N0 Level Research Articles

Optimizing nitrogen application rates to maximize productivity while reducing environmental risk by regulating nitrogen and water utilization in mixed cropping systems

Optimizing the nitrogen (N) fertilization level and cropping system is critically important for achieving good production performance with low environmental pollution. However, there is a knowledge gap on the relationship between crop production sustainability, water and nitrogen consumption, greenhouse gas (GHG) emission under the change in N application rate under cereal and legume mixed systems. A 3-year field experiment with two cropping systems [sole forage sorghum (SS) and forage sorghum/lablab mixed cropping (SL) with four N fertilizer application rates (N0, 0 kg N ha−1; N90, 90 kg N ha−1; N180, 180 kg N ha−1; and N270, 270 kg N ha−1)] was conducted. Results obtained showed that mixed cropping combined with N fertilization enhanced forage biomass and crude protein yield by 34.0 % and 51.1 %, respectively, particularly in mixed cropping combined with the N180 treatment compared with the N0 level in the sole cropping system. Similar improvements were observed for yield stability and sustainability (2.97 % and 0.95, respectively), which reached maximum values at N180 in the mixed cropping system. In addition, mixed cropping increased the water productivity of dry matter yield (WPDM) and water productivity of crude protein yield (WPCPY) by 17.2 % and 27.6 %, respectively, at 180 kg N ha−1 compared with the corresponding treatments of the sole planting system. Furthermore, mixed cropping combined with appropriate N application significantly improved N physiological efficiency (PEN) and reduced GHG intensity (GHGI), where N application of 180 kg ha−1 N increased PEN by 21.3 % and reduced GHGI by 17.6 % compared with the corresponding monoculture in the mixed cropping system. This study demonstrated that reducing N fertilization in cereal–legume cropping systems can promote forage productivity by optimizing water and N management while decreasing environmental pollution. Therefore, forage sorghum mixed with lablab and fertilization at 180 kg N ha–1 is a preferable approach for sustainable agricultural production in the Northwest arid region of China.

Development of critical K dilution curves for diagnosing sweetpotato K status.

Scientific and reasonable application of potassium fertilizer is an important agronomic measure to achieve high yield and high quality of sweetpotato, and it is of great significance to determine the appropriate amount of potassium fertilizer in the field. For this we constructing a model of the critical K dilution curve (CKDC) of sweetpotato under different N levels to determine crop nutritional statuses. In this study, a 3-year field experiment was conducted in Zhejiang Province in China, using two nitrogen levels (N0: 0kg ha-1 and N1: 120kg ha-1) and five K fertilization rates (K0: 0, K1: 75, K2: 150, K3: 225, K4: 300kg ha-1) for two sweetpotato cultivars of 'Shang 19' and 'Yan 25'. Plant dry matter first increased and then decreased and the K concentration increased continuously with an increase in K application rate. The required amount of K fertilizer to achieve maximum sweetpotato yield under high N conditions was greater than that under low nitrogen conditions. A new CKDC based on dry matter and K concentration was created to assess K nutrition in sweetpotato. At two N levels, CKDC was expressed by the negative power function equation, aboveground: Kc(N0)=5.30W-0.463, R2=0.79, and Kc(N1)=4.23W-0.298, R2=0.78, under-ground: Kc(N0)=1.38W-0.125, R2=0.81, and Kc(N1)=1.32W-0.132, R2=0.72;whole-plant: Kc(N0)=4.31W-0.421, R2=0.80; Kc(N1)=3.89W-0.415, R2=0.79. There is no significantly different for CKDC of whole-plant and underground between N0 and N1 levels, while there is significantly different for CKDC of aboveground between N0 and N1 levels. N fertilizer can strengthen the dilution effect of K concentration, and its effect on the aboveground is greater than that on the underground and whole-plant. Then, potassium nutrition indexes were constructed to identify K nutrition status and could be used as a reliable indicator for K nutrition diagnosis of sweetpotato. The results provide a theoretical basis to improve K fertilization management and sustainability of sweetpotato.

