We previously reported that SM934, a water-soluble artemisinin derivative, was a viable treatment in murine lupus models. In the current study, we further investigated the therapeutic effects of a modified dosage regi...We previously reported that SM934, a water-soluble artemisinin derivative, was a viable treatment in murine lupus models. In the current study, we further investigated the therapeutic effects of a modified dosage regimen of SM934 on lupus-prone MRIJIpr mice and explored its effects on B cell responses, a central pathogenic event in systemic lupus erythematosus （SLE）. When orally administered twice-daily, SM934 significantly prolonged the life-span of MRL/Ipr mice, ameliorated the lymphadenopathy symptoms and decreased the levels of serum anti-nuclear antibodies （ANAs） and of the pathogenic cytokines IL-6, IL-10 and I L-21. Furthermore, SM934 treatment restored the B-cell compartment in the spleen of MRL/Ipr mice by increasing quiescent B cell numbers, maintaining germinal center B-cell numbers, decreasing activated B cell numbers and reducing plasma cell （PC） numbers. Ex vivo, SM934 suppressed the Toll-like receptor （TLR）-triggered activation and proliferation of B cells, as well as antibody secretion. Moreover, the present study demonstrated that SM934 interfered with the B-cell intrinsic pathway by downregulating TLR7/9 mRNA expression, MyD88 protein expression and NF-KB phosphorylation. In human peripheral blood mononuclear cells （PBMCs）, consistent with the results in MRIJIprmice, SM934 inhibited TLR-associated B-cell activation and PC differentiation. In conclusion, a twice daily dosing regimen of SM934 had therapeutic effects on lupus-prone MRL/Iprmice by suppressing B cell activation and plasma cell formation.展开更多
Cervical cancer is one of the leading causes of cancer death among females worldwide and its behavior epidemiologically likes a venereal disease of low infectiousness. Early age at first intercourse and multiple sexua...Cervical cancer is one of the leading causes of cancer death among females worldwide and its behavior epidemiologically likes a venereal disease of low infectiousness. Early age at first intercourse and multiple sexual partners have been shown to exert strong effects on risk. The wide differences in the incidence among different countries also influenced by the introduction of screening. Although the general picture remains one of decreasing incidence and mortality, there are signs of an increasing cervical cancer risk probably due to changes in sexual behavior. Smoking and human papillomavirus(HPV) 16/18 are currently important issues in a concept of multifactorial, stepwise carcinogenesis at the cervix uteri. Therefore, society-based preventive and control measures, screening activities and HPV vaccination are recommended. Cervical cancer screening methods have evolved from cell morphology observation to molecular testing. High-risk HPV genotyping and liquid-based cytology are common methods which have been widely recommended and used worldwide. In future, accurate,cheap, fast and easy-to-use methods would be more popular. Artificial intelligence also shows to be promising in cervical cancer screening by integrating image recognition with big data technology. Meanwhile, China has achieved numerous breakthroughs in cervical cancer prevention and control which could be a great demonstration for other developing and resource-limited areas. In conclusion, although cervical cancer threatens female health, it could be the first cancer that would be eliminated by human beings with comprehensive preventive and control strategy.展开更多
A detailed understanding of genetic architecture of mRNA expression by millions of genetic variants is important for studying quantitative trait variation. In this study, we identified 1.25M SNPs with a minor allele f...A detailed understanding of genetic architecture of mRNA expression by millions of genetic variants is important for studying quantitative trait variation. In this study, we identified 1.25M SNPs with a minor allele frequency greater than 0.05 by combining reduced genome sequencing （GBS）, high- density array technologies （600K）, and previous deep RNA-sequencing data from 368 diverse inbred lines of maize. The balanced allelic frequencies and distributions in a relatively large and diverse natural panel helped to identify expression quantitative trait loci （eQTLs） associated with more than 18 000 genes （63.4% of tested genes）. We found that distant eQTLs were more frequent （~75% of all eQTLs） across the whole genome. Thirteen novel associated loci affecting maize kernel oil concentration were identified using the new dataset, among which one intergenic locus affected the kernel oil variation by controlling expression of three other known oil-related genes. Altogether, this study provides resources for expanding our understanding of cellular regulatory mechanisms of transcriptome variation and the landscape of functional variants within the maize genome, thereby enhancing the understanding of quantitative variations.展开更多
As a primary defense technique, intrusion detection becomes more and more significant since the security of the networks is one of the most critical issues in the world. We present an adaptive collaboration intrusion ...As a primary defense technique, intrusion detection becomes more and more significant since the security of the networks is one of the most critical issues in the world. We present an adaptive collaboration intrusion detection method to improve the safety of a network. A self-adaptive and collaborative intrusion detection model is built by applying the Environmentsclasses, agents, roles, groups, and objects(E-CARGO) model. The objects, roles, agents, and groups are designed by using decision trees(DTs) and support vector machines(SVMs), and adaptive scheduling mechanisms are set up. The KDD CUP 1999 data set is used to verify the effectiveness of the method. The experimental results demonstrate the feasibility and efficiency of the proposed collaborative and adaptive intrusion detection method. Also, the proposed method is shown to be more predominant than the methods that use a set of single type support vector machine(SVM) in terms of detection precision rate and recall rate.展开更多
Background:Treatment options for Chinese patients with locally advanced or metastatic squamous-cell non-small-cell lung cancer(sqNSCLC)after failure of first-line chemotherapy are limited.This study(ORIENT-3)aimed to ...Background:Treatment options for Chinese patients with locally advanced or metastatic squamous-cell non-small-cell lung cancer(sqNSCLC)after failure of first-line chemotherapy are limited.This study(ORIENT-3)aimed to evaluate the efficacy and safety of sintilimab versus docetaxel as second-line treatment in patients with locally advanced or metastatic sqNSCLC.Methods:ORIENT-3 was an open-label,multicenter,randomized controlled phase 3 trial that recruited patients with stage IIIB/IIIC/IV sqNSCLC after failure with first-line platinum-based chemotherapy.Patients were randomized in a 1:1 ratio to receive either 200 mg of sintilimab or 75 mg/m^(2) of docetaxel intravenously every 3 weeks,stratified by the Eastern Cooperative Oncology Group performance status.The primary endpoint was overall survival(OS)in the full analysis set(FAS).Secondary endpoints included progression-free survival(PFS),objective response rate(ORR),disease control rate(DCR),duration of response(DoR)and safety.Results:Between August 25,2017,and November 7,2018,290 patients were randomized.For FAS,10 patients fromthe docetaxel armwere excluded.Themedian OS was 11.79(n=145;95%confidence interval[CI],10.28-15.57)months with sintilimab versus 8.25(n=135;95%CI,6.47-9.82)months with docetaxel(hazard ratio[HR]:0.74;95%CI,0.56-0.96;P=0.025).Sintilimab treatment significantly prolonged PFS(median 4.30 vs.2.79 months;HR:0.52;95%CI,0.39-0.68;P<0.001)and showed higher ORR(25.50%vs.2.20%,P<0.001)and DCR(65.50%vs.37.80%,P<0.001)than the docetaxel arm.The median DoRwas 12.45(95%CI,4.86-25.33)months in the sintilimab arm and 4.14(95%CI,1.41-7.23)months in the docetaxel arm(P=0.045).Treatment-related adverse events of grade≥3were reported in 26(18.1%)patients in the sintilimab arm and 47(36.2%)patients in the docetaxel arm.Exploratory biomarker analysis showed potential predictive values of expression levels of two transcription factors,including OVOL2(HR:0.35;P<0.001)and CTCF(HR:3.50;P<0.001),for sintilimab treatment.Conclusions:Compared with docetaxel,sintili展开更多
