTs to promote Pi absorption,thus facilitating the balance between nitrogen and phosphorus uptake in rice.Importantly,we found that NSP1p:NSP1 and NSP2p:NSP2 transgenic plants show improved agronomic traits and grain yield under low-and medium-phosphorus conditions.Taken together,these results revealed a novel regulatory mechanism of SL biosynthesis and signaling in response to Pi starvation,providing genetic resources for improving plant architecture and nutrient-use efficiency in low-Pi environments.

N-Aryl diketopyrrolopyrrole derivatives towards organic optical and electronic materials

Diketopyrrolopyrrole(DPP)and related derivatives have drawn great attention due to their applications in organic optical/electronic materials.Progress in these materials is associated with developments in the syntheses of the DPP family.Chemical modification of DPP at nitrogen atom,including N-alkylation and N-arylation,is an effective strategy to improve its physical and chemical properties,such as solubility,optical and semiconducting properties.However,N-arylation of DPPs remains challenging compared to the easily accessible N-alkylation.Herein,the synthesis of N-aryl DPP derivatives and correlatedπ-expanded DPPs are summarized,and their optical/electronic properties are introduced.The future perspectives of N-aryl DPP derivatives are also discussed.

National survey of the awareness and implementation status of early pulmonary rehabilitation for patients with critical illness in departments of pulmonary and critical care medicine in 2019

To the Editor:The aim of early pulmonary rehabilitation(PR)in the intensive care unit(ICU)is to reduce the incidence of post-ICU syndrome,increase the number of ventilator-free days,reestablish and improve functional capacity,improve health-related life quality,promote mental health,and enhance participation in everyday life.PR in the ICU is highly effective and plays an important role in recovery of patients with reduced exercise endurance,functional capacity,and health-related life quality.Several surveys outside China have assessed the implementation of early rehabilitation in the ICU,[1]but there are few data from China.This study aimed to investigate the awareness and implementation of early PR in secondary-and tertiary-class hospitals with pulmonary and critical care medicine(PCCM)standardized certification.PCCM staff members were recruited to fill out a selfdesigned questionnaire.We defined early PR as PR within 5 days of ICU admission.

Salicylic Acid Regulates Pollen Tip Growth ：hrough an NPR3/NPR4-1ndependent Pathway

Tip growth is a common strategy for the rapid elongation of cells to forage the environment and/or to target to long-distance destinations. In the model tip growth system of Arabidopsis pollen tubes, several small- molecule hormones regulate their elongation, but how these rapidly diffusing molecules control extremely localized growth remains mysterious. Here we show that the interconvertible salicylic acid （SA） and meth- ylated SA （MESA）, well characterized for their roles in plant defense, oppositely regulate Arabidopsis pollen tip growth with SA being inhibitory and MeSA stimulatory. The effect of SA and MeSA was independent of known NPR3/NPR4 SA receptor-mediated signaling pathways. SA inhibited clathrin-mediated endocytosis in pollen tubes associated with an increased accumulation of less stretchable demethylated pectin in the apical wall, whereas MeSA did the opposite. Furthermore, SA and MeSA alter the apical activation of ROP1 GTPase, a key regulator of tip growth in pollen tubes, in an opposite manner. Interestingly, both MeSA methylesterase and SA methyltransferase, which catalyze the interconversion between SA and MESA, are localized at the apical region of pollen tubes, indicating of the tip-localized production of SA and MeSA and consistent with their effects on the apical cellular activities. These findings suggest that local generation of a highly diffusible signal can regulate polarized cell growth, providing a novel mechanism of cell polarity control apart from the one involving protein and mRNA polarization.

OsMPK4 promotes phosphorylation and degradation of IPA1 in response to salt stress to confer salt tolerance in rice

Salt stress adversely affects plant growth,development,and crop yield.Rice(Oryza sativa L.)is one of the most salt-sensitive cereal crops,especially at the early seedling stage.Mitogen-activated protein kinase(MAPK/MPK)cascades have been shown to play critical roles in salt response in Arabidopsis.However,the roles of the MPK cascade signaling in rice salt response and substrates of Os MPK remain largely unknown.Here,we report that the salt-induced Os MPK4-Ideal Plant Architecture 1(IPA1)signaling pathway regulates the salt tolerance in rice.Under salt stress,Os MPK4 could interact with IPA1 and phosphorylate IPA1 at Thr180,leading to degradation of IPA1.Genetic evidence shows that IPA1 is a negative regulator of salt tolerance in rice,whereas Os MPK4 promotes salt response in an IPA1-dependent manner.Taken together,our results uncover an Os MPK4-IPA1 signal cascade that modulates the salt stress response in rice and sheds new light on the breeding of salt-tolerant rice varieties.

Preparation and characterization of PVDF-glass fiber composite membrane reinforced by interfacial UV-grafting copolymerization

A novel inorganic-organic composite membrane,namely poly（vinylidene fluoride） PVDF-glass fiber（PGF） composite membrane,was prepared and reinforced by interfacial ultraviolet（UV）-grafting copolymerization to improve the interfacial bonding strength between the membrane layer and the glass fiber.The interfacial polymerization between inorganic-organic interfaces is a chemical cross-linking reaction that depends on the functionalized glass fiber with silane coupling（KH570） as the initiator and the polymer solution with acrylamide monomer（AM） as the grafting block.The Fourier transform infrared spectrometer-attenuated total reflectance（FTIR-ATR） spectra and the energy dispersive X-ray（EDX） pictures of the interface between the glass fiber and polymer matrix confirmed that the AM was grafted to the surface of the glass fiber fabric and that the grafting polymer was successfully embedded in the membrane matrix.The formation mechanisms,permeation,and anti-fouling performance of the PGF composite membrane were measured with different amounts of AM in the doping solutions.The results showed that the grafting composite membrane improved the interfacial bonding strength and permeability,and the peeling strength was improved by 32.6% for PGF composite membranes with an AM concentration at 2 wt.%.