Soil aggregates associated carbon and enzyme activities under long-term nitrogen and rice straw incorporation in Rice-Wheat system

ABSTRACT Intensive tillage and burning or removal of crop residues have led to a decline in soil organic carbon (SOC) content, posing a significant threat to soil quality and global food production. To mitigate this, adoption of conservation-agriculture practices, including residue retention/incorporation, is necessary to promote soil structural stability, increase SOC content, and enzyme activities, and restore carbon (C) sustainability in the rice-wheat system (RWS). Therefore, the long-term effects (10 years) of rice straw incorporation (RS) (0, 5, 7.5, and 10 Mg ha−1) and nitrogen (N) levels (0, 90, 120, and 150 kg N ha−1) in wheat on soil aggregate associated C pools and enzyme activities were studied. The results revealed that RS incorporation levels of RS7.5 and RS10 had 15.1% and 15.5% higher water-stable aggregates. Within the aggregate fractions, enzyme activities and C pools were significantly higher in the macro-aggregates fraction (Ma-A >0.25 mm) and least in micro-aggregates (Mi-A <0.25 mm). Under Ma-A fraction, treatments RS10 and N150 had higher enzyme activity compared to RS0 and N0. Under Ma-A, very labile C, labile C, less labile C, and recalcitrant C were increased by 34%, 25%, 33%, and 48% in RS10 over RS0 and by 20%, 28%, 23%, and 15% in N150 over the N0 level, respectively. Thus, the study concluded that the addition of crop residues (7.5 and 10 Mg ha−1) along with the N level of 150 kg ha−1 is a suitable management practice to promote soil structural stability and enzyme activities encouraging long-term SOC sustainability in the RWS.

Wheat and Faba Bean Intercropping Together with Nitrogen Modulation Is a Good Option for Balancing the Trade-Off Relationship between Grain Yield and Quality in the Southwest of China

Cereal and legume intercropping could improve cereal yield, but the role of intercropping in grain quality still lacks a full understanding. A two-year bi-factorial trial was conducted to investigate the role of two planting patterns (mono-cropped wheat (MW) and intercropped wheat+faba bean (IW)) and four nitrogen (N) fertilization levels (N0, no N fertilizer applied to both wheat and faba bean; N1, 90 and 45 kg N ha–1 applied to wheat and faba bean; N2, 180 and 90 kg N ha–1 applied to wheat and faba bean; N3, 270 and 135 kg N ha–1 applied to wheat and faba bean), as well as their interaction on the productivity of wheat grain yield (GY) and quality. The results showed that intercropping increased both the yields of wheat grain protein and amino acids (AAs) relative to MW in both years. No difference in Aas content between IW and MW was found but the 9% grain protein content (GPC) of IW was higher than that of MW in 2020. By contrast, wheat gliadin content was increased by 8–14% when wheat was intercropped with faba bean in both years, and some AAs fractions including essential and non-essential AAs were increased under N0 and N1 levels but declined at the N3 level. This means that intercropping increased the grain quality either for protein and AAs content or for fractions. There was no negative relationship between GPC and GY in the present study, and intercropping tended to increase GPC with increasing GY. In conclusion, wheat and faba bean mainly affected GPC and fractions rather than AAs, and intercropping presented a potential to improve both wheat quality and yield concurrently. Modulated N rates benefitted the stimulation of intercropping advantages in terms of grain yield and quality in the southwest of China and similar regions.

Nitrogen addition alters plant growth in China's Yellow River Delta coastal wetland through direct and indirect effects.

In the coastal wetland, nitrogen is a limiting element for plant growth and reproduction. However, nitrogen inputs increase annually due to the rise in nitrogen emissions from human activity in coastal wetlands. Nitrogen additions may alter the coastal wetlands’ soil properties, bacterial compositions, and plant growth. The majority of nitrogen addition studies, however, are conducted in grasslands and forests, and the relationship between soil properties, bacterial compositions, and plant growth driven by nitrogen addition is poorly understood in coastal marshes. We conducted an experiment involving nitrogen addition in the Phragmites australis population of the tidal marsh of the Yellow River Delta. Since 2017, four nitrogen addition levels (N0:0 g • m-2 • year-1, N1:5 g • m-2 • year-1, N2:20 g • m-2 • year-1, N3:50 g • m-2 • year-1) have been established in the experiment. From 2017 to 2020, we examined soil properties and plant traits. In 2018, we also measured soil bacterial composition. We analyzed the effect of nitrogen addition on soil properties, plant growth, reproduction, and plant nutrients using linear mixed-effect models. Moreover, structural equation modeling (SEM) was utilized to determine the direct and indirect effects of nitrogen addition, soil properties, and bacterial diversity on plant growth. The results demonstrated that nitrogen addition significantly affected plant traits of P. australis. N1 and N2 levels generally resulted in higher plant height, diameter, leaf length, leaf breadth, and leaf TC than N0 and N3 levels. Nitrogen addition had significantly impacted soil properties, including pH, salinity, soil TC, and soil TS. The SEM revealed that nitrogen addition had a direct and positive influence on plant height. By modifying soil bacterial diversity, nitrogen addition also had an small indirect and positive impact on plant height. However, nitrogen addition had a great negative indirect impact on plant height through altering soil properties. Thus, nitrogen inputs may directly enhance the growth of P. australis at N1 and N2 levels. Nonetheless, the maximum nitrogen addition (N3) may impede P. australis growth by reducing soil pH. Therefore, to conserve the coastal tidal marsh, it is recommended that an excess of nitrogen input be regulated.