Horizontal axis wind turbine(HAWT)often works under yaw due to the stochastic variation of wind direction.Yaw also can be used as one of control methods for load reduction and wake redirection of HAWT.Thus,the aerodyn...Horizontal axis wind turbine(HAWT)often works under yaw due to the stochastic variation of wind direction.Yaw also can be used as one of control methods for load reduction and wake redirection of HAWT.Thus,the aerodynamic performance under yaw is very important to the design of HAWT.For further insight into the highly unsteady characteristics aerodynamics of HAWT under yaw,this paper investigates the unsteady variations of the aerodynamic performance of a small wind turbine under static yawed and yawing process with sliding grid method,as well as the there-dimensional effect on the unsteady characteristics,using unsteady Reynolds-averaged Navier-Stokes(URANS)simulations.The simulation results are validated with experimental data and blade element momentum(BEM)results.The comparisons show that the CFD results have better agreement with the experimental data than both BEM results.The wind turbine power decreases according to a cosine law with the increase of yaw angle.The torque under yaw shows lower frequency fluctuations than the non-yawed condition due to velocity component of rotation and the influence of spinner.Dynamic yawing causes larger fluctuate than static yaw,and the reason is analyzed.The aerodynamic fluctuation becomes more prominent in the retreating side than that in the advancing side for dynamic yawing case.Variations of effective angle of attack and aerodynamic forces along the blade span are analyzed.The biggest loading position moves from middle span to outer span with the increase of yaw angle.Three-dimensional stall effect presents load fluctuations at the inner board of blade,and becomes stronger with the increase of yaw angle.展开更多
Herein,we report a unique approach towards the preparation of C-modified and N-doped TiO2 hollow spheres(C/N-TiO2).TEM,SEM,and XPS analyses were used to confirm that the carbon and nitrogen co-decorated TiO2 photocata...Herein,we report a unique approach towards the preparation of C-modified and N-doped TiO2 hollow spheres(C/N-TiO2).TEM,SEM,and XPS analyses were used to confirm that the carbon and nitrogen co-decorated TiO2 photocatalyst was formed.Carbon-decoration improves the visible-light absorption and speeds up the separation of the photo-generated electron-hole pairs.C/N-TiO2 not only narrows the band gap of TiO2,but also exhibits excellent photocatalytic activity for the degradation of tetracycline and tetracycline hydrochloride.In addition,the C/N-TiO2 photocatalyst shows excellent recyclability for water decontamination,making it a promising candidate to purify aquatic contaminants.展开更多
Although inoculation of COVID-19 vaccines has rolled out globally,there is still a critical need for safe and effective vaccines to ensure fair and equitable supply for all countries.Here,we report on the development ...Although inoculation of COVID-19 vaccines has rolled out globally,there is still a critical need for safe and effective vaccines to ensure fair and equitable supply for all countries.Here,we report on the development of a highly efficacious mRNA vaccine,SW0123 that is composed of sequence-modified mRNA encoding the full-length SARS-CoV-2 Spike protein packaged in core-shell structured lipopolyplex(LPP)nanoparticles.SWOT 23 is easy to produce using a large-scale microfluidics-based apparatus.The unique core-shell structured nanoparticle facilitates vaccine uptake and demonstrates a high colloidal stability,and a desirable biodistribution pattern with low liver targeting effect upon intramuscular administration.Extensive evaluations in mice and nonhuman primates revealed strong immunogenicity of SW0123,represented by induction of Th1-polarized T cell responses and high levels of antibodies that were capable of neutralizing not only the wild-type SARS-CoV-2,but also a panel of variants including D614G and N501Y variants.In addition,SW0123 conferred effective protection in both mice and non-human primates upon SARS-CoV-2 challenge.Taken together,SW0123 is a promising vaccine candidate that holds prospects for further evaluation in humans.展开更多
To research techniques for removing the water blocking effect caused by hydraulic applications in coal seams,the use of surfactants is proposed,based on the mechanics of the water blocking effect.Centrifugal experimen...To research techniques for removing the water blocking effect caused by hydraulic applications in coal seams,the use of surfactants is proposed,based on the mechanics of the water blocking effect.Centrifugal experiments were used to validate the effects of using surfactants;the results show that after dealing with vacuum saturation with water,the volume of micropores decreases,which results in a larger average pore size,and the volume of transitional pores,mesopores,macropores and total pores increases.Based on the distribution of pore size,the operation mode of ‘‘water infusion after gas extraction,then continuing gas extraction" is recommended to improve the volume of coal mine gas drainage.When the reflectance of vitrinite in coal samples is less than 1,using the surfactants Fast T,1631,APG,BS can mitigate the damage caused by the water blocking effect.But when the reflectance of vitrinite is larger than 1.4,the damage caused by the water blocking effect can be increased.When the surfactant CMC is used in hydraulic applications,the capillary forces of coal samples are almost negative,which means the capillary force is in the same direction as the gas extraction.The direction of capillary forces benefits the gas flow.So,using CMC can play an active role in removing the water blocking effect.Centrifugal experiments confirm that using CMC can effectively remove the water blocking effect,which has a beneficial effect on improving the gas drainage volume.展开更多
Global warming poses a serious threat to crops.Calcium-dependent protein kinases(CDPKs)/CPKs play vital roles in plant stress responses,but their exact roles in plant thermotolerance remains elusive.Here,we explored t...Global warming poses a serious threat to crops.Calcium-dependent protein kinases(CDPKs)/CPKs play vital roles in plant stress responses,but their exact roles in plant thermotolerance remains elusive.Here,we explored the roles of heat-induced ZmCDPK7 in thermotolerance in maize.ZmCDPK7-overexpressing maize plants displayed higher thermotolerance,photosynthetic rates,and antioxidant enzyme activity but lower H2 O2 and malondialdehyde(MDA)contents than wild-type plants under heat stress.ZmCDPK7-knockdown plants displayed the opposite patterns.ZmCDPK7 is attached to the plasma membrane but can translocate to the cytosol under heat stress.ZmCDPK7 interacts with the small heat shock protein sHSP17.4,phosphorylates sHSP17.4 at Ser-44 and the respiratory burst oxidase homolog RBOHB at Ser-99,and up regulates their expression.Site-directed mutagenesis of sHSP17.4 to generate a Ser-44-Ala substitution reduced ZmCDPK7’s enhancement of catalase activity but enhanced ZmCDPK7’s suppression of MDA accumulation in heat-stressed maize protoplasts.sHSP17.4,ZmCDPK7,and RBOHB were less strongly upregulated in response to heat stress in the abscisic acid-deficient mutant vp5 versus the wild type.Pretreatment with an RBOH inhibitor suppressed sHSP17.4 and ZmCDPK7 expression.Therefore,abscisic acid-induced ZmCDPK7 functions both upstream and downstream of RBOH and participates in thermotolerance in maize by mediating the phosphorylation of sHSP17.4,which might be essential for its chaperone function.展开更多
