Mechanical superiority of Pseudoxytenanthera bamboo for sustainable engineering solutions.

The advancement in natural fibre composites has replaced synthetic fibres in various commercial sectors. Bamboo species possess high mechanical properties due to their lignocellulosic fibre content, which makes them suitable for engineering applications and potential alternatives to solid wood. However, despite Bamboo being composed of 130 genera and 1700 different species, out of which many still remains underexplored. In this study, we investigated the, Lignocellulosic profiling, fibre strength, and mechanical characterization of two species of Pseudoxytenanthera Bamboo: Pseudoxytenanthera ritchiei, Pseudopxytenanthera stocksii, and the results obtained were compared with Bambusa balcooa, one of the priority species of bamboo identified by The International Plant Genetic Resources Institute (IPGRI). BET (Brunauer-Emmett-Teller) was used to quantify the samples' density, while SEM-EDX and FTIR spectroscopy were used for elemental analysis. The samples were then subjected to tensile test in addition, thermogravimetric analysis and water absorption test were carried out for the three species. The results showed that Pseudoxytenanthera species possessed superior chemical and mechanical characteristics compared to the priority species of bamboo used for composites. Out of the two Pseudoxytenanthera species studied, Pseudoxytenanthera stocksii exhibited the highest values of cellulose, hemicellulose, lignin, pectin, ash, carbon, and silicon, indicating its chemical superiority. Moreover, Pseudoxytenanthera stocksii also showed higher mechanical values for tensile strength, making it suitable for a variety of engineering applications. The TGA values also indicated that Pseudoxytenanthera stocksii is stable at high temperatures when compared with other natural fibres.

Primary care services in the English NHS: are they a thorn in the side of integrated care systems? A qualitative analysis.

BACKGROUND: As integrated care systems are embedded across England there are regions where the integration process has been evaluated and continues to evolve. Evaluation of these integrated systems contributes to our understanding of the challenges and facilitators to this ongoing process. This can support integrated care systems nationwide as they continue to develop. We describe how two integrated care partnerships in different localities, at differing stages of integration with contrasting approaches experienced challenges specifically when integrating with primary care services. The aim of this analysis was to focus on primary care services and how their existing structures impacted on the development of integrated care systems. METHODS: We carried out an exploratory approach to re-analysing our previously conducted 51 interviews as part of our prior evaluations of integrated health and care services which included primary care services. The interview data were thematically analysed, focussing on the role and engagement of primary care services with the integrated care systems in these two localities. RESULTS: Four key themes from the data are discussed: (i) Workforce engagement (engagement with integration), (ii) Organisational communication (information sharing), (iii) Financial issues, (iv) Managerial information systems (data sharing, IT systems and quality improvement data). We report on the challenges of ensuring the workforce feel engaged and informed. Communication is a factor in workforce relationships and trust which impacts on the success of integrated working. Financial issues highlight the conflict between budget decisions made by the integrated care systems when primary care services are set up as individual businesses. The incompatibility of information technology systems hinders integration of care systems with primary care. CONCLUSIONS: Integrated care systems are national policy. Their alignment with primary care services, long considered to be the cornerstone of the NHS, is more crucial than ever. The two localities we evaluated as integration developed both described different challenges and facilitators between primary care and integrated care systems. Differences between the two localities allow us to explore where progress has been made and why.

Chinese chestnut shell polyphenol extract regulates the JAK2/STAT3 pathway to alleviate high-fat diet-induced, leptin-resistant obesity in mice.