NUT Carcinoma in Children and Adolescents: The Expert European Standard Clinical Practice Harmonized Recommendations.

Nuclear protein of the testis ( NUT ) carcinoma (NC) is a rare and highly aggressive tumor mainly occurring in adolescents and young adults, defined by the presence of a somatic NUTM1 rearrangement. The aim is to establish internationally harmonized consensus recommendations for the diagnosis and treatment of adolescents and young adults with NC in the framework of the European Reference Network for Paediatric Oncology. The European Cooperative Study Group for Pediatric Rare Tumors developed recommendations according to the Consensus Conference Standard Operating procedure methodology and reviewed by external "experts." No evidence of level I to II exists. Recommendations were developed based on published prospective (level III), but more frequently retrospective series (level IV), case reports (level V), and personal expertise (level V). In addition, "strength" of recommendations were categorized by grading (grade A to E). Histology is mandatory for the diagnosis of NC, including immunolabeling with anti-NUT antibodies and molecular biology ( NUTM1 rearrangement) (level V; grade A). Treatment of NC usually combines aggressive approaches in multimodal regimens. Chemotherapy should be considered as first-line treatment (neoadjuvant vincristine-adriamycin-ifosfamide/cisplatin-adriamycin-ifsofamide or vincristine-doxorubicin-cyclophosphamide/ifosfamide-etoposide) for unresectable or metastatic tumor (ie, 3 courses), rapidly followed by local treatment (level IV; grade B). Referral to a specialized surgical oncology center is highly recommended (level V; grade A). In localized NC, a complete microscopic surgical resection should be attempted whenever and as soon as possible, followed by primary irradiation (60 to 70Gy) and involved lymph nodes area (level IV; grade B). For head and neck tumors, a systematic neck dissection might be considered, even if N0 (level V; grade C). Adjuvant postirradiation chemotherapy is recommended, for a total of 9 to 12 courses (level IV; grade B). For first-line resected tumors, concomitant adjuvant chemotherapy to radiotherapy may be discussed (level IV; grade B). Targeted therapies and immunotherapeutic regimens should be delivered in the setting of prospective trials (level V; grade B). This project leads to a consensus strategy based on international experience with this very rare disease.

Interspecies interaction for nitrogen use efficiency via up-regulated glutamine and glutamate synthase under wheat-faba bean intercropping

• Intercropping drove higher grain N and total N accumulation, NTE, and NUE. • Interspecies interaction upregulated GS/GOGAT activity and gene expression in leaves. • GS/GOGAT stimulated by intercropping linked with higher straw and total N accumulation. • Upregulated GS/GOGAT after wheat heading stages contributed to higher NTE and NUE. Glutamine synthetase (GS) and the glutamate synthase (GOGAT) cycle are closely related to plant nitrogen (N) uptake, translocation, and remobilization, but little attention has been paid to their role in intercropping systems. A two-factor field trial involving two planting patterns (mono-cropped wheat [MW] and wheat intercropped with faba bean) and four N levels (N0, N1, N2, and N3 with respective application rates of 0, 90, 180, and 270 kg ha −1 for wheat) were studied. Nitrogen accumulation and allocation were determined, and the GS and GOGAT activities and their gene expression in the leaves were analyzed. The results showed that wheat total aboveground N accumulation and grain N accumulation were increased when wheat was intercropped with faba bean. Intercropped wheat (IW) presented higher N translocation efficiency (NTE) than MW (except for the N3 level during 2018–2019) during the reproductive growth stage. Thus, the grain yield (except for the N3 level), N harvest index (NHI), and apparent N recovery rate (ANR) were higher in IW than in MW. In addition, total GS, Fd-GOGAT, and NADH-GOGAT activities in the wheat leaves were increased by 27 %–42 %, 17 %–44 %, and 15 %–25 %, respectively, under the N0, N1, and N2 levels from the stem elongation to filling stages when wheat was intercropped with faba bean. On average, GS1, GS2, Fd-GOGAT, and NADH-GOGAT gene expression in the IW flag leaves was 1.4–4.3 times, 1.2–3.6 times, 1.2–2.2 times, and 1.4–6.7 times higher, respectively, than that in MW. Both GS and GOGAT activity and gene expression were tightly related to straw N accumulation and NTE rather than grain N accumulation based on simple correlation analysis. In addition, wheat total N accumulation at maturity was more sensitive to GS and GOGAT activity and gene expression in the flag leaves during the heading, flowering, and filling stages, and ANR only linked with GS and GOGAT activity at the filling stage. Hence, it could be concluded that up-regulated GS and GOGAT activity and gene expression induced by intercropping during the reproductive growth stages contributed to higher NTE and NUE in intercropping. These findings suggest that interspecies interactions modulated GS and GOGAT, which play a crucial role in the intercropping advantage and provide insight into the mechanism of enhanced NUE under intercropping.

