Some new 2-thioxo thiazole, 2-thioxo 1,3,4- thiadiazole and 3-thioxo-1,3,4-triazole derivatives (3-17) have been synthesized through ring closure reactions ofdithioic formic acid hydrazones 2 with functional reagent...Some new 2-thioxo thiazole, 2-thioxo 1,3,4- thiadiazole and 3-thioxo-1,3,4-triazole derivatives (3-17) have been synthesized through ring closure reactions ofdithioic formic acid hydrazones 2 with functional reagents in different medium. Former structures of the products have been established by the help of elemental and spectral analysis. Most of the obtained targets showed a moderate activity towards some microbes in comparison with two antibiotics Pipercillin and Mycostatine.展开更多
Some more new sulfur compounds bearing heterocyclic systems mainly 2-thioxo-1,3,4-thiadiazinone derivatives 2-7 and 3-thioxo-1,2,4-triazole derivatives 9 have been synthetic via alkylation, acylation and condensation ...Some more new sulfur compounds bearing heterocyclic systems mainly 2-thioxo-1,3,4-thiadiazinone derivatives 2-7 and 3-thioxo-1,2,4-triazole derivatives 9 have been synthetic via alkylation, acylation and condensation of dithioic formic acid hydrazide 1 through ring closure reactions with α,β-bi functional groups compounds. Most of the obtained target showed a highly activity towards some microbial in compare with two references antibiotics, Pipercillin and Mycostatine. The structures of the products have been established from their elemental and spectral analysis.展开更多
This study focused on the identification of the filamentous fungi associated with soapstone samples exposed to outdoor conditions and the biocidal effect of gamma radiations on isolated fungal populations in Minas Ger...This study focused on the identification of the filamentous fungi associated with soapstone samples exposed to outdoor conditions and the biocidal effect of gamma radiations on isolated fungal populations in Minas Gerais State in Brazil. Two soapstone blocks were placed outdoors under tropical environmental conditions for 12 months. A total of 9 filamentous fungal populations were identified on their surfaces, namely Acremomium (cf.) alternatum, Alternaria alternata, Aspergillusfumigatus, Calcarisporium (cf.) arbuscula, Cladosporium cladosporioides, Curvularia lunata, Epicoccum nigrum, Fusarium equiseti and Penicillium citrinum. The gamma radiation assay was then carried out as a test of biocidal action by exposing all fungal populations to the ionizing radiation. The results showed that only the C. cladosporioides species was resistant to this biocidal agent, since it was able to increase its population post exposure. Scanning electron microscopy images identified the microbial colonization on the soapstone blocks and the stone elementar composition was analyzed by energy dispersive X-ray spectrometry. After treatment, there was no structural and aesthetic alteration in the soapstone samples, and evidencing that gamma radiation can be used as a biocidal agent. However, the resistance of the black fungal population indicates caution in the choice of gamma irradiation as biocidal treatment.展开更多
Objective:To evaluate in vitro effects of Tagetes minuta L. essential oil(TEO) on L3 Anisakis larvae type 1. Methods:In order to evaluate the potential use of Tagetes minuta essential oil against L3 Anisakis larvae th...Objective:To evaluate in vitro effects of Tagetes minuta L. essential oil(TEO) on L3 Anisakis larvae type 1. Methods:In order to evaluate the potential use of Tagetes minuta essential oil against L3 Anisakis larvae three different media were tested:1) a saline solution(SS); 2) an industrial marinating solution; 3) sunflower seeds oil(SO). For each media and concentrations of TEO(0.1%,0.5%,1.0% and 5.0% v/v),20 parasites were introduced into plastic Petri dishes(diameter 90 mm) and maintained at room temperature. As controls,larvae were maintained without TEO under identical experimental conditions in SS,MS and SO. A total of 900 larvae were tested. The normalized mean viability,LT100,LT50 and the percentage of inactivation at 24 hours were calculated. Results:In vitro tests revealed a complete inactivation of parasites in saline solution after 2 hours with 5% and 1% of TEO. In marinating solution,a complete inactivation of parasites was observed after 4 hours at all concentrations used. A slower activity for all TEO concentration was reported in SO. Conclusions:The results obtained,showing a strong activity against Anisakis larvae,confirm TEO as a larvicidal agent in the treatment of human anisakidosis and in the industrial marinating process.展开更多
Silver Nanoparticles were synthesized by Esche- richia coli using Silver nitrate in the growth me-dium and characterized in X-Ray Diffraction, UV-Vis Spectrophotometer and Scanning Electron Microscope. They exhibited ...Silver Nanoparticles were synthesized by Esche- richia coli using Silver nitrate in the growth me-dium and characterized in X-Ray Diffraction, UV-Vis Spectrophotometer and Scanning Electron Microscope. They exhibited antimicrobial activity against human pathogens except Escherichia Coli. Nanoparticles were impregnated in yarn and ana-lyzed for their inhibition in the broth culture. The Minimal Inhibitory Concentratio was calculated for the human pathogens in Microtitre plate. The toxicity assessment of the nanoparticles in the embry-onic Zebrafish showed many organogensis deformi-ties like cardiac malformations, eye and head edema, tail and trunk flexure were observed in the organ system of the developing embryos for 1 to 5 day post fertilization in different concentrations of Ag Nanoparticles. The Organogenesis disruptive effects were found in 14 - 20 ng/ml of silver nanoparticles but the inhibition was found in 4-10ng/ml for the pathogens in vitro and 10ng/ml in embryos. Nevertheless, in Cardiac assay, the Heart Beat rates were calculated as 42 - 45 for 15 Sec in the concentrations ranging from 10 - 20 ng/ml of Silver nanoparticles. The blood flows, rhythmicity, contractility of heart beat rates were observed normal. The Mean value of blood Cell counting did not showed any notable effects in the Nanoparticle treated Zebrafish embryos and control. The LC50 value for the Biosynthesized nanoparticle was at 22 ng/ml in all the developmental stages of the em-bryos. Our results shows silver nanoparticles dis-rupts the normal organogenesis during development and further detailed studies are needed to prove silver nanopartcles are an antimicrobial agent for use in humans.展开更多