Dental caries is one of the most prevalent human diseases resulting from tooth demineralization caused by acid production of bacteria plaque.It remains challenges for current practice to specifically identify,interven...Dental caries is one of the most prevalent human diseases resulting from tooth demineralization caused by acid production of bacteria plaque.It remains challenges for current practice to specifically identify,intervene and interrupt the development of caries while restoring defects.In this study,inspired by natural dental plaque,a stimuli-responsive multidrug delivery system(PMs@NaF-SAP)has been developed to prevent tooth decay and promote enamel restoration.Classic spherical core-shell structures of micelles dual-loaded with antibacterial and restorative agents are self-assembled into bacteria-responsive multidrug delivery system based on the pH-cleavable boronate ester bond,followed by conjugation with salivary-acquired peptide(SAP)to endow the nanoparticle with strong adhesion to tooth enamel.The constructed PMs@NaF-SAP specifically adheres to tooth,identifies cariogenic conditions and intelligently releases drugs at acidic pH,thereby providing antibacterial adhesion and cariogenic biofilm resistance,and restoring the microarchitecture and mechanical properties of demineralized teeth.Topical treatment with PMs@NaF-SAP effectively diminishes the onset and severity of caries without impacting oral microbiota diversity or surrounding mucosal tissues.These findings demonstrate this novel nanotherapy has potential as a promising biomedical application for caries prevention and tooth defect restoration while resisting biofilm-associated diseases in a controlled manner activated by pathological bacteria.展开更多
Objective: Hyperlipidemia is a representative nutritional metabolic disease in clinic, which is easy to induce atherosclerotic cardiovascular and cerebrovascular diseases, with complex classification. Traditional Chin...Objective: Hyperlipidemia is a representative nutritional metabolic disease in clinic, which is easy to induce atherosclerotic cardiovascular and cerebrovascular diseases, with complex classification. Traditional Chinese Medicine (TCM) syndrome aims to reflect the characteristics of diseases and is the basic principle of TCM treatment of diseases. This study aimed to summarize the distribution pattern of TCM syndromes in patients with hyperlipidemia. Methods: The frequency, characteristics and distribution of all TCM syndromes of 1012 patients with hyperlipidemia were analyzed. Results: The main disease types determined by frequency of 1012 patients included hypertriglyceridemia combined with hypo high-density lipoprotein cholesterolemia (19.76%), hypo high-density lipoprotein cholesterolemia (18.58%), hypercholesterolemia (16.50%), mixed hyperlipidemia (16.40%), and hypertriglyceridemia (15.12%). The distribution of TCM syndromes, in order of frequency, was as follows: Qi-deficiency and blood stasis syndrome (23.52%), liver depression and spleen deficiency (9.88%), syndrome of qi stagnation and blood stasis (9.29%), phlegm stasis syndrome (7.41%), and syndrome of yang deficiency of spleen and kidney (6.92%). Conclusion: Qi-deficiency and blood stasis syndrome and liver depression and spleen deficiency are the most common TCM syndromes in patients with hyperlipidemia.展开更多
The purpose of this research is to investigate the hydration behavior and cementitious properties of the mixture of calcium carbonate and aluminate, and to explore whether it can be adopted as a new low-carbon cementi...The purpose of this research is to investigate the hydration behavior and cementitious properties of the mixture of calcium carbonate and aluminate, and to explore whether it can be adopted as a new low-carbon cementitious material. The composite system of calcium carbonate and aluminate minerals is studied by measuring the component of hydration products, the hydration heat, setting time and compressive strength.The results prove that the composite system has certain cementitious properties and is feasible to prepare new low-carbon cement.展开更多
Lignans are a powerful weapon for plants to resist stresses and have diverse bioactive functions to protect human health.Elucidating the mechanisms of stereoselective biosynthesis and response to stresses of lignans i...Lignans are a powerful weapon for plants to resist stresses and have diverse bioactive functions to protect human health.Elucidating the mechanisms of stereoselective biosynthesis and response to stresses of lignans is important for the guidance of plant improvement.Here,we identified the complete pathway to stereoselectively synthesize antiviral(-)-lariciresinol glucosides in Isatis indigotica roots,which consists of three-step sequential stereoselective enzymes DIR1/2,PLR,and UGT71B2.DIR1 was further identified as the key gene in respoJanuary 2024nse to stresses and was able to trigger stress defenses by mediating the elevation in lignan content.Mechanistically,the phytohormone-responsive ERF transcription factor LTF1 colocalized with DIR1 in the cell periphery of the vascular regions in mature roots and helped resist biotic and abiotic stresses by directly regulating the expression of DIR1.These systematic results suggest that DIR1 as the first common step of the lignan pathway cooperates with PLR and UGT71B2 to stereoselectively synthesize(-)-lariciresinol derived antiviral lignans in I.indigotica roots and is also a part of the LTF1-mediated regulatory network to resist stresses.In conclusion,the LTF1-DIR1 module is an ideal engineering target to improve plant Defenses while increasing the content of valuable lignans in plants.展开更多
The air quality in China has improved significantly in the last decade and,correspondingly,the characteristics of PM_(2.5)have also changed.We studied the interannual variation of PM_(2.5)in Chengdu,one of the most he...The air quality in China has improved significantly in the last decade and,correspondingly,the characteristics of PM_(2.5)have also changed.We studied the interannual variation of PM_(2.5)in Chengdu,one of the most heavily polluted megacities in southwest China,during the most polluted season(winter).Our results show that the mass concentrations of PM_(2.5)decreased significantly year-by-year,from 195.8±91.0μg/m~3in winter 2016 to 96.1±39.3μg/m^(3)in winter 2020.The mass concentrations of organic matter(OM),SO_()4^(2-),NH_(4)^(+)and NO_(3)^(-)decreased by 49.6%,57.1%,49.7% and 28.7%,respectively.The differential reduction in the concentrations of chemical components increased the contributions from secondary organic carbon and NO_(3)^(-)and there was a larger contribution from mobile sources.The contribution of OM and NO_(3)^(-)not only increased with increasing levels of pollution,but also increased year-by-year at the same level of pollution.Four sources of PM_(2.5)were identified:combustion sources,vehicular emissions,dust and secondary aerosols.Secondary aerosols made the highest contribution and increased year-by-year,from 40.6%in winter 2016 to 46.3% in winter 2020.By contrast,the contribution from combustion sources decreased from 14.4% to 8.7%.Our results show the effectiveness of earlier pollution reduction policies and emphasizes that priority should be given to key pollutants(e.g.,OM and NO_(3)^(-))and sources(secondary aerosols and vehicular emissions)in future policies for the reduction of pollution in Chengdu during the winter months.展开更多
