Effect of full substituting compound fertilizer with different organic manure on reactive nitrogen losses and crop productivity in intensive vegetable production system of China.

How substituting compound fertilizer with organic manure affects crop productivity and reactive nitrogen (Nr) losses from vegetable production system during the cradle-to-gate life cycle is not well understood. We thus investigated the impact of substituting compound fertilizer with various organic manures (stored solid manure and composted manure) on spinach productivity, Nr losses (e.g. NH3, N2O, NOx, N-leaching) and yield-based Nr losses in Changsha, Hunan, China. We found that the application of stored solid manure and composted manure decreased the total Nr losses by 58.1% and 75.0%, respectively, compared with compound fertilizer, but the spinach productivity was also decreased by 27.9% and 16.4%. Overall, substituting compound fertilizer with organic manure decreased yield-based Nr loss by 41.9-70.1%. These results highlight that substituting compound fertilizer with organic manure, particularly composted manure, may be beneficial to the environment at the expense of vegetable productivity. Strategies should be developed to decrease Nr losses from N input without compromising productivity in intensive vegetable production system.

Photoinduced Absorption Spectroscopy of Photoelectrocatalytic Methylene Blue Oxidation on Titania and Hematite: The Thermodynamic and Kinetic Impacts on Reaction Pathways.

Photoelectrochemical oxidation of methylene blue is investigated, with particular focus on the difference in kinetics and thermodynamics of decoloration and mineralization employing photoinduced absorption spectroscopy. Hematite and titania photoanodes are used for the comparison of both reactions, which is determined to be associated with the depth of the valence band (3.2 vs 2.5 V for titania and hematite, respectively). Methylene blue is mineralized by the titania photoanode, however it is only oxidized to small fragments by hematite. Such difference is related to the valence band potential that provides the thermodynamic driving force for photogenerated holes in both materials. In addition, the kinetic competition of water oxidation is found to occur on titania by controlling the pH of the electrolyte. In the pH 14 electrolyte, mineralization of methylene blue is suppressed due to the faster and dominant kinetics of water oxidation, in contrast to the complete mineralization in the near neutral electrolyte where water oxidation kinetics are modest. These results clearly address the importance considering both thermodynamic and kinetic challenges of methylene blue oxidation, which has been thought to be an easy molecule to oxidize, as the model reaction in the application of photo(electro)catalysis using metal oxides.

Effects of Exercise on Patients with Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis.

With exercise being more frequently utilized in treatment for obstructive sleep apnea (OSA), a systematic review of the intervention efficacy of exercise on OSA is necessary. PubMed, EBSCO, Web of Science, VIP, and CNKI databases were searched to collect randomized controlled trials (RCTs) of exercise applied to OSA from January 2000 to January 2022. The literature screening, data extraction, and risk of bias assessment of included studies were conducted independently by two reviewers. Meta-analysis was then performed using Rev Man 5.4 software. A total of 9 RCTs were included, including 444 patients. Compared with the control group, exercise made an improvement in apnea-hypopnea index (AHI) [MD = -6.65, 95% CI (-7.77, -5.53), p < 0.00001], minimum oxygen saturation (SaO2min%) [MD = 1.67, 95% CI (0.82, 2.52), p = 0.0001], peak oxygen uptake (VO2peak) [SMD = 0.54, 95% CI (0.31, 0.78), p < 0.00001], Pittsburgh sleep quality index (PSQI) [MD = -2.08, 95% CI (-3.95, -0.21), p = 0.03], and Epworth Sleepiness Scale (ESS) values [MD = -1.64, 95% CI, (-3.07, -0.22), p = 0.02]. However, there were no significant changes in body mass index (BMI). As for the results of subgroup analysis, aerobic exercise combined with resistance exercise [MD = -7.36, 95% CI (-8.64, -6.08), p < 0.00001] had a better effect on AHI reduction than aerobic exercise alone [MD = -4.36, 95% CI (-6.67, -2.06), p = 0.0002]. This systematic review demonstrates that exercise reduces the severity of OSA with no changes in BMI, and the effect of aerobic exercise combined with resistance training is better than aerobic exercise alone in AHI reduction. Exercise also improves cardiopulmonary fitness, sleep quality, and excessive daytime sleepiness.

Detection of 20 endogenous anabolic steroid esters with Girard's Reagent P derivatization in dried blood spots using UPLC-Q-Orbitrap-MS.