PSXII-3 Identification of key metabolic mediators during dietary tryptophan supplementation in low-birth-weight pigs by RNA sequencing

Abstract Low birth weight (LBW) is associated with the development of metabolic syndrome, diabetes mellitus and insulin resistance. While tryptophan (Trp), one of essential amino acids supplied by diet, plays an essential role in fetal growth and development, the effects of Trp supplementation on metabolic processes of postnatal LBW individuals remain unclear. The objective of this study was to identify differentially expressed (DE) genes and altered biological processes in liver of LBW and normal birth weight (NBW) piglets supplemented with Trp. RNA was isolated from liver tissues of three weeks old piglets supplemented with Trp (NBW-0% and LBW-0, 0.4, and 0.8%) and was used for RNA sequencing (RNAseq). There were 100, 191 and 39 DE genes in NBW (N0) and LBW tryptophan 0.4%, 0.8% (L4 and L8) when compared to LBW without Trp supplementation (L0). To determine whether Trp supplementation can resume metabolic regulation-related gene expression to N0 level, DE genes from N0 vs. L0 were clustered into 3 groups based on co-expression trends and clusters were enriched for genes associated with lipid catabolic process, circadian regulation of gene expression and fatty acid response. Further, eight hub genes (PID1, PAFAH2, MAP3K15, ANKRD44, CYP2J34, N4BP2L1, RUSC1 and SALL1) identified in co-expression networks based on Pearson correlation coefficient had strong co-expression coefficients (|r| &amp;gt; 0.9) with each other. In particular, PID1 was significantly associated with many neurological, metabolic, environmental and cardiovascular traits based on phenome-wide association analysis (Phe-WAS). In summary, our study provides novel insights into the molecular mechanism underlying LBW metabolic changes with Trp supplementation in porcine liver tissue and highlights that LBW metabolism restoration may be regulated by genes participating in fatty acid response and cardiovascular diseases.

Soil Mineral and Nitrate Nitrogen, Plant N Uptake, N Use Efficiencies and Yield as Influenced by Tillage and Nitrogen Management under Wheat Crop in Sub-Tropical Eastern India

Accumulation of mineral nitrogen (min-N) in soil profile (0-90 cm) was significantly (p&lt;0.05) higher in conventional tillage (CT) than zero tillage (ZT) treatment plots both at 42 days after sowing (DAS) and 84 DAS of wheat, the increase over ZT being 58% and 44% respectively; but at the harvest stage an opposite trend was noted. Min-N accumulation in soil also varied significantly (p&lt;0.05) amongst N application rates with its highest value at N150 followed by subsequent reductions with decreasing N levels at all stages of wheat growth, except at harvest where N0 level had the highest accumulation (341.06 kg ha-1) which is ascribed to poor growth and very low plant N uptake. Significant effect of tillage was found on grain yield, dry matter yield and higher plant N uptake recorded under ZT plots over CT. Of the N application levels, N150 produced the highest grain yield and it was significantly (p&lt;0.05) higher than all other N treatments. ZT showed highest nitrogen use efficiencies [agronomic efficiency (AE), physiological efficiency (PE) and apparent recovery of nitrogen (ARN)] as compared to CT, whereas maximum values of AE (36.28) and PE (29.59) was observed at N120 and these were significantly higher than all other N treatments. As anticipated, highest ARN value was seen at N60 followed by its decrease with increasing levels of N application. Relative proportion of residual inorganic nitrogen (mineral vs. nitrate) in soil profile when compared at the harvest of wheat, a very high proportion of mineral (NH4+ + NO3-) as compared to nitrate nitrogen was evident under both the tillage treatments and more so in ZT than CT plots irrespective of N levels, indicating thereby the predominance NH4+ form of nitrogen in all the layers up to 90 cm soil profile which may be explained by lower nitrification rate due to high water storage in the soil profile during the entire wheat growing season. From the results, it is inferred that plots under ZT combined with N application @150 kg ha-1 proved superior to all other treatment combinations in respect of crop yield, nitrogen use efficiencies, plant N uptake and water storage in soil profile.