Ferrocyanides of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) were synthesized and characterized by IR spectra, magnetic susceptibility, thermal gravimetric analysis, elemental analysis and X ray diffraction studies. Ant...Ferrocyanides of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) were synthesized and characterized by IR spectra, magnetic susceptibility, thermal gravimetric analysis, elemental analysis and X ray diffraction studies. Antimicrobial potential of these complexes have been evaluated. Antifungal screening of these complexes has been carried out against Mycogone perniciosa and Verticillium fungicola causing wet and dry bubble diseases of button mushroom respectively. Nickel ferrocyanide has been found to be most effective against Mycogone perniciosa with 60% inhibitory effect while cadmium ferrocyanide has exhibited significant potential of 85% against Verticillium fungicola.展开更多
The viscosity property of Cr^3+, Al^3+, and compound ion cross-linked polymer gel solution in the anaerobic and aerobic environment was investigated aiming at meeting the practical demand of the oil field. The visco...The viscosity property of Cr^3+, Al^3+, and compound ion cross-linked polymer gel solution in the anaerobic and aerobic environment was investigated aiming at meeting the practical demand of the oil field. The viscosity reserving effect after adding the biocide and the gelation in the anaerobic and aerobic environments was also studied in the paper. The results indicate that the viscosity of the cross-linked polymer gel solution caused by the water produced in aerobic environment is higher than that in anaerobic environment, and that the viscosity value of the cross-linked polymer gel solutions after adding biocides has improved to some extent and polymer gel has gelated well in anaerobic environment.展开更多
Nanoparticles have been used as diagnostic and therapeutic agents in the human medical field for quite some time, though their application in veterinary medicine and animal production is still relatively new. Recently...Nanoparticles have been used as diagnostic and therapeutic agents in the human medical field for quite some time, though their application in veterinary medicine and animal production is still relatively new. Recently,production demands on the livestock industry have been centered around the use of antibiotics as growth promoters due to growing concern over microbial antibiotic resistance. With many countries reporting increased incidences of antibiotic-resistant bacteria, laws and regulations are being updated to end in-feed antibiotic use in the animal production industry. This sets the need for suitable alternatives to be established for inclusion in feed.Many reports have shown evidence that nanoparticles may be good candidates for animal growth promotion and antimicrobials. The current status and advancements of nanotechnological applications in animal production will be the focus of this review and the emerging roles of nanoparticles for nutrient delivery, biocidal agents, and tools in veterinary medicine and reproduction will be discussed. Additionally, influences on meat, egg, and milk quality will be reviewed.展开更多
The use of seawater for industrial cooling is a vital technology that poses some of the most profound environmental impact on the water quality in the Arabian Gulf. Biocide (chlorine) is added to the seawater to contr...The use of seawater for industrial cooling is a vital technology that poses some of the most profound environmental impact on the water quality in the Arabian Gulf. Biocide (chlorine) is added to the seawater to control biofouling of the cooling system. This added chlorine reacts with bromide and other chemicals naturally exist in the water to form a wide range of oxidants. Regrettably, reactions between the residual oxidants and natural organic matter in the water lead to formation of toxic halogenated organic compounds that have detrimental effects on the environment when they are discharged into the Gulf. This paper describes the formation of trihalomethanes (THMs) in seawater cooling systems. Results of kinetic experiments have shown that concentrations of THMs increased rapidly with time during the first half hour. Chlorination of seawater has shown significant increase in total THMs (TTHMs) and in bromoform concentrations. Rapid decrease of UV absorbance at 254 nm was also observed during seawater chlorination which is indicative of natural organic matter degradation into small organic molecules including THMs and other by-products. The increase in chlorine dose was accompanied with an increase in TTHMs and bromoform concentrations. Linear relationships between total chlorine concentration and both final TTHMs and bromoform concentrations were established. First order exponential decay and exponential associate functions were developed to correlate chlorine dose with formed THMs.展开更多