The esters of endogenous anabolic steroids are the most frequently used doping agents for prolonging the half-life of exogenously ingested endogenous anabolic steroids. As a cost- and time-saving matrix, dried blood spots (DBSs) are valuable for directly detecting endogenous anabolic steroid esters in blood and for providing conclusive evidence of their abuse. In this study, a method for simultaneous detection of 20 endogenous anabolic steroid esters in DBSs based on ultra-high performance liquid chromatography-quadrupole-Orbitrap mass spectrometry (UPLC-Q-Orbitrap-MS) with parallel reaction monitoring (PRM) was developed and validated, and 10 of these esters were analyzed in DBSs for the first time. This method analyzes the greatest number and types of endogenous anabolic steroid esters of any current method using DBSs. Girard's Reagent P (GRP) was used for the derivatization of endogenous anabolic steroid esters in a DBS matrix for the first time, and the conditions of the derivatization reaction were optimized to achieve a higher sensitivity compared to previous methods. Selectivity, limit of detection (LOD), extraction recovery, precision (intra- and inter-), matrix effects, and carry-over were analyzed to validate the method. The LODs were lower and the recoveries were higher than those of previous studies. The relative standard deviation of the intraday precision was below 20% and the interday precision was below 35%. A product ion analysis of GRP nandrolone ester, GRP boldenone ester, GRP dehydroepiandrosterone acetate, and GRP androstanolone ester derivatives was performed, and the structures of the fragment ions were proposed for the first time.

Identification and characterization of higenamine metabolites in human urine by quadrupole-orbitrap LC-MS/MS for doping control.

Higenamine is an alkaloid found in aconite, Annona squamosa, nanzhu (sacred bamboo), and other plants. It can be used to treat coughing, asthma, heart failure, and erectile dysfunction as well as aid in weight loss. It is also a banned substance in and out of competition as defined by the World Anti-Doping Agency (WADA). In this work, higenamine metabolic profiles were investigated in detail. Two healthy volunteers (one male and one female) took a higenamine tablet (5 mg), and urine samples were collected for two weeks. Solid-phase extraction (SPE) without enzymatic hydrolysis was used to clean the urine samples, and the urine extracts were then analyzed by liquid chromatography-quadrupole-orbitrap mass spectrometry (quadrupole-orbitrap LC-MS/MS) with accurate mass measurements. Higenamine and 32 metabolites were detected: 6 methylated, 10 sulfated and 16 glucuronidated metabolites. The chemical structures were elucidated by their fragmentation patterns, and accurate molecular formula determination was obtained for these newly reported metabolites. Three metabolic pathways containing methylation, glucuronidation, sulfation, and combinations of these were provided with methylation as the main metabolic pathway. The post-dose detection windows within urine of all 32 metabolites were compared with that of the parent drug, and a new potential biomarker (M7) was suggested for higenamine misuse. All urine samples were processed by two sample preparation methods: the dilute-and-shoot (DS) procedure and acid hydrolysis followed by SPE, and the time periods for a higenamine positive trails of two methods were compared. Although the DS method used to process the urine samples of athletes in the most of WADA-accredited laboratories to detect only free higenamine, acid hydrolysis followed by SPE is preferable and offers routine analysis to avoid false-negative results.

Mechanistic Insights into Selective Acetaldehyde Formation from Ethanol Oxidation on Hematite Photoanodes by Operando Spectroelectrochemistry.

This study employed operando spectroelectrochemical l and photoelectrochemical methods to investigate the charge carrier dynamics of photogenerated holes in hematite for ethanol oxidation and its possible over-oxidation. Ethanol oxidation was found to form acetaldehyde with around 100 % initial selectivity and faradaic efficiency. The overoxidation of acetaldehyde was suppressed by being unable to kinetically compete with ethanol oxidation in terms of turnover frequency by a factor of ten. Temperature-dependent rate law analyses were applied to determine the activation energies of these two oxidations. For the ethanol oxidation, the activation energy was 195 meV, compared to 398 meV for acetaldehyde oxidation. These results were correlated with the valence band potential to elucidate the advantage of using hematite for safer and sustainable value-added aldehyde synthesis compared to the industrial method. The dynamics of ethanol oxidation also addressed the challenges in broad-spectrum deep oxidation of organic compounds in water purification using metal oxides.

