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Abstract Background Corrected QT (QTc) interval has been reported to be associated with type 2 diabetes. This study aimed to explore the relationship between different glucose tolerance and QTc intervals among middle-aged and older Chinese individuals. Methods We conducted a cross-sectional analysis that included 9898 subjects (3194 men and 6704 women) in a Chinese population. Glucose tolerance was studied during the oral glucose tolerance test (OGTT). Insulin, blood pressure, hemoglobin A1c (HbA1c), serum lipids, hepatic transaminases and waist-to-hip ratio were assessed. The QTc interval was derived from ECG recordings, and the subjects were stratified based on different glucose tolerance. Results QTc interval levels were increased significantly in the subjects with abnormal glucose metabolism compared with the normal glucose regulation group. Multiple regression analyses showed that the QTc interval was significantly associated with fasting plasma glucose, 2-h OGTT plasma glucose and HbA1c. The odds ratio of prolonged QTc was 1.396 for impaired glucose regulation (IFG)/impaired fasting glucose (IGT) (95% CI 0.126–1.730), and 1.342 for type 2 diabetes (95% CI 0.142–1.577) after all potential confounders were adjusted. Conclusions Impaired glucose tolerance (IGR) and diabetes are associated with prolonged QTc intervals among middle-aged and older Chinese individuals. Abnormal glucose regulation can be used to monitor the QTc interval in the population.

ObjectiveTo assess the iodine status and its associations with thyroid function in pregnant women of Shanghai.MethodsIn this cross-sectional study, a total of 562 pregnant women were enrolled from January to December 2021. Both serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), thyroid peroxidase antibody (TPOAB), thyroglobulin antibody (TGAB), and urinary iodine concentration (UIC) were detected. Participants were divided into four groups based on their UIC values. Correlation analysis was used to investigate the association between UIC and thyroid function-associated parameters.ResultsThe median UIC of the pregnant women studied was 158.25µg/L (interquartile range [IQR] 90.15, 245.65µg/L). Among all the subjects, 45.55% had iodine deficiency according to the World Health Organization (WHO) criteria, and 15.65% had thyroid autoimmunity. FT3, FT4, TSH, TPOAB and TGAB levels were not different among different UIC groups (P > 0.05). UIC and TSH were negatively correlated (r=-0.127, p=0.043) in UIC

Abstract Background An association between hemoglobin and metabolic syndrome (MetS) has been reported. However, the relationships between hemoglobin and individual MetS components remain unclear. Therefore, we investigated these associations at baseline and at the 3-year follow-up. Methods We enrolled 9960 middle-aged and elderly subjects (6726 women and 3234 men) and performed a 3-year follow-up cohort study. All subjects completed a questionnaire and underwent anthropometric measurements and laboratory tests. Logistic regression models were developed to assess the association between hemoglobin and MetS and its components. Results MetS was present in 45.1% of women and 41.4% of men at baseline. The hemoglobin concentration was positively correlated with SBP, DBP, TGs, WC, FPG, insulin, HOMA-IR, BMI and uric acid (p

5-Aminolevulinic acid (5-ALA) is an intermediate in haem biosynthesis and has anti-apoptotic, anti-inflammatory, antioxidant, and other pharmacological effects. This study aimed to investigate the effect of dietary supplementation with 5-ALA on growth performance, antioxidant capacity, and inflammatory response of the lipopolysaccharide (LPS)-challenged broiler chickens. The experiment was designed as a 2 × 2 factorial arrangement with dietary 5-ALA (0 or 60 mg/kg) and LPS (injection of saline or 0.5 mg/kg BW) levels as treatments. A total of 240 one-day-old Arbor Acres broilers were distributed into four treatments consisting of six replicates of 10 birds. All the experimental broilers were intraperitoneally injected with LPS or sterile saline at 16, 18, and 20 days of age. Our results showed that dietary 5-ALA supplementation reduced (P