Marine fouling is the settlement and growth of a variety of marine organisms, such as bacteria, diatoms, protozoa and algae spores on structures immersed in seawater, such as ship's hulls, navigation buoys, and sonar...Marine fouling is the settlement and growth of a variety of marine organisms, such as bacteria, diatoms, protozoa and algae spores on structures immersed in seawater, such as ship's hulls, navigation buoys, and sonar equipment. Anti-fouling refers to material or systems used to prevent the accumulation of biological material on submerged surfaces. Bio-fouling results in higher fuel consumption and can also facilitate the transport of harmful NIS (Non-Indigenous Species). Antifouling technologies incorporating biocides (e.g., Tributyltin) have been developed to prevent fouling. Their widespread use, however, raised concerns about their toxic effects on marine communities. The AFS Convention (International Convention on the Control of Harmful Anti-fouling Systems in Ships) is a 2001 IMO (International Maritime Organization) treaty, whereby states agree to ban the use of harmful anti-fouling paints and other anti-fouling systems that contain harmful substances. Particularly, the use of the organotinTributyltin is prohibited, since leaching of that chemical from the hulls of ships has been shown to cause deleterious effects on some sea creatures. Although the AFS Convention has entered into force, its full implementation has not yet been appropriately achieved. Most of the ratifying States have delegated the Classification Society to inspect their ships to ensure the implementation of the provisions of the Convention. Since painting ships takes place in dry docks, the full control falls in the hands of Classification Societies.展开更多
Background: Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. Methods: We report herein the biocide effects of natural acetogenins from Annona squamosa, ...Background: Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. Methods: We report herein the biocide effects of natural acetogenins from Annona squamosa, A.?muricata and A. montana seeds: annonacin, cis-annonacin, cis-annonacin-10- one, asimicin, rolliniastatin-2, cherimolin-1, cherimolin-2, almuñequin, and two β-OH acetogenins: laherradurin and itrabin on Spodoptera frugiperda Smith (Lepidoptera: Noctuidae). Also, some acetylated and methoxy methylated ACG derivatives were synthesized and evaluated: annonacin (3 OAc), annonacin (4 OAc), asimicin (3 OAc), rolliniastatin-2 (3 OAc), rolliniastatin-2 (MOM), laherradurin (3 OAc) and itrabin (3 OAc). Results: The natural acetogenin rolliniastatin-2 (100 μg·g-1 of diet) produced the most important toxic action causing 100% mortality of early instar larvae. Derivatization of ACG yielded compounds that produced nutritional alterations. The incorporation of rolliniastatin-2 (3 OAc) and rolliniastatin-2 (3 MOM) (100 μg·g-1) into the artificial diet of Spodoptera frugiperdadisplayed the strongest antifeedant effects causing marked decreasings in larval growth and adult lethal malformations. Conclusion: Natural acetogenins are promising metabolites for insect control. Derivatization of these compounds reduces their toxicity to early instar larvae.展开更多
The science and technology interact with the art in several ways. Biotechnological coupled with analytical approaches can play an important role in protecting and preserving cultural heritage for future generations. M...The science and technology interact with the art in several ways. Biotechnological coupled with analytical approaches can play an important role in protecting and preserving cultural heritage for future generations. Many microorganisms influenced by environmental conditions are the main responsible for biological contamination in built heritage. Biocides based on chemical compounds have been used to mitigate this problem. Thus, it is vitally important to develop proper remediation actions based on environmentally innocuous alternative. Bacillus specie is emerging as an optimistic alternative for built heritage treatment due to their capacity to produce secondary metabolites with antagonistic activities against many fungal pathogens. Therefore, the intent of this work was to access a rapid evaluation of antifungal potential of bioactive metabolites produced by Bacillus strains and simultaneously their characterization using spectroscopic (NMR) and chromatographic techniques (LC-ESI-MS). The high antifungal activity obtained for Bacillus sp. active compounds produced in this study confirms the great potential to suppress biodeteriogenic fungi growth on historical artworks. Additionally, the proposed methodology allowed to access bioactive metabolites produced without need of the laborious total previous isolation and could be used as a viable alternative to be employed for screening and production of new green biocides.展开更多
Two experiments were conducted during 2006-2007 in Complete Randomized Design (CRD) to test the biological activity of Pseudomonas bacteria as biocides to protect sesame crop from some fungi and to evaluate its eff...Two experiments were conducted during 2006-2007 in Complete Randomized Design (CRD) to test the biological activity of Pseudomonas bacteria as biocides to protect sesame crop from some fungi and to evaluate its efficiency as plant growth promoting First experiment investigated the effects of Pseudomonas putida2 and Pseudomonas fluorescens3 on germination and seedlings growth of sesame crop against Pythium, Alternaria and Fusarium under plastic house conditions. Second experiment conducted in large pots to investigate the effects of the two bacterial isolates on some morphological, productive and physiological characters of sesame plants against same fungi under normal conditions. Results showed very low germination and slowly seedlings growth in Pythium, Fusarium and Alternaria treatments respectively, but adding bacterial vaccine of Pseudomonas putida2 and Pseudomonas fluorescens3 as a Biocide to fungi treatments, increased the germination percent and seedlings growth of sesame crop significantly, 20 days after planting compared with control treatment. In the second experiment, control treatment scored germination by 52%, while vaccines of Pseudornonas putida2 and Pseudomonas fluorescence3 treatments increased germination percentage in Fusarium, Pythium and Alternaria treatments significantly in average more than 