Performance evaluation of deep learning-based post-processing and diagnostic reporting system for coronary CT angiography: a clinical comparative study

To the Editor:Coronary computed tomography angiography(CCTA)has been increasingly,widely performed for diagnosing coronary artery,disease,lAnatomical diagnosis,that is,stenosis grading,is stillthe main diagnostic index provided'by most CCTA tests.Post-processing and interpretation of stenosis are 2 essential'steps that need to be performed bycardiovascular imaging professionals from scan completion to diagnosis conclusion,which is repetitive and time-consuming,taking an average of 30 minutes each case in China and becoming the bottleneck and gradually creating an imbalance between supply and demand.In ine with the rapid development of artificial intelligence(Al)technology in recent years,it has been expected to solve these specific problems.We developed an AI system for automating post-processing and diagnostic reporting of CCTA data using deep learning algorithms to establishanew1-clickworkflowforeverydayuse,namely,CCTA-AI(Figure 1).To further assess its capabilities,this study intends to answer 2 following questions:To what extent can it improve the efficiency of post-processing?To what extent can CCTA-AI detect and calculate coronary artery stenosis due to each atherosclerotic plaque?

Influence of carbon sources on nutrient removal in A2/O-MBRs： Availability assessment of internal carbon source

Both intemal carbon source and some external carbon sources were used to improve the nutrient removal in Anaerobic-Anoxic-Oxic-Membrane Bioreactor （A2/O-MBRs）, and their technical and cost analysis was investigated. The experimental results showed that the nutrient removals were improved by all the carbon source additions. The total nitrogen and phosphorus removal efficiency were higher in the experiments with external carbon source additions than that with internal carbon source addition. It was found that pathways of nitrogen and phosphorus transform were different dependent on different carbon source additions by the mass balance analysis. With extemal carbon source addition, the simultaneous nitrification and denitrification occurred in aerobic zone, and the P-uptake in aerobic phase was evident. Therefore, with addition of C-MHP （internal carbon source produced from sludge pretreatment by microwave-H2O2 process）, the denitrification and phosphorus-uptake in anoxic zone was notable. Cost analysis showed that the unit nitrogen removal costs were 57.13 CNY/kg N of C-acetate addition and 54.48 CNY/kgN of C-MHP addition, respectively. The results indicated that the C-MHP has a good technical and economic feasibility to substitute extemal carbon sources partially for nutrient removal.

Modifying glass fiber surface with grafting acrylamide by UV-grafting copolymerization for preparation of glass fiber reinforced PVDF composite membrane

Experimental design and response surface methodology（RSM） were used to optimize the modification of conditions for glass surface grafting with acrylamide（AM） monomer for preparation of a glass fiber reinforced poly（vinylidene fluoride）（PVDF） composite membrane（GFRP-CM）. The factors considered for experimental design were the UV（ultraviolet）-irradiation time, the concentrations of the initiator and solvent, and the kinds and concentrations of the silane coupling agent. The optimum operating conditions determined were UV-irradiation time of 25 min, an initiator concentration of 0–0.25 wt.%,solvent of N-Dimethylacetamide（DMAC）, and silane coupling agent KH570 with a concentration of 7 wt.%. The obtained optimal parameters were located in the valid region and the experimental confirmation tests conducted showed good accordance between predicted and experimental values. Under these optimal conditions, the water absorption of the grafted modified glass fiber was improved from 13.6% to 23%; the tensile strength was enhanced and the peeling strength of the glass fiber reinforced PVDF composite membrane was improved by 23.7% and 32.6% with an AM concentration at 1 wt.% and 2 wt.%. The surface composition and microstructure of AM grafted glass fiber were studied via several techniques including Field Emission Scanning Electron Microscopy（FESEM）, Fourier transform infrared spectroscopy-attenuated total reflectance（FTIR-ATR） and energy dispersive X-ray spectroscopy（EDX）. The analysis of the EDX and FTIR-ATR results confirmed that the AM was grafted to the glass fiber successfully by detecting and proving the existence of nitrogen atoms in the GFRP-CM.

Feasibility analysis for attitude estimation based on pulsar polarization measurement

One of the important characteristics of pulsar radiation is polarization.It is considered not only as a probe for recognizing the structure of a magnetic field,but also as a lighthouse for estimating spacecraft attitude via orientation information between the pulsar and the detector.Although polarization of a pulsar has been studied for decades,until recently applications to determination of spacecraft attitude have been seldom reported.This paper deals with analysis of the feasibility of applying polarization information to attitude estimation.The stability factor(SFR) and observation fluctuation factor(OFR) are introduced to analyze the stability of a pulsar's polarized position angle.Based on European Pulsar Network(EPN) data,several simulated instances are used to demonstrate that the accuracy requirement of attitude determination can be met via polarization measurement.The SFR of a pulsar is evaluated using simulated polarization data,and the OFR is used to analyze the relationship between fluctuation extent and observation time.Simulation results show that the polarized measurement of candidate pulsars PSR B0470-28 and PSR B2319+60 reaches the specification for attitude determination.