Hebei Agricultural University

Excessive N fertilization in intensive agricultural areas of China has resulted in serious environmental problems because of atmospheric, soil, and water enrichment with reactive N of agricultural origin. This study examines grain yields and N loss pathways using a synthetic approach in 2 of the most intensive double-cropping systems in China: waterlogged rice/upland wheat in the Taihu region of east China versus irrigated wheat/rainfed maize on the North China Plain. When compared with knowledge-based optimum N fertilization with 30-60% N savings, we found that current agricultural N practices with 550-600 kg of N per hectare fertilizer annually do not significantly increase crop yields but do lead to about 2 times larger N losses to the environment. The higher N loss rates and lower N retention rates indicate little utilization of residual N by the succeeding crop in rice/wheat systems in comparison with wheat/maize systems. Periodic waterlogging of upland systems caused large N losses by denitrification in the Taihu region. Calcareous soils and concentrated summer rainfall resulted in ammonia volatilization (19% for wheat and 24% for maize) and nitrate leaching being the main N loss pathways in wheat/maize systems. More than 2-fold increases in atmospheric deposition and irrigation water N reflect heavy air and water pollution and these have become important N sources to agricultural ecosystems. A better N balance can be achieved without sacrificing crop yields but significantly reducing environmental risk by adopting optimum N fertilization techniques, controlling the primary N loss pathways, and improving the performance of the agricultural Extension Service.

Fusarium oxysporum f. sp. elaeidis (FOE) a pathogen that causes fusarium wilt disease in oil palm can be detected using polymerase chain reaction (PCR) but very time consuming. Loop-Mediated Isothermal Amplification (LAMP) was used to rapidly detect Fusarium oxysporum f. sp. elaeidis (FOE) in oil palm seedlings. Eight additional Fusarium oxysporum isolates collected from symptomatic oil palm trees (i.e., presumed-FOE as their pathogenicity was not confirmed) and five other non-FOE isolates were sampled from symptomatic mature oil palm trees and tomato respectively to broaden the scope of the research. The identities of FOE, presumed-FOE and non-FOE were established via sequencing. LAMP primers designed for detecting FOE or presumed-FOE was based on partial sequences of Secreted in Xylem (SIX8) and P-450 cytochrome. The earliest detection time for SIX8 and P-450 cytochrome primers were 4:00 mins and 6:45 mins respectively with both recording late time for detection at 26:30 mins. Annealing derivative curves were used for assessing the level of specificity for both SIX8 and P-450 cytochrome, but none of the LAMP primers could distinguish between FOE, presumed-FOE and non-FOE.

Mobile robot path planning refers to the design of the safely collision-free path with shortest distance and least time-consuming from the starting point to the end point by a mobile robot autonomously. In this paper, a systematic review of mobile robot path planning techniques is presented. Firstly, path planning is classified into global path planning and local path planning according to the mastery of environmental information. In the global path planning, environment modeling methods and path evaluation method are introduced. The methods of environment modeling include grid method, topology method, geometric feature method and mixed representation method. In the local path planning, we introduce the sensors commonly used in the detection environment, including laser radar and visual sensor. Next, according to the characteristics of algorithms, mobile robot path planning algorithms are divided into three categories: classical algorithms, bionic algorithms and artificial intelligence algorithms. Among the classical algorithms, we introduce the cell decomposition method, sampling based method, graph search algorithm, artificial potential field method and dynamic window method. In the algorithm based on bionics, we introduce genetic algorithm, ant colony algorithm, gray wolf algorithm, etc. in detail. In artificial intelligence algorithm, we introduce neural network algorithm and fuzzy logic. Finally, we compare the key technologies of mobile robot path planning in the form of graphs and charts based on the classification statistics of the collected literature to provide references for future research.