Genomic and Transcriptomic Analyses Reveal Pathways and Genes Associated With Brittle Stalk Phenotype in Maize.

The mechanical strength of the stalk affects the lodging resistance and digestibility of the stalk in maize. The molecular mechanisms regulating the brittleness of stalks in maize remain undefined. In this study, we constructed the maize brittle stalk mutant (bk5) by crossing the W22:Mu line with the Zheng 58 line. The brittle phenotype of the mutant bk5 existed in all of the plant organs after the five-leaf stage. Compared to wild-type (WT) plants, the sclerenchyma cells of bk5 stalks had a looser cell arrangement and thinner cell wall. Determination of cell wall composition showed that obvious differences in cellulose content, lignin content, starch content, and total soluble sugar were found between bk5 and WT stalks. Furthermore, we identified 226 differentially expressed genes (DEGs), with 164 genes significantly upregulated and 62 genes significantly downregulated in RNA-seq analysis. Some pathways related to cellulose and lignin synthesis, such as endocytosis and glycosylphosphatidylinositol (GPI)-anchored biosynthesis, were identified by the Kyoto Encyclopedia of Gene and Genomes (KEGG) and gene ontology (GO) analysis. In bulked-segregant sequence analysis (BSA-seq), we detected 2,931,692 high-quality Single Nucleotide Polymorphisms (SNPs) and identified five overlapped regions (11.2 Mb) containing 17 candidate genes with missense mutations or premature termination codons using the SNP-index methods. Some genes were involved in the cellulose synthesis-related genes such as ENTH/ANTH/VHS superfamily protein gene (endocytosis-related gene) and the lignin synthesis-related genes such as the cytochrome p450 gene. Some of these candidate genes identified from BSA-seq also existed with differential expression in RNA-seq analysis. These findings increase our understanding of the molecular mechanisms regulating the brittle stalk phenotype in maize.

Dried blood spots in doping analysis.

A series of dried blood spot (DBS) detection methods for doping agents have been developed in the last two decades. The DBS technique minimizes invasiveness and reduces storage and shipping costs. Recently, the World Anti-Doping Agency announced the use of DBS for the 2022 Beijing Winter Olympic Games and Paralympic Games owing to the advantages of the DBS application in routine doping control. Therefore the further development of detection methods for doping agents in DBS is important and urgent. This review summarizes five aspects of DBS application in doping analysis: sample collection, storage conditions, pretreatment, instrumentation and validation according to the Prohibited List issued by the World Anti-Doping Agency, and proposes some suggestions for future studies of DBS in doping analysis.

A Cytochrome B5-Like Heme/Steroid Binding Domain Protein, PlCB5L1, Regulates Mycelial Growth, Pathogenicity and Oxidative Stress Tolerance in Peronophythora litchii.

As an electron transport component, cytochrome b5 is an essential component of the Class II cytochrome P450 monooxygenation system and widely present in animals, plants, and fungi. However, the roles of Cyt-b5 domain proteins in pathogenic oomycetes remain unknown. Peronophythora litchii is an oomycete pathogen that causes litchi downy blight, the most destructive disease of litchi. In this study, we identified a gene, designated PlCB5L1, that encodes a Cyt-b5 domain protein in P. litchii, and characterized its function. PlCB5L1 is highly expressed in the zoospores, cysts, germinated cysts, and during early stages of infection. PlCB5L1 knockout mutants showed reduced growth rate and ß-sitosterol utilization. Importantly, we also found that PlCB5L1 is required for the full pathogenicity of P. litchii. Compared with the wild-type strain, the PlCB5L1 mutants exhibited significantly higher tolerance to SDS and sorbitol, but impaired tolerance to cell wall stress, osmotic stress, and oxidative stress. Further, the expression of genes involved in oxidative stress tolerance, including peroxidase, cytochrome P450, and laccase genes, were down-regulated in PlCB5L1 mutants under oxidative stress. This is the first report that a Cyt-b5 domain protein contributes to the development, stress response, and pathogenicity in plant pathogenic oomycetes.

[Emission of NH3 and N2O from Spinach Field Treated with Different Fertilizers].