Abstract Background The effects of visceral adiposity on decreased lung function have drawn much attention. Recently, the visceral adiposity index (VAI) has been proposed as a visceral fat distribution and dysfunction marker. However, the relationship between the VAI and lung function has not been investigated. The objective of the study was to analyze the association between the VAI and lung function and evaluate the potential of VAI as a predictor of lung function. Methods We collected data from a population-based study of 1786 subjects aged 40 years or older. All subjects completed a questionnaire and underwent anthropometric measurements and laboratory tests. Linear and logistic regression models were developed to assess the association between the VAI and lung function. Results The VAI was inversely related to FVC%predicted in men and negatively associated with both FVC%predicted and FEV1%predicted in women. In the linear regression analysis, the decrease in FVC%predicted associated with each 10% increase in the VAI was 1.127% in men and 1.943% in women; the decrease in FEV1%predicted associated with each 10%increase in the VAI was 0.663% in men and 1.738% in women. Further regression analysis revealed that the VAI was positively correlated with FVC and FEV1 impairment in women. Conclusions We were the first to show a clear correlation between the VAI and lung function impairment in the Chinese population. The VAI could be a simple and reliable approach in daily practice, and individuals, especially women with a high VAI, should receive additional screening and preventive interventions for respiratory disease.

Abstract Background The mid-upper arm circumference (MUAC) is a proxy for subcutaneous fat in the upper body and is a reliable screening measure for identifying individuals with abnormal regional fat distribution. The purpose of this study was to evaluate the association between MUAC and metabolic syndrome (MetS) in middle-aged and elderly individuals. Methods We measured the MUAC in a cross-sectional sample with a total of 9787 subjects aged 40 years and older. The measurement of MUAC is performed on the right arm using a non-elastic tape held midway between the acromion and the olecranon processes in duplicate, with the arm hanging loosely at the side of the body. The MetS was defined according to the Joint Statement of the International Diabetes Federation Task Force on Epidemiology and Prevention. Results MUAC was positively correlated with waist circumference (r = 0.437, P

Objective: A small thigh circumference is associated with an increased risk of diabetes, cardiovascular diseases, and total mortality. The purpose of this study was to evaluate the association between thigh circumference and hypertension in the middle-aged and elderly population. Methods: A total of 9520 individuals aged 40 years and older with measurement of thigh circumference were available for analysis. The measurement of thigh circumference was performed directly below the gluteal fold of the thigh. The association of thigh circumference with hypertension was tested in logistic regression analyses and reported as odds ratio (OR) with 95% CI. Results: Thigh circumference was negatively correlated with systolic blood pressure, diastolic blood pressure, fasting glucose, and total cholesterol. Compared with the lowest thigh circumference tertile group, the risk of hypertens ion was significantly lower in the highest tertile group, both in overweight individuals (OR 0.68; 95% CI 0.59–0.79, P < 0.001) and obese individuals (OR 0.51; 95% CI 0.38–0.70, P < 0.001). Conclusion: In the present study, large thigh circumference is associated with lower risk of hypertension in overweight and obese Chinese individuals.

The soluble dietary fiber polydextrose (PDX) is a randomly linked glucose oligomer containing small amounts of sorbitol and citric acid and is widely used in the food industry. However, whether PDX can prevent and treat obesity in high-fat diet (HFD)-fed mice has not been directly investigated, and further studies are needed to better understand the complex interactions among PDX, adipose tissue inflammation and the gut microbiota. In the present study, PDX reduced body weight, fasting blood glucose (FBG), adipose tissue accumulation, adipocyte hypertrophy, serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels in HFD-fed mice. Moreover, PDX alleviated serum lipopolysaccharide (LPS) levels and macrophage infiltration in epididymal adipose tissue and resulted in macrophage polarization toward the M2 phenotype. Gut microbiota analysis revealed that PDX promoted the growth of beneficial microbes such as Bacteroides, Parabacteroides, Alloprevotella, Muribaculum, Akkermansia, Ruminococcaceae_UCG-014 and UBA1819 in obese mice, which were negatively correlated with subcutaneous fat, epididymal fat, body weight, FBG, serum TC, HDL-C, LDL-C and LPS levels. Our results indicates that PDX can prevent and treat obesity in HFD-fed mice, specifically in alleviating glucolipid metabolism disorders and adipose tissue inflammation, which may be mediated by modulating the structure of the gut microbiota. Therefore, PDX may become a promising nondrug therapy for obesity.