Chinese chestnut shell is a by-product of chestnut food processing and is rich in polyphenols. This study sought to investigate the effect of chestnut shell polyphenol extract (CSP) on weight loss and lipid reduction in a 12-week high-fat diet (HFD)-induced murine obesity model. CSP (300 mg per kg body weight) was administered intragastrically daily. AG490, a JAK2 protein tyrosine kinase inhibitor, was also intraperitoneally injected. The results showed that an HFD induced leptin resistance (LR). Compared to corresponding values in the HFD group, CSP treatment improved blood lipid levels, weight, and leptin levels in obese mice (p < 0.01). Additionally, CSP treatment enhanced enzyme activity by improving total antioxidant capacity, attenuating oxidative stress, and reducing fat droplet accumulation and inflammation in the liver, epididymal, and retroperitoneal adipose tissue. CSP also activated the LEPR-JAK2/STAT3-PTP1B-SOCS-3 signal transduction pathway in hypothalamus tissue and improved LR while regulating the expression of proteins related to lipid metabolism (PPARγ, FAS, and LPL) in white adipose tissue in the retroperitoneal cavity. However, the amelioration of lipid metabolism by CSP was dependent on JAK2. Molecular docking simulation further demonstrated the strong binding affinity of procyanidin C1 (-10.3983297 kcal mol-1) and procyanidin B1 (-9.12686729 kcal mol-1) to the crystal structure of JAK2. These results suggest that CSP may be used to reduce HFD-induced obesity with potential application as a functional food additive.

The metaphysics of fibre bundles.

Recently, Dewar (2019) has suggested that one can apply the strategy of 'sophistication'-as exemplified by sophisticated substantivalism as a response to the diffeomorphism invariance of General Relativity-to gauge theories such as electrodynamics. This requires a shift to the formalism of fibre bundles. In this paper, I develop and defend this suggestion. Where my approach differs from previous discussions is that I focus on the metaphysical picture underlying the fibre bundle formalism. In particular, I aim to affirm the physical reality of gauge properties. I argue that this allows for a local and separable explanation of the Aharonov-Bohm effect. Its puzzling features are explained by a form of holism inherent to fibre bundles.

Biorational Control of Callosobruchus maculatus (Coleoptera: Buchidae) in Stored Grains with Botanical Extracts.

Globally, around 2000 plant species are used against pest control. The utilization of botanicals is considered the most economic and biodegradable methods for the control of stored grains pests. Therefore, the current study was carried out to investigate the repellency potential of five botanicals against Callosbruchus maculatus F. in Haripur, Pakistan. The concentrations of Azadirachta indica L., Nicotiana tabacum L., Melia azedarach L., Nicotiana rustica L., and Thuja orientalis L. were, i.e., 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0% in four replicates to establish contact effects. The data were recorded after 1, 2, 3, 6, 24, 48, 72, and 96 hours. The repellency effect of these plant species against C. maculatus were increased in both the time- and dose-dependent manner, and highest effect was observed at 72 h. In addition, the repellency effect was 91% for A. indica (class: V), 86% M. azedarach, 82%, N. tabacum (class: V), 79% N. rustica (class: IV), and 75% T. orientalis (class: IV) at 3% concentration against C. maculatus. Furthermore, following 96 hours' exposure to treatment the sensitivity response of insects decreases as the time interval increases, i.e., 86% A. indica (class: V) was followed by 71% M. azedarach (class: IV), 65% N. tabacum (class: IV), 61% N. rustica (class: IV), and T. orientalis 57% (class: III) repellency at highest concentration of 3%. The current study concluded that A. indica and M. azedarach can be incorporated for the management of C. maculatus and these plant species might be helpful in the productions of new biopesticides.

Fiber Preparation from Micronized Oat By-Products: Antioxidant Properties and Interactions between Bioactive Compounds.

This study aimed to investigate the possibility of utilizing oat by-products for fiber preparation. Oat husk (OH) and oat bran (OB) were micronized and used to prepare a novel product rich in fiber and with enhanced antioxidant properties. The basic chemical composition and phenolic acid profile were determined in OH and OB. The antioxidant properties of OH and OB were also analyzed. The type and strength of interactions between the biologically active compounds from their mixtures were characterized by an isobolographic analysis. The analyses showed that the sum of phenolic acids was higher in OH than in OB. Ferulic acid was dominant in both OH and OB; however, its content in OH was over sixfold higher than that in OB. The results also suggested that both OH and OB can be used for preparing fiber with enhanced antioxidant properties. The optimal composition of the preparation, with 60-70% of OH and 30-40% of OB, allows for obtaining a product with 60-70% fiber and enhanced antioxidant activity due to bioactive substances and their synergistic effect. The resulting product can be a valuable additive to various food and dietary supplements.