Agricultural management techniques such as fertilizer or manure application have substantial influence on NH3 and N2O emissions and, by understanding this influence, management strategies can be developed to reduce them. An experiment was conducted in a greenhouse at Hunan Agricultural University during 2012 to 2013, to investigate effects of different fertilizers on NH3 and N2O emissions. The treatments included control without fertilizer (CK), swine composting fertilizer (SC), stored swine manure fertilizer (SS), and chemical fertilizer (FC). The fluxes of NH3 and N2O were collected by venting method and static-chamber method, respectively. The results showed that during the spinach growth season, compared with FC, loss of both NH3 and N2O for SC were reduced by 52.9% and 95.12%, respectively(P<0.01). However, loss of NH3 for SS increased by 24.8%, and loss of N2O reduced by 48.8% compared with FC. Loss rate of NH3 were SS (10.97%) > FC (4.19%) > SC(2.74%), and emission coefficient for N2O were FC(4.50%) > SC(2.21%) > SS(0.60%). Yield and utilization of nitrogen for SC were reduced by 19.61% and 13.20% compared with FC, respectively, but not significantly; and significantly reduced by 27.9% and 40.0% compared with SS, respectively. Loss of gases (NH3 and N2O) for SC were 1.83%, which was the lowest, while utilization of nitrogen for SC was 13.20%, similar with FC. Greenhouse temperature was not the critical factor during the spinach planting in winter, but soil water was. Therefore, optimizing manure management could reduce ammonia volatilization and N2O emission loss without decreasing vegetables production, and the present data indicated that SC would be optimal for better yields with reduced ammonia volatilization and N2O emission loss.

[Emissions of NH3, N2O, and NO from swine manure solid storage in winter].

Swine manure solid storage is a typical management in rural area of China. In order to investigate the characteristics of NH3, N2O and NO emissions during manure storage in winter (Nov., 2012 to Feb., 2013), two treatments were conducted: non-covered (NC) and covered (C) with straws, and each treatment had three times of pile-turning during the 73 days storage. The emission fluxes of three nitrogen gases (NH3, N2O and NO) were measured and the profile-N2O concentrations inside the swine pile profile and in the soil under the pile were also measured. The results indicated that 2.1%-2.6%, 0.02% and -0.000 25% of total nitrogen were lost in the form of NH3, N2O and NO respectively during the whole swine manure solid storage. The nitrogen gases in the two treatments had the same variation characteristics, but all the nitrogen gases were reduced in the covered treatment. In the early storage stage, NH3 emission peak occurred first and then the emissions of N2O and NO started increasing. In the middle storage stage, the emissions of NH3 and NO showed mutual growth and decline trend. In the late storage stage, N2O emission peak was twice higher than that in the early stage, while NH3 and NO emissions showed a slight increase. Before and after pile-turning operation, NH3 emission had little change, but N2O emission was decreasing and NO emission was rising after pile-turning.

[Performance of nitrogen and phosphorus removal of sulfur/limestone autotrophic denitrification system].

In order to investigate the performance of nitrogen and phosphorus removal of the sulfur/limestone system from low C/N municipal sewage, a sulfur/limestone packed column reactor fed with synthetic wastewater, and operated in the way of anaerobic biological filter was constructed. The effects of HRT, initial concentration of phosphate, pH and temperature on nitrogen and phosphorus removal were studied. The results showed that with influent of NO3(-) -N 30 mg/L, PO4(3-) -P 15 mg/L, the optimal HRT value was 6 h, and removal rates of TN and phosphorus were 100% and 44.64% respectively. Initial concentration of phosphate and initial pH had a significant influence on nitrogen and phosphorus removal. In order to keep nitrogen removal rate higher than 90%, initial concentration of phosphate should not be below 0.4 mg/L; the optimal pH value was 6.5, and removal rates of TN and phosphorus were 91.51% and 47.68% respectively. Temperature had a positive impact on that system, the nitrogen and phosphorus removal rate decreased with decreasing temperature. The nitrate removal efficiency was high in the temperature range of 18-30 degrees C, and the efficiency of phosphorus removal rate reached about 50%, when the temperature was between 25-30 degrees C. The dephosphorization behavior of sulfur/ limestone system correlated closely with autotrophic denitrification process, and the mechanism of phosphate removal of the SLAD system was mainly due to chemical precipitation. The system had the performance of nitrogen and phosphorus removal from low C/N municipal sewage, the highest phosphorus removal rate could reach 50%.