ObjectiveTo investigate the association between hemoglobin A1c (HbA1c) 7.0%–8.0% and cardiovascular disease (CVD) risk among Chinese patients with type 2 diabetes mellitus (T2DM) with different baseline 10-year atherosclerotic CVD (ASCVD) risk stratification.Research design and methodsA prospective population-based cohort of 10 060 adults aged 40–70 years in Chongming District of Shanghai was established in 2011. These participants were followed up for 3.25 years and CVD information was recorded. We investigated this association between HbA1c categories and incident CVD stratified by the 10-year ASCVD risk using multiple Cox regression analysis among 1880 patients with T2DM without CVD history. CVD events were defined as cardiovascular death, non-fatal myocardial infarction or non-fatal stroke.ResultsThe corresponding incidence of CVD per 1000 person-years for the HbA1c≤6.5%, 6.6%–6.9%, 7.0%–8.0% and >8.0% groups were 12.5, 21.8, 22.9 and 28.9, respectively. The HbA1c>8.0% group was significantly associated with a higher CVD risk in patients with T2DM. The HbA1c 7.0%–8.0% group was significantly associated with a higher CVD risk in patients with T2DM with moderate baseline ASCVD risk (HR 2.48; 95% CI 1.15 to 5.32).ConclusionHbA1c of 7.0%–8.0% may result in a significantly higher CVD risk among patients with T2DM with moderate baseline ASCVD risk, which support the use of HbA1c combined with baseline ASCVD risk assessment to determine future glucose-lowering treatment decisions among patients with T2DM with basic to moderate risk.

The association between white blood cell (WBC) and nonalcoholic fatty liver disease (NAFLD) has been studied before, but whether different WBC subtypes were related to NAFLD was not detailed. The aim of our study was to investigate the relationship between WBC subtypes and NAFLD cross-sectionally and prospectively. The detailed research design has been described previously. At baseline, there were 9930 participants who had complete information, in the end a total of 8079 participants (2588 men and 5491 women) were eventually included in this study. Hepatic ultrasound examination was performed on each participant at baseline and at the end of follow-up. Alcohol abuse and hepatitis were excluded. WBC subtypes and other serum indices were measured at baseline. We found that the total WBC, neutrophil, and lymphocyte counts were independently associated with the prevalence and incidence of NAFLD. After multiple adjustments for age, gender, body mass index (BMI), insulin, HOMA-IR, TG, TC, LDL, and HDL, increased odds ratios (ORs) for new onset NAFLD were observed from the 1st to the 4th quartiles of WBC, neutrophil, and lymphocyte (all P

Abstract Background Flavivirus is a highly prevalent and outbreak-prone disease, affecting billions of individuals annually and posing substantial public health challenges. Vaccination is critical to reducing the global impact of flavivirus infections, making the development of a safe and effective vaccine a top priority. The self-assembled pan-epitope vaccine presents key advantages for improving immunogenicity and safety without relying on external vectors or adding immunomodulatory elements, both of which are essential for successful vaccine development. Results In this study, the pan-epitope peptide TBT was combined with adjuvant CpG to form the TBT-CpG nanovaccine (TBT-CpG NaVs), which was found to be spherical, uniform in shape, and demonstrated strong serum stability. In vitro studies showed that the TBT-CpG NaVs were efficiently taken up and internalized by bone marrow-derived dendritic cells (BMDCs). Flow cytometry and transcriptomic analysis indicated that the antigens were effectively presented to antigen-presenting cells (APCs) via the MHC II pathway, which facilitated BMDCs maturation and promoted the release of pro-inflammatory cytokines IL-1β, TNF-α, and IL-6. In vivo studies confirmed that TBT-CpG NaVs enhanced antigen-specific IgG levels, significantly increased IFN-γ and IL-4 expression in spleen cells, and offered protective effects against Dengue virus (DENV) and Zika virus (ZIKV) infections. Safety evaluations revealed no hepatotoxicity and no significant organ damage in immunized mice. Conclusion The self-assembled candidate nanovaccine TBT-CpG NaVs effectively activates BMDCs and triggers a targeted immune response, providing antiviral effects against DENV and ZIKV. This vaccine demonstrates good immunogenicity and safety, establishing a promising foundation and a new strategy for the development of safe and effective vaccines. Graphical Abstract

BackgroundNurses’ competencies are crucial for infectious disease prevention and control. We aimed to investigate competencies in responding to infectious disease outbreaks of nurses in primary healthcare institutions and identify their training needs.MethodsA cross-sectional study was conducted from June to September 2022, recruiting nurses from primary healthcare institutions across Sichuan Province. Their competencies and training needs were assessed using a modified Emergency Response Competency Scale for Infectious Diseases. Additionally, their sociodemographic characteristics and experience in infectious disease outbreak trainings were collected. Univariate analyses were used to compare competencies and training needs by participant characteristics. Multiple linear regression was conducted to identify determinants of their competencies.ResultsA total of 1,439 nurses from 44 primary healthcare institutions participated in this study. The overall competency and training needs had a median of 3.6 (IQR [3.1, 4.0]) and 4.0 (IQR [3.9, 4.7]), respectively. Age (β = −0.074, p = 0.005), experience in higher authority hospitals (β = 0.057, p = 0.035), infectious disease outbreak trainings attended within the last 5 years (β = 0.212, p