Respiratory tract viral infection caused by viruses or bacteria is one of the most common diseases in human worldwide, while those caused by emerging viruses, such as the novel coronavirus, 2019-nCoV that caused the pneumonia outbreak in Wuhan, China most recently, have posed great threats to global public health. Identification of the causative viral pathogens of respiratory tract viral infections is important to select an appropriate treatment, save people's lives, stop the epidemics, and avoid unnecessary use of antibiotics. Conventional diagnostic tests, such as the assays for rapid detection of antiviral antibodies or viral antigens, are widely used in many clinical laboratories. With the development of modern technologies, new diagnostic strategies, including multiplex nucleic acid amplification and microarray-based assays, are emerging. This review summarizes currently available and novel emerging diagnostic methods for the detection of common respiratory viruses, such as influenza virus, human respiratory syncytial virus, coronavirus, human adenovirus, and human rhinovirus. Multiplex assays for simultaneous detection of multiple respiratory viruses are also described. It is anticipated that such data will assist researchers and clinicians to develop appropriate diagnostic strategies for timely and effective detection of respiratory virus infections.

BACKGROUND AND AIMS: Corn (Zea mays) responds to salt stress via changes in gene expression, metabolism and physiology. This adaptation is achieved through the regulation of gene expression at the transcriptional and post-transcriptional levels. MicroRNAs (miRNAs) have been found to act as key regulating factors of post-transcriptional gene expression. However, little is known about the role of miRNAs in plants' responses to abiotic stresses. METHODS: A custom microparaflo microfluidic array containing release version 10.1 plant miRNA probes (http://microrna.sanger.ac.uk/) was used to discover salt stress-responsive miRNAs using the differences in miRNA expression between the salt-tolerant maize inbred line 'NC286' and the salt-sensitive maize line 'Huangzao4'. Key Results miRNA microarray hybridization revealed that a total of 98 miRNAs, from 27 plant miRNA families, had significantly altered expression after salt treatment. These miRNAs displayed different activities in the salt response, and miRNAs belonging to the same miRNA family showed the same behaviour. Interestingly, 18 miRNAs were found which were only expressed in the salt-tolerant maize line, and 25 miRNAs that showed a delayed regulation pattern in the salt-sensitive line. A gene model was proposed that showed how miRNAs could regulate the abiotic stress-associated process and the gene networks coping with the stress. CONCLUSIONS: Salt-responsive miRNAs are involved in the regulation of metabolic, morphological and physiological adaptations of maize seedlings at the post-transcriptional level. The miRNA genotype-specific expression model might explain the distinct salt sensitivities between maize lines.

The increasing antimicrobial resistance in manure-amended soil can potentially enter food chain, representing an important vehicle for antibiotic resistance genes (ARGs) transmission into human microbiome. However, the pathways for transmission of ARGs from soil to plant remain unclear. Here, we explored the impacts of poultry and cattle manure application on the patterns of resistome in soil and lettuce microbiome including rhizosphere, root endosphere, leaf endosphere and phyllosphere, to identify the potential transmission routes of ARGs in the soil-plant system. After 90 days of cultivation, a total of 144 ARGs were detected in all samples using high-throughput quantitative PCR. Rhizosphere soil samples harbored the most diverse ARGs compared with other components of lettuce. Cattle manure application increased the abundance of ARGs in root endophyte, while poultry manure application increased ARGs in rhizosphere, root endophyte and phyllosphere, suggesting that poultry manure may have a stronger impact on lettuce resistomes. The ARG profiles were significantly correlated with the bacterial community, and the enrichment of soil and plant resistomes was strongly affected by the bacterial taxa including Solibacteres, Chloroflexi, Acidobacteria, Gemm-1 and Gemmatimonadetes, as revealed by the network analyses. Moreover, the overlaps of ARGs between lettuce tissues and soil were identified, which indicated that plant and environmental resistomes are interconnected. Our findings provide insights into the transmission routes of ARGs from manured soil to vegetables, and highlight the potential risks of plant resistome migration to the human food chain.