71%. Both isolates increased significantly Leaf number per plant, leaf area per plant, height of plant, branches number per plant, total dry weight of shoot per plant and chlorophyll content compared with other and control treatments. Similar significant effect for both isolates was recorded in seeds number per pod per plant, total weight of 1,000 seeds per plant and pods number per plant and percentage of N, P, K in total dry weight of shoot per plant and oil percentage in seeds per plant compared with other and control treatments. P. putida2 increased oil percentage in seeds by 43.3, 48.0 and 45.0% respectively while with P. fluorescens3 increased to 42.7, 44.0 and 43.7% respectively compared with control treatment (27.7%). In general Pseudomonas putida2 increased most of growth characters much higher than Pseudomonas fluorescens3, it may related to siderophores compound and genetic factors.展开更多
Technological advances in the past 30 years have boosted the use of PSM (membrane separation processes), important for its efficiency and flexibility of operation. These processes can be used in many types of separa...Technological advances in the past 30 years have boosted the use of PSM (membrane separation processes), important for its efficiency and flexibility of operation. These processes can be used in many types of separation, with some advantages over the usual separation processes. NF (nanofiltration) is a membrane separation technique, which has properties intermediate between reverse osmosis and ultrafiltration in terms of separated species, because the average of the pores is in the range of 1/2 to 10 nm, and the separation occurs in function of load and size of the species. Usually removes species in solution with an effective diameter of about 1 nm or larger and multivalent ions to a greater extent than monovalent ions. The objective was to study the formation of biofouling on the surface of commercial nanofiltration membrane (Osmonics/GE) and surface membrane synthesized in our laboratory. The study was conducted in permeation system with filtration cell with tangential displacement of 15 bar for 8 days flow. DBNPA (2,2-dibromo-3-nitrilopropionamide) was used as a biocide agent, and an anti-fouling, in concentrations of 5 and 300 ppm, respectively, added to the water coming from the Beach Sea Galleon, RJ. The results demonstrated that there was no change in the flow and rejection of sulphate ions, even in the presence of anti-fouling. The count of aerobic, anaerobic and BRS (sulfate reducing bacteria) in seawater before and after using the DBNPA showed efficiency in controlling these groups of microorganisms and biofouling microbial consortium consisting of the existing in seawater.展开更多
Toxic pollutants are metabolic poisons that can seriously injure or destroy the photosynthetic organisms upon which the food chain depends. Since microalgae play a key role in marine ecosystems, marine microalgae are ...Toxic pollutants are metabolic poisons that can seriously injure or destroy the photosynthetic organisms upon which the food chain depends. Since microalgae play a key role in marine ecosystems, marine microalgae are proposed as excellent bio-indicators of pollution due to their high sensitivity, which can give warning of the toxic effects of chemicals sooner than any other species. The aim of this work concentrated on the effect of different concentrations of the antifouling biocide (Irgarol 1051) on growth and chlorophylls content (as an essential metabolite) of the two marine unicellular green algae Chlorella salina and Dunaliella bardawil that usually used in fish feeding. The growth of the wall-less Dunaliella bardawil was more sensitive to Irgarol 1051 than the walled cells Chlorella salina, although the concentrations used were greatly different. The product of photosynthesis in the two algal species greatly affected since in the presence of Irgarol 1051, a serious destructive effect was observed. The cell wall appeared to play a significant role in protecting the organism against toxicity of the antifouling agent either by adsorption or degradation. The strength of toxicity depends mainly on the concentration of the antifouling agent, the length of culturing period and the type of organism tested.展开更多
Seawater desalination is one of the major industrial activities along the coastline of Kuwait that poses profound environmental impact on the quality of seawater.This study focuses on investigating the potential conta...Seawater desalination is one of the major industrial activities along the coastline of Kuwait that poses profound environmental impact on the quality of seawater.This study focuses on investigating the potential contamination of biocides,volatile organic hydrocarbons(VOCs)and other halogenated hydrocarbons discharged from Az-Zour desalination plant.Chemical contamination by residual chlorine(RC)and some VOCs was detected in effluents from inside and at the vicinity of the plant.RC ranged between 0.15 and 0.49 mg/L while bromoform(CHBr3)was the highest of all the VOCs detected and ranged between 0.22 and 3.30μg/L.Benzinoides(benzene,toluene,xylene and ethylbenzene)were also detected at 0.1μg/L and 0.25μg/L.The levels of RC as measured in the vicinity of the Az-Zour plant are below the limit set up by Kuwait EPA.However,it still poses effects to the nearby aquatic life and therefore,it is important to lower the concentration of RC in the discharge effluent.展开更多