Abstract Although acute kidney injury (AKI) is a frequent postoperative complication after liver transplantation, renal function following living‐related liver transplantation (LRLT) in infants remains understudied. The aim of this study was to identify the prevalence of AKI and the impact of AKI on outcomes in infant recipients with biliary atresia. We retrospectively reviewed infants who underwent LRLT surgery between January 2018 and January 2021. The primary outcome was the risk of postoperative AKI occurrence in the first 7 postoperative days. A multivariate regression analysis model was used to investigate risk factors for AKI, and the incidence and impacts of AKI on outcomes were analyzed. A total of 98 patients were included in the analysis. AKI occurred in 59 patients (60.2%) within 7 days after surgery. Logistic regression analysis revealed that preoperative transfusion (p < 0.05) and lower serum creatinine (SCr) (p < 0.05) were independent risk factors for AKI. The incidence of serious complications was significantly higher in the AKI group than in the non‐AKI group (p < 0.05). The postoperative mechanical ventilation time (p < 0.05) and hospital stay (p = 0.019) were significantly longer in the AKI group. There was no evidence of chronic kidney disease (CKD) in any surviving infants within 1 year after surgery. In conclusion, AKI is common in infant LRLT (60.2%), and preoperative transfusion and lower SCr levels were independently associated with AKI. AKI may be associated with the incidence of serious complications, prolonged use of ventilators, and hospital stays. No CKD occurred within 1 year.

Abstract Background To examine standardized uptake valuemax of the primary lesion (pSUVmax) and tumor markers (TMs) for clinically predicting distant metastasis in novo lung adenocarcinoma. Methods The current retrospective observational study examined individuals diagnosed with de novo lung adenocarcinoma at Shanxi Cancer Hospital between February 2015 and December 2019. Results Totally, 532 de novo lung adenocarcinoma cases were included. They were aged 60.8 ± 9.7 years and comprised 224 women and 268 patients with distant metastasis. The areas under the curves (AUCs) of pSUVmax, lactate dehydrogenase (LDH), carcinoembryonic antigen (CEA), cytokeratin‐19 fragment (CYFRA21‐1), carbohydrate antigen 125 (CA125), and Grade of TMs for predicting distant metastasis were 0.742, 0.601, 0.671, 0.700, 0.736, and 0.745, respectively. The combination of pSUVmax, LDH, CEA, CYFRA21‐1, CA125, and grade of TMs in predicting distant metastasis had an AUC value of 0.816 (95%CI: 0.781–0.851), with sensitivity of 89.2%, specificity of 58.7%, positive predictive value of 73.7%, and negative predictive value of 79.7%, respectively. Conclusions pSUVmax combined with serum levels of LDH, CEA, CYFRA21‐1, CA125, and the grade of TMs may have good performance in predicting distant metastasis of de novo lung adenocarcinoma.

Abstract The artificial photosynthesis technology has been recognized as a promising solution for CO2 utilization. Photothermal catalysis has been proposed as a novel strategy to promote the efficiency of artificial photosynthesis by coupling both photochemistry and thermochemistry. However, strategies for maximizing the use of solar spectra with different frequencies in photothermal catalysis are urgently needed. Here, a hierarchical full‐spectrum solar light utilization strategy is proposed. Based on this strategy, a Cu@hollow titanium silicalite‐1 zeolite (TS‐1) nanoreactor with spatially separated photo/thermal catalytic sites is designed to realize high‐efficiency photothermal catalytic artificial photosynthesis. The space–time yield of alcohol products over the optimal catalyst reached 64.4 μmol g−1 h−1, with the selectivity of CH3CH2OH of 69.5%. This rationally designed hierarchical utilization strategy for solar light can be summarized as follows: (1) high‐energy ultraviolet light is utilized to drive the initial and difficult CO2 activation step on the TS‐1 shell; (2) visible light can induce the localized surface plasmon resonance effect on plasmonic Cu to generate hot electrons for H2O dissociation and subsequent reaction steps; and (3) low‐energy near‐infrared light is converted into heat by the simulated greenhouse effect by cavities to accelerate the carrier dynamics. This work provides some scientific and experimental bases for research on novel, highly efficient photothermal catalysts for artificial photosynthesis.