Quantification of nitrogen transformation and leaching response to agronomic management for maize crop under rainfed and irrigated condition

Nitrogen (N) plays an important role in agriculture crop production but the increasing application of nitrogen increases the possibilities of groundwater contamination through nitrate leaching. Nitrate leaching is the inevitable part of agriculture production which occurs during nitrogen fertilization. Hence, the quantification of nitrogen fertilizer is required to reduce nitrate leaching. In this study, nitrogen transformation and transport such as ammonium (NH4+) and nitrate (NO3−) at different soil depths and maize crop growth stages were measured during field experiments for two sowing dates (timely and delay) and four N fertilization levels under irrigated (year 2013 and 2014) and rainfed (year 2012 and 2014) conditions for maize crop. NH4+, NO3− and total nitrogen concentrations were measured using spectrophotometer at 410 nm and Kjeldahl method at varying soil depths and maize crop growth stages. Thereafter, nitrogen balance approach was used to estimate the NO3− leaching. Results indicated that NO3− leaching in irrigated condition was higher 109% in N75, 179% in N100, and 292% in N125 level respectively in comparison to the N0 level in timely sowing date, while in delayed sowing date, leaching was higher 54% in N75, 123% in N100, and 184% in N125 level respectively in comparison to N0 level. In rainfed, the NO3− leaching was higher 30% in N60, 59% in N80, and 99% in N100 level respectively in comparison to N0 level for the timely sowing date, while in delayed sowing, leaching was higher 23% in N60, 44% in N80, and 78% in N100 level respectively in comparison to N0 level. The results indicate that leaching losses were less in timely sowing dates for both rainfed and irrigated maize. The study further reveals that sowing dates combination with N levels could be an effective management strategy to reduce NO3− leaching by minimizing the N fertilization.

Plant-Based Biostimulants Influence the Agronomical, Physiological, and Qualitative Responses of Baby Rocket Leaves under Diverse Nitrogen Conditions.

Nitrogen is the primary technical means responsible for food production increase, but on the other hand, wise management is needed because its excessive use can have a negative impact on the environment and on green leafy vegetable quality, such as that rocket. Rocket has the characteristics of accumulating nitrate in leaves with possible impacts on human health. In order to overcome this issue, researchers are focusing their attention on the use of alternative means, such as plant biostimulant application. The scope of this study was to assess the effect of legume-derived protein hydrolysate(LDPH) and tropical plant extract(TPE), combined with various doses of nitrogen (0 kg ha−1 non-fertilized; N0); 60 kg ha−1 (sub-optimal; N1); 80 kg ha−1 (optimal; N2); and 100 kg ha−1 (supra-optimal; N3)), in order to reduce nitrogen use, boost yield, and enhance the chemical and nutritional value of leaves without significantly accumulating nitrate. Both vegetal-based plant biostimulants enhanced plant growth, boosted the marketable yield (especially at N0 and N1 levels, by 38.2% and 28.2%, respectively, compared to the non-treated control), and increased the SPAD (Soil Plant Analysis Development) index and leaf pigments content, such as chlorophyll and carotenoids, especially in treated-LDPH rocket. The plant-based biostimulants also produced a major amplification in lipophilic antioxidant activity (+ 48%) and total ascorbic acid content (average + 95.6%), especially at low nitrogen fertilization levels, and maintained nitrate content under the legal European Comission limits.

Effects of nitrogen management and intercropping on faba bean chocolate spot disease development

Chocolate spot disease, incited by Botrytis fabae, is a serious faba bean disease that occurs globally. The exploration of reasonable fertilization and planting patterns will help better control this disease. Four N levels (N0: 0 kg N ha−1, N1: 45 kg N ha−1, N2: 90 kg N ha−1, and N3: 135 kg N ha−1) and two cropping patterns (faba bean monocropping, faba bean and wheat intercropping) were examined for their effects on faba bean chocolate spot disease in Kunming, Yunnan Province, China, from 2015 to 2017. Nitrogen application increased the incidence and disease index of faba bean chocolate spot disease using monocropping and intercropping. Compared with the N0 level, the N1–N3 levels increased the incidence and disease index by 5.8%–42.0% and 3.8%–46.3%, respectively. Nitrogen application also reduced the temperature and increased the relative humidity of the canopy. Compared with monocropping, intercropping created a better ecological environment within the canopy by significantly increasing the temperature and reducing the relative humidity of the canopy. The incidence and incidence index of faba bean chocolate spot disease were significantly reduced, and the disease index decreased the most using the N2 level, which showed the best disease control effect. Compared with monocropping, the faba bean yield using intercropping increased by 21.6%–46.7%, and intercropping had a high land equivalent ratio (1.28–1.42). Considering the effects of faba bean disease control and increased yield, faba bean-wheat intercropping and a nitrogen application level of 90 kg N ha−1 is a good method to control chocolate spot disease and increase the faba bean yield. This work will increase the understanding of the impact of biodiverse cultivation and fertilization on sustainable agriculture and provide information on food security.

