Eco-friendly biodegradable polyurethane based coating for antibacterial and antifouling performance

Biofouling, which comprises the absorption of proteins and the adhesion of bacteria to the surface of living entities, is a severe concern for the maritime sector since it ultimately leads to hydrodynamic drag,resulting in a higher increase in fuel consumption. As a result, polymer resins are crucial in the marine sector for anti-biofouling coatings. In this work, the poly(caprolactone-ethylene glycol-caprolactone)-p olyurethane(PECL-PU) are prepared through ε-caprolactone(CL), poly(ethylene glycol)(PEG), 4,4'-methylene bis(cyclohexyl isocyanate) and 1,4 butanediol. Our study demonstrate that the PECL-PU copolymer degraded in artificial seawater(5.21%), enzymatic solution(12.63%), and seawater(13.75%)due to the presence of PEG segments in the laboratory-based test under static condition. Because the addition of PEG segments are increased the polymer's amorphous area and decreased the crystallization of the polycaprolactone(PCL) in the copolymer, as demonstrated by differential scanning calorimetry, X-ray diffraction, and water contact angle studies. Therefore, the hydrolysis rates of PECL-PU were higher than the caprolactone-co-polyurethane(CL-PU). The antifouling test showed that PECL-PU3 copolymer had about 90.29% protein resistance, 85.2% Escherichia coli(E. coli) reduction and 94.61% marine diatom Navicula incerta reduction comparison to the control. We have developed an eco-friendly and inexpensive promising degradable polyurethane for reduction of bacterial biofilm, which can preserve the formation of biofouling on marine coating under practical sea conditions.

Insight into Hydrolytic Stability and Tribological Properties of B-N Coordination Tung Oil-Based Lubricant Additive in Water

A tung oil-based boron-nitrogen coordination polymer(TWE-BN)was specially designed and synthesized as a highly efficient water-based lubricant additive,which has been beneficial to both energy conservation and conducive to environmental protection.Its hydrolysis stability and tribological properties in water were investigated.To better research the lubricating properties,and thus to understand the interaction between the surface and the lubricating additives.Herein,both experimental and theoretical computations based on density functional theory(DFT)were performed.The addition of TWE-BN reduces the water friction coefficient and wear scar diameter,and the maximum non-seizure load increased from 93 to 726 N.Moreover,the anti-corrosion ability on copper was classified as 1b level.The stainless-steel surface was analyzed using scanning electron microscopy(SEM)and X-ray photoelectron spectroscopy(XPS).In hydrolytic stability testing,TWE-BN was better than nitrogen-free tung oil-based lubricant additive(TWE-B)and remained non-hydrolyzed for at least 15 days,implying the feasibility of tung oil-based boron-nitrogen coordination as highly effective and hydrolytic stability lubricant additives.

Effects of Lanthanum on Hydrolytic Enzyme Activities in Red Soil

The effects of La on some hydrolytic enzyme activities in red soil were studied in incubation and pot culture experiments. In the incubation experiment, La slightly stimulates the activities of urease and acidic phosphatase in soil and strongly stimulates sucrase activity in soil. In the pot culture experiment, La stimulates the activities of urease, acidic phosphatase and sucrase to different degrees. The stimulative effects of rare earth elements (REE) on hydrolytic enzyme activities in soil may result in increasing yield of crops.

THE EFFECT OF THE ACID CATALYST ON THE PREPARATION OF MQ SILICONE RESINS

MQ silicone resins were prepared through hydrolytic condensation of ethyl polysilicate or tetraethoxysilane and hexamethyl disiloxane. The unit ratio of the MQ resins was determined by Si-29-NMR. The relationship of the unit ratio of the product resins with that in the feed was studied. When the reaction was catalyzed by aqueous hydrochloric acid, and the unit ratio of M to Q in the feed was more than 1, the unit ratio of the product was usually lower than that of the feed. The MQ silicon with an unit ratio of M/Q > 2 could not be obtained. However, if the reaction was catalyzed by concentrated sulfuric acid and the reverse hydrolysis process was employed, MQ silicone resin with very high M/Q ratio was successfully prepared.

