Enhancement of gaseous mercury(Hg^0) adsorption for the modified activated carbons by surface acid oxygen function groups

This article discussed the benzoic acid activated carbons which have changed the types and content of acid oxygen-function groups on the surface of activated carbons and their effect on the adsorption for Hg^0 in simulated flue gas at 140 ℃. These surface acid oxygen function groups were identified by Boehm titration, Fourier transformation infrared spectrum, temperature programmed desorption and X-ray photoelectron spectroscopy. It indicates that the carboxyl, lactone and phenolic were formed when the benzoic acid is loaded on the surface of activated carbons. Among the surface acid oxygen function groups, the carboxyl groups enhance the adsorption capacities of Hg^0 for activated carbons to a greater extent.

Propyl-Sulfonic Acid Functionalized Nanoparticles as Catalyst for Pretreatment of Corn Stover

Propyl-sulfonic (PS) acid-functionalized nanoparticles were synthesized, characterized and evaluated as catalysts for pretreatment of corn stover. Silica coated nanoparticles were functionalized with 0.5% mercaptopropyltrimethoxysilane (MPTMS) at neutral pH in a mixture of water and ethanol. Sulfur contents of the acid functionalized nanoparticles, measured in a CHNS analyzer, varied from 6%-10%, and the acid load ranged from 0.040 to 0.066 mmol H+/g. A Box-Behnken design was employed to calculate the minimum number experiments required to obtain an estimate of the surface response for temperature, catalyst load, and %S content of the catalyst. Pretreatment of corn stover was carried out at three temperature levels 160, 180, and 200°C for 1 h. Three levels of catalyst load were used 0.1, 0.2, and 0.3 g of catalyst per gram of biomass. Hydro-thermolysis controls were carried at each temperature level. The catalyst load did not have an effect on the glucose yield at 160°C, and the average glucose yield obtained at this temperature was 59.0%. The glucose yield was linearly correlated to the catalyst load during pretreatment at 180°C, and a maximum glucose yield of 90% was reached when using 0.2 g of PS nanoparticles that had a total sulfur content of 6.1%. Complete hydrolysis of glucose was reached at 200°C but the average xylose yield was 4.6%, and about 20.2% of the combined glucose and xylose were lost as hydroxymethylfurfural and furfural. Results showed that acid-functionalized nanoparticles can be potential catalysts for the pretreatment of biomass for its later conversion to ethanol.

Bronsted-acidic ionic liquids as catalysts for synthesizing trioxane

The batch reaction experiments have been made for the first time to investigate the effect of ionic structure on the reactivity and selectivity of the trioxane-forming reaction catalyzed by a Br?nsted-acidic ionic liquid(IL).The ILs considered include 1-cyclohexyl-2-pyrrolidinonium trifluoromethanesulfonate([NCy P][TfO ]),1-cyclohexyl-2-pyrrolidinonium benzenesulfonate([NCyP ][BSA]),1-cyclohexyl-2-pyrrolidinonium p-toluenesulfonate([NCyP ][pTSA]),1-octyl-2-pyrrolidinonium 2,4-dinitrobenzenesulfonate([NOP][DNBSA]),1-octyl-2-pyrrolidinonium benzenesulfonate([NOP][BSA]),1-octyl-2-pyrrolidinonium methanesulfonate([NOP][MSA]),and 1-octyl-2-pyrrolidinonium trifluoromethanesulfonate([NOP][Tf O]).It is found that the yield of trioxane in the reaction solution correlates inversely with the Hammett acidity function H0 of the aqueous solution of the corresponding ILs.Variation of the cation structure from [NCyP ]+to [NOP]+exerts little influence on the yield and the selectivity of trioxane in the reaction solution.Using [TfO ]-or [DNBSA]-in place of [MSA]-or [BSA]-apparently increases the yield of trioxane,but only slightly increases the concentration of formic acid in the reaction solution.The continuous production experiments have been made to investigate the performance of [NOP][MSA],[NOP][DNBSA],[NCyP ][TfO ],and H2SO4 as an extraction distillation agent.Such effect of [NCyP ][TfO ] considerably overrides that of H2SO4.The yield and the selectivity of trioxane are both increased when [NCyP ][TfO ] is used instead of H2SO4 at a reaction time 5 h.