Research on CRISPR-Cas（clustered regularly interspaced short palindromic repeats-CRISPR associated protein） systems has led to the revolutionary CRISPR/Cas9 genome editing technique. However, for most archaea and ha...Research on CRISPR-Cas（clustered regularly interspaced short palindromic repeats-CRISPR associated protein） systems has led to the revolutionary CRISPR/Cas9 genome editing technique. However, for most archaea and half of bacteria, exploitation of their native CRISPR-Cas machineries may be more straightforward and convenient. In this study, we harnessed the native type I-B CRISPR-Cas system for precise genome editing in the polyploid haloarchaeon Haloarcula hispanica. After testing different designs, the editing tool was optimized to be a single plasmid that carries both the self-targeting miniCRISPR and a 600-800 bp donor. Significantly, chromosomal modifications, such as gene deletion, gene tagging or single nucleotide substitution, were precisely introduced into the vast majority of the transformants. Moreover, we showed that simultaneous editing of two genomic loci could also be readily achieved by one step. In summary, our data demonstrate that the haloarchaeal CRISPR-Cas system can be harnessed for genome editing in this polyploid archaeon, and highlight the convenience and efficiency of the native CRISPR-based genome editing strategy.展开更多
Nowadays, the soar of photovoltaic performance of perovskite solar cells has set off a fever in the study of metal halide perovskite materials. The excellent optoelectronic properties and defect tolerance feature allo...Nowadays, the soar of photovoltaic performance of perovskite solar cells has set off a fever in the study of metal halide perovskite materials. The excellent optoelectronic properties and defect tolerance feature allow metal halide perovskite to be employed in a wide variety of applications. This article provides a holistic review over the current progress and future prospects of metal halide perovskite materials in representative promising applications, including traditional optoelectronic devices(solar cells, light-emitting diodes, photodetectors, lasers), and cutting-edge technologies in terms of neuromorphic devices(artificial synapses and memristors) and pressure-induced emission. This review highlights the fundamentals, the current progress and the remaining challenges for each application, aiming to provide a comprehensive overview of the development status and a navigation of future research for metal halide perovskite materials and devices.展开更多
The juvenile-to-adult phase change with first flowering as the indicator plays a crucial role in the lifecycle of fruit trees. However, the molecular mechanisms underlying phase change in fruit trees remain largely un...The juvenile-to-adult phase change with first flowering as the indicator plays a crucial role in the lifecycle of fruit trees. However, the molecular mechanisms underlying phase change in fruit trees remain largely unknown. Shikimic acid (ShA) pathway is a main metabolic pathway closely related to the synthesis of hormones and many important secondary metabolites participating in plant phase change. So,whether ShA regulates phase change in plants is worth clarifying. Here, the distinct morphological characteristics and the underlying mechanisms of phase change in jujube (Ziziphus jujuba Mill.), an important fruit tree native to China with nutritious fruit and outstanding tolerance abiotic stresses, were clarified. A combined transcriptome and metabolome analysis found that ShA is positively involved in jujube(Yuhong’×Xing 16’) phase change. The genes in the upstream of ShA synthesis pathway (ZjDAHPS, ZjDHQS and ZjSDH), the contents of ShA and the downstream secondary metabolites like phenols were significantly upregulated in the phase change period. Further, the treatment of spraying exogenous ShA verified that ShA at a very low concentration (60 mg·L^(-1)) can substantially speed up the phase change and flowering of jujube and other tested plants including Arabidopsis, tomato and wheat. The exogenous ShA (60 mg·L^(-1)) treatment in jujube seedlings could increase the accumulation of endogenous ShA, enhance leaf photosynthesis and the synthesis of phenols especially flavonoids and phenolic acids, and promote the expression of genes (ZjCOs, ZjNFYs and ZjPHYs) involved in flowering pathway. Basing on above results, we put forward a propose for the underlying mechanism of ShA regulating phase change, and a hypothesis that ShA could be considered a phytohormone-like substance because it is endogenous, ubiquitous, movable and highly efficient at very low concentrations. This study highlights the critical role of ShA in plant phase change and its phytohormone-like properties.展开更多
Space deployable structures with large calibers, high accuracy, and large folding ratios are indispensable equipment in the aerospace field. Given that the single-DOF 3 RR-3 RRR deployable unit cannot be fully folded,...Space deployable structures with large calibers, high accuracy, and large folding ratios are indispensable equipment in the aerospace field. Given that the single-DOF 3 RR-3 RRR deployable unit cannot be fully folded, this study proposes a 3 UU-3 URU deployable unit with two kinds of DOF: folding movement and orientation adjustment. First, based on the G-K formula, the DOF of the 3 UU-3 URU unit is analyzed. Then, the 3 UU-3 URU unit is used to construct a deployable truss antenna with a curved surface, and the DOF of the whole deployable antenna containing multiple 3 UU-3 URU units is calculated. The structural design of a deployable antenna with two loops is carried out with specific parameters and geometric relations. Next, a DOF simulation of a basic combination unit composed of three 3 UU-3 URU units is performed. Finally, a prototype of the basic combination unit is manufactured, and the DOF of the mechanism is experimentally verified.展开更多
Titanium dioxide nanoparticles(TiO_2 NPs) are one of the most widely used nanomaterials in the consumer products, agriculture, and energy sectors. Their large demand and widespread applications will inevitably cause d...Titanium dioxide nanoparticles(TiO_2 NPs) are one of the most widely used nanomaterials in the consumer products, agriculture, and energy sectors. Their large demand and widespread applications will inevitably cause damage to organisms and ecosystems. A better understanding of TiO_2 NP toxicity in living organisms may promote risk assessment and safe use practices of these nanomaterials. This review summarizes the toxic effects of TiO_2 NPs on multiple taxa of microorganisms, algae, plants, invertebrates, and vertebrates. The mechanism of TiO_2 NP toxicity to organisms can be outlined in three aspects: The Reactive Oxygen Species(ROS)produced by TiO_2 NPs following the induction of electron–hole pairs; cell wall damage and lipid peroxidation of the cell membrane caused by NP-cell attachment by electrostatic force owing to the large surface area of TiO_2 NPs; and TiO_2 NP attachment to intracellular organelles and biological macromolecules following damage to the cell membranes.展开更多
文摘We previously reported that SM934, a water-soluble artemisinin derivative, was a viable treatment in murine lupus models. In the current study, we further investigated the therapeutic effects of a modified dosage regimen of SM934 on lupus-prone MRIJIpr mice and explored its effects on B cell responses, a central pathogenic event in systemic lupus erythematosus （SLE）. When orally administered twice-daily, SM934 significantly prolonged the life-span of MRL/Ipr mice, ameliorated the lymphadenopathy symptoms and decreased the levels of serum anti-nuclear antibodies （ANAs） and of the pathogenic cytokines IL-6, IL-10 and I L-21. Furthermore, SM934 treatment restored the B-cell compartment in the spleen of MRL/Ipr mice by increasing quiescent B cell numbers, maintaining germinal center B-cell numbers, decreasing activated B cell numbers and reducing plasma cell （PC） numbers. Ex vivo, SM934 suppressed the Toll-like receptor （TLR）-triggered activation and proliferation of B cells, as well as antibody secretion. Moreover, the present study demonstrated that SM934 interfered with the B-cell intrinsic pathway by downregulating TLR7/9 mRNA expression, MyD88 protein expression and NF-KB phosphorylation. In human peripheral blood mononuclear cells （PBMCs）, consistent with the results in MRIJIprmice, SM934 inhibited TLR-associated B-cell activation and PC differentiation. In conclusion, a twice daily dosing regimen of SM934 had therapeutic effects on lupus-prone MRL/Iprmice by suppressing B cell activation and plasma cell formation.
