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Abstract To analyze the quantitative mapping relationship between the geometric errors of the five-axis CNC machine tool and the tooth surface deviation of spiral bevel gears, and identify the key geometric errors that affect the machining deviation of the spiral bevel gear tooth surface, a sensitivity analysis method for tooth surface machining deviation of spiral bevel gear based on screw theory and EFAST method is proposed. Firstly, the machining model of the spiral bevel gear tooth surface based on the five-axis CNC machine tool is established. Then, the geometric error transfer model of the machine tool is established based on the screw theory. Combined with the EFAST global sensitivity analysis method, the key geometric errors that affect tooth surface deviation are identified. Finally, the reliability and effectiveness tests are performed by comparing the results to the local sensitivity analysis method and simulating compensation for the key geometric errors. The result of compensation shows that the tooth surface deviation is reduced significantly according to global sensitivity analysis. The feasibility of applying sensitivity analysis to control the tooth surface deviation of spiral bevel gears has been demonstrated.

In the production process of electronic grade ultrapure water, trace H2O2 is mainly compounded by hydroxyl radicals generated by vacuum UV degradation devices, which can corrode certain specific processes of semiconductor materials surface cleaning. The application of multiphase nanocatalysation technology in advanced process semiconductor ultrapure water preparation system can effectively remove the micropollution H2O2 produced by vacuum ultraviolet irradiation, which is a green cleaning technology to promote the rapid dissociation of active oxygen species containing O—O bonds. The generation of micropollution H2O2 and its influence on the cleaning process of semiconductor materials were briefly discussed. The reaction pathway and mechanism of platinum series metal nanoparticles in group Ⅷ transition elements to catalyze H2O2 dissociation were analyzed. The effects of metal surface adsorption configuration, adsorption energy, electronic structure, carrier chemical properties, halogen anions in water and other factors on the enhanced removal characteristics of nanoparticles were also discussed. The application and research progress of group Ⅷ transition metals in ultrapure water production, detection and semiconductor assisted process systems were reviewed. The research provided reference for the construction of a new reaction system in ultrapure water process and the development and application of water treatment materials.

The recommended amino acid requirements of the infant are based on the amino acid composition of mature human breast milk. The amino acid composition of breast milk is usually determined following either acid or alkaline (for tryptophan) hydrolysis. For accuracy, however, the known effect of hydrolysis time on amino acid composition should be accounted for. Also, ideally the amino acid composition of breast milk should be given in units of digested (assumed to be absorbed) amino acids. A review of the literature is presented which gives mean total amino acid concentrations in mature human milk (n = 26 studies), mean hydrolysis correction factors (n = 3 studies) and mean true ileal amino acid digestibility coefficients (n = 3 studies, suckling piglet). There were differences between the estimates of amino acid concentration corrected for hydrolysis time and digestibility, and current FAO (2013) recommendations that were not corrected for these factors. The values based on the published literature up until 2023 (mg/g true protein) corrected for hydrolysis time and digestibility gave higher values (more than 16% higher) for leucine, lysine and threonine, and considerably higher values (greater than 30%) for histidine and tryptophan. Current recommendations may need revision.

The objective of the review is to revisit the findings of the 2011 Food and Agriculture Organization of the United Nations (FAO) Expert Consultation on Dietary Protein Quality Evaluation in Human Nutrition, and to report on progress on uptake of the findings. It is evident that since 2011 there has been a concerted research effort to enhance an understanding of the protein quality of foods. The validity of the growing pig ileal protein digestibility assay has been confirmed and numerous studies reported using the growing pig as a model to give true ileal amino acid digestibility values for foods as consumed by humans. This has allowed for the determination of digestible indispensable amino acid scores (DIAAS) for a range of foods. A new non-invasive true ileal amino acid digestibility assay in humans which can be applied in different physiological states, called the dual-isotope assay, has been developed and applied to determine the DIAAS values of foods. It is concluded that DIAAS is currently the most accurate score for routinely assessing the protein quality rating of single source proteins. In the future, the accuracy of DIAAS can be enhanced by improved information on: the ideal dietary amino acid balance including the ideal dispensable to indispensable amino acid ratio; dietary indispensable amino acid requirements; effects of processing on ileal amino acid digestibility and lysine bioavailability. There is a need to develop rapid, inexpensive in vitro digestibility assays. Conceptual issues relating DIAAS to food regulatory claims, and to holistic indices of food nutritional and health status are discussed. The first recommendation of the 2011 Consultation regarding treating each indispensable amino acid as an individual nutrient has received little attention. Consideration should be given to providing food label information on the digestible contents of specific indispensable amino acids.