Functional nucleic acid-based biosensors for virus detection

A growing number of viruses pose significant threats to human health,impact agricultural production and compromise food safety.Minimizing the impact of viral infections demands for effective technologies that can deliver sensitive viral detection under various settings.Functional nucleic acids(FNAs)–natural or synthetic nucleic acid molecules with catalytic and/or binding properties–have been increasingly explored as key components for setting up diagnostic tests for viral detection.FNA-based viral biosensors offer distinct advantages,such as the ability to achieve sensitive viral detection in complex biological samples,ease of use,scalability,and cost-effectiveness.This mini-review will be dedicated to appraising progress made in recent years in FNA-based biosensors for diagnosing diverse human and animal viruses.We will first describe virus structures and potential biomarkers that can be utilized as the targets for FNA probe engineering.This is followed by reviewing the latest advances in two classes of FNAs-DNAzyme and DNA aptamers,with focuses on DNAzyme-and DNA aptamerbased biosensors that employ diverse signal transduction mechanisms to achieve sensitive viral detections.Finally,we will discuss current challenges in the field and suggest future research directions that can address these challenges.

Recent Advances in Swine Amino Acid Nutrition

Recent advances in swine protein nutrition are characterized by the development of functional a- mino acids （AA） in regulating fetal and postnatal survival, growth and development. These AA include arginine, glutamine, glutamate, proline, leucine, cyste- ine and tryptophan. Due to limited knowledge on AA nutrition, pork producers have traditionally paid little attention to supplementing the arginine family of AA to swine diets. Results of recent studies indicate that functional AA serve important regulatory functions in nutrient metabolism, protein turnover, and immune function, therefore enhancing efficiency of feed utili- zation by pigs. The underlying mechanisms include activation of nitric oxide, mammalian target of rapam- ycin, gaseous signaling, and AMP-activated protein ki- nase pathways, as well as anti-oxidative function. Di- etary supplementation with arginine, glutamine, pro- line or leucine to weanling piglets enhances theirgrowth performance. Arginine or glutamine is also ef- fective in increasing milk production by lactating sows. Furthermore, supplementing arginine to the diet of pregnant gilts between days 30 and 114 of gestation increases the number of live-born piglets and litter birth-weight. Availability of feed-grade functional AA holds great promise for improving animal health and nutrient utilization in pig production worldwide. Addi- tionally, feedstuffs of animal origin [ e. g. , blood meal （ ring dried ）, feather meal （ hydrolyzed ）, meat and bone meal, porcine protein meal, and poultry by-prod- uct meal （both feed- and petfood-grades） ] are excel- lent and cost-effective sources of both essential and functional AA for formulating balanced swine diets. New knowledge on AA nutrition provides a much needed scientific basis for revising the next edition of swine nutrient requirements.

Ginkgolide B promotes the proliferation and differentiation of neural stem cells following cerebral ischemia/reperfusion injury,both in vivo and in vitro

Neural stem cells have great potential for the development of novel therapies for nervous system diseases.However,the proliferation of endogenous neural stem cells following brain ischemia is insufficient for central nervous system self-repair.Ginkgolide B has a robust neuroprotective effect.In this study,we investigated the cell and molecular mechanisms underlying the neuroprotective effect of ginkgolide B on focal cerebral ischemia/reperfusion injury in vitro and in vivo.Neural stem cells were treated with 20,40 and 60 mg/L ginkgolide B in vitro.Immunofluorescence staining was used to assess cellular expression of neuron-specific enolase,glial fibrillary acid protein and suppressor of cytokine signaling 2.After treatment with 40 and 60 mg/L ginkgolide B,cells were large,with long processes.Moreover,the proportions of neuron-specific enolase-,glial fibrillary acid protein-and suppressor of cytokine signaling 2-positive cells increased.A rat model of cerebral ischemia/reperfusion injury was established by middle cerebral artery occlusion.Six hours after ischemia,ginkgolide B（20 mg/kg） was intraperitoneally injected,once a day.Zea Longa＇s method was used to assess neurological function.Immunohistochemistry was performed to evaluate the proportion of nestin-,neuron-specific enolase-and glial fibrillary acid protein-positive cells.Real-time quantitative polymerase chain reaction was used to measure m RNA expression of brain-derived neurotrophic factor and epidermal growth factor.Western blot assay was used to analyze the expression levels of brain-derived neurotrophic factor and suppressor of cytokine signaling 2.Ginkgolide B decreased the neurological deficit score,increased the proportion of nestin-,neuron-specific enolase-and glial fibrillary acid protein-positive cells,increased the m RNA expression of brain-derived neurotrophic factor and epidermal growth factor,and increased the expression levels of brain-derived neurotrophic factor and suppressor of cytokine signaling 2 in the ischemic penumbra.Together,the in vivo and in vitro findings suggest that ginkgolide B improves neurological function by promoting the proliferation and differentiation of neural stem cells in rats with cerebral ischemia/reperfusion injury.