Genus Lilium: A review on traditional uses, phytochemistry and pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: The genus Lilium (family Liliaceae) is native to China and is mainly distributed in the temperate regions of the Northern Hemisphere such as Eastern Asia, Europe, and North America. There are about 109 species of this genus and 55 species in China. In America, the bulbs were used as food. In Europe, the petals and bulbs of Lilium candidum uesd as pectoral poultices, wound-healing remedy and a treatment for mastitis and shingles, the bulbs of L. martagon were used to treat every liver disease. In India, the bulbs are used medicinally as galactagogue, expectorant, aphrodisiac, diuretic, antipyretic and revitalizing tonic. In Asia, bulbs of this genus are often used to treat coughs, lung diseases, burns and swellings. AIM OF THE STUDY: The aim of this work was to summarize traditional uses, phytochemistry, pharmacology and toxicity, which provided a theoretical basis for the further study of Lilium plants and their applications in medicine, food and other industries. MATERIALS AND METHODS: Online scientific databases including Science Direct, American chemical society (ACS), Wiley Online Library, the Web of Science, China national knowledge internet (CNKI) and others were searched to identify eligible studies. More data were obtained from other Chinese medicine books. RESULTS: The literature survey revealed diverse traditional uses of the genus Lilium, mainly for the treatment of lung deficiency, hemostasis, anxiety, palpitations, asthma and vomiting. Over 180 compounds have been isolated and identified from the genus Lilium, including steroidal saponins, polysaccharides, phenolic glycerides, flavonoids and alkaloids. Different extracts and monomer compounds were so far evaluated for number of pharmacological activities including anti-tumor, anti-inflammatory, antioxidant, antibacterial, immunomodulatory, antidepressant and hepatoprotective activities. CONCLUSIONS: Lilium spp. are of much significance as ornamental flowers, but also have potential to treat various diseases, especially anti-inflammatory and antioxidant. However, most of the studies on pharmacological effects are still in in vitro, and further studies on mechanism-based pharmacological activities in vivo and in vitro are needed in the future. At present, there are limited researches on its safety and toxicological effects, which should be further explored.

Review on Green Synthesis of Silver Nanoparticles through Plants.

Nature has the potential to reduce metal salts to their relative nanoparticles. Traditionally, physical and chemical methods were used for the synthesis of nanoparticles but due to the use of toxic chemicals, non-ecofriendly methods and other harmful effects, green chemistry approaches are now employed for synthesizing nanoparticles which are basically the most cost effective, ecofriendly and non-hazardous methods. In this review, we aimed to evaluate and study the details of various mechanisms used for green synthesis of silver nanoparticles from plants, their size, shape and potential applications. A total of 150 articles comprising both research and review articles from 2009 to 2019 were selected and studied in detail to get in-depth knowledge about the synthesis of silver nanoparticles specifically through green chemistry approaches. Silver ions and their salts are well known for their antimicrobial properties and have been used in various medical and non-medical applications since the emergence of human civilization. Miscellaneous attempts have been made to synthesize nanoparticles using plants and such nanoparticles are more efficient and beneficial in terms of their antibacterial, antifungal, antioxidant, anti-biofilm and cytotoxic activities than nanoparticles synthesized through physical and chemical processes. Silver nanoparticles have been studied as an important research area due to their specific and tunable properties and their application in the field of biomedicine such as tissue and tumor imaging and drug delivery. These nanoparticles can be further investigated to find out their antimicrobial potential in cell lines and animal models.

Plant components affect bacterial biofilms development by altering their cell surface physicochemical properties: a predictability study using Actinomyces naeslundii.