Abstract A two-stage computational framework is proposed to optimize the radiated noise and weight of a large mining planetary gear reducer under the rated conditions, based on a combination of response surface methodology and multi-objective optimization. The well-established transient dynamic analysis model of a large mining planetary gear reducer, which is used to analyze the mechanical strength and acoustic characteristics of the gear reducer. A unified experimental design is developed to obtain the response surface of the gearbox radiated noise and the mass of the gearbox housing. After obtaining the multi-objective optimization function, the multi-objective optimization problem for a lightweight and low-noise gearbox is performed using non-dominated sorting from the Genetic Algorithm II (NSGA-II). The research results demonstrates the effectiveness of the proposed optimization method in reducing vibrating amplitude and weight of the gearbox. This is crucial for minimizing energy consumption and enhancing the overall performance of the system. Additionally, the optimized gearbox design not only saves energy but also contributes to the reduction of carbon emissions, making it environmentally friendly.

Abstract Background Mechanical ventilation is an essential means of life support for patients with severe burns. However, prolonged mechanical ventilation (PMV) increases the incidence of complications and length of hospital stay. Therefore, studying the risk factors of mechanical ventilation duration is of great significance for reducing the duration of mechanical ventilation, reducing related complications, and improving the success rate of severe burn treatment. Method This study was a retrospective study of patients with burns ≥30% of the area admitted to the BICU of Guangzhou Red Cross Hospital affiliated with Jinan University from January 2016 to January 2023 who were mechanically ventilated. Patients were classified into the prolonged mechanical ventilation group if they were mechanically ventilated for ≥21 days. Then, independent risk factors for prolonged mechanical ventilation were determined by logistic regression analysis of the collected data. Result Of all the 112 enrolled patients, 79 had prolonged mechanical ventilation, with an incidence of 70.5%. Logistic regression analysis revealed that including abbreviated burn severity index (ABSI%) (P

Given the deformation issues in machining segmented equal-base bevel gears, this paper investigates the variations of additional stress during the machining process, considering the gear blank material, residual internal stress, and gear blank design. A model for calculating internal additional stress and torque during gear machining has been developed. The calculation formula for the bending deformation of the gear blank has been derived using the torque–area method. By analyzing the time-varying stiffness of the blank, a calculation model for the bending deformation of the gear blank has been constructed, and the projection analysis of gear stock deformation has been completed. Based on the cumulative superposition effect of its deformation projection, a calculation model for the overall deformation of the segmented gear blank has been formulated. The deformation calculation model has been validated through finite element simulation, deformation calculation, actual machining, and measurement verification.

Mangroves, which have extremely high primary productivity, are efficient coastal blue carbon ecosystems. Aboveground biomass (AGB) is an important component of vegetation carbon pools. Thus, accurate estimation of mangrove AGB is critical for studying carbon cycle and climate change. While the practical significance and application of information obtained on mangrove AGB in China is apparent, studies of this nature in China at a national scale have rarely been reported. Remote sensing technology is convenient, efficient, has a wide observational range, and can be used for large-scale ecosystem monitoring. Canopy height is a structural parameter that is positively correlated with the AGB of vegetation. The Global Ecosystem Dynamics Investigation (GEDI) spaceborne Light Detection and Ranging (LiDAR) satellite, launched in recent years, is able to obtain vegetation canopy height. This study employed forest canopy height derived from GEDI satellite-based LiDAR and an allometric equation based on the allometric theory to estimate mangrove AGB in China in 2019, and the quantitative and spatial distribution of mangrove biomass and their main influencing factors were analyzed. The results showed that the total and mean AGB of mangroves in China in 2019 were about 1,974,827 t and 73.0 t/hm2, respectively. Guangdong-Hong Kong-Macao area showed the largest total mangrove AGB, reaching 843,836 t. The mean values of AGB in each province (region) with mangrove ecosystems nationwide ranged from 53.3 to 92.1 t/hm2, of which the largest was found in Hainan Province, reaching 92.1 t/hm2. In Hainan, Taiwan, and Fujian provinces, mean mangrove AGB was higher than the national mean. Considering nature reserves, the mean AGBs of mangroves in Neilingdingdao-Futian and Mai Po mangrove nature reserves in Shenzhen Bay in the Guangdong-Hong Kong-Macao area and Dongzhaigang mangrove nature reserve in Hainan province were relatively high, with values greater than 110 t/hm2. The accumulation and distribution of mangrove AGB in China are affected by latitude and anthropogenic factors. This study provides a comprehensive analysis of mangrove AGB in China based on remote sensing and an allometric equation and can provide a database and technical reference for estimating carbon storage in mangrove ecosystems. It will also contribute to the implementation of ecological restoration and protection measures for coastal mangroves, as well as carbon emission control in China.