基金grants from the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences (No.2017-I2M-B&R-03 and No.2016-I2M-1-019)。
文摘Cervical cancer is one of the leading causes of cancer death among females worldwide and its behavior epidemiologically likes a venereal disease of low infectiousness. Early age at first intercourse and multiple sexual partners have been shown to exert strong effects on risk. The wide differences in the incidence among different countries also influenced by the introduction of screening. Although the general picture remains one of decreasing incidence and mortality, there are signs of an increasing cervical cancer risk probably due to changes in sexual behavior. Smoking and human papillomavirus(HPV) 16/18 are currently important issues in a concept of multifactorial, stepwise carcinogenesis at the cervix uteri. Therefore, society-based preventive and control measures, screening activities and HPV vaccination are recommended. Cervical cancer screening methods have evolved from cell morphology observation to molecular testing. High-risk HPV genotyping and liquid-based cytology are common methods which have been widely recommended and used worldwide. In future, accurate,cheap, fast and easy-to-use methods would be more popular. Artificial intelligence also shows to be promising in cervical cancer screening by integrating image recognition with big data technology. Meanwhile, China has achieved numerous breakthroughs in cervical cancer prevention and control which could be a great demonstration for other developing and resource-limited areas. In conclusion, although cervical cancer threatens female health, it could be the first cancer that would be eliminated by human beings with comprehensive preventive and control strategy.
文摘A detailed understanding of genetic architecture of mRNA expression by millions of genetic variants is important for studying quantitative trait variation. In this study, we identified 1.25M SNPs with a minor allele frequency greater than 0.05 by combining reduced genome sequencing （GBS）, high- density array technologies （600K）, and previous deep RNA-sequencing data from 368 diverse inbred lines of maize. The balanced allelic frequencies and distributions in a relatively large and diverse natural panel helped to identify expression quantitative trait loci （eQTLs） associated with more than 18 000 genes （63.4% of tested genes）. We found that distant eQTLs were more frequent （~75% of all eQTLs） across the whole genome. Thirteen novel associated loci affecting maize kernel oil concentration were identified using the new dataset, among which one intergenic locus affected the kernel oil variation by controlling expression of three other known oil-related genes. Altogether, this study provides resources for expanding our understanding of cellular regulatory mechanisms of transcriptome variation and the landscape of functional variants within the maize genome, thereby enhancing the understanding of quantitative variations.
基金supported in part by the National Natural Science Foundation of China(61772141,61673123)Guangdong Provincial Science&Technology Project(2015B090901016,2016B010108007)+1 种基金Guangdong Education Department Project(Guangdong Higher Education letter 2015[133])the Guangzhou Science&Technology Project(201508010067,201604020145201604046017,and 2016201604030034)
文摘As a primary defense technique, intrusion detection becomes more and more significant since the security of the networks is one of the most critical issues in the world. We present an adaptive collaboration intrusion detection method to improve the safety of a network. A self-adaptive and collaborative intrusion detection model is built by applying the Environmentsclasses, agents, roles, groups, and objects(E-CARGO) model. The objects, roles, agents, and groups are designed by using decision trees(DTs) and support vector machines(SVMs), and adaptive scheduling mechanisms are set up. The KDD CUP 1999 data set is used to verify the effectiveness of the method. The experimental results demonstrate the feasibility and efficiency of the proposed collaborative and adaptive intrusion detection method. Also, the proposed method is shown to be more predominant than the methods that use a set of single type support vector machine(SVM) in terms of detection precision rate and recall rate.
基金funded by Innovent biologics,Inc.Eli Lilly and Companypartly supported by China National Major Project for New Drug Innovation(2017ZX09304015).
文摘Background:Treatment options for Chinese patients with locally advanced or metastatic squamous-cell non-small-cell lung cancer(sqNSCLC)after failure of first-line chemotherapy are limited.This study(ORIENT-3)aimed to evaluate the efficacy and safety of sintilimab versus docetaxel as second-line treatment in patients with locally advanced or metastatic sqNSCLC.Methods:ORIENT-3 was an open-label,multicenter,randomized controlled phase 3 trial that recruited patients with stage IIIB/IIIC/IV sqNSCLC after failure with first-line platinum-based chemotherapy.Patients were randomized in a 1:1 ratio to receive either 200 mg of sintilimab or 75 mg/m^(2) of docetaxel intravenously every 3 weeks,stratified by the Eastern Cooperative Oncology Group performance status.The primary endpoint was overall survival(OS)in the full analysis set(FAS).Secondary endpoints included progression-free survival(PFS),objective response rate(ORR),disease control rate(DCR),duration of response(DoR)and safety.Results:Between August 25,2017,and November 7,2018,290 patients were randomized.For FAS,10 patients fromthe docetaxel armwere excluded.Themedian OS was 11.79(n=145;95%confidence interval[CI],10.28-15.57)months with sintilimab versus 8.25(n=135;95%CI,6.47-9.82)months with docetaxel(hazard ratio[HR]:0.74;95%CI,0.56-0.96;P=0.025).Sintilimab treatment significantly prolonged PFS(median 4.30 vs.2.79 months;HR:0.52;95%CI,0.39-0.68;P<0.001)and showed higher ORR(25.50%vs.2.20%,P<0.001)and DCR(65.50%vs.37.80%,P<0.001)than the docetaxel arm.The median DoRwas 12.45(95%CI,4.86-25.33)months in the sintilimab arm and 4.14(95%CI,1.41-7.23)months in the docetaxel arm(P=0.045).Treatment-related adverse events of grade≥3were reported in 26(18.1%)patients in the sintilimab arm and 47(36.2%)patients in the docetaxel arm.Exploratory biomarker analysis showed potential predictive values of expression levels of two transcription factors,including OVOL2(HR:0.35;P<0.001)and CTCF(HR:3.50;P<0.001),for sintilimab treatment.Conclusions:Compared with docetaxel,sintili
基金the National Natural Science Foundation of China(Grants 51876063 and 51576065)the Science and Technology Project of Huaneng Group(Grant HNKJ18-H33)on research and demonstration application of onshore wind energy efficiency improvement technology.