We hypothesized that the initial events leading to biofilm formation by bacteria, in general, are predominantly mediated by cell surface physicochemical interactions, and that natural products can impact the process by altering cell surface physicochemical properties. We exemplified this phenomenon using Actinomyces naeslundii as the model organism, and using tea products to modify its cell surface physicochemical properties. To test the hypothesis, a non-linear multiple regression model incorporating a normal distribution curve was constructed to explain the impact of tea extracts on the physiochemical processes of biofilm formation by A. naeslundii. The model utilized tea extract-induced changes in cell surface physicochemical properties as independent variables, and the corresponding biofilm formation as a dependent variable. Five different tea extracts were used to treat A. naeslundii, and their impact on the cell surface hydrophobicity, charge, auto-aggregation, attachment and biofilm formation on four different hard surfaces were measured and the data were used to construct the model. The established model was then tested in independent experiments involving other plant extracts and purified phytochemicals. Experimental results showed that the tea extracts significantly reduced cell surface hydrophobicity (by up to 21.3%), increased cell surface charge and auto-aggregation (by up to 4.5 mV and 14.9%, respectively), inhibited attachment (by 0.6-2.5 log CFU cm-2) and affected biofilm formation (by up to 0.6 log CFU cm-2). The model indicated that both cell surface hydrophobicity and charge played an important role in bacterial auto-aggregation and attachment, and that the latter two phenomena significantly correlated with subsequent biofilm development. The accuracy of the model construct was approximately 64%. This modelling approach can be employed for other microbial colonization systems to predict biofilm formation, and to study the impact of cell surface physicochemical properties in biofilm development.

A review on antimicrobial botanicals, phytochemicals and natural resistance modifying agents from Apocynaceae family: Possible therapeutic approaches against multidrug resistance in pathogenic microorganisms.

Accelerated emergence of drug- resistant pathogenic microbes, their unbeatable virulence and a gradual loss of efficacy of currently used antimicrobial agents over the last decade, have expanded the scope of herbal medicine to combat this emerging challenge to have a wide spectrum of activity to develop effective medicines with lesser untoward side effects. Plant-based natural products should be of utmost interest to today's pharmaceutical industries since they are a primary source of new chemical entities directed at new drug targets. Apocynaceae or 'Dogbane' family has attained a global reputation as a source of some life-saving plant-derived products and novel compounds. Members of this family have also been extensively investigated against several nosocomial pathogenic microbes through in vitro and in vivo experimental settings. Several plant-derived components obtained from members of this family have also exhibited remarkable microbial growth inhibitory properties. Popular and widely accepted international databases such as PubMed, Science Direct, ResearchGate, Scopus, Google Scholar, JSTOR and more were searched using the various search strings such as Apocynaceae, antimicrobials, multidrug resistance, resistance modifying agents and pathogenic microorganisms were used in various combinations to retrieve several citations related to the topic. The current review encompasses recent developments in experimental studies and phytochemical analyses which correlates with antimicrobial efficacy of selected Apocynaceous plants along with synergistic mechanism and structural details. The present review recognizes and leverages the importance of Apocynaceae plants, which could be of significant interest in the development of more effective and less toxic antimicrobial drugs which may surmount multidrug resistance. Three different paradigm models harnessing clinical antimicrobial resistance (AMR) including the plant family Apocynaceae, Gram-positive and Gram-negative bacterial species have been broadly discussed in this review. In a nutshell, the present review represents a comprehensive account on the antimicrobials and resistance modifying agents obtained from the members of the plant family Apocynaceae and derived phytochemicals. It also gives an insight into the underlying mode of action of these phytochemicals against an array of pathogenic bacteria, their mechanism of antibiosis, plant parts from which the phytochemicals were isolated or the extracts was prepared with a critical discussion on the botanically-derived antibiotics as a template for antimicrobial drug development.

Antiviral and Cytotoxic Activity of Different Plant Parts of Banana (Musa spp.).