In order to research the sulfur fixation performance of steel slag in the coal-fired sulfur fixation process, the effect of single parameters such as calcium-sulfur ratio, air flow rate, furnace temperature, and furnace residence time on the sulfur fixation efficiency was studied. In addition, orthogonal experiments were constructed to assess the effect of each variable on the main and secondary order of sulfur fixation efficiency, and the ideal experiment design was identified. Utilizing XRF, the slagging features of the ash and the sulfur-fixing effect of the steel slag were analyzed.XRD was utilized to characterize the diffraction peaks of steel slag and sulfur fixation slag, which indicated the steel slag's capacity to fixate sulfur. SEM was used to describe the microscopic morphology of sulfur fixing ash, and the surface structure and microscopic morphology of steel slag before and after sulfur fixing were compared to evaluate the validity of other characterisation results. The results suggest that the slag has a good sulfur fixation capacity at 900 ℃, with a sulfur fixation efficiency of 63.17%, and that the sulfur fixation efficiency of the slag may reach 70.08% when 2% Na2CO3 is added.

In this study, a two-stage system known as the PV/T-ST system with a series photovoltaic/thermal (PV/T) module and a solar thermal (ST) collector combining thermoelectric conversion technology is proposed. In the daytime, the PV/T module generates power and captures low-temperature heat simultaneously. The ST module achieves secondary heating of water and secondary thermal-electric output by the thermoelectric generators (TEG). In the nighttime, the water heated by day continues to circulate, providing heat for TEG, thus achieving round-the-clock electrical output. Theoretical research reveals that the system’s total electrical power reaches its maximum value at 11:57, measuring 97.43 W. The maximum heat gain amounts to 380.67 W. During the night, TEG operates continuously and experiences a gradual decline in electrical output, with an average electrical efficiency of 0.43%.

ABSTRACT Bradyrhizobium guangxiense CCBAU53363 efficiently nodulates peanut but exhibits incompatible interaction with mung bean. By comparing the common nod region with those of other peanut bradyrhizobia efficiently nodulating these two hosts, distinctive characteristics with a single nodD isoform (nodD1) and a truncated nolA were identified. However, the regulatory roles of NodD1 and NolA and their coordination in legume-bradyrhizobial interactions remain largely unknown in terms of explaining the contrasting symbiotic compatibility. Here, we report that nolA was important for CCBAU53363 symbiosis with peanut but restricted nodulation on mung bean, while nodD1 was dispensable for CCBAU53363 symbiosis with peanut but essential for nodulation on mung bean. Moreover, nolA exerted a cumulative contribution with nodD1 to efficient symbiosis with peanut. Additionally, mutants lacking nolA delayed nodulation on peanut, and both nolA and nodD1 were required for competitive nodule colonization. It is noteworth that most of the nodulation genes and type III secretion system (T3SS)-related genes were significantly downregulated in a strain 53ΔnodD1nolA mutant compared to wild-type strain CCBAU53363, and the downregulated nodulation genes also had a greater impact than T3SS-related genes on the symbiotic defect of 53ΔnodD1nolA on peanut, which was supported by a more severe symbiotic defect induced by 53ΔnodC than that with the 53ΔnodD1nopP, 53ΔnodD1rhcJ, and 53ΔnodD1ttsI mutants. NolA did not regulate nod gene expression but did regulate the T3SS effector gene nopP in an indirect way. Meanwhile, nolA, nodW, and some T3SS-related genes besides nopP were also demonstrated as new “repressors” that seriously impaired CCBAU53363 symbiosis with mung bean. Taken together, the roles and essentiality of nolA and nodD1 in modulating symbiotic compatibility are sophisticated and host dependent. IMPORTANCE The main findings of this study were that we clarified that the roles and essentiality of nodD1 and nolA are host dependent. Importantly, for the first time, NolA was found to positively regulate T3SS effector gene nopP to mediate incompatibility on mung bean. Additionally, NolA does not regulate nod genes, which are activated by NodD1. nolA exerts a cumulative effect with nodD1 on CCBAU53363 symbiosis with peanut. These findings shed new light on our understanding of coordinated regulation of NodD1 and NolA in peanut bradyrhizobia with different hosts.

