Cold Nitrogen Research Articles

Efficient low-temperature wastewater treatment by Pseudomonas zhanjiangensis sp. nov.: a novel cold-tolerant bacterium isolated from mangrove sediment.

A novel heterotrophic, cold-tolerant bacterium, designated Pseudomonas zhanjiangensis 25A3ET, was isolated from mangrove sediment and demonstrated excellent efficiency in cold wastewater treatment. Phylogenetic analysis based on 16S rRNA gene sequences positioned strain 25A3ET within the genus Pseudomonas, showing the highest similarity (98.7%) with Pseudomonas kurunegalensis LMG 32023T. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values were below the species delineation thresholds (70% for dDDH, 95% for ANI), indicating that strain 25A3ET represents a novel species. This strain demonstrated high efficiency in removing nitrogen (N) and organic pollutants under low-temperature conditions. Specifically, it achieved 72.9% removal of chemical oxygen demand (COD), 70.6% removal of ammoniacal nitrogen (NH4 +-N), and 69.1% removal of total nitrogen (TN) after 96 h at 10°C. Genomic analysis identified key genes associated with cold adaptation, nitrogen removal and organic matter degradation. These findings indicate that Pseudomonas zhanjiangensis 25A3ET holds significant potential for application in cold temperature wastewater treatment, offering a promising solution for environmental remediation in regions with low ambient temperatures.

Design and verification of high-precision dynamic temperature control system

In view of the fact that the current temperature environment simulation equipment is difficult to realize the temperature offset test of temperature-sensitive scientific payloads in deep space exploration, a high-precision dynamic temperature control system was designed and built, and then tested and verified. The system uses liquid nitrogen cold plate as the cold source, and realizes high-precision static 300 mm × 300 mm and dynamic temperature control on the contact surface of the payload through electric heating temperature control, heat pipe heat transfer and firmware heat conduction. The test results show that in the case of scientific payload-10 ∘C ∼ 45 ∘CWithin the working temperature range, the contact surface between the temperature control system and the scientificpayload can achieve high-precision temperature stability control, and the temperature fluctuation is better than ± 0.001 ∘C; at the same time, it can also realize ± 0.05 ∘C/1000 s ∼ 1 ∘C/1000 slinear control of the heating and cooling rate of the scientific payload contact surface. Compared with the temperature curve set by the temperature offset test, the maximum errors of the whole temperaturetracking are 0.003 ∘C and respectively 0.04 ∘C . The established temperature control system has the ability of high-precision temperature dynamic offset test, and has considerable application prospects in tasks such as deep space exploration payload development test.

Assessing the Opportunities and Risks of DUS and VCU Variety Testing for Sustainable Production through SWOT Analysis Results

Within the European Union (EU), new plant varieties to be included in the Common catalog of a member state have to be registered on the national list after plant variety testing processes to establish whether the candidate variety is distinguishable, uniform, and stable (DUS) and meets the cultivation or use value requirement (VCU). Technical development, climate change, and changing consumer needs, including the detection of GMOs, necessitate the innovation of plant variety testing methods. In our study, we assessed new characters, testing methods, and inclusion of additional data for the potential to benefit the DUS and VCU protocols. To achieve our goal, we asked experts to fill in questionnaires for the DUS and VCU methods currently used for a selection of common crops, including potato, maize, lentil, oilseed rape, and perennial grass. Within the EU-funded “InnoVar” project, partners sent out questionnaires to 19 European Countries and to 3 countries outside Europe. Surveys were aimed at analyzing the strengths, weaknesses, opportunities, and threats (SWOT) of the current methods. With their help, it is possible to look for a new direction, opportunity, and strategy to incorporate, together with the innovative new techniques, into the development of the new methods. Our study demonstrated that the SWOT analysis could be used to achieve the set goals. Results obtained after evaluation of surveys confirmed that introduction of new characters such as cold tolerance, nitrogen and water efficiency, etc. has become necessary, as has the inclusion of new test methods (molecular markers, precision techniques, organic farming). The development of high-yielding, disease and/or pest-resistant plant varieties with good adaptability and the accurate evaluation of genotypes play a crucial role in ensuring that farmers can access high-performing plant varieties and contribute to sustainable food production.