Deficit irrigation combined with reduced N-fertilizer rate can mitigate the high nitrous oxide emissions from Chinese drip-fertigated maize field

Agricultural soils are major sources of the greenhouse gas N2O, particularly under maize with high nitrogen (N) inputs and excessive irrigation. To determine how N and water management can mitigate N2O emissions from drip-irrigated maize fields, a field study was carried out in the North China Plain during the maize growing season. The objective of the study was to investigate the individual and combined effects of irrigation level and N input on N2O emissions and grain yields, as well as N and water use efficiency (WUE), under drip-fertigation management. The main treatments were two irrigation levels: 50 mm/event (sufficient irrigation, WH) and 25 mm/event (limited irrigation, WL), with four N application rates: 0 (N0), 90 (N1), 180 (N2), and 270 (N3) kg N ha−1. Pulses of N2O emissions were recorded every 2–3 d following each irrigation or fertigation (irrigation + fertilization) event. N input, irrigation, and their interactions all significantly influenced N2O emissions. A significant exponential relationship (P < 0.05) was observed between N application rate and cumulative and yield-scaled N2O emissions in both irrigation treatments. The cumulative N2O emission fluxes from the N0, N1, N2, and N3 levels of fertilizer with WL were 11.4, 13.8, 27.2, and 58.8% lower, respectively, than those from the same N levels with WH; this occurred because high pulses of N2O were avoided during low irrigation conditions. Under WH, denitrification was the likely source of the high amounts of N2O, whereas nitrification was likely the main source of N2O emissions under WL. The variations in the water-filled pore space (WFPS) between the two irrigation treatments may explain these results. The effect of N fertilizer on grain yield and WUE depended on the availability of soil water. Based on the available soil water content, the regulation of N fertilizer application can increase yield and also reduce cumulative and yield-scaled N2O emissions.

Application of WeChat combined with Wenjuanxing platform in hemodialysis nursing training

Objective To evaluate the effect of WeChat and Wenjuanxing platform on hemodialysis nursing training. Methods Since June, 2017, WeChat and Wejuanxing platform have been used as tools for nurse training assessment. According to time, the control group was from July, 2016 to May, 2017 and took traditional training and assessment methods; and the observation group was from June, 2017 to March, 2018. In the observation group, a WeChat combining Wenjuanxing platform management team was established; the training team arranged the content of monthly business learning, and uploaded the content to the WeChat platform after each business study; and each clinically responsible nurse could uploaded the problems discovered or existed at work to the WeChat platform through videos, pictures, etc. for learning and discussion. The team leader gave a solution after the WeChat consultation. At the end of each month, the team used the design questionnaire to conduct assessment, summary, and analysis. Results Compared with those in the control group, the first passing rate was higher and the theoretical examine time was significantly shorter in the observation group (both P<0.001). The first passing rates of theoretical examination were significantly higher in N0 (P<0.001) and N1 level (P < 0.001) nurses in the observation group than in the control group. Conclusions As new network tools, Wechat and Wenjuanxing platform are convenient and fast, and can save nurses’ time. The new nursing training tools stimulate nurses enthusiasm for professional study. At the same time, they improve the effectiveness of training, which can be widely available for clinical nursing training. Key words: WeChat; Wenjuanxing; Nursing training; Hemodialysis

Salinity mediates the effects of nitrogen enrichment on the growth, photosynthesis, and biochemical composition of Ulva prolifera.

To study the combined effects of multiple nitrogen (N) sources and salinity on the growth and physiology on macroalgae, we cultured Ulva prolifera under three N levels (N0, 0.1235 mg L-1; N1, 0.6 mg L-1; and N2, 4.4 mg L-1; the ratios were 18:74:8 for NH4-N, NO3-N, and NO2-N, respectively) and three salinity conditions (15, 25, and 35). Then, the growth, pigment content, photosynthetic performance, superoxide dismutase (SOD) activity, and contents of soluble protein and carbohydrates were measured. The results showed the following: (1) Compared to that grown at salinity 25, the growth of U. prolifera decreased under salinity 35, especially under the N0 and N2 levels, but there were no significant effects of salinity 15 under any of the N levels. (2) There were no significant effects of salinity on the chlorophyll a (Chla) content, but compared to the content at salinity 25, the chlorophyll b (Chlb) content was enhanced by salinity 15 and 35; lower ratio values between Chla and carotenoids (Car) occurred under the salinity 25 treatment. Under each salinity condition, the pigments were enhanced by a high N level. (3) A relatively higher salinity level decreased the photosynthetic oxygen evolution rate, while a higher N level increased this value. Compared to the rate at salinity 25, the dark respiration rate (Rd) significantly increased at salinity 15 under the N0 condition. (4) SOD activity was enhanced by a high N level, but no significant effects of salinity were observed. (5) The carbohydrate content was enhanced at salinity 35 under the N0 and N1 levels, and under salinity 15, this value increased with increasing N levels. In conclusion, although the growth of U. prolifera decreased at high N levels under high salinity conditions, a high N level induced an increase in photosynthesis, while no significant decrease in growth occurred. These findings indicate that low salinity and high N levels may be nonnegligible reasons why this species thrives, and low salinity was the better choice when this species was used for wastewater treatment.