In this research we decided to analyze the addition of silver(Ag°)on zinc oxide(ZnO)utilizing two nanoparticles:the synthesized zinc oxide-doped-silver nanoparticles(ZnO/Ag_Lab)utilizing the zinc nitrate as metal...In this research we decided to analyze the addition of silver(Ag°)on zinc oxide(ZnO)utilizing two nanoparticles:the synthesized zinc oxide-doped-silver nanoparticles(ZnO/Ag_Lab)utilizing the zinc nitrate as metal precursor for ZnO and silver nitrate as metal precursor for Ag°;and the commercial nanoparticle ZnO/Ag.For the study of application of the nanoparticles,they were processed in the form of films and the polymer utilized was the blend of HMSPP(high melt strength polypropylene)and styrene-ethylene/butadiene-styrene.For the study of nanoparticles,they were submitted to biocide tests against Staphylococcus aureus(ATCC 6538)and Escherichia coli(ATCC8739)and XRD(X-Ray Diffraction).The XRD analysis results indicated,in both of nanoparticles,with the presence of wurtzite phase of ZnO,being that on the commercial nanoparticles the intensity of peak was higher than that of synthesized one,on other hand,the peaks attributed to Ag°,were more intense in the synthesized nanoparticle.展开更多
Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. <em>Spodoptera frugiperda</em> is a pest that affects corn crops among others and has a gre...Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. <em>Spodoptera frugiperda</em> is a pest that affects corn crops among others and has a great capacity to develop resistance to traditional insecticides, which represents sufficient reasons for the search for new alternatives for their control. The objective of this study was to determine the appropriate concentration and screening new natural insecticides against second instar larvae of <em>S. frugiperda</em>, under glasshouse conditions on <em>Zea mays</em> L. Natural products such as annonaceous acetogenins and some acetylated and methoxy methylated ACG derivatives and the commercial product Lambda-cyhalotrin (LC) were evaluated. The percent mortalities of <em>S. frugiperda </em>larvae in glasshouse conditions were recorded after 24, 48 and 72 h of treatment application. The results showed that the acetogenins tested were significantly (P < 0.05) different in relation to pest mortality than untreated check. After 72 h of treatment application the highest percent mortalities were obtained with the mixture of two natural products, rolliniastatin-2 (<strong>5</strong>) (100 μg/mL) + squamocin (<strong>6</strong>) (100 μg/mL) + LC (50 μg/mL) that proved the most effective and gave (100%), while rolliniastatin-2 (<strong>5</strong>) at 100 μg/mL alone, gave lowest percent mortality (65%), followed by squamocin (<strong>6</strong>) at 100 μg/mL (55%) and LC at 50 μg/mL (30%). The acetylated and methoxy methylated ACGs derivatives caused very low mortality (25% - 35%). It is recommended the mixture as a management option of <em>S. frugiperda</em> as a component of integrated pest management. The results allow us to infer that the addition of natural ACGs synergizes the insecticidal activity of the commercial product. Finding a new ecological alternative for insect control.展开更多
Emulsive polymerization of mono- and dy(meth)acrylates of butandiol, decid(meth)acrylate, methyl-α-alkilacrylates with industrial acrylic monomers—butylacrylate, methylacrylate, methacrylic acid, methyl(meth)acrylat...Emulsive polymerization of mono- and dy(meth)acrylates of butandiol, decid(meth)acrylate, methyl-α-alkilacrylates with industrial acrylic monomers—butylacrylate, methylacrylate, methacrylic acid, methyl(meth)acrylate has been investigated. Structurization of copolymers using dy(meth)acrylates of butandiol, braking of emulsive polymerization using water insoluble biocides, dy(meth)acrylates of butandiol and methyl-α-alkilacrylates have been determined. The mechanism of emulsive polymerization of (meth)acrylic monomers using methyl-α-alkilacrylates has been investigated.展开更多
文摘Some new 2-thioxo thiazole, 2-thioxo 1,3,4- thiadiazole and 3-thioxo-1,3,4-triazole derivatives (3-17) have been synthesized through ring closure reactions ofdithioic formic acid hydrazones 2 with functional reagents in different medium. Former structures of the products have been established by the help of elemental and spectral analysis. Most of the obtained targets showed a moderate activity towards some microbes in comparison with two antibiotics Pipercillin and Mycostatine.
文摘Some more new sulfur compounds bearing heterocyclic systems mainly 2-thioxo-1,3,4-thiadiazinone derivatives 2-7 and 3-thioxo-1,2,4-triazole derivatives 9 have been synthetic via alkylation, acylation and condensation of dithioic formic acid hydrazide 1 through ring closure reactions with α,β-bi functional groups compounds. Most of the obtained target showed a highly activity towards some microbial in compare with two references antibiotics, Pipercillin and Mycostatine. The structures of the products have been established from their elemental and spectral analysis.
文摘This study focused on the identification of the filamentous fungi associated with soapstone samples exposed to outdoor conditions and the biocidal effect of gamma radiations on isolated fungal populations in Minas Gerais State in Brazil. Two soapstone blocks were placed outdoors under tropical environmental conditions for 12 months. A total of 9 filamentous fungal populations were identified on their surfaces, namely Acremomium (cf.) alternatum, Alternaria alternata, Aspergillusfumigatus, Calcarisporium (cf.) arbuscula, Cladosporium cladosporioides, Curvularia lunata, Epicoccum nigrum, Fusarium equiseti and Penicillium citrinum. The gamma radiation assay was then carried out as a test of biocidal action by exposing all fungal populations to the ionizing radiation. The results showed that only the C. cladosporioides species was resistant to this biocidal agent, since it was able to increase its population post exposure. Scanning electron microscopy images identified the microbial colonization on the soapstone blocks and the stone elementar composition was analyzed by energy dispersive X-ray spectrometry. After treatment, there was no structural and aesthetic alteration in the soapstone samples, and evidencing that gamma radiation can be used as a biocidal agent. However, the resistance of the black fungal population indicates caution in the choice of gamma irradiation as biocidal treatment.