Air cold plasmas as a new tool for nitrogen fixation in agriculture: underlying mechanisms and current experimental insights

Nitrogen fixation is crucial for plant growth and global agriculture, especially with the projected population growth requiring a significant increase in food production. Traditional nitrogen fixation relies on the Haber-Bosch (H-B) process, which is energy-intensive and environmentally harmful due to greenhouse gas emissions. Emerging technologies, such as cold plasma, offer promising alternatives with lower energy consumption. Cold plasma facilitates reactive nitrogen species generation under ambient conditions, potentially improving the production efficiency of nitrogen oxides (NOx). However, optimizing cold plasma nitrogen fixation requires a synergy between experimental and theoretical approaches. Accurate input data are essential for refining theoretical models, which can then guide the design of more efficient processes. This integrated approach can leverage renewable energy, operate on smaller scales, and minimize environmental impacts, making cold plasma a sustainable solution for future nitrogen fixation needs.

Cold Nitrogen Plasma: A Groundbreaking Eco-Friendly Technique for the Surface Modification of Activated Carbon Aimed at Elevating Its Carbon Dioxide Adsorption Capacity

The commercially available activated carbon was modified using barrier and spark discharge low-temperature nitrogen plasma treatment. The samples were investigated using nitrogen sorption at a temperature of −196 °C, XRD, SEM, and FTIR methods, and elemental analysis. The nitrogen content on the surface was increased, but other properties, such as specific surface area, total pore volume, pseudocrystallite height, and pseudocrystallite width, remained unchanged. The activated carbons after nitrogen plasma treatment indicated higher CO2 adsorption than the pristine ones. Since the investigated materials only differed in their nitrogen content, it has been unequivocally demonstrated that the increased presence of nitrogen is responsible for the enhanced adsorption of CO2. The low-temperature nitrogen plasma treatment of activated carbon is a promising method for enhancing CO2 capture.

Analysis of short-term treatment effects of dielectric barrier discharge plasma to improve germination characteristics of wheat seeds

In this work, an effort has been made to show that a cold atmospheric pressure plasma (CAPP) can be applied to promote the growth and development of wheat seedlings. A dielectric barrier discharge (DBD) plasma-based reactor has been developed having two-roller conveyor rollers running on sprockets to generate cold plasma. Wheat seeds (Triticum aestivum) are treated with cold plasma for shorter durations to examine their germination parameters. In the cold plasma, reactive oxygen and nitrogen species (RONS) are generated which alter the surface of the seeds. This results in enhanced germination, growth, and enduring vitality of the plants enhance seed germination. After plasma treatment, the germination rate was enhanced from 84% to 98%. Also, after treatment surfaces of wheat seeds became more hydrophilic, as confirmed by a decrease in the water contact angle which results in higher seed germination. It is inferred that plasma is a viable alternative to the conventional pre-sowing seed treatment for germination due to its uniform treatment without degradation and the use of pesticides.

Grass-Endophyte Interactions and Their Associated Alkaloids as a Potential Management Strategy for Plant Parasitic Nematodes.

Claviceptaceous endophytic fungi in the genus Epichloë mostly form a symbiotic relationship with cool-season grasses. Epichloë spp. are capable of producing bioactive alkaloids such as peramines, lolines, ergot alkaloids, and indole-diterpenes, which protect the host plant from herbivory by animals, insects, and nematodes. The host also benefits from enhanced tolerance to abiotic stresses, such as salt, drought, waterlogging, cold, heavy metals, and low nitrogen stress. The bioactive alkaloids produced can have both direct and indirect effects towards plant parasitic nematodes. Direct interaction with nematodes' motile stages can cause paralysis (nematostatic effect) or death (nematicidal effect). Indirectly, the metabolites may induce host immunity which inhibits feeding and subsequent nematode development. This review highlights the different mechanisms through which this interaction and the metabolites produced have been explored in the suppression of plant parasitic nematodes and also how the specific interactions between different grass genotypes and endophyte strains result in variable suppression of different nematode species. An understanding of the different grass-endophyte interactions and their successes and failures in suppressing various nematode species is essential to enable the proper selection of grass-endophyte combinations to identify the alkaloids produced, concentrations required, and determine which nematodes are sensitive to which specific alkaloids.