Chikungunya and yellow fever virus cause vector-borne viral diseases in humans. There is currently no specific antiviral drug for either of these diseases. Banana plants are used in traditional medicine for treating viral diseases such as measles and chickenpox. Therefore, we tested selected banana cultivars for their antiviral but also cytotoxic properties. Different parts such as leaf, pseudostem and corm, collected separately and extracted with four different solvents (hexane, acetone, ethanol, and water), were tested for in vitro antiviral activity against Chikungunya virus (CHIKV), enterovirus 71 (EV71), and yellow fever virus (YFV). Extracts prepared with acetone and ethanol from leaf parts of several cultivars exhibited strong (EC50 around 10 µg/mL) anti-CHIKV activity. Interestingly, none of the banana plant extracts (concentration 1-100 µg/mL) were active against EV71. Activity against YFV was restricted to two cultivars: Namwa Khom-Pseudostem-Ethanol (5.9 ± 5.4), Namwa Khom-Corm-Ethanol (0.79 ± 0.1) and Fougamou-Corm-Acetone (2.5 ± 1.5). In most cases, the cytotoxic activity of the extracts was generally 5- to 10-fold lower than the antiviral activity, suggesting a reasonable therapeutic window.

Phytochemical composition profile and space-time accumulation of secondary metabolites for Dracocephalum moldavica Linn. via UPLC-Q/TOF-MS and HPLC-DAD method.

The aerial parts of Dracocephalum moldavica L. are extensively used in traditional ethnic medicines in China as a remedy for cardiovascular and cerebrovascular damage. However, the chemical composition and the accumulation of main secondary metabolites of D. moldavica in different natural environments remain unclear. This study aimed to conduct a qualitative and quantitative analysis of the main secondary metabolites to explore the quality variation of D. moldavica in markets. The evaluation of space-time accumulation of main secondary metabolites in D. moldavica was carried out during different growth periods and in different geographical locations. A total of 35 ingredients were detected and 24 identified, including 21 flavonoids, two phenolic acids and one coumarin by UPLC-QTOF-MS method. Furthermore, a simple and convenient HPLC method was successfully developed for the simultaneous determination of lutelin-7-O-glucuronide and tilianin and rosmarinic acid in D. moldavica. The results of space-time accumulation analysis showed the distinct variation of secondary metabolites of D. moldavica with the growth period and geographical location. Finally, the current study provided a meaningful and useful approach for comprehensively evaluating the quality of D. moldavica.

Current Knowledge on Selenium Biofortification to Improve the Nutraceutical Profile of Food: A Comprehensive Review.

Selenium (Se) is an important micronutrient for living organisms, since it is involved in several physiological and metabolic processes. Se intake in humans is often low and very seldom excessive, and its bioavailability depends also on its chemical form, with organic Se as the most available after ingestion. The main dietary source of Se for humans is represented by plants, since many species are able to metabolize and accumulate organic Se in edible parts to be consumed directly (leaves, flowers, fruits, seeds, and sprouts) or after processing (oil, wine, etc.). Countless studies have recently investigated the Se biofortification of plants to produce Se-enriched foods and elicit the production of secondary metabolites, which may benefit human health when incorporated into the diet. Moreover, feeding animals Se-rich diets may provide Se-enriched meat. This work reviews the most recent literature on the nutraceutical profile of Se-enriched foods from plant and animal sources.

Aamar-e-Advia (shelf-lives) of drugs in Unani system of medicine: A conceptual review.