文摘Horizontal axis wind turbine(HAWT)often works under yaw due to the stochastic variation of wind direction.Yaw also can be used as one of control methods for load reduction and wake redirection of HAWT.Thus,the aerodynamic performance under yaw is very important to the design of HAWT.For further insight into the highly unsteady characteristics aerodynamics of HAWT under yaw,this paper investigates the unsteady variations of the aerodynamic performance of a small wind turbine under static yawed and yawing process with sliding grid method,as well as the there-dimensional effect on the unsteady characteristics,using unsteady Reynolds-averaged Navier-Stokes(URANS)simulations.The simulation results are validated with experimental data and blade element momentum(BEM)results.The comparisons show that the CFD results have better agreement with the experimental data than both BEM results.The wind turbine power decreases according to a cosine law with the increase of yaw angle.The torque under yaw shows lower frequency fluctuations than the non-yawed condition due to velocity component of rotation and the influence of spinner.Dynamic yawing causes larger fluctuate than static yaw,and the reason is analyzed.The aerodynamic fluctuation becomes more prominent in the retreating side than that in the advancing side for dynamic yawing case.Variations of effective angle of attack and aerodynamic forces along the blade span are analyzed.The biggest loading position moves from middle span to outer span with the increase of yaw angle.Three-dimensional stall effect presents load fluctuations at the inner board of blade,and becomes stronger with the increase of yaw angle.
基金supported by the National Natural Science Foundation of China(21876069,21707054)the Six Talent Peaks Project in Jiangsu(XCL-018)the China Postdoctoral Science Foundation(2016M601744)~~
文摘Herein,we report a unique approach towards the preparation of C-modified and N-doped TiO2 hollow spheres(C/N-TiO2).TEM,SEM,and XPS analyses were used to confirm that the carbon and nitrogen co-decorated TiO2 photocatalyst was formed.Carbon-decoration improves the visible-light absorption and speeds up the separation of the photo-generated electron-hole pairs.C/N-TiO2 not only narrows the band gap of TiO2,but also exhibits excellent photocatalytic activity for the degradation of tetracycline and tetracycline hydrochloride.In addition,the C/N-TiO2 photocatalyst shows excellent recyclability for water decontamination,making it a promising candidate to purify aquatic contaminants.
基金supported by the National Key Research and Development Program of China(2016YFD0500301,2020YFC0840900,and 2020YFC0842200)the National Natural Science Foundation of China(82041041,82061138008)+1 种基金Shanghai Pujiang Talent Program(2020PJD068,to A.L.)internal funds from Stemirna Therapeutics.
文摘Although inoculation of COVID-19 vaccines has rolled out globally,there is still a critical need for safe and effective vaccines to ensure fair and equitable supply for all countries.Here,we report on the development of a highly efficacious mRNA vaccine,SW0123 that is composed of sequence-modified mRNA encoding the full-length SARS-CoV-2 Spike protein packaged in core-shell structured lipopolyplex(LPP)nanoparticles.SWOT 23 is easy to produce using a large-scale microfluidics-based apparatus.The unique core-shell structured nanoparticle facilitates vaccine uptake and demonstrates a high colloidal stability,and a desirable biodistribution pattern with low liver targeting effect upon intramuscular administration.Extensive evaluations in mice and nonhuman primates revealed strong immunogenicity of SW0123,represented by induction of Th1-polarized T cell responses and high levels of antibodies that were capable of neutralizing not only the wild-type SARS-CoV-2,but also a panel of variants including D614G and N501Y variants.In addition,SW0123 conferred effective protection in both mice and non-human primates upon SARS-CoV-2 challenge.Taken together,SW0123 is a promising vaccine candidate that holds prospects for further evaluation in humans.
基金financially supported by the National Natural Science Foundation of China (No.51504084)the Education Department of Fujian Province (No.JA15493)
文摘To research techniques for removing the water blocking effect caused by hydraulic applications in coal seams,the use of surfactants is proposed,based on the mechanics of the water blocking effect.Centrifugal experiments were used to validate the effects of using surfactants;the results show that after dealing with vacuum saturation with water,the volume of micropores decreases,which results in a larger average pore size,and the volume of transitional pores,mesopores,macropores and total pores increases.Based on the distribution of pore size,the operation mode of ‘‘water infusion after gas extraction,then continuing gas extraction" is recommended to improve the volume of coal mine gas drainage.When the reflectance of vitrinite in coal samples is less than 1,using the surfactants Fast T,1631,APG,BS can mitigate the damage caused by the water blocking effect.But when the reflectance of vitrinite is larger than 1.4,the damage caused by the water blocking effect can be increased.When the surfactant CMC is used in hydraulic applications,the capillary forces of coal samples are almost negative,which means the capillary force is in the same direction as the gas extraction.The direction of capillary forces benefits the gas flow.So,using CMC can play an active role in removing the water blocking effect.Centrifugal experiments confirm that using CMC can effectively remove the water blocking effect,which has a beneficial effect on improving the gas drainage volume.
基金supported by the National Natural Science Foundation of Henan Joint Fund(U1604101 to XLH)the Key R&D and Promotion Projects of Henan Province(192102110009 to XLH,192102110004 to HY)。
文摘Global warming poses a serious threat to crops.Calcium-dependent protein kinases(CDPKs)/CPKs play vital roles in plant stress responses,but their exact roles in plant thermotolerance remains elusive.Here,we explored the roles of heat-induced ZmCDPK7 in thermotolerance in maize.ZmCDPK7-overexpressing maize plants displayed higher thermotolerance,photosynthetic rates,and antioxidant enzyme activity but lower H2 O2 and malondialdehyde(MDA)contents than wild-type plants under heat stress.ZmCDPK7-knockdown plants displayed the opposite patterns.ZmCDPK7 is attached to the plasma membrane but can translocate to the cytosol under heat stress.ZmCDPK7 interacts with the small heat shock protein sHSP17.4,phosphorylates sHSP17.4 at Ser-44 and the respiratory burst oxidase homolog RBOHB at Ser-99,and up regulates their expression.Site-directed mutagenesis of sHSP17.4 to generate a Ser-44-Ala substitution reduced ZmCDPK7’s enhancement of catalase activity but enhanced ZmCDPK7’s suppression of MDA accumulation in heat-stressed maize protoplasts.sHSP17.4,ZmCDPK7,and RBOHB were less strongly upregulated in response to heat stress in the abscisic acid-deficient mutant vp5 versus the wild type.Pretreatment with an RBOH inhibitor suppressed sHSP17.4 and ZmCDPK7 expression.Therefore,abscisic acid-induced ZmCDPK7 functions both upstream and downstream of RBOH and participates in thermotolerance in maize by mediating the phosphorylation of sHSP17.4,which might be essential for its chaperone function.