文摘Objective:To evaluate in vitro effects of Tagetes minuta L. essential oil(TEO) on L3 Anisakis larvae type 1. Methods:In order to evaluate the potential use of Tagetes minuta essential oil against L3 Anisakis larvae three different media were tested:1) a saline solution(SS); 2) an industrial marinating solution; 3) sunflower seeds oil(SO). For each media and concentrations of TEO(0.1%,0.5%,1.0% and 5.0% v/v),20 parasites were introduced into plastic Petri dishes(diameter 90 mm) and maintained at room temperature. As controls,larvae were maintained without TEO under identical experimental conditions in SS,MS and SO. A total of 900 larvae were tested. The normalized mean viability,LT100,LT50 and the percentage of inactivation at 24 hours were calculated. Results:In vitro tests revealed a complete inactivation of parasites in saline solution after 2 hours with 5% and 1% of TEO. In marinating solution,a complete inactivation of parasites was observed after 4 hours at all concentrations used. A slower activity for all TEO concentration was reported in SO. Conclusions:The results obtained,showing a strong activity against Anisakis larvae,confirm TEO as a larvicidal agent in the treatment of human anisakidosis and in the industrial marinating process.
文摘Silver Nanoparticles were synthesized by Esche- richia coli using Silver nitrate in the growth me-dium and characterized in X-Ray Diffraction, UV-Vis Spectrophotometer and Scanning Electron Microscope. They exhibited antimicrobial activity against human pathogens except Escherichia Coli. Nanoparticles were impregnated in yarn and ana-lyzed for their inhibition in the broth culture. The Minimal Inhibitory Concentratio was calculated for the human pathogens in Microtitre plate. The toxicity assessment of the nanoparticles in the embry-onic Zebrafish showed many organogensis deformi-ties like cardiac malformations, eye and head edema, tail and trunk flexure were observed in the organ system of the developing embryos for 1 to 5 day post fertilization in different concentrations of Ag Nanoparticles. The Organogenesis disruptive effects were found in 14 - 20 ng/ml of silver nanoparticles but the inhibition was found in 4-10ng/ml for the pathogens in vitro and 10ng/ml in embryos. Nevertheless, in Cardiac assay, the Heart Beat rates were calculated as 42 - 45 for 15 Sec in the concentrations ranging from 10 - 20 ng/ml of Silver nanoparticles. The blood flows, rhythmicity, contractility of heart beat rates were observed normal. The Mean value of blood Cell counting did not showed any notable effects in the Nanoparticle treated Zebrafish embryos and control. The LC50 value for the Biosynthesized nanoparticle was at 22 ng/ml in all the developmental stages of the em-bryos. Our results shows silver nanoparticles dis-rupts the normal organogenesis during development and further detailed studies are needed to prove silver nanopartcles are an antimicrobial agent for use in humans.
文摘Ferrocyanides of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) were synthesized and characterized by IR spectra, magnetic susceptibility, thermal gravimetric analysis, elemental analysis and X ray diffraction studies. Antimicrobial potential of these complexes have been evaluated. Antifungal screening of these complexes has been carried out against Mycogone perniciosa and Verticillium fungicola causing wet and dry bubble diseases of button mushroom respectively. Nickel ferrocyanide has been found to be most effective against Mycogone perniciosa with 60% inhibitory effect while cadmium ferrocyanide has exhibited significant potential of 85% against Verticillium fungicola.
基金the Chinese National Natural Science Foundation(No.50634020)Scientific and Technological Project of China National Offshore Oil Corporation(No.SC06TJ-PWL-080).
文摘The viscosity property of Cr^3+, Al^3+, and compound ion cross-linked polymer gel solution in the anaerobic and aerobic environment was investigated aiming at meeting the practical demand of the oil field. The viscosity reserving effect after adding the biocide and the gelation in the anaerobic and aerobic environments was also studied in the paper. The results indicate that the viscosity of the cross-linked polymer gel solution caused by the water produced in aerobic environment is higher than that in anaerobic environment, and that the viscosity value of the cross-linked polymer gel solutions after adding biocides has improved to some extent and polymer gel has gelated well in anaerobic environment.
基金the funding support from Foshan University,Chinathe Natural Sciences and Engineering Research Council of Canada(NSERC)
文摘Nanoparticles have been used as diagnostic and therapeutic agents in the human medical field for quite some time, though their application in veterinary medicine and animal production is still relatively new. Recently,production demands on the livestock industry have been centered around the use of antibiotics as growth promoters due to growing concern over microbial antibiotic resistance. With many countries reporting increased incidences of antibiotic-resistant bacteria, laws and regulations are being updated to end in-feed antibiotic use in the animal production industry. This sets the need for suitable alternatives to be established for inclusion in feed.Many reports have shown evidence that nanoparticles may be good candidates for animal growth promotion and antimicrobials. The current status and advancements of nanotechnological applications in animal production will be the focus of this review and the emerging roles of nanoparticles for nutrient delivery, biocidal agents, and tools in veterinary medicine and reproduction will be discussed. Additionally, influences on meat, egg, and milk quality will be reviewed.