Objective To summarize the clinical, laboratory, imaging, electrophysiological and histopathological features and therapeutic responses of patients with paranodopathy with positive anti⁃neurofascin 155 (NF155) antibody. Methods and Results Five patients who visited Xuanwu Hospital, Capital Medical University in January 2017 to August 2020 with positive anti⁃NF155 antibody, were men with onset ages 10 to 61 years old. The clinical manifestations were subacute onset, gradual progress, distal limb weakness, numbness, tremor and ataxia. The distal limbs were more severe than the proximal and lower limbs were more severe than the upper. Five patients were positive NF155⁃IgG4. Cerebrospinal fluid protein was significant increased. There were cervical and lumbosacral nerve roots enlargement. The distal latency of compound muscle action potential (CMAP) prolonged, the conduction velocity decreased, and the F⁃wave latency extended. Sural nerve biopsy showed axonal degeneration, the Ranvier node widened, the transverse band disappeared, and the space between the myelin loop and axon increased without inflammatory cell infiltration and "onion bulb" structure. Glucocorticoid therapy and intravenous immunoglobulin (IVIg) were not effective or initially effective, then failed, while rituximab was effective. Conclusions Patients with positive anti⁃NF155 antibody paranodopathy showed heterogeneity in clinical characteristics and treatment. Early stage should do antibody examination and diagnosis. Early treatment could prevent myelin and axonal injury and preserve nerve function.

The effects of γ-ray irradiation on the thermal stability and creep resistance of ultra-high molecular weight polyethylene (UHMWPE) were studied. First, UHMWPE powder was hot pressed into 1 mm thick sheets using a vulcanization molding machine. The chemical structure, thermal stability, microstructure, tensile properties, and creep properties of the irradiated plate samples were studied. The results demonstrated that, after γ-ray irradiation, the melting points, crystallinity, and thermal stability increased; the gel content increased to 89%; and the motility of molecular chains decreased. Compared with the creep resistance of the unirradiated sample, that of the irradiated sample increased by approximately 40%. In this study, the thermal stability and creep resistance of UHMWPE were significantly improved via the radiation cross-linking process, which provided a method for the preparation of UHMWPE materials with high creep resistance and high thermal stability.

Ammonium affects plant root development through different mechanisms than nitrate. Here, the authors show that the Arabidopsis cell wall-localized ferroxidase LPR2 is required to attenuate root growth in response to ammonium.

We present a deep learning method for the segmentation of new lesions in longitudinal FLAIR MRI sequences acquired at two different time points. In our approach, the 3D volumes are processed slice-wise across the coronal, axial, and sagittal planes and the predictions from the three orientations are merged using an optimized voting strategy. Our method achieved best F1 score (0.541) among all participating methods in the MICCAI 2021 challenge Multiple sclerosis new lesions segmentation (MSSEG-2). Moreover, we show that our method is on par with the challenge's expert neuroradiologists: on an unbiased ground truth, our method achieves results comparable to those of the four experts in terms of detection (F1 score) and segmentation accuracy (Dice score).

The effects of γ-ray irradiation on the lipophilic and hydrophobic properties of two types of polypropylene (PP) foam materials were systematically studied. Isotactic polypropylene (iPP) and high-melt-strength polypropylene (HMSPP) sheets were prepared by hot pressing with a thickness of 1 mm, and then PP foams were prepared by supercritical CO2 batch foaming. Finally, the foamed samples were irradiated with γ-rays. The results showed that the melting points and crystallization temperatures of the two foams decreased after irradiation. The scanning electron microscope images showed that the cell walls of both PP foams appeared cracks and the roughness of the foam’s cross-section increased significantly. The water contact angle of iPP foam largely increased by 26.4%, and the contact angle of HMSPP foam increased from 135.2° to 141.8°, which almost reached the super-hydrophobic level. The enhanced roughness increased the hydrophilic defects and the droplet adhesion resistance. Moreover, the appearance of the cracks in the cell walls increased the connectivity between cells, which largely increased the foam oil absorption permeability and the oil absorption quantity. This study provides a method for preparing lipophilic and hydrophobic foam.