基金supported by the National Natural Science Foundation of China(No.82001106,81970918,81901043).
文摘Dental caries is one of the most prevalent human diseases resulting from tooth demineralization caused by acid production of bacteria plaque.It remains challenges for current practice to specifically identify,intervene and interrupt the development of caries while restoring defects.In this study,inspired by natural dental plaque,a stimuli-responsive multidrug delivery system(PMs@NaF-SAP)has been developed to prevent tooth decay and promote enamel restoration.Classic spherical core-shell structures of micelles dual-loaded with antibacterial and restorative agents are self-assembled into bacteria-responsive multidrug delivery system based on the pH-cleavable boronate ester bond,followed by conjugation with salivary-acquired peptide(SAP)to endow the nanoparticle with strong adhesion to tooth enamel.The constructed PMs@NaF-SAP specifically adheres to tooth,identifies cariogenic conditions and intelligently releases drugs at acidic pH,thereby providing antibacterial adhesion and cariogenic biofilm resistance,and restoring the microarchitecture and mechanical properties of demineralized teeth.Topical treatment with PMs@NaF-SAP effectively diminishes the onset and severity of caries without impacting oral microbiota diversity or surrounding mucosal tissues.These findings demonstrate this novel nanotherapy has potential as a promising biomedical application for caries prevention and tooth defect restoration while resisting biofilm-associated diseases in a controlled manner activated by pathological bacteria.
文摘Objective: Hyperlipidemia is a representative nutritional metabolic disease in clinic, which is easy to induce atherosclerotic cardiovascular and cerebrovascular diseases, with complex classification. Traditional Chinese Medicine (TCM) syndrome aims to reflect the characteristics of diseases and is the basic principle of TCM treatment of diseases. This study aimed to summarize the distribution pattern of TCM syndromes in patients with hyperlipidemia. Methods: The frequency, characteristics and distribution of all TCM syndromes of 1012 patients with hyperlipidemia were analyzed. Results: The main disease types determined by frequency of 1012 patients included hypertriglyceridemia combined with hypo high-density lipoprotein cholesterolemia (19.76%), hypo high-density lipoprotein cholesterolemia (18.58%), hypercholesterolemia (16.50%), mixed hyperlipidemia (16.40%), and hypertriglyceridemia (15.12%). The distribution of TCM syndromes, in order of frequency, was as follows: Qi-deficiency and blood stasis syndrome (23.52%), liver depression and spleen deficiency (9.88%), syndrome of qi stagnation and blood stasis (9.29%), phlegm stasis syndrome (7.41%), and syndrome of yang deficiency of spleen and kidney (6.92%). Conclusion: Qi-deficiency and blood stasis syndrome and liver depression and spleen deficiency are the most common TCM syndromes in patients with hyperlipidemia.
基金Funded by the National Natural Science Foundation of China (Nos.51772033, 52002040)the National Key Research and Development Program of China (No. 2023YFB3711400)。
文摘The purpose of this research is to investigate the hydration behavior and cementitious properties of the mixture of calcium carbonate and aluminate, and to explore whether it can be adopted as a new low-carbon cementitious material. The composite system of calcium carbonate and aluminate minerals is studied by measuring the component of hydration products, the hydration heat, setting time and compressive strength.The results prove that the composite system has certain cementitious properties and is feasible to prepare new low-carbon cement.
基金The authors would like to acknowledge Professor Jiankang Zhu and his lab at the Shanghai Center for Plant Stress Biology,Chinese Center for Plant Stress Biology,for providing the CRISPR/Cas9 system plasmids.All authors declare no competing financial or nonfinancial interests.This work was funded by the National Natural Science Foundation of China(grant Nos.82225047,32000231,31970316,and 32170274)the National Key Research and Development Program of China(grant no.2022YFC3501703)+1 种基金Shanghai Science and Technology Development Funds(23QA1411400,China)Key project at central government level(The ability establishment of sustainable use for valuable Chinese medicine resources,2060302).
文摘Lignans are a powerful weapon for plants to resist stresses and have diverse bioactive functions to protect human health.Elucidating the mechanisms of stereoselective biosynthesis and response to stresses of lignans is important for the guidance of plant improvement.Here,we identified the complete pathway to stereoselectively synthesize antiviral(-)-lariciresinol glucosides in Isatis indigotica roots,which consists of three-step sequential stereoselective enzymes DIR1/2,PLR,and UGT71B2.DIR1 was further identified as the key gene in respoJanuary 2024nse to stresses and was able to trigger stress defenses by mediating the elevation in lignan content.Mechanistically,the phytohormone-responsive ERF transcription factor LTF1 colocalized with DIR1 in the cell periphery of the vascular regions in mature roots and helped resist biotic and abiotic stresses by directly regulating the expression of DIR1.These systematic results suggest that DIR1 as the first common step of the lignan pathway cooperates with PLR and UGT71B2 to stereoselectively synthesize(-)-lariciresinol derived antiviral lignans in I.indigotica roots and is also a part of the LTF1-mediated regulatory network to resist stresses.In conclusion,the LTF1-DIR1 module is an ideal engineering target to improve plant Defenses while increasing the content of valuable lignans in plants.
基金supported by the National Natural Science Foundation of China(Nos.42205100 and 41805095)the Sichuan Science and Technology Program(Nos.2019YFS0476and 2022NSFSC0982)support from the Sichuan comprehensive monitoring station for environmental air quality。
文摘The air quality in China has improved significantly in the last decade and,correspondingly,the characteristics of PM_(2.5)have also changed.We studied the interannual variation of PM_(2.5)in Chengdu,one of the most heavily polluted megacities in southwest China,during the most polluted season(winter).Our results show that the mass concentrations of PM_(2.5)decreased significantly year-by-year,from 195.8±91.0μg/m~3in winter 2016 to 96.1±39.3μg/m^(3)in winter 2020.The mass concentrations of organic matter(OM),SO_()4^(2-),NH_(4)^(+)and NO_(3)^(-)decreased by 49.6%,57.1%,49.7% and 28.7%,respectively.The differential reduction in the concentrations of chemical components increased the contributions from secondary organic carbon and NO_(3)^(-)and there was a larger contribution from mobile sources.The contribution of OM and NO_(3)^(-)not only increased with increasing levels of pollution,but also increased year-by-year at the same level of pollution.Four sources of PM_(2.5)were identified:combustion sources,vehicular emissions,dust and secondary aerosols.Secondary aerosols made the highest contribution and increased year-by-year,from 40.6%in winter 2016 to 46.3% in winter 2020.By contrast,the contribution from combustion sources decreased from 14.4% to 8.7%.Our results show the effectiveness of earlier pollution reduction policies and emphasizes that priority should be given to key pollutants(e.g.,OM and NO_(3)^(-))and sources(secondary aerosols and vehicular emissions)in future policies for the reduction of pollution in Chengdu during the winter months.