Evaluating effective Trichoderma isolates for biocontrol of Rhizoctonia solani causing root rot of Vigna unguiculata

The highly diverse genus Trichoderma has provided many formulations that are alternatives to the chemical pesticides in agriculture.The present study was undertaken to investigate the biocontrol potential of eight Trichoderma species,T.atrobrunneum,T.guizhouense,T.paratroviride,T.pyramidale,T.rufobrunneum,T.simmonsii,T.thermophilum and T.viridulum,against the phytopathogenic fungus Rhizoctonia solani.Trichoderma isolates were first evaluated in vitro by dual culture tests for their antagonism,mycoparasitic ability and antifungal activity against R.solani.Their growth promoting potential was further assessed in relation to phosphate solubilization,indole acetic acid and siderophore production.Five of the isolates were selected and evaluated for their abilities to prompt plant growth and to control R.solani infecting Vigna unguiculata(cowpea)seedlings in vivo.Two most effective isolates,T.guizhouense 9185 and T.simmonsii 8702,significantly(P<0.05)reduced the disease severity incidences(36.6 and 45.0%,respectively)and promoted plant growth,which have good prospects for application.

Synthesis and Characterization of Soluble and Meltable Poly(aminopropyl/phenylsilsesquioxane)

The hydrolytic co-condensation of hydrophobic phenyltriethoxysilane （PTES） and hydrophilic γ-aminopropyltriethoxysilane （APS） was investigated in toluene and water by using hydrochloric acid （HCl） catalyst. A soluble and meltable poly（aminopropyl/phenylsilsesquioxane） （PAPSQ） was formed by controlling HCl amounts, APS/PTES molar ratios, water/silane molar ratios （Rw/si）, organic co-solvents and re-equilibration steps as well. The compositions of PAPSQ bearing aminopropyl and phenyl groups with the capping of trimethylsilyl group were confirmed by element analysis, fourier-transform infrared spectroscopy （FT-IR）, nuclear magnetic resonance （NMR） and thermogravimetric analysis （TGA）. Differential scanning calorimetry （DSC） was employed to characterize the melting behavior of the product. PAPSQ can be easily employed as functional molecular building blocks for the synthesis of diverse and novel inorganic-organic materials.

Hydrolytic Degradation Study of Lansoprazole, Identification, Isolation and Characterisation of Base Degradation Product

Lansoprazole degradation is accelerated in both acidic and basic medium in water. The present investigation deals with the hydrolytic degradation of Lansoprazole. Acidic medium degradation show all known impurities and degradation products whereas basic degradation studies show new impurity which has higher molecular weight than Lansoprazole. New impurity was identified, isolated using mass based auto purification system and characterised by 1H NMR, 13C NMR, HMBC, HSQC, NOE, COSY and HRMS experiments. Isolated impurity was showing molecular weight of 467.10, molecular formula of C23H16F3N5OS and its name is 7-(3-Methyl-4-(2,2,2-trifluoroethoxy) pyridin-2-yl)-7H-benzo[4,5]imidazo[2,1-b]benzo[4,5]imidazo[2,1-d][1,3,5]thiadiazine.

Studies of artificial Hydrolytic metalloenzymes The catalytic carboxyester hydrolysis by novel nucleophile containing phenolic pendant macrocyclic polyamines

Zinc(II) complexes of new macrocyclic tetraamines (cyclam derivatives) having a strategically appended phenolate group, have ben examined as catalyst for the hyd rolysis of 4nitrophenyl acetate(NA). It ovas proven that coordinated phenolate can serve as a good nucleophile that efficiently catalyze 4-nitrophenyl acetate(NA) hydrolysis.

DNA Cleavage of the Copper(II) Complexes with a Polyamine Ditopic Ligand

A new binuclear complex [Cu2L(OH)](ClO4)3·2H2O has been synthesized and characterized, where L=2,6-bis{[bis-(2-aminoethyl)amino]methyl}-benzene. In the presence of 0.5 mmol/L complex at pH 8.10 and 37°C, the complex can efficiently cleavage pBR322 DNA with a rate constant kobs of 1.35×10-4 s-1. The cleavage occurred by a non-oxidative mechanism showing activity to be dependent on pH.