Abstract Background Advanced Practice Nursing (APN) have been highly valued and an integral part of the health care system. Development and establishment of new APN roles is a complex process that has resulted from a wide variety of reasons, key component is a lack of a competency map delineation and role evaluation. Currently, however, competence framework has not been compared at an international level. In mainland China, APN have been introduced in some organizations but their competency domains have not yet been clearly defined, this study aimed to identify the core competencies for advanced practice nursing. Methods This study was performed in two phases: first, in-depth and semi-structured individual interviews with 46 participants from key stakeholders were carried out followed by a qualitative content analysis, then an item pool of core competencies was constructed by extracting data from the first phase and the results from previous studies, scales and documents; second, a Delphi technique was conducted with the participation of 28 experts from 7 areas of China to form the final core competency framework for advanced practice nursing. Results Through the qualitative phase, the core competency framework with six domains and 70 items emerged and then entered into the Delphi phase. Twenty-eight of 30 experts finished 2 rounds of Delphi approaches. The final core competencies for advanced practice nursing consisted of six domains with 61 items, including direct clinical nursing practice, research and evidence-based nursing practice, professional development, organization and management, mentoring and consultation, and ethical/legal practice. Conclusion This core competency framework consisted of six domains with 61 items can be used in competency-based education to cultivate advanced practice nurses as well as competency level assessment.

The dengue virus, the primary cause of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome, is the most widespread mosquito-borne virus worldwide. In recent decades, the prevalence of dengue fever has increased markedly, presenting substantial public health challenges. Consequently, the development of an efficacious vaccine against dengue remains a critical goal for mitigating its spread. Our research utilized Celcradle™, an innovative tidal bioreactor optimized for high-density cell cultures, to grow Vero cells for dengue virus production. By maintaining optimal pH levels (7.0 to 7.4) and glucose concentrations (1.5 g/L to 3.5 g/L) during the proliferation of cells and viruses, we achieved a peak Vero cell count of approximately 2.46 × 109, nearly ten times the initial count. The use of Celcradle™ substantially decreased the time required for cell yield and virus production compared to conventional Petri dish methods. Moreover, our evaluation of the immunogenicity of the Celcradle™-produced inactivated DENV4 through immunization of mice revealed that sera from these mice demonstrated cross-reactivity with DENV4 cultured in Petri dishes and showed elevated antibody titers compared to those from mice immunized with virus from Petri dishes. These results indicate that the dengue virus cultivated using the Celcradle™ system exhibited enhanced immunogenicity relative to that produced in traditional methods. In conclusion, our study highlights the potential of the Celcradle™ bioreactor for large-scale production of inactivated dengue virus vaccines, offering significant promise for reducing the global impact of dengue virus infections and accelerating the development of effective vaccination strategies.

Transient γ-radiation and laser-simulated experiments were carried out to investigate the transient dose rate effect (TDRE) in SiGe heterojunction bipolar transistors (HBTs) for the first time. The results indicate that IBM43RF0100 SiGe HBTs experience a significant sensitivity of TDRE. For the laser-simulated experiment, the duration of transient current and charge collection are matched well with that of transient γ-radiation. The amplitude of transient photocurrent induced by the lower energy order of μJ approaches the transient photocurrent induced by transient γ-radiation. It is demonstrated that laser-simulated experiments are a candidate and a convenient method to evaluate the TDRE response of SiGe HBTs, which avoids serious electromagnetic interference in the transient γ-radiation environment.

Serum anti-phospholipase A2 receptor (anti-PLA2R) antibody is used for the noninvasive diagnosis of idiopathic membranous nephropathy (IMN). However, the cutoff value of anti-PLA2R antibodies in IMN patients is debatable. This study aimed to investigate the cutoff value of anti-PLA2R antibodies for diagnosing IMN and the correlation of anti-PLA2R antibodies with clinical parameters and prognosis. A total of 252 IMN patients and 521 non-IMN patients with both renal biopsy and serum anti-PLA2R antibody data from April 2017 to November 2019 were enrolled. Anti-PLA2R antibody was detected by an enzyme-linked immunosorbent assay. The anti-PLA2R antibody titer was higher in the IMN group than in the non-IMN group (153.1 ± 22.4 vs. 2.0 ± 0.2 RU/mL, p