Intestinal epithelial cells (IECs) contribute to regulation of gut injury after intestinal ischemia/reperfusion (II/R). Exosomes are well documented to deliver bioactive molecules to recipient cells for the purpose of modulating cell function. However, the role of IEC-derived exosomes in gut damage after II/R and the underlying mechanisms remain unclear. Here, we investigated the effects of exosomal miR-23a-3p on gut damage using primary IECs that underwent oxygen-glucose deprivation (OGD) as well as II/R rats. We observed that exosomes released by IECs attenuated damage in IECs that underwent OGD in vitro (P

Delamination damage to spar caps seriously endangers the operation safety of offshore wind turbines. The effect of initial delamination of various depths and areas on the ultimate tensile load of laminates is studied based on experiments and numerical simulation, and an effective method for predicting the residual tensile strength of laminates with high thickness is proposed. Three groups of initial delamination specimens with different characteristics were fabricated, and static displacement tensile tests were carried out. An accurate three-dimensional numerical analysis model was established, and the results were in good agreement with the experimental values, with the overall error of the failure load being less than 6%. Furthermore, a numerical model for a 20-ply high-thickness spar cap laminate was established to predict the effect of delamination on tensile strength. The results showed that, for the same depth of initial delamination, the difference in delamination area had little influence on the tensile strength. The dangerous locations of delamination were at the shallow surface and at the ratio of 0.3–0.4 in the thickness direction, and the maximum decrease in tensile strength was 14.86%; meanwhile, it was found that delamination on the middle surface had no significant effect on tensile strength.

Rule extraction of decision information system is one of the important research contents of data analysis. Formal concept analysis is efficient for data analysis and information processing. Based on formal concept, com-prehensive concepts and central concepts are defined in this paper, and then the algorithm for concise rule extraction is proposed. In this process, the decision attributes of the formal decision context take participate in the generation of the concepts. After removing redundant comprehensive concepts at each level, the rest parts are central concepts and they are the decision rules. The central concepts reflect the implication relationship between conditional attributes and decision attributes in information systems, and make formal concepts with richer knowledge. Meanwhile they also effectively combine decision rules with concepts together. The corresponding Hasse diagram is more meaningful than the traditional one. The proposed algorithm avoids the complexity of traditional methods which have to generate conditional concepts and decision concepts respectively and then to get rules by complex computation. Finally, the effectiveness and correctness of the algorithm are verified by case analysis and comparative experiments with UCI datasets.

Student–teacher relationships (STRs) have been examined by many studies. However, an omission still exists, the existing scales are not appropriate for studying STRs in private colleges because of the special character of these schools. This paper presents the development and validation of Private-College Student–Teacher Relationship Scale (PCSTRS), the first instrument to evaluate student–teacher relationships (STRs) in private colleges. The PCSTRS has six dimensions: trust, interaction, intimacy, care, approval, and comfort. In our main study, the validity and reliability of the six-factor PCSTRS model were demonstrated. The result of internal consistency coefficient indicated the high reliability of the scale, and the result of concurrent validity indicated the significant correlational relationships between the PCSTRS with other STR measures. In supplementary study, the PCSTRS was administered to 360 participants to confirm the applicability of PCSTRS and investigate the relation of STRs and students’ traits, performance, and wellbeing, as well as the differences between the private school and the public school in this relation; the analyses revealed that there were significant differences in trust, intimacy, and care between private and public colleges; positive correlations were found between STRs and self-esteem, self-efficacy, academic performance, extracurricular activity involvement, and subjective wellbeing. Present research firstly develops the PCSTRS, examined the reliability and validity, and provides the proposed nomological network among related constructs.

As an important theory of policy process analysis, multiple–streams theory provides a highly explanatory analytical framework and perspective for exploring the dynamics of policy change. This paper uses multiple–streams theory to analyze the history of china’s drug procurement policy changes, found that the china’s drug procurement policy has gone through four development stages. Each change in drug procurement policy is due to a particular problem that is highlighted, focal issues enter the policy agenda when problem streams, policy streams and politics streams are highly coupled and the issue window opens, then the policy changes. This paper provides an outlook on the key directions of china’s drug procurement policy, in order to provide useful reference for the study of multiple–streams theory and the study of china’s drug procurement system.