China's livestock industry has experienced a vast transition during the last three decades, with profound effects on domestic and global food provision, resource use, nitrogen and phosphorus losses, and greenhouse gas (GHG) emissions. We provide a comprehensive analysis of the driving forces around this transition and its national and global consequences. The number of livestock units (LUs) tripled in China in less than 30 years, mainly through the growth of landless industrial livestock production systems and the increase in monogastric livestock (from 62 to 74% of total LUs). Changes were fueled through increases in demand as well as, supply of new breeds, new technology, and government support. Production of animal source protein increased 4.9 times, nitrogen use efficiency at herd level tripled, and average feed use and GHG emissions per gram protein produced decreased by a factor of 2 between 1980 and 2010. In the same period, animal feed imports have increased 49 times, total ammonia and GHG emissions to the atmosphere doubled, and nitrogen losses to watercourses tripled. As a consequence, China's livestock transition has significant global impact. Forecasts for 2050, using the Shared Socio-economic Pathways scenarios, indicate major further changes in livestock production and impacts. On the basis of these possible trajectories, we suggest an alternative transition, which should be implemented by government, processing industries, consumers, and retailers. This new transition is targeted to increase production efficiency and environmental performance at system level, with coupling of crop-livestock production, whole chain manure management, and spatial planning as major components.

Abstract. A Nationwide Nitrogen Deposition Monitoring Network (NNDMN) containing 43 monitoring sites was established in China to measure gaseous NH3, NO2, and HNO3 and particulate NH4+ and NO3− in air and/or precipitation from 2010 to 2014. Wet/bulk deposition fluxes of Nr species were collected by precipitation gauge method and measured by continuous-flow analyzer; dry deposition fluxes were estimated using airborne concentration measurements and inferential models. Our observations reveal large spatial variations of atmospheric Nr concentrations and dry and wet/bulk Nr deposition. On a national basis, the annual average concentrations (1.3–47.0 μg N m−3) and dry plus wet/bulk deposition fluxes (2.9–83.3 kg N ha−1 yr−1) of inorganic Nr species are ranked by land use as urban > rural > background sites and by regions as north China > southeast China > southwest China > northeast China > northwest China > Tibetan Plateau, reflecting the impact of anthropogenic Nr emission. Average dry and wet/bulk N deposition fluxes were 20.6 ± 11.2 (mean ± standard deviation) and 19.3 ± 9.2 kg N ha−1 yr−1 across China, with reduced N deposition dominating both dry and wet/bulk deposition. Our results suggest atmospheric dry N deposition is equally important to wet/bulk N deposition at the national scale. Therefore, both deposition forms should be included when considering the impacts of N deposition on environment and ecosystem health.

Abstract Recycling of livestock manure to agricultural land may reduce the use of synthetic fertilizer and thereby enhance the sustainability of food production. However, the effects of substitution of fertilizer by manure on crop yield, nitrogen use efficiency (NUE), and emissions of ammonia (NH 3 ), nitrous oxide (N 2 O) and methane (CH 4 ) as function of soil and manure properties, experimental duration and application strategies have not been quantified systematically and convincingly yet. Here, we present a meta‐analysis of these effects using results of 143 published studies in China. Results indicate that the partial substitution of synthetic fertilizers by manure significantly increased the yield by 6.6% and 3.3% for upland crop and paddy rice, respectively, but full substitution significantly decreased yields (by 9.6% and 4.1%). The response of crop yields to manure substitution varied with soil pH and experimental durations, with relatively large positive responses in acidic soils and long‐term experiments. NUE increased significantly at a moderate ratio (<40%) of substitution. NH 3 emissions were significantly lower with full substitution (62%–77%), but not with partial substitution. Emissions of CH 4 from paddy rice significantly increased with substitution ratio (SR), and varied by application rates and manure types, but N 2 O emissions decreased. The SR did not significantly influence N 2 O emissions from upland soils, and a relative scarcity of data on certain manure characteristic was found to hamper identification of the mechanisms. We derived overall mean N 2 O emission factors (EF) of 0.56% and 0.17%, as well as NH 3 EFs of 11.1% and 6.5% for the manure N applied to upland and paddy soils, respectively. Our study shows that partial substitution of fertilizer by manure can increase crop yields, and decrease emissions of NH 3 and N 2 O, but depending on site‐specific conditions. Manure addition to paddy rice soils is recommended only if abatement strategies for CH 4 emissions are also implemented.