Reignition characteristics of lignite affected by pre-oxidation and liquid nitrogen cold soaking

The propensity of residual oxidized coal to be reignited within enclosed fire areas in coal mines under liquid nitrogen (LN2) cold soaking remains unclear. Therefore, scanning electron microscopy (SEM), low-temperature nitrogen adsorption (LTNA), and thermogravimetric (TG) experiments were conducted to characterize the pore structure and secondary oxidation of oxidized cold-soaked coal. The results indicate that pre-oxidation or cold soaking alone can promote the generation and merging of pores and make the pore structure more complex, especially when pre-oxidized. However, pore evolution is suppressed and then improves when lignite is simultaneously subjected to pre-oxidation and cold soaking. In particular, the macropore volume and specific surface area decrease and then increase. The cryogenic shrinking of the LN2 results in the collapse of the loose coal matrix, which subsequently blocks the macropores. In contrast, vaporization expansion enhances pore connectivity with continuous LN2 injections, transforming mesopores into macropores, especially in the pore ranges of 2–5 nm and >50 nm. Additionally, pre-oxidation or cold soaking alone improves the oxidizing activity and combustion performance of raw coal. However, continuous cold soaking initially increases and subsequently decreases the characteristic temperatures and activation energy of oxidized coal. Oxidization at 200 °C with one cold soaking can further lower reignition propensity. The average activation energy of oxidized coal decreases by 22.9%–29 % when soaked more than three times. The improvement in combustion property is closely related to the increasing number of macropores because a larger pore volume and specific surface area are conducive to oxygen diffusion and adsorption. Therefore, pre-oxidation and cold soaking promote and inhibit the reignition of coal when performed simultaneously. These results provide theoretical guidance for rational liquid-nitrogen injection to control coal fires.

Modification of Experimental Model of Necrotizing Enterocolitis (NEC) in Rat Pups by Single Exposure to Hypothermia and Hypoxia and Impact of Mother's Milk on Incidence of Disease.

BACKGROUND Necrotizing enterocolitis (NEC) is a potentially life-threatening disease that affects the intestine of the neonate, causing necrosis and general inflammation. Treatment consists of feeding cessation and antibiotic therapy. In more severe cases, surgical intervention is necessary. Recently, different NEC models have been used to study the development of novel diagnostic and therapeutic methods. This work modified an experimental NEC model in rat pups by a single exposure of animals to NEC-causing factors and testing the impact of mother's milk on prevalence of the disease. MATERIAL AND METHODS Fifty rat pups were subjected to the NEC protocol, in which they were exposed to 100% nitrogen atmosphere and cold stress for set periods of time and formula feeding with exposure to mother's milk and artificial milk. Twenty-nine pups were used for control. After a set time of 72 h, bowel fragments were obtained and examined histologically by hematoxylin-eosin staining with a modified 3-grade scale. RESULTS Histological features of NEC were present in most of the samples (10/14) in the group exposed to 1 min of hypoxia (P=0.016), 10 min of cold stress (P=0.4) and formula feeding every 3 h with no mother's milk (P=0.001). In the group of 11 animals with the same stress conditions but fed mother's milk right after birth, only 1 sample of NEC was present. CONCLUSIONS The modified experimental NEC model based on formula feeding and single exposure to hypothermia and hypoxia was assessed statistically and histologically. In this model, mother's milk had a protective effect against necrotizing enterocolitis.

Analyzing the nitrogen removal performance and cold adaptation mechanism of immobilized cold-acclimation ANAMMOX granules at low temperatures.

To improve the treatment performance of anaerobic ammonium oxidation (ANAMMOX) processes at low temperatures, the immobilized cold-acclimation ANAMMOX granules (R3) were prepared and their low-temperature nitrogen removal ability as well as the cold adaptation mechanism were analyzed. The results indicated that the total inorganic nitrogen (TIN) removal efficiency of R3 was significantly higher than that of R2 (cold-acclimation granules without immobilization) and R1 (common granules), especially at 11 ± 2 and 7±2°C (68% and 54%). These were attributed to the remarkable biomass retention capacity of R3, high up to 4.3-4.9mg/gVSS even at 5-18°C. Besides, higher protein (PN) content of tightly bound extracellular polymeric substances (TB-EPS) also facilitated microbial aggregation in R3. Meanwhile, R3 granules retained higher ANAMMOX activity and heme c content at 5-25°C. The original dominant ANAMMOX genus (Candidatus Kuenenia) in R3 kept higher abundance (49%-57%) at 23 ±2 and 16 ±2°C, whereas Candidatus Brocadia became the dominant ANAMMOX genus (25%-32%) in R3 at 11 ±2 and 7±2°C. Notably, different ANAMMOX genera in R3 may adapt to cold environment by regulating the expression of cold-stress proteins (CspA, CspB, PpiD, and UspA). PRACTITIONER POINTS: Immobilized cold-acclimation ANAMMOX granules showed higher nitrogen removal efficiency at 23°C → 5°C. Immobilization method effectively retained biomass (Candidatus Kuenenia and Candidatus Brocadia). Immobilization facilitated TB-EPS release and biological aggregation in cold-acclimation granules. Expression of cold-stress proteins in immobilized cold-acclimation granules was more active.