Peer-to-Peer (P2P) electricity transaction is an emerging power trading model, which can effectively solve the drawbacks of traditional power trading that requires the exist of intermediaries. As the application spreads, P2P electricity transaction faces some regulatory issues. At present, some existing regulatory models are based on centralized trusteeship centers. There is no distributed regulatory mechanism, and no dynamic addition and deletion mechanism to prevent malicious collusion of regulators. In this article, we propose a multi-party audit and regulatory mechanism for P2P electricity transaction, which is based on a dynamic distributed traceable linkable group signature (DDT-LGS) scheme. This solution realizes the distributed trace and audit for P2P electricity transaction, and further realizes the dynamic permission of regulators to join and exit. We give the system architecture of multi-party audit and regulatory mechanism, formally define the algorithm process, and give a specific DDT-LGS construction. Security and performance analysis shows that the proposed scheme holds strong security, more comprehensive functions and better performance, that is suitable for P2P power trading scenarios.

The objective of this study was to investigate how nitrogen and slow-release fertilizers affect the traits of leaf senescence and quinoa production in order to explore the optimal slow-release fertilizer and nitrogen fertilizer ratios suitable for quinoa production, as well as to provide theoretical references for the planting of quinoa fertilization methods and fertilizer amount. In this experiment, the main local strain Quinoa 77 was selected as the experimental material, and six treatments were set up: CK: no nitrogen fertilizer; T1: 100% urea (N); T2: 100% slow-release fertilizer (C); T3: 5:5 (C5N5); T4: 3:7 (C3N7); and T5: 7:3 (C7N3). This was done in order to investigate how various treatments affect the activities of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD); malondialdehyde (MDA) content; and yield of quinoa leaves. The findings revealed the following: (1) As the reproductive period progressed, the activities of CAT, POD, and SOD in quinoa leaves treated differently showed a tendency to increase and subsequently decrease, and they reached the peak value at the early stage of filling. The activity of CAT, POD, and SOD in the T3 treatment was the highest, and the average activities were 3148.74 U·g−1, 2197.84 U·g−1, and 118.51 U·g−1, respectively, which increased by 78.90%, 101.99%, and 108.14%, respectively, compared with CK. The content of MDA continued to increase with the progress of fertility. The average T3 treatment was 36.41 nmol·g−1, which was 46.87% lower than that of CK. (2) Out of all the treatments, T3 had the highest yield with an average of 3829.43 kg·hm−2, T5 the second with an average of 3313.52 kg·hm−2, and T4 the third with 2847.47 kg·hm−2, which increased yields by 96.18%, 69.75%, and 45.87%, respectively, compared with CK. (3) Yield was highly significantly and positively correlated with thousand kernel weight; number of grains per spike per plant; and the early filling stages of CAT, POD, and SOD sports, and it had a negative, extremely significant correlation with MDA content. Comprehensive analysis showed that slow-release fertilizer and nitrogen fertilizer can improve the antioxidant enzyme activity of quinoa leaves, inhibit MDA content, improve the physiological characteristics of quinoa, and delay the purpose of leaf senescence, with a better effect of yield and income, of which the T3 treatment had the high-quality impact of increasing yields and was a more scientific and reasonable fertilization method.

Quinoa (Chenopodium quinoa Willd.) is gaining recognition as a pseudocereal due to its nutritional attributes and adaptability to challenging conditions and marginal soils. However, understanding the optimal fertilization for quinoa growth remains a challenge. This study investigates the effects of nitrogen fertilization (0, 90, 120, and 150 kg using urea) on quinoa phenology, growth, and photosynthesis in the Loess Plateau region of China, a critical area facing soil erosion and ecological degradation. The results showed that nitrogen fertilization significantly influenced quinoa phenology, prompting early flowering and shorter growth at an optimum rate of 120 kg ha−1. Nitrogen application enhanced growth traits such as plant height, stem diameter, and chlorophyll content, particularly at the heading and flowering stages. Photosynthesis-related parameters, including net photosynthesis rate, transpiration rate, stomatal conductance, and intercellular CO2 concentration, were affected by nitrogen application, with higher values observed at 120 kg ha−1. Non-photochemical quenching was significantly increased by nitrogen application, indicating the efficient dissipation of excess energy. The study demonstrated a positive correlation between grain yield and growth traits, photosynthesis-related traits, and chlorophyll content. In conclusion, quinoa yield could be significantly improved at the Loess Plateau region under rainfed conditions by an optimal nitrogen fertilizer rate of 120 kg ha−1, which reduces the growth duration while increasing photosynthesis traits.