An outbreak in Wuhan, China in late 2019 of a highly infectious new coronary pneumonia (COVID-19) led to the imposition of countrywide confinement measures from January to March 2020. This is a longitudinal study on changes in the mental health status of a college population before and after their COVID-19 confinement for the first two weeks, focusing on states of psychological distress, depression, anxiety and affectivity. The influence of possible stressors on their mental health were investigated, including inadequate supplies and fears of infection. Five hundred and fifty-five undergraduate students were recruited from Hebei Agricultural University in Baoding, China. The participants completed two online surveys—on anxiety and depression, and on positive and negative affect. One survey was conducted before the confinement and the other was conducted 15–17 days after the start of the confinement. Increases in negative affect and symptoms of anxiety and depression (p-values < 0.001) were observed after 2 weeks of confinement. Inadequate supplies of hand sanitizers, a higher year of study, and higher scores on anxiety and depression were common predictors of increased negative affect, anxiety, and depression across the confinement period. The results suggest that healthcare policymakers should carefully consider the appropriate confinement duration, and ensure adequate supplies of basic infection-control materials.

The jujube (Ziziphus jujuba Mill.), a member of family Rhamnaceae, is a major dry fruit and a traditional herbal medicine for more than one billion people. Here we present a high-quality sequence for the complex jujube genome, the first genome sequence of Rhamnaceae, using an integrated strategy. The final assembly spans 437.65 Mb (98.6% of the estimated) with 321.45 Mb anchored to the 12 pseudo-chromosomes and contains 32,808 genes. The jujube genome has undergone frequent inter-chromosome fusions and segmental duplications, but no recent whole-genome duplication. Further analyses of the jujube-specific genes and transcriptome data from 15 tissues reveal the molecular mechanisms underlying some specific properties of the jujube. Its high vitamin C content can be attributed to a unique high level expression of genes involved in both biosynthesis and regeneration. Our study provides insights into jujube-specific biology and valuable genomic resources for the improvement of Rhamnaceae plants and other fruit trees. The jujube is a major dry fruit crop in China and is commonly used for medicinal purposes. Here the authors sequence the genome and transcriptome of the most widely cultivated jujube cultivar, Dongzao, and highlight the genetic and molecular basis of agronomically important jujube traits, such as vitamin C content.

Abstract Combined chemo/chemodynamic therapy is a promising strategy to achieve an improved anticancer effect. However, the hypoxic microenvironment and limited amount of H 2 O 2 in most solid tumors severely restrict the efficacy of this treatment. Herein, the construction of a nanocatalytic medicine, CaO 2 @DOX@ZIF‐67, via a bottom‐up approach is described. CaO 2 @DOX@ZIF‐67 simultaneously supplies O 2 and H 2 O 2 to achieve improved chemo/chemodynamic therapy. In the weakly acidic environment within tumors, CaO 2 @DOX@ZIF‐67 is broken down to rapidly release the Fenton‐like catalyst Co 2+ and the chemotherapy drug doxorubicin (DOX). The unprotected CaO 2 reacts with H 2 O to generate both O 2 and H 2 O 2 . The generated O 2 relieves the hypoxia in the tumor and further improve the efficacy of DOX. Meanwhile, the generated H 2 O 2 reacts with Co 2+ ions to produce highly toxic •OH through a Fenton‐like reaction, resulting in improved chemodynamic therapy.

• Inorganic arsenic (iAs) is a ubiquitous human carcinogen, and rice (Oryza sativa) is the main contributor to iAs in the diet. Methylated pentavalent As species are less toxic and are routinely found in plants; however, it is currently unknown whether plants are able to methylate As. • Rice, tomato (Solanum lycopersicum) and red clover (Trifolium pratense) were exposed to iAs, monomethylarsonic acid (MMA(V)), or dimethylarsinic acid (DMA(V)), under axenic conditions. Rice seedlings were also grown in two soils under nonsterile flooded conditions, and rice plants exposed to arsenite or DMA(V) were grown to maturity in nonsterile hydroponic culture. Arsenic speciation in samples was determined by HPLC-ICP-MS. • Methylated arsenicals were not found in the three plant species exposed to iAs under axenic conditions. Axenically grown rice was able to take up MMA(V) or DMA(V), and reduce MMA(V) to MMA(III) but not convert it to DMA(V). Methylated As was detected in the shoots of soil-grown rice, and in rice grain from nonsterile hydroponic culture. GeoChip analysis of microbial genes in a Bangladeshi paddy soil showed the presence of the microbial As methyltransferase gene arsM. • Our results suggest that plants are unable to methylate iAs, and instead take up methylated As produced by microorganisms.

The pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has resulted in an unprecedented setback for global economy and health. SARS-CoV-2 has an exceptionally high level of transmissibility and extremely broad tissue tropism. However, the underlying molecular mechanism responsible for sustaining this degree of virulence remains largely unexplored. In this article, we review the current knowledge and crucial information about how SARS-CoV-2 attaches on the surface of host cells through a variety of receptors, such as ACE2, neuropilin-1, AXL, and antibody-FcγR complexes. We further explain how its spike (S) protein undergoes conformational transition from prefusion to postfusion with the help of proteases like furin, TMPRSS2, and cathepsins. We then review the ongoing experimental studies and clinical trials of antibodies, peptides, or small-molecule compounds with anti-SARS-CoV-2 activity, and discuss how these antiviral therapies targeting host-pathogen interaction could potentially suppress viral attachment, reduce the exposure of fusion peptide to curtail membrane fusion and block the formation of six-helix bundle (6-HB) fusion core. Finally, the specter of rapidly emerging SARS-CoV-2 variants deserves a serious review of broad-spectrum drugs or vaccines for long-term prevention and control of COVID-19 in the future.

• A hydroponic experiment was conducted to investigate the effect of phosphorus (P) nutrition and iron plaque on root surfaces on arsenate uptake by, and translocation within, the seedlings of three cultivars of rice (Oryza sativa). • Supply of 0.5 mg As l−1 had no significant effects on dry weights of shoots or roots, but resulted in elevated concentrations of As in tissues, particularly in roots. Rice roots appeared reddish after 24 h in –P solution (without P), indicating the formation of iron plaque. • Arsenic concentrations in iron plaque (determined in dithionite–citrate–bicarbonate (DCB)-extracts) were significantly higher in –P plants (up to 1180 mg kg−1 in cultivar CDR22) than in +P plants. Concentrations of arsenic in shoots were significantly lower in –P plants than in +P plants. This indicates that iron plaque might sequestrate As, and consequently reduce the translocation of arsenic from roots to shoots. • Values for the total uptake of As show that As in –P rice plants was mainly concentrated in the DCB-extracts or on the surface of rice roots, whereas most arsenic in +P plants was accumulated in the roots. Arsenic significantly decreased the concentrations of iron (Fe) in roots and shoots (P < 0.001) and slightly reduced P concentrations in shoots, except for the –P cultivar CDR22.

Increasing nitrogen (N) and phosphorus (P) inputs have greatly contributed to the increasing food production in China during the last decades, but have also increased N and P losses to the environment. The pathways and magnitude of these losses are not well quantified. Here, we report on N and P use efficiencies and losses at a national scale in 2005, using the model NUFER (NUtrient flows in Food chains, Environment and Resources use). Total amount of "new" N imported to the food chain was 48.8 Tg in 2005. Only 4.4.Tg reached households as food. Average N use efficiencies in crop production, animal production, and the whole food chain were 26, 11, and 9%, respectively. Most of the imported N was lost to the environment, that is, 23 Tg N to atmosphere, as ammonia (57%), nitrous oxide (2%), dinitrogen (33%), and nitrogen oxides (8%), and 20 Tg to waters. The total P input into the food chain was 7.8 Tg. The average P use efficiencies in crop production, animal production, and the whole food chain were 36, 5, and 7%, respectively. This is the first comprehensive overview of N and P balances, losses, and use efficiencies of the food chain in China. It shows that the N and P costs of food are high (for N 11 kg kg(-1), for P 13 kg kg(-1)). Key measures for lowering the N and P costs of food production are (i) increasing crop and animal production, (ii) balanced fertilization, and (iii) improved manure management.