Camouflaging attenuated Salmonella by cryo-shocked macrophages for tumor-targeted therapy

Live bacteria-mediated antitumor therapies mark a pivotal point in cancer immunotherapy. However, the difficulty in reconciling the safety and efficacy of bacterial therapies has limited their application. Improving bacterial tumor-targeted delivery while maintaining biosafety is a critical hurdle for the clinical translation of live microbial therapy for cancer. Here, we developed “dead” yet “functional” Salmonella-loaded macrophages using liquid nitrogen cold shock of an attenuated Salmonella typhimurium VNP20009-contained macrophage cell line. The obtained “dead” macrophages achieve an average loading of approximately 257 live bacteria per 100 cells. The engineered cells maintain an intact cellular structure but lose their original pathogenicity, while intracellular bacteria retain their original biological activity and are delay freed, followed by proliferation. This “Trojan horse”-like bacterial camouflage strategy avoids bacterial immunogenicity-induced neutrophil recruitment and activation in peripheral blood, reduces the clearance of bacteria by neutrophils and enhances bacterial tumor enrichment efficiently after systemic administration. Furthermore, this strategy also strongly activated the tumor microenvironment, including increasing antitumor effector cells (including M1-like macrophages and CD8+ Teffs) and decreasing protumor effector cells (including M2-like macrophages and CD4+ Tregs), and ultimately improved antitumor efficacy in a subcutaneous H22 tumor-bearing mouse model. The cryo-shocked macrophage-mediated bacterial delivery strategy holds promise for expanding the therapeutic applications of living bacteria for cancer.

Comparative Analysis and Characterization of Varying Molar Ratios of Urea Formaldehyde (UF) Modified Rice-Straw as Slow – Release Fertilizer

A comparative analysis and characterization of varying molar ratios of urea formaldehyde (1:2, 1:2.5 and 1:3) modified Rice-straw was done. The swell index, cold water insoluble nitrogen (% CWIN) at 250C and hot water insoluble nitrogen (% HWIN) at 980C were determined. Also, the slowly available nitrogen and the activity index (AI) were evaluated. The result from these characterizations shows that rice-straw has a good water retention capacity due to its high swell index of 1535% facilitating the slow release of nutrients. All the various formulations of urea formaldehyde in this work have their % CWIN values above the 60 % minimum, 78 % for UF 1:2, 80 % for UF 1:2.5 and 84 % for UF 1:3 while the activity indices stood at 17.9 %, 41.3% and 25% for UF 1:2, UF1:2.5 and UF 1:3 respectively. UF modified Rice-straw with molar ratio 1:2.5 whose AI is 41.3% which is within the good quality level and has the highest amount of slowly release nitrogen is therefore adduced to be a better slow- release fertilizer than the rest.

Experimental Study on the Evolution of Fracture Aperture of Single‐Fracture Granite during Liquid Nitrogen Cold Shock Cycling

Fractures in hot dry rock (HDR) reservoirs are the locations where heating fluid flows exchange heat with the HDR matrix. Cold shock with liquid nitrogen is one method for stimulating cracks. This study investigates the evolution law of fracture aperture under cold shock with liquid nitrogen. The real‐time high‐temperature triaxial servo control rock testing machine was used to conduct permeability experiments to examine the fracture aperture of single‐fracture granite during liquid nitrogen shock cycles at various temperatures. The effects of pore pressure, temperature, and shocking cycles on the fracture aperture are analyzed, and the difference in fracture aperture variation under liquid nitrogen cooling and natural cooling modes is compared. The results showed that (1) during liquid nitrogen cooling, the fracture aperture expands as pore pressure rises; the effect of pore pressure on the fracture aperture becomes more robust as the number of liquid nitrogen shocking cycles and initial temperature increases; (2) under 1‐2 soaking cycles, fracture aperture decreases as the temperature rises. Under two or more soaking cycles, the fracture aperture first increases and then decreases with increasing temperature; (3) when the initial temperature of fractured granite is 100°C, the fracture aperture is not significantly changed by repeated cold soaking cycles. However, with a higher initial temperature, the fracture aperture develops with more liquid nitrogen cold soaking cycles. The liquid nitrogen cooling method is more conducive to increasing the fracture aperture than natural cooling. The experimental results can provide primary experimental data for future research into controlling the evolution of granite cracks.