文摘The use of seawater for industrial cooling is a vital technology that poses some of the most profound environmental impact on the water quality in the Arabian Gulf. Biocide (chlorine) is added to the seawater to control biofouling of the cooling system. This added chlorine reacts with bromide and other chemicals naturally exist in the water to form a wide range of oxidants. Regrettably, reactions between the residual oxidants and natural organic matter in the water lead to formation of toxic halogenated organic compounds that have detrimental effects on the environment when they are discharged into the Gulf. This paper describes the formation of trihalomethanes (THMs) in seawater cooling systems. Results of kinetic experiments have shown that concentrations of THMs increased rapidly with time during the first half hour. Chlorination of seawater has shown significant increase in total THMs (TTHMs) and in bromoform concentrations. Rapid decrease of UV absorbance at 254 nm was also observed during seawater chlorination which is indicative of natural organic matter degradation into small organic molecules including THMs and other by-products. The increase in chlorine dose was accompanied with an increase in TTHMs and bromoform concentrations. Linear relationships between total chlorine concentration and both final TTHMs and bromoform concentrations were established. First order exponential decay and exponential associate functions were developed to correlate chlorine dose with formed THMs.
文摘Marine fouling is the settlement and growth of a variety of marine organisms, such as bacteria, diatoms, protozoa and algae spores on structures immersed in seawater, such as ship's hulls, navigation buoys, and sonar equipment. Anti-fouling refers to material or systems used to prevent the accumulation of biological material on submerged surfaces. Bio-fouling results in higher fuel consumption and can also facilitate the transport of harmful NIS (Non-Indigenous Species). Antifouling technologies incorporating biocides (e.g., Tributyltin) have been developed to prevent fouling. Their widespread use, however, raised concerns about their toxic effects on marine communities. The AFS Convention (International Convention on the Control of Harmful Anti-fouling Systems in Ships) is a 2001 IMO (International Maritime Organization) treaty, whereby states agree to ban the use of harmful anti-fouling paints and other anti-fouling systems that contain harmful substances. Particularly, the use of the organotinTributyltin is prohibited, since leaching of that chemical from the hulls of ships has been shown to cause deleterious effects on some sea creatures. Although the AFS Convention has entered into force, its full implementation has not yet been appropriately achieved. Most of the ratifying States have delegated the Classification Society to inspect their ships to ensure the implementation of the provisions of the Convention. Since painting ships takes place in dry docks, the full control falls in the hands of Classification Societies.
文摘Background: Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. Methods: We report herein the biocide effects of natural acetogenins from Annona squamosa, A.?muricata and A. montana seeds: annonacin, cis-annonacin, cis-annonacin-10- one, asimicin, rolliniastatin-2, cherimolin-1, cherimolin-2, almuñequin, and two β-OH acetogenins: laherradurin and itrabin on Spodoptera frugiperda Smith (Lepidoptera: Noctuidae). Also, some acetylated and methoxy methylated ACG derivatives were synthesized and evaluated: annonacin (3 OAc), annonacin (4 OAc), asimicin (3 OAc), rolliniastatin-2 (3 OAc), rolliniastatin-2 (MOM), laherradurin (3 OAc) and itrabin (3 OAc). Results: The natural acetogenin rolliniastatin-2 (100 μg·g-1 of diet) produced the most important toxic action causing 100% mortality of early instar larvae. Derivatization of ACG yielded compounds that produced nutritional alterations. The incorporation of rolliniastatin-2 (3 OAc) and rolliniastatin-2 (3 MOM) (100 μg·g-1) into the artificial diet of Spodoptera frugiperdadisplayed the strongest antifeedant effects causing marked decreasings in larval growth and adult lethal malformations. Conclusion: Natural acetogenins are promising metabolites for insect control. Derivatization of these compounds reduces their toxicity to early instar larvae.
文摘The science and technology interact with the art in several ways. Biotechnological coupled with analytical approaches can play an important role in protecting and preserving cultural heritage for future generations. Many microorganisms influenced by environmental conditions are the main responsible for biological contamination in built heritage. Biocides based on chemical compounds have been used to mitigate this problem. Thus, it is vitally important to develop proper remediation actions based on environmentally innocuous alternative. Bacillus specie is emerging as an optimistic alternative for built heritage treatment due to their capacity to produce secondary metabolites with antagonistic activities against many fungal pathogens. Therefore, the intent of this work was to access a rapid evaluation of antifungal potential of bioactive metabolites produced by Bacillus strains and simultaneously their characterization using spectroscopic (NMR) and chromatographic techniques (LC-ESI-MS). The high antifungal activity obtained for Bacillus sp. active compounds produced in this study confirms the great potential to suppress biodeteriogenic fungi growth on historical artworks. Additionally, the proposed methodology allowed to access bioactive metabolites produced without need of the laborious total previous isolation and could be used as a viable alternative to be employed for screening and production of new green biocides.