The present study aimed to investigate the effects of root surface iron plaque on the uptake kinetics of arsenite and arsenate by excised roots of rice (Oryza sativa) seedlings. The results demonstrated that the presence of iron plaque enhanced arsenite and decreased arsenate uptake. Arsenite and arsenate uptake kinetics were adequately fitted by the Michaelis-Menten function in the absence of plaque, but produced poor fits to this function in the presence of plaque. Phosphate in the uptake solution did not have a significant effect on arsenite uptake irrespective of the presence of iron plaque; however phosphate had a significant effect on arsenate uptake. Without iron plaque, phosphate inhibited arsenate uptake. The presence of iron plaque diminished the effect of phosphate on arsenate uptake, possibly through a combined effect of arsenate desorption from iron plaque.

Basil (Ocimum basilicum) is one of the most important crops with essential oils as well as polyphenols, phenolics, flavonoids and phenolic acids. This annual plant belongs to mint family, and indigenous to tropical regions. Basil leaves also has tremendous pharmaceutical benefits and it is common to use in rice, meat, stews and soups. Traditionally, it has been used in kidney problems, as a haemostyptic in childbirth, earache, menstrual irregularities, arthritis, anorexia, treatment of colds and malaria. Basil has been shown positive effects against viral, fungal, bacterial and some infections. Basil leaves have been used in treatment of fevers, coughs, flu, asthma, bronchitis, influenza and diarrhea. Basil Seed Mucilage, commonly known as basil seed gum. Basil seed mucilage can be considered as thickening, stabilizing, fat substitute, texurizer, surface-active and emulsifying hydrocolloid. The most important pharmacological uses of basil are anti-cancer activity, radioprotective activity, anti-microbial activity, anti-inflammatory effects, immunomodulatory activity, anti-stress activity, anti-diabetic activity, anti-pyretic activity, anti-arthritic activity, anti-oxidant activity, as a prophylactic agent and in cardiovascular disease.

Abstract Multi‐wall Sn/SnO 2 @carbon hollow nanofibers evolved from SnO 2 nanofibers are designed and programable synthesized by electrospinning, polypyrrole coating, and annealing reduction. The synthesized hollow nanofibers have a special wire‐in‐double‐wall‐tube structure with larger specific surface area and abundant inner spaces, which can provide effective contacting area of electrolyte with electrode materials and more active sites for redox reaction. It shows excellent cycling stability by virtue of effectively alleviating pulverization of tin‐based electrode materials caused by volume expansion. Even after 2000 cycles, the wire‐in‐double‐wall‐tube Sn/SnO 2 @carbon nanofibers exhibit a high specific capacity of 986.3 mAh g −1 (1 A g −1 ) and still maintains 508.2 mAh g −1 at high current density of 5 A g −1 . This outstanding electrochemical performance suggests the multi‐wall Sn/SnO 2 @ carbon hollow nanofibers are great promising for high performance energy storage systems.

The largest livestock production and greatest fertilizer use in the world occurs in China. However, quantification of the nutrient flows through the manure management chain and their interactions with management-related measures is lacking. Herein, we present a detailed analysis of the nutrient flows and losses in the “feed intake–excretion–housing–storage–treatment–application” manure chain, while considering differences among livestock production systems. We estimated the environmental loss from the manure chain in 2010 to be up to 78% of the excreted nitrogen and over 50% of the excreted phosphorus and potassium. The greatest losses occurred from housing and storage stages through NH3 emissions (39% of total nitrogen losses) and direct discharge of manure into water bodies or landfill (30–73% of total nutrient losses). There are large differences among animal production systems, where the landless system has the lowest manure recycling. Scenario analyses for the year 2020 suggest that significant reductions of fertilizer use (27–100%) and nutrient losses (27–56%) can be achieved through a combination of prohibiting manure discharge, improving manure collection and storages infrastructures, and improving manure application to cropland. We recommend that current policies and subsidies targeted at the fertilizer industry should shift to reduce the costs of manure storage, transport, and application.