The influence of the outer reinforcement layers on the repair structure and aerodynamic performance was studied. Firstly, a continuous damage mechanics model was established, and the 3D Hashin criterion and cohesive zone material model were used to analyze the damage repair model. The failure load deviation was 5.5%. Secondly, on the basis of the γ−Reθ transition model and SST–ω turbulence model, the aerodynamic analysis model of DU300 airfoil was established. The numerical simulation results showed that the lift coefficient and pressure distribution at the angle of attack of 10° and 15° were deviated from the experimental values by 2%. Furthermore, 27 structural repair models, nine 2D aerodynamic repair models, and a 3D full-scale blade model were designed. It was found that, when the repair length accounted for 60% of the total model length, the failure load increased by 22%, but the aerodynamic power with the repair length of 10 m was decreased by 0.137%. When the repair area was large and the repair height was from 4 mm to 6 mm, the failure load was greatly increased by about 30%, and the aerodynamic pressure distribution and static pressure field fluctuated significantly. The results show that the structural and aerodynamic characteristics were closely related to the repair parameters.

The purpose of this study was to explore instructional designs for promoting inquiry practices in secondary school textbooks. Three criteria were employed to select the textbooks: (1) approved by the Ministry of Education in Singapore and the Ministry of Education and Culture in Indonesia, (2) used in secondary schools, and (3) included content and practices based on the current curriculum. Based on these criteria, six science textbooks from Singapore and three from Indonesia were selected for further coding in the dimensions of learning goals of inquiry skills, nature of scientific inquiry, and inquiry types. The results showed that more activities in both the Singaporean and Indonesian textbooks focus on observing and interpreting skills. However, few activities in the textbooks from either country provide an opportunity for students to engage nature of scientific inquiry. In addition, more activities in the Singaporean textbooks were designed as guided inquiry than those in the Indonesian textbooks. Finally, it is suggested that inquiry activities in textbooks should be revised to include nature of scientific inquiry, and more textbook analysis studies are needed to reveal characteristics of inquiry activities in textbooks for different subjects.

SARS-CoV-2 infection leads to severe lung damage due to pneumonia and, in more severe cases, leads to acute respiratory distress syndrome, or ARDS. This affects the viability of bronchoalveolar cells. An important role in the pathogenesis of these complications is the hyperactivation of the renin-angiotensin-aldosterone (RAA) pathway and induction of cytokine storm that occurs in an Nlrp3 inflammasome-dependent manner. To shed more light on the susceptibility of lung tissue to SARS-CoV-2 infection, we evaluated murine bronchioalveolar stem cells (BASC), alveolar type II cells (AT2), and 3D-derived organoids expression of mRNA encoding genes involved in virus entry into cells, components of RAA, and genes that comprise elements of the Nlrp3 inflammasome pathway. We noticed that all these genes are expressed by lung alveolar stem cells and organoids-derived from these cells. Interestingly, all these cells express a high level of ACE2 that, on the one hand, serves as an entry receptor for SARS-CoV-2 and, on the other, converts angiotensin II into its physiological antagonist, angiotensin 1–7 (Ang 1–7), which has been reported to have a protective role in lung damage. To shed more light on the role of Ang 1–7 on lung tissue, we exposed lung-derived BASC and AT2 cells to this mediator of RAA and noticed that it increases the proliferation of these cells. Based on this, Ang 1–7 could be employed to alleviate the damage to lung alveolar stem/progenitor cells during SARS-CoV-2 infection.

The floral transition stage is pivotal for sustaining plant populations and is affected by several environmental factors, including photoperiod. However, the mechanisms underlying photoperiodic flowering responses are not fully understood. Herein, we have shown that exposure to an extended photoperiod effectively induced early flowering in Arabidopsis plants, at a range of different nitrate concentrations. However, these photoperiodic flowering responses were attenuated when the nitrate levels were suboptimal for flowering. An extended photoperiod also improved the root nitrate uptake of by NITRATE TRANSPORTER 1.1 (NRT1.1) and NITRATE TRANSPORTER 2.1 (NRT2.1), whereas the loss of function of NRT1.1/NRT2.1 in the nrt1.1-1/2.1-2 mutants suppressed the expression of the key flowering genes CONSTANS (CO) and FLOWERING LOCUS T (FT), and reduced the sensitivity of the photoperiodic flowering responses to elevated levels of nitrate. These results suggest that the upregulation of root nitrate uptake during extended photoperiods, contributed to the observed early flowering. The results also showed that the sensitivity of photoperiodic flowering responses to elevated levels of nitrate, were also reduced by either the replacement of nitrate with its assimilation intermediate product, ammonium, or by the dysfunction of the nitrate assimilation pathway. This indicates that nitrate serves as both a nutrient source for plant growth and as a signaling molecule for floral induction during extended photoperiods.