Status quo of primary nurse at different levels in a Class III Grade A hospital in Yantai City

Objective To explore the status quo of workload in primary nurses at different levels and to provide a basis for hierarchical management over nursing staff. Methods Totally 45 wards of a Class Ⅲ Grade A hospital in Yantai City were selected by cluster sampling from February 20th to March 19th, 2017, including 23 from internal medicine departments and 22 from surgery departments. Nursing workers were divided into 5 levels ranging from N0 to N4 according to hierarchical management protocols. The self-designed workload questionnaire was used to investigate all primary nurses at different levels in terms of patients in charge, direct and indirect nursing items and walking distance during work. The workload of totally 7 113 nurses at different levels was investigated. Results There was statistical difference in the number of patients in charge, critical patients, high-risk patients with pressure ulcers, high-risk patients with pressure falls and severely dependent patients between nurses at different levels (P<0.05) . The top 3 time-consuming nursing items in primary nurses at different levels were identical, which were drug therapy, severity assessment and observation and health education. Primary nurses at N0 and N1 levels needed more time for therapy-related preparation than primary nurses at N2 and N3 levels (P<0.05) . There was statistical difference in number of steps per shift during work between nurses at different levels (P<0.01) . Conclusions The number of patients in charge and the patients' severity correspond to the levels of primary nurses. The nursing work of these primary nurses at different levels are basically the same except for clinical teaching items. Nursing managers shall explore a hierarchical management model over nurses, properly configuring nurses at different levels, giving full play to the force of the nursing team, and managing the nursing team scientifically according to clinical practice in China. Key words: Nurses; Nursing management research; Nursing workload; Hierarchical management

Source-sink relations and kernel weight in maize inbred lines and hybrids: Responses to contrasting nitrogen supply levels

Maize (Zea mays, L.) kernel weight (KW) is regulated by the source-sink relationship at the early grain-filling period, when potential kernel size is defined, and at the effective grain-filling period, when final KW is established. The relative importance of each period is expected to depend upon the occurrence or not of environmental restrictions to plant growth. The objective of this study was to analyze the effect of nitrogen (N) availability on KW determination in two different groups of genotypes (inbreds and hybrids) when it is caused by changes in the source-sink relationship at mentioned periods. Six inbred lines of different genetic background and their F1 derived hybrids were tested in the field under two contrasting soil N levels (N0: low; N1: high). Almost all evaluated traits had greater mean values (P < 0.001) at N1 than at N0 level, except the plant growth rate per kernel during the critical period for kernel set (PGRCP kernel−1). However, the magnitude of the response to increased N was considerably higher for hybrids than for inbreds. Under contrasting N availability, plant growth during grain filling (PGGF) was the main determinant of increments registered in the source-sink ratio during this stage (i.e. PGGF kernel−1), and KW was chiefly associated with this ratio (r2 ≥ 0.50, P < 0.001). By contrast, the association between KW and PGRCP kernel-1 was important only at N1, and more robust for hybrids (r2 = 0.61, P < 0.001) than for inbreds (r2 = 0.34, P < 0.001). The uncoupling between both source-sink ratios observed at N0, as a result of a decreased post-flowering growth in this treatment, was responsible for differences in KW response to the PGRCP kernel−1 detected between N levels. The KW of inbreds was almost unaffected by mentioned N effects on the analyzed source-sink ratios, a trend attributed to negative inbreeding depression effects on traits controlling seed expansion. These differential responses between genotypic groups should be considered in breeding programs targeting KW increase.