Silage Feeding with Water Hyacinth in the Tropics: A Research Note

Water hyacinth has ecological significance in addition to its agricultural and energy uses. Lower quality silage is defined in this paper as requiring nitrogen supplementation and treatment to improve nutritive value (NV). Ensilage of water hyacinth as a test case centers largely around the process to optimize protein nitrogen retention in silage-based regimens. A previous hypothesis proposed earlier by the author of that of functional amino acid ratios [tyrosine (TYR): large neutral amino acids (LNAA), tyrosine (TYR): phenylalanine (PHE)] were subsequently found to be counter to what the given schemata predicts. And subsequently with another study there was no corroborative evidence for it to support the espoused hypothesis using the same schemata. The role of N status is still the most viable option among factors from studies continuing how amino acids like histidine (HIS) and arginine (ARG) and their growth-related endocrine functions play a role. There are other schemas illustrating non-homeostatic type regulation with protein intake. To focus on molecular-level mechanisms to ruminal protein digestion it is becoming clear what factors in feed and microbial cell fermentation contribute to optimizing microbial cell protein (MCP) synthesis from ATP with organic matter (OM) digestibility and preformed amino acids (PFAA) from peptides and free amino acids in addition to non-protein nitrogen (NPN), the former more efficiently assimilated in MCP than NPN in the rumen. Accordingly, it has been recommended that soluble proteins fed to dairy cows not exceed microbial requirements along with high dietary escape protein fed with a sufficient amino acid profile to meet dairy production.

Functional nucleic acid-based cell imaging and manipulation

Cells are the basic structural and functional units of organisms.Dynamic analysis and manipulation of specific components in living cells would provide valuable information for the study of related biological processes.Advances in fluorescence microscopy have allowed real-time monitoring of biological events at the molecular level.Meanwhile,the development of highperformance fluorescence probes has become a critical issue.Functional nucleic acids(FNAs)are oligonucleotides with special chemical and biological functions,and aptamers with excellent molecular recognition capability are one of the most important representatives.They have attracted extensive attention in the field of live-cell study,owing to intrinsic advantages of simple synthesis,convenient modification,low immunogenicity and high programmability.This review focuses on recent research progress in fluorescence imaging and manipulation of cells using FNAs,particularly aptamers,as the molecular tools.Finally,a summary is provided and the related challenges are discussed.

Synthesis of unnatural amino acids through palladium-catalyzed C(sp^3)-H functionalization

Unnatural a-amino acids have been extensively used in the modern drug discovery and protein engineering studies. They have also found applications in the development of chiral molecular catalysts and the total synthesis of diverse natural products. Accordingly the development of cost-effective approaches for the preparation of unnatural a-amino acids has received increasing attentions. Among all the available methods for this purpose, direct C–H functionalization of simple amino acids represents one of the most attractive approaches because it exhibits good atom-economy and step-efficiency. In particular, selective functionalization of either the primary or secondary C（sp^3）–H bonds in the amino acids has been explored to make versatile C–C, C–N, C–O, C–B and C–F bonds to modify the side chain of amino acids and even peptides. The present review surveys the recent advances of synthesis of chiral unnatural a-amino acids and peptides through palladium-catalyzed functionalization of un-activated C（sp^3）–H bonds.

Electrostatic assembly functionalization of poly(γ-glutamic acid)for biomedical antibacterial applications

Poly(γ-glutamic acid)(γ-PGA)has been found widespread applications in biomedical field because of its excellent water solubility,biocompatibility,and bioactivity.Herein,a water-insoluble γ-PGA antibacterial compound is facilely fabricated via one-pot electrostatic assembly of γ-PGA with cationic ethyl lauroyl arginate(ELA).The functionalized γ-PGA compound(γ-PGA-ELA)ethanol solution can facilely produce colorless and transparent coatings on various inorganic,metal,and polymeric substrates,especially for the lumen of slender catheters(length up to 2 m,and inner diameter down to 1 mm).The functionalized γ-PGA coating presents remarkable antibacterial efficacy in vitro and in vivo.In addition,the γ-PGA compound is used as antibacterial additives of polyolefin via melting extrusion,and the asprepared antibacterial polyolefin demonstrates advantageous antibacterial efficacy.More importantly,the functionalized γ-PGA coating exhibit good hemocompatibility,low cytotoxicity,and satisfactory histocompatibility.The as-proposed γ-PGA compound has a great potential to serve as a safe and multifunctional antibacterial candidate to combat biomedical devices-related infections.