Quantification of liquid nitrogen injection efficiency and phase change expansion boost laws in coal seam borehole

The implementation of liquid nitrogen injection into coal seam boreholes is a prerequisite for its application to increase coal seam permeation. Exploring the efficiency of liquid nitrogen injection is of great significance in optimizing the settings of key injection parameters, thereby reducing costs. By using high-pressure liquid nitrogen tank, flowmeter, endoscope, thermocouple and mass balance, experiments of different liquid nitrogen injection rates were carried out in 1 m long coal seam borehole. The rules for changing the liquid nitrogen net level in the borehole at different injection rates were obtained: slow growth-linearly growth-slowly growth to stability, and the maximum net liquid level could reach 60 cm. The effective convection coefficient and radiation coefficient during the transient film boiling at the early stages of liquid nitrogen injection were calculated, and it was found that convective heat transfer dominated this stage. The liquid nitrogen injection efficiency at different injection rates was quantitatively investigated, and the maximum efficiency was 8.75 %, and the injection efficiency increases with the increase of injection rate. After stopping the injection, the net liquid nitrogen level in the borehole was analyzed, and they all decreased exponentially. A liquid nitrogen phase change expansion boost model was established and experimental verification passed. Further, it was calculated that the maximum value of liquid nitrogen phase change expansion pressure in a closed borehole of 1 m long coal seam was 45.8 MPa. The expansion pressure can play a dominant role in fracture propagation during the fracturing process, and combined with the damaging effects of liquid nitrogen cold shock on coal, it has a great development prospect in the field of coal seam permeability enhancement.

Effect of plasma processing gas on Ara h 1 in peanut protein extract

Peanut allergen Ara h 1 is one of the most common food allergens in the world, and it is highly allergenic owing to its stable structure. Cold plasma is an emerging non-thermal processing technology that generates reactive radicals that enable the rapid degradation of allergenic protein. In this study, the effectiveness of two plasma treatment gases on the inhibition of the Ara h 1 allergen in peanut protein extract was investigated as the gases were expected to react with the allergen differently. The results revealed that the antigenicity of Ara h 1 decreased by approximately 55% after 13 min of cold plasma treatment. This may be attributed to the destruction of the α-helix structure. In addition, compared to air cold plasma treatment, nitrogen plasma treatment only caused less than one third of oxidative damage to the samples. In summary, air and nitrogen plasmas are both effective in reducing peanut allergen Ara h 1, but the peanut maintained most of its original quality after nitrogen cold plasma treatment. The result of this study demonstrated that nitrogen cold plasma is a great candidate for reducing Ara h 1 for effective food processing.

Research and Application of Digital Emergency Decontamination System

With the development of nuclear energy, tritium is extensively used in fusion reactors, nuclear power plants, and tritium-related systems. A digital Emergency Detritiation System (EDS) was developed by combining an ionization chamber, a dew point meter, a circulating pump, a drying bed, a liquid nitrogen condenser, etc. to monitor the system and the tritium gas in the industrial exhaust in real time as well as recover and remove the tritium gas in the exhaust. In the work of a factory, the online monitoring of tritium-containing gas in industrial tail gas was realized. A large amount of tritium gas in industrial tail gas was treated by catalytic oxidation of precious metal oxidation bed to form HTO, and finally, HTO was recovered by a liquid nitrogen cold trap. The complex process flow is visualized and automated by the system integration software to improve the efficiency of scientific research. The results demonstrate that the system can monitor the amount of tritium in tail gas instantaneously and accurately. The removal efficiency of tritium from the industrial exhaust can be up to 99%. After repeated regeneration and activation, the working efficiency of the molecular sieve can still reach 99%, ensuring that the composite emission standards of tritiation-related sites or fusion reactors and other plants are met.