In an era of globalization and increased global demand for herbal medicines, it is essential to ensure the quality and consistency of drugs. Changes in the quality of an herbal product over time should be detectable. The assessments of chemical quality and therapeutic efficacy of herbal drugs are necessary to establish their shelf-lives. Thus, stability testing is needed to establish standards for herbal products. Unani medicine has its own conceptual framework for studying health and disease. The mode of treatment includes Ilaj bit Tadbeer (regimental therapy), Ilaj bil Ghiza (dietotherapy), Ilaj bil Dawa (pharmacotherapy) and Ilaj bil Yad/Jarahat (surgery) as a final option. Ilaj bil Dawa is the most used mode of treatment. The drugs include either crude drugs prepared from plant, animal and mineral sources, called Mufrad (single) drugs or various formulations prepared from these crude drugs, called Murakkab (compound) drugs. To date, stability studies have been carried out on compound drugs, whereas only a few single drugs had had their stability tested. These studies are needed to understand how the quality of an herbal drug varies over the time when it is prepared and consumed. This may also help to standardize procedures for manufacturing compound formulations ab initio. The present study reviews the concept of Aamar-e-Advia (shelf-lives) described in the literature of the Unani system of medicine. Further, various factors that are considered important to assess the shelf-life of Unani drugs are discussed in the context of contemporary protocols for shelf-life assessment.

Characteristics and Diversity of Endophytic Bacteria in Endangered Chinese Herb Glehnia littoralis Based on Illumina Sequencing.

Glehnia littoralis is an endangered medicinal plant growing in the coastal ecological environment and plays an important role in coastal ecosystems. The endophytes in the plant have a significant role in promoting plant growth and enhancing plant stress resistance. However, the endophytic bacterial structure associated with halophyte G. littoralis is still not revealed. In this project, the construction and diversity of endophytic bacterial consortium associated with different tissues of G. littoralis were illustrated with high throughput sequencing of the V3-V4 region of the bacterial 16S rRNA. The results resolved that the diversity and richness of endophytic bacteria were significantly higher in root than in leaf and stem. The operational taxonomic units (OTU) analysis demonstrated that the Actinobacteria and Proteobacteria were dominant in all the samples at the phylum level, and Pseudomonas, Bacillus, Rhizobium were the dominant genera. Our results unraveled that the bacterial communities differed among different tissues of G. littoralis. Endophytic bacterial communities in leaf and stem shared more similarity than that in the root. Furthermore, the difference of bacteria community and structure among different tissues were also detected by principal coordinate analysis. Taken altogether, we can conclude that the bacterial communities of different tissues are unique, which could facilitate understanding the diversity of endophytic bacteria in G. littoralis.

Chemical composition of the essential oils and headspace volatiles of Ferulago sylvatica (Besser) Reichenb. from Serbia.

Chemical composition of the headspace volatiles and essential oils isolated from different parts of Ferulago sylvatica was determined by GC and GC/MS analyses. The results showed that headspace volatiles obtained from the aerial parts and roots were similar regarding the number of identified compounds and main components. However, essential oils obtained from different plant organs showed significant differences in chemical composition. Myrcene was the most abundant component of the inflorescences and shoots volatiles, while α-pinene make up over 50% of the root volatiles. Only three components were identified in the root essential oil with 2,3,6-trimethyl benzaldehyde (92.7%) as the main component. In the shoots sample the terpenoid fractions represented 56% of the oil, unevenly distributed between monoterpenoids and sesquiterpenoids with germacrene D (32.5%) recognized as the main constituent. On the other hand, more than 94% of the inflorescences oils were monoterpenoids with myrcene as the most abundant contributor (29.2%).

Effectiveness of Passion Fruit Peel Flour (Passiflora edulis L.) versus Turmeric Flour (Curcuma longa L.) on Glycemic Control: Systematic Review and Meta-Analysis.

BACKGROUND: It is undeniable that diabetes may cause several health complications for the population. Many of these complications are associated with poor glycemic control. Due to this, strategies to handle this problem are of great clinical importance and may contribute to reducing the various complications from diabetes. OBJECTIVE: The aim of this study was to compare the effectiveness of the passion fruit peel flour versus turmeric flour on glycemic control. METHODS: This is a systematic review and meta-analysis following the PRISMA protocol. The following inclusion criteria were applied: (1) Case-control studies, cohort studies, and clinical trials, due to the improved statistical analysis and, in restrict cases, cross-sectional studies; (2) Articles published in any language. The databases used for the search were PubMed, Scopus, Web of Science, Cochrane, and LILACS. A bias analysis and a meta-analyses were undertaken using R Studio (version 3.3.1) using effect- size models. RESULTS: A total of 565 studies were identified from which 11 met the inclusion and exclusion criteria. Through isolated analysis, the effectiveness of turmeric flour on glycemic control was in the order of 0.73 CI (Confidence Interval) (from 0.68 to 0.79) and the effectiveness of passion fruit peel flour was 0.32 CI (0.23 to 0.45). The joint analysis resulted in 0.59 CI (0.52 to 0.68). The assessment of blood glucose was by glycated hemoglobin levels. All values were significant at a p < 0.05 level. CONCLUSION: Both interventions showed significant effects on glycemic control.