Functional Xeno Nucleic Acids for Biomedical Application

Functional nucleic acids(FNAs)refer to a type of oligonucleotides with functions over the traditional genetic roles of nucleic acids,which have been widely applied in screening,sensing and imaging fields.However,the potential application of FNAs in biomedical field is still restricted by the unsatisfactory stability,biocompatibility,biodistribution and immunity of natural nucleic acids(DNA/RNA).Xeno nucleic acids(XNAs)are a kind of nucleic acid analogues with chemically modified sugar groups that possess improved biological properties,including improved biological stability,increased binding affinity,reduced immune responses,and enhanced cell penetration or tissue specificity.In the last two decades,scientists have made great progress in the research of functional xeno nucleic acids,which makes it an emerging attractive biomedical application material.In this review,we summarized the design of functional xeno nucleic acids and their applications in the biomedical field.

Dynamic DNA nanomachines for amplification imaging of diseased cells based on stimuli-responsive mechanism

As a basic functional unit,living cell with sophisticated structures play an indispensable role in life activities.Since the abnormality of important molecules inside cells is closely related to diseases,the dynamic analysis and spatio-temporal monitoring of specific molecules in living cells can provide precious information for the diagnosis and treatment of diseases.More recently,DNA has not only been recognized as the carrier of genetic information,but has also used as a robust building block for the assembly of multitudinous nanoscale structures due to the intrinsic advantages of high programmability of classic Watson–Crick base-pairing rule.Intensive study promotes the rapid progress of nanotechnology in various fields,such as bioimaging,diagnosis,and therapeutics.Among numerous well-defined DNA nanomaterials,DNA nanomachines have been widely exploited in cell imaging owing to their desirable ability to achieve high-resolution temporal and spatial images in response to endogenous or exogenous stimuli.In brief,elaborate DNA nanomachines can undergo structural changes upon the stimuli of target analytes or environmental factors,resulting in rapid increase or reduction of output signals and thereby indirectly reflecting the expression level of targets.DNA nanomachines with high sensitivity and specificity contribute to the recognition of diseased tissues.In this review,we introduce the basic assembly modules of DNA nanomachines and summarize the recent advances in dynamic DNA nanomachines for diseased-cell imaging.Finally,the current challenges and future directions of DNA nanomachines for bioimaging are discussed.

Alumina-supported heteropoly acid:An efficient catalyst for the synthesis of azaarene substituted 3-hydroxy-2-oxindole derivatives via C(sp^3)-H bond functionalization

A method of C（sp^3）-H bond functionalization of methyl azaarenes catalyzed by alumina-supported heteropoly acid and addition to isatins was developed. This transformation could be used for the synthesis of biologically important 3-hydroxy-2-oxindole derivatives in good to excellent yields and the catalyst could be reused for six times without significant decrease in activity.

Synthesis and Antitumor Activity of Novel Coumarin Deriva- tives via a Three-component Reaction in Water

An efficient synthesis of novel coumarin derivatives via a three-component condensation of 4-hydroxycoumarin, aldehydes and aromatic amines catalyzed by sulfonic acid functionalized ionic liquid L-2-（hydroxymethyl）- 1-（4-sulfobutyl）pyrrolidinium hydrogen sulfate （[HYSBPI]·HSO4） is reported. The condensed product was obtained with excellent yields in water under microwave irradiation condition. The antitumor activities of all the synthesized compounds were assessed on two different human cancer cell lines （A-549 and MCF-7）, and the results showed that these compounds had weak-to-good antitumor activities and their IC50 ranged from 0.05 to more than 100 μmol.L-1.

A highly sensitive DNA-AIEgen-based ＂turn-on＂ fluorescence chemosensor for amplification analysis of Hg^2+ ions in real samples and living cells

Functional nucleic acids(FNAs)-based biosensors have shown great potential in heavy metal ions detection due to their low-cost and easy to operate merits. However, in most FNAs based fluorescence probes, the ingenious designs of double-labeled(fluorophore and quencher group) DNA sequence, not only bring the annoyance of organic synthesis, but also restrict its use as a robust biosensor in practical duties. In this paper, we design a simple AIEgens functional nucleic acids(AFNAs) probe which consists of only fluorogen but no quencher group. With the help of duplex-specific nuclease(DSN) enzyme based target recycling, high fluorescence signal and superior sensitivity towards Hg^(2+) are achieved. This robust assay allows for sensitive and selective detection of Hg^(2+) in real water samples and mapping of intracellular Hg^(2+), without double-labeling of oligonucleotide with a dye-quencher pair, nor the multiple assay steps.