Approach to the Synthesis of Dimeric Salen-Co(Ⅲ):A Recoverable Catalyst for Rac-Eprichlorohydrin HKR

The synthesis of chiral dimeric Salen ligand 5, 5＇-methylene-di-[（R, R ）-｜ N-（3-tert-butylsalicylidine）-N＇- （ 3＇, 5＇-di- tert-butylsalicylidene） ｜ - 1, 2-cyclohexanediamine ] which using 2-tert-butylphenol as starting material is reported. This compound reacts with cobalt （Ⅱ） acetate and then oxidized by air to give dimeric Salen catalyst 5 in this paper, which catalyzes the hydrolytic kinetic resolution （HKR） of racemic epichlorohydrin to afford biologically important chiral epoxides and diols. Ee values of diol up to 97 % were obtained, and the catalyst was recovered with no apparent loss.

Site-specifically cleavage of oxidized insulin B chain with Zn(Ⅱ) ion studied by electrospray ionization mass spectrometry

The electrospray ionization mass spectrometry and tandem mass spectrometry investigation showed that the binding sites of Zn^2＋ with oxidized insulin B chain are His 5, His 10, and Arg 22, which lead to the selective cleavages of the peptide bonds at Ash 3- Gin 4, His 5-Leu 6, Gly 8-Ser 9, and Glu 21-Arg 22 of oxidized insulin B chain.

Mass spectrometry assisted assignments of binding and cleavage sites of Zn(Ⅱ)complex towards oxidized insulin B chain

The electrospray ionization mass spectrometry investigation showed that the binding sites of [ZnL]^2＋, where L is 2-[bis（2- aminoethyl）amino]ethanol, with oxidized insulin B chain are Phel, His5 and Arg22, which lead to the selective cleavages of the peptide bonds at Phe1-Val2, His5-Leu6, Glu21-Arg22, and Arg22-Gly23 of oxidized insulin B chain.

DNA Cleavage by Copper (Ⅱ) Complexes Without added Coreactants

The cleavage activity of complexes between copper (Ⅱ) and four different amino acidor amino acid methyl ester on DNA was tested at physioloical pH and temperature., It was found that Cu (Ⅱ)-L-His and Cu (Ⅱ)-L-His methyl ester complexes could cleane DNA. The extent ofDNA cleavage is largely dependent on the metal ion-to-ligand ratio. The cleavage of doublestranded DNA mediated by Cu (Ⅱ)-L-His complexes occurs via a hydrolytie mechanism.

Comparative Analysis of Hydrolytic Amino Acids in Human and Cow Milk of Different Lactation Periods

In this study,the hydrolytic amino acids of Chinese human and Holstein cow milk of different lactation periods were analyzed by the advanced isobaric tags for relative and absolute quantitation(iTRAQ)combined with the high performance liquid chromatography-mass spectrometry(HPLC-MS/MS)approach.The total contents of the hydrolytic amino acids in cow colostrum,cow mature milk,human colostrum and human mature milk were 5.00,4.38,2.12 and 2.48 g·L^(-1),respectively.Among these,the contents of the hydrolytic amino acids in cow milk were higher than those in human milk,indicating a decreasing trend with the prolongation of lactation.Additionally,principal component and hierarchical cluster analyses were used to further screen the differentially expressed amino acids.These results enhanced the understanding of the hydrolytic amino acids in cow and human milk across different lactation periods,which could provide potential directions for newborn dairy powder and nutritious supplementary.

Sponge-associated bacteria of Lakshadweep coral reefs, India: resource for extracellular hydrolytic enzymes