Experimental study of effect of liquid nitrogen cold soaking on coal pore structure and fractal characteristics

Experimental study of effect of liquid nitrogen cold soaking on coal pore structure and fractal characteristics

Bactericidal efficacy difference between air and nitrogen cold atmospheric plasma on Bacillus cereus: Inactivation mechanism of Gram-positive bacteria at the cellular and molecular level

As an emerging food processing technology, cold atmospheric plasma (CAP) has attracted great attention in the field of microbial inactivation. Although CAP has been proven to effectively inactivate a variety of foodborne pathogens, there is less research on the inactivation of Bacillus cereus, and the exact inactivation mechanism is still unclear. Elucidating the inactivation mechanism will help to develop and optimize this sterilization method, with the prospective application in industrialized food production. This study aims to explore the bactericidal efficacy difference between air and nitrogen CAP on B. cereus, a typical Gram-positive bacterium, and reveals the inactivation mechanism of CAP at the cellular and molecular level, by observing the change of the cell membrane, cell morphological damage, intracellular antioxidant enzyme activity and cellular biomacromolecules changes. The results showed that both air CAP and nitrogen CAP could effectively inactivate B. cereus, which was due to the reactive oxygen and nitrogen species (RONS) generated by the plasma causing bacterial death. The damage pathways of CAP on Gram-positive bacteria could be explained by disrupting the bacterial cell membrane and cell morphology, disturbing the intracellular redox homeostasis, and destroying biomacromolecules in the cells. The differences in active species generated by the plasma were the main reason for the different bactericidal efficiencies of air CAP and nitrogen CAP, where air CAP producing RONS with stronger oxidative capacity in a shorter time. This study indicates that air CAP is an effective, inexpensive and green technology for B. cereus inactivation, providing a basis for industrial application in food processing.

Nitrogen cold plasma treatment stabilizes Cu0/Cu+ electrocatalysts to enhance CO2 to C2 conversion

Cu-based materials are ideal catalysts for CO2 electrocatalytic reduction reaction (CO2RR) into multi-carbon products. However, such reactions require stringent conditions on local environments of catalyst surfaces, which currently are the global pressing challenges. Here, a stabilized activation of Cu0/Cu+-on-Ag interface by N2 cold plasma treatment was developed for improving Faradaic efficiency (FE) of CO2RR into C2 products. The resultant Ag@Cu-CuNx exhibits a C2 FE of 72% with a partial current density of −14.9 mA cm−2 at −1.0 V vs. RHE (reversible hydrogen electrode). Combining density functional theory (DFT) and experimental investigations, we unveiled that Cu0/Cu+ species can be controllably tuned by the incorporation of nitrogen to form CuNx on Ag surface, i.e., Ag@Cu-CuNx. This strategy enhances *CO intermediates generation and accelerates C–C coupling both thermodynamically and kinetically. The intermediates O*C*CO, *COOH, and *CO were detected by in-situ attenuated total internal reflection surface enhanced infrared absorption spectroscopy (ATR-SEIRAS). The uncovered CO2RR-into-C2 products were carried out along CO2→ *COOH → *CO → O*C*CO → *C2H3O → *C2H4O → C2H5OH (or *C2H3O → *O + C2H4) paths over Ag@Cu-CuNx electrocatalyst. This work provides a new approach to design Cu-based electrocatalysts with high-efficiency, mild condition, and stable CO2RR to C2 products.

Genome-Wide Identification and Expression Analysis of NPF Genes in Cucumber (Cucumis sativus L.)

The NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER family (NPF) proteins perform an essential role in regulating plant nitrate absorption and distribution and in improving plant nitrogen use efficiency. In this study, cucumber (Cucumis sativus L.) NPF genes were comprehensively analyzed at the whole genome level, and 54 NPF genes were found to be unevenly distributed on seven chromosomes in the cucumber genome. The phylogenetic analysis showed that these genes could be divided into eight subfamilies. We renamed all CsNPF genes according to the international nomenclature, based on their homology with AtNPF genes. By surveying the expression profiles of CsNPF genes in various tissues, we found that CsNPF6.4 was specifically expressed in roots, indicating that CsNPF6.4 may play a role in N absorption; CsNPF6.3 was highly expressed in petioles, which may be related to NO3- storage in petioles; and CsNPF2.8 was highly expressed in fruits, which may promote NO3- transport to the embryos. We further examined their expression patterns under different abiotic stress and nitrogen conditions, and found that CsNPF7.2 and CsNPF7.3 responded to salt, cold, and low nitrogen stress. Taken together, our study lays a foundation for further exploration of the molecular and physiological functions of cucumber nitrate transporters.