Grain yield and nitrogen use efficiency of various modern rice cultivars grown at different nitrogen levels

ABSTRACTField trials were conducted to study the responses of grain yield and nitrogen (N) use efficiency at five input rates (N0, N82.5, N165, N247.5, and N330 kg ha−1) in a set of nine of the most representative rice cultivars. Grain yields of rice across the nine cultivars were increased significantly by N level. All the cultivars contained a significant linear plus plateau or quadratic relationship between N levels and grain yields.The minimum yields (means of 2 years) at N0, N82.5, N165, N247.5, and N330 level all occurred in No. 2 cultivar. Compared with the grain yield of No. 2 at different N levels, those of the maximum cultivars increased by 37.1 (No. 8), 39.1 (No. 7), 48.4 (No.3), 43.3 (No. 4), and 43.9% (No. 3), respectively. In 2011, the highest average apparent nitrogen recovery efficiency (ANRE) in grain of the 4 N levels occurred in No. 3 cultivar (45.9%), followed by No. 4, No. 6, and No. 1, and the highest average agronomic efficiency (AE) in grain of the 4 N levels occurred in No. 9 cultivar [29.0 kg (kg N)−1], followed by No. 3, No. 1, and No. 4. For the second-season planting, the highest average ANRE occurred in No. 4 cultivar (28.4%), followed by No. 3, No. 5, and No. 6, and the highest average AE occurred in No. 5 cultivar [18.1 kg (kg N)−1], followed by No. 4, No. 3, and No. 7. Overall, No. 3 and No. 4 cultivars were the ideal ones that not only increased the grain yield but also improved the N use efficiency.

Influence of patient and provider factors on the workload of on-call physicians: A general internal medicine cohort observational study.

Factors associated with the physician workload are scarcely reported. The study aims to investigate the associated factors of on-call physician workload based on a published conceptual framework.The study was conducted in a general internal medicine unit of National Taiwan University Hospital. On-call physician workloads were recorded on a shift basis from 1198 hospitalized patients between May 2010 and April 2011. The proxy of on-call workloads included night calls, bedside evaluation/management (E/M), and performing clinical procedures in a shift. Multivariable logistic and negative binomial regression models were used to determine the factors associated with the workloads of on-call physicians.During the study period, 378 (31.6%) of patients had night calls with related workloads. Multivariate analysis showed that the number of patients with unstable conditions in a shift (odds ratio [OR] 1.89 and 1.66, respectively) and the intensive care unit (ICU) training of the nurse leader (OR 2.87 and 3.08, respectively) resulted in higher likelihood of night calls to and bedside E/M visits by the on-call physician. However, ICU training of nurses (OR = 0.37, 95% confidence interval: 0.16–0.86) decreased the demand of performing clinical procedures by the on-call physician. Moreover, number of patients with unstable conditions (risk ratio [RR] 1.52 and 1.55, respectively) had significantly increased the number of night calls and bedside E/M by on-call physicians by around 50%. Nurses with N1 level (RR 2.16 and 2.71, respectively) were more likely to place night calls and facilitate bedside E/M by the on-call physician compared to nurses with N0 level. In addition, the nurse leaders with ICU training (RR 1.72 and 3.07, respectively) had significant increases in night calls and bedside E/M by the on-call physician compared to those without ICU training.On-call physician workload is associated with patient factors and the training of nurses. Number of unstable patients in a shift may be considered in predicting workload. The training of nurses may improve patient safety and decrease demand for clinical procedure.

Impacts of laparoscopic hysterectomy on functions of coagulation and fibrinolysis system.

The main objective of the study is to compare the impacts of laparoscopic hysterectomy and total abdominal hysterectomy on the functions of coagulation and fibrinolysis system. Seventy-five patients who had undergone hysterectomy were randomly divided into laparoscopic hysterectomy group (n = 38) and total abdominal hysterectomy group (n = 37). The prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen, D-dimer, von Willebrand factor, α-granule membrane protein-140, thrombin-activated fibrinolysis inhibitor (TAFI) and platelet count were detected at preoperative 24 h (N0), postoperative 24 h (N1) and postoperative 48 h (N2). Compared with N0, values of PT, APTT and TT were significantly decreased at N1 in both groups, whereas von Willebrand factor, platelet count and α-granule membrane protein-140 levels at N1 were significantly increased (P < 0.05). There was no significant difference between N0 and N2 (P > 0.05). Compared with N0, fibrinogen, D-dimer and TAFI levels in both groups were significantly higher at N1 (P < 0.05), and there was no significant difference between N0 and N2 (P > 0.05). The intergroup comparison showed no significant difference of above indexes between two groups (P > 0.05). The univariate analysis showed that TAFI was negatively correlated with TT (r = -0.365, P < 0.01), APTT (r = -0.183, P < 0.05) and PT (r = -0.121, P < 0.05), whereas not correlated with other indicators. Laparoscopic hysterectomy may increase the risk of postoperative venous thrombosis.