Sponges (Phylum: Porifera) is one of the major groups in the Lakshadweep coral reefs. These sponges harbor diverse bacteria with metabolic potentiality. From biodiversity to biotechnological prospecting, scientific investigations related to sponge associated microorganisms have expanded, but remain rather limited to few geographic locations. In this study, culturable bacteria associated with two demosponges viz Dysidea granulosa, Sigmadocia fibulata and the ambient water were screened for commercially important enzymes such as amylase, protease, gelatinase, lipase, deoxyribonucleic, phosphatase and urease. Amylase and phosphatase were the predominant enzymes produced by >80% of sponge-associated bacteria compared to the ambient water. Nearly 50% of the sponge-associated bacteria expressed multiple enzymatic activities (> 4) with variation in the percentage of expression of individual enzymes. More than 65% of the culturable heterotrophic bacteria associated with sponges were Gammaproteobacteria. The order Vibrionales was the main source for multiple enzyme production. Sponge associated bacteria formed more closely related clusters than the water isolates based upon their activity pattern. High recovery of sponge-associated bacteria with multiple enzymatic activities suggest that these versatile bacteria are yet unexploited potential for bioprospecting.

Optimization of the Production of Biogas in Anaerobic Digestion by the Addition of Hydrolytic Microorganisms

It is well known that fossil fuels are one of the major pollutants that contribute to climate change and there is a need to develop alternatives to their uses.One option is the use of a renewable fuel such as biogas obtained from the breaking down of organic matter in the anaerobic digestion process.When biogas is cleaned up to a certain quality,it can substitute the use of natural gas.However,this slow process requires optimization to increase the amount of gas.There are chemical,physical and biological treatments for organic matter to increase the amount and quality of biogas.In the former research,a biological treatment was tested by adding a selection of microorganisms that showed hydrolytic activity to an anaerobic digester for its optimization.First,a selection of microorganisms with the ability to grow in fresh sewage sludge as only nutrient was selected.Then,the lipolytic,cellulolytic and PA(Proteolytic Activity)of microorganisms was tested using selective growth media.Finally,10 samples with the greatest hydrolytic activity were used to evaluate their effects in the increasing of biogas production in the anaerobic process.The results showed that 83%of the microorganisms with the ability to grow in sewage sludge were proteolytic,while the percentage of lipolytic and cellulolytic microorganisms was smaller.Furthermore,it was found that proteolytic microorganisms are the ones that increase biogas yield in a maximum of 80%with a COD(Chemical Oxygen Demand)reduction of 58%.

Fuelization of Italian Ryegrass and Napier Grass through a Biological Treatment and Photocatalytic Reforming

Fuelization of Italian ryegrass and Napier grass was examined by the combination of biological treatments and photocatalytic reforming (photo-Reform). The alkali-pretreated Italian ryegrass and Napier grass were subjected to the enzymatic saccharification using cellulase and xylanase. Xylose and glucose were produced in 56.6% and 71.1% from Italian ryegrass and in 49.5% and 67.3% from Napier grass, respectively. Xylose and glucose were converted to hydrogen by the photo-Reform using a Pt-loaded titanium oxide (Pt/TiO2) under UV irradiation. Moreover, a low-moisture anhydrous ammonia (LMAA) pretreatment was performed for Italian ryegrass and Napier grass by keeping moist powdered biomass under NH3 gas atmosphere at room temperature for four weeks. The Italian ryegrass and Napier grass which were pretreated by LMAA method were subjected to simultaneous saccharification and fermentation (SSF) using a mixture of cellulase and xylanase as well as Saccharomyces cerevisiae in acetate buffer (pH 5.0). Ethanol and xylose were produced in 91.6% and 51.6% from LMAA-pretreated Italian ryegrass and 78.6% and 68.8% from Napier grass, respectively. After the evaporation of ethanol, xylose was converted to hydrogen by the photo-Reform. In the case of saccharification→photo-Reform, energy was recovered as hydrogen from the alkali-pretreated Italian ryegrass and Napier grass in 71.9% and 77.0% of energy recovery efficiency, respectively. In the case of SSF→photo-Reform, the energy was recovered in 82.7% and 77.2% as ethanol and hydrogen from the LMAA-pretreated Italian ryegrass and Napier grass, respectively.

A New Metallomicelle with Hydrolytic Metalloenzymatic Activity

A new metallomicelle, formed by Cu2+ Or Zn2+ ion and N-tetradecyl-2-(N-2-hydroxyethyl aminomethyl) imidazol in the presence of cetyltrimethylammonium bromide, was found to possess remarkable catalytic activity to the hydrolysis of p-nitrophenyl picolinate.