Microcos paniculata: a review on its botany, traditional uses, phytochemistry and pharmacology.

The shrub Microcos paniulata (MPL; Tiliaceae), distributed in south China, south and southeast Asia, yields a phytomedicine used to treat heat stroke, fever, dyspepsia, diarrhea, insect bites and jaundice. Phytochemical investigations on different parts of MPL indicate the presence of flavonoids, alkaloids, triterpenoids and organic acids. The MPL leaves, fruits, barks and roots extracts showed antidiarrheal, antimicrobial and insecticidal, anti-inflammation, hepatoprotective, cardiovascular protective, blood lipids reducing, analgesic, jaundice-relieving and antipyretic activities, etc. The review aims to summary the traditional uses, botany, phytochemistry, pharmacological bioactivity, quality control, toxicology and potential mechanisms of MPL. Additionally, this review will highlight the existing research gaps in knowledge and provide a foundation for further investigations on this plant.

Antioxidant enzyme activity and growth responses of Huangguogan citrus cultivar to nitrogen supplementation.

This study examined the physiological effects of different amounts of nitrogen (N) supplementation (0 to 2.72 kg/year) on the citrus cultivar Huangguogan (Citrus reticulata × Citrus sinensis). Root activity, chlorophyll content, and fruit quality were measured, and the activities of the antioxidant enzymes superoxide dismutase (SOD), guaiacol peroxidase (POD), and catalase (CAT), and the contents of malondialdehyde (MDA) and soluble protein in root, leaf, and fruit tissues were examined at different developmental stages. Root activity, chlorophyll content, fruit quality, antioxidant enzyme activity, MDA content, and soluble protein content increased in plants treated with an appropriate amount of N. Both excessive N and N deficiency decreased the content of MDA and the activities of antioxidant enzymes. Application of 1.36-1.81 kg N/year is suggested for citrus fertilization and the lower end of this range is recommended for minimizing environmental impact and production cost.

Impacts of selenium supplementation on soil mercury speciation, and inorganic mercury and methylmercury uptake in rice (Oryza sativa L.).

Rice grain is known to accumulate methylmercury (MeHg) and has been confirmed to be the major pathway of MeHg exposure to residents in mercury (Hg) mining areas in China. Selenium (Se) supplementation has been proven to be effective in mitigating the toxicity of Hg. To understand how Se supplementation influences soil Hg speciation, a wide range of Se (0-500 mg/kg) was applied to Hg polluted paddy soils in this study, which decreased MeHg concentration in soil from 2.95 ±â€¯0.36 to 0.69 ±â€¯0.16 µg/kg (or 77%). After Se addition, humic acid state Hg (F4) was transformed into strong-complexed state Hg (F5), indicating that Hg bound up to the non-sulfur functional groups of humic acid (non-RSH) was released and reabsorbed by strong binding Se functional group (F5). As a result, inorganic Hg (IHg) was reduced by >48%, 18%, and 80% in root, stem, and grain, respectively, however, the reduction was not apparent in leaf. Substantial reductions were also found for MeHg in grain and root, but not in stem and leaf. Soil is suggested to be the main source of both MeHg and IHg in rice grain. Such a finding may provide an idea for improving Hg-polluted paddies through controlling soil IHg and MeHg. Further research on the molecular structure of the strong-complexed Hg in F5 should be conducted to elucidate the mechanism of Hg-Se antagonism.