基金supported by the grants from the National Natural Science Foundation of China(No.31571283)the CASSAFEA International Partnership Program for Creative Research Teams
文摘Research on CRISPR-Cas（clustered regularly interspaced short palindromic repeats-CRISPR associated protein） systems has led to the revolutionary CRISPR/Cas9 genome editing technique. However, for most archaea and half of bacteria, exploitation of their native CRISPR-Cas machineries may be more straightforward and convenient. In this study, we harnessed the native type I-B CRISPR-Cas system for precise genome editing in the polyploid haloarchaeon Haloarcula hispanica. After testing different designs, the editing tool was optimized to be a single plasmid that carries both the self-targeting miniCRISPR and a 600-800 bp donor. Significantly, chromosomal modifications, such as gene deletion, gene tagging or single nucleotide substitution, were precisely introduced into the vast majority of the transformants. Moreover, we showed that simultaneous editing of two genomic loci could also be readily achieved by one step. In summary, our data demonstrate that the haloarchaeal CRISPR-Cas system can be harnessed for genome editing in this polyploid archaeon, and highlight the convenience and efficiency of the native CRISPR-based genome editing strategy.
基金the National Key Research and Development Program of China (2022YFB3803300)the open research fund of Songshan Lake Materials Laboratory (2021SLABFK02)the National Natural Science Foundation of China (21961160720)。
文摘Nowadays, the soar of photovoltaic performance of perovskite solar cells has set off a fever in the study of metal halide perovskite materials. The excellent optoelectronic properties and defect tolerance feature allow metal halide perovskite to be employed in a wide variety of applications. This article provides a holistic review over the current progress and future prospects of metal halide perovskite materials in representative promising applications, including traditional optoelectronic devices(solar cells, light-emitting diodes, photodetectors, lasers), and cutting-edge technologies in terms of neuromorphic devices(artificial synapses and memristors) and pressure-induced emission. This review highlights the fundamentals, the current progress and the remaining challenges for each application, aiming to provide a comprehensive overview of the development status and a navigation of future research for metal halide perovskite materials and devices.
基金partially supported by the National Natural Science Foundation of China (Grant No.31772285)the National Key R&D Program Project Funding (Grant No.2018YFD1000607)Foundation for 100 Innovative Talents of Hebei Province(Grant No.SLRC2019031)。
文摘The juvenile-to-adult phase change with first flowering as the indicator plays a crucial role in the lifecycle of fruit trees. However, the molecular mechanisms underlying phase change in fruit trees remain largely unknown. Shikimic acid (ShA) pathway is a main metabolic pathway closely related to the synthesis of hormones and many important secondary metabolites participating in plant phase change. So,whether ShA regulates phase change in plants is worth clarifying. Here, the distinct morphological characteristics and the underlying mechanisms of phase change in jujube (Ziziphus jujuba Mill.), an important fruit tree native to China with nutritious fruit and outstanding tolerance abiotic stresses, were clarified. A combined transcriptome and metabolome analysis found that ShA is positively involved in jujube(Yuhong’×Xing 16’) phase change. The genes in the upstream of ShA synthesis pathway (ZjDAHPS, ZjDHQS and ZjSDH), the contents of ShA and the downstream secondary metabolites like phenols were significantly upregulated in the phase change period. Further, the treatment of spraying exogenous ShA verified that ShA at a very low concentration (60 mg·L^(-1)) can substantially speed up the phase change and flowering of jujube and other tested plants including Arabidopsis, tomato and wheat. The exogenous ShA (60 mg·L^(-1)) treatment in jujube seedlings could increase the accumulation of endogenous ShA, enhance leaf photosynthesis and the synthesis of phenols especially flavonoids and phenolic acids, and promote the expression of genes (ZjCOs, ZjNFYs and ZjPHYs) involved in flowering pathway. Basing on above results, we put forward a propose for the underlying mechanism of ShA regulating phase change, and a hypothesis that ShA could be considered a phytohormone-like substance because it is endogenous, ubiquitous, movable and highly efficient at very low concentrations. This study highlights the critical role of ShA in plant phase change and its phytohormone-like properties.
基金co-supported by the National Natural Science Foundation of China (No. 51675458)the Key Project of Natural Science Foundation of Hebei Province of China (No. E2017203335)the Youth Top Talent Project of Hebei Province Higher Education of China (No. BJ2017060)
文摘Space deployable structures with large calibers, high accuracy, and large folding ratios are indispensable equipment in the aerospace field. Given that the single-DOF 3 RR-3 RRR deployable unit cannot be fully folded, this study proposes a 3 UU-3 URU deployable unit with two kinds of DOF: folding movement and orientation adjustment. First, based on the G-K formula, the DOF of the 3 UU-3 URU unit is analyzed. Then, the 3 UU-3 URU unit is used to construct a deployable truss antenna with a curved surface, and the DOF of the whole deployable antenna containing multiple 3 UU-3 URU units is calculated. The structural design of a deployable antenna with two loops is carried out with specific parameters and geometric relations. Next, a DOF simulation of a basic combination unit composed of three 3 UU-3 URU units is performed. Finally, a prototype of the basic combination unit is manufactured, and the DOF of the mechanism is experimentally verified.
基金supported by the National Natural Science Foundation of China (Nos.21607043,21577032)the Youth Innovation Promotion Association,Chinese Academy of Sciences (No.2018054)+1 种基金the Fundamental Research Funds for the Central Universities (Nos.2016ZZD06,2018ZD11)the Open Project of Key Laboratory of Environmental Biotechnology,CAS (No.kf2016009)
文摘Titanium dioxide nanoparticles(TiO_2 NPs) are one of the most widely used nanomaterials in the consumer products, agriculture, and energy sectors. Their large demand and widespread applications will inevitably cause damage to organisms and ecosystems. A better understanding of TiO_2 NP toxicity in living organisms may promote risk assessment and safe use practices of these nanomaterials. This review summarizes the toxic effects of TiO_2 NPs on multiple taxa of microorganisms, algae, plants, invertebrates, and vertebrates. The mechanism of TiO_2 NP toxicity to organisms can be outlined in three aspects: The Reactive Oxygen Species(ROS)produced by TiO_2 NPs following the induction of electron–hole pairs; cell wall damage and lipid peroxidation of the cell membrane caused by NP-cell attachment by electrostatic force owing to the large surface area of TiO_2 NPs; and TiO_2 NP attachment to intracellular organelles and biological macromolecules following damage to the cell membranes.