文摘Two experiments were conducted during 2006-2007 in Complete Randomized Design (CRD) to test the biological activity of Pseudomonas bacteria as biocides to protect sesame crop from some fungi and to evaluate its efficiency as plant growth promoting First experiment investigated the effects of Pseudomonas putida2 and Pseudomonas fluorescens3 on germination and seedlings growth of sesame crop against Pythium, Alternaria and Fusarium under plastic house conditions. Second experiment conducted in large pots to investigate the effects of the two bacterial isolates on some morphological, productive and physiological characters of sesame plants against same fungi under normal conditions. Results showed very low germination and slowly seedlings growth in Pythium, Fusarium and Alternaria treatments respectively, but adding bacterial vaccine of Pseudomonas putida2 and Pseudomonas fluorescens3 as a Biocide to fungi treatments, increased the germination percent and seedlings growth of sesame crop significantly, 20 days after planting compared with control treatment. In the second experiment, control treatment scored germination by 52%, while vaccines of Pseudornonas putida2 and Pseudomonas fluorescence3 treatments increased germination percentage in Fusarium, Pythium and Alternaria treatments significantly in average more than 71%. Both isolates increased significantly Leaf number per plant, leaf area per plant, height of plant, branches number per plant, total dry weight of shoot per plant and chlorophyll content compared with other and control treatments. Similar significant effect for both isolates was recorded in seeds number per pod per plant, total weight of 1,000 seeds per plant and pods number per plant and percentage of N, P, K in total dry weight of shoot per plant and oil percentage in seeds per plant compared with other and control treatments. P. putida2 increased oil percentage in seeds by 43.3, 48.0 and 45.0% respectively while with P. fluorescens3 increased to 42.7, 44.0 and 43.7% respectively compared with control treatment (27.7%). In general Pseudomonas putida2 increased most of growth characters much higher than Pseudomonas fluorescens3, it may related to siderophores compound and genetic factors.
文摘Technological advances in the past 30 years have boosted the use of PSM (membrane separation processes), important for its efficiency and flexibility of operation. These processes can be used in many types of separation, with some advantages over the usual separation processes. NF (nanofiltration) is a membrane separation technique, which has properties intermediate between reverse osmosis and ultrafiltration in terms of separated species, because the average of the pores is in the range of 1/2 to 10 nm, and the separation occurs in function of load and size of the species. Usually removes species in solution with an effective diameter of about 1 nm or larger and multivalent ions to a greater extent than monovalent ions. The objective was to study the formation of biofouling on the surface of commercial nanofiltration membrane (Osmonics/GE) and surface membrane synthesized in our laboratory. The study was conducted in permeation system with filtration cell with tangential displacement of 15 bar for 8 days flow. DBNPA (2,2-dibromo-3-nitrilopropionamide) was used as a biocide agent, and an anti-fouling, in concentrations of 5 and 300 ppm, respectively, added to the water coming from the Beach Sea Galleon, RJ. The results demonstrated that there was no change in the flow and rejection of sulphate ions, even in the presence of anti-fouling. The count of aerobic, anaerobic and BRS (sulfate reducing bacteria) in seawater before and after using the DBNPA showed efficiency in controlling these groups of microorganisms and biofouling microbial consortium consisting of the existing in seawater.
文摘Toxic pollutants are metabolic poisons that can seriously injure or destroy the photosynthetic organisms upon which the food chain depends. Since microalgae play a key role in marine ecosystems, marine microalgae are proposed as excellent bio-indicators of pollution due to their high sensitivity, which can give warning of the toxic effects of chemicals sooner than any other species. The aim of this work concentrated on the effect of different concentrations of the antifouling biocide (Irgarol 1051) on growth and chlorophylls content (as an essential metabolite) of the two marine unicellular green algae Chlorella salina and Dunaliella bardawil that usually used in fish feeding. The growth of the wall-less Dunaliella bardawil was more sensitive to Irgarol 1051 than the walled cells Chlorella salina, although the concentrations used were greatly different. The product of photosynthesis in the two algal species greatly affected since in the presence of Irgarol 1051, a serious destructive effect was observed. The cell wall appeared to play a significant role in protecting the organism against toxicity of the antifouling agent either by adsorption or degradation. The strength of toxicity depends mainly on the concentration of the antifouling agent, the length of culturing period and the type of organism tested.
文摘Seawater desalination is one of the major industrial activities along the coastline of Kuwait that poses profound environmental impact on the quality of seawater.This study focuses on investigating the potential contamination of biocides,volatile organic hydrocarbons(VOCs)and other halogenated hydrocarbons discharged from Az-Zour desalination plant.Chemical contamination by residual chlorine(RC)and some VOCs was detected in effluents from inside and at the vicinity of the plant.RC ranged between 0.15 and 0.49 mg/L while bromoform(CHBr3)was the highest of all the VOCs detected and ranged between 0.22 and 3.30μg/L.Benzinoides(benzene,toluene,xylene and ethylbenzene)were also detected at 0.1μg/L and 0.25μg/L.The levels of RC as measured in the vicinity of the Az-Zour plant are below the limit set up by Kuwait EPA.However,it still poses effects to the nearby aquatic life and therefore,it is important to lower the concentration of RC in the discharge effluent.
文摘In this research we decided to analyze the addition of silver(Ag°)on zinc oxide(ZnO)utilizing two nanoparticles:the synthesized zinc oxide-doped-silver nanoparticles(ZnO/Ag_Lab)utilizing the zinc nitrate as metal precursor for ZnO and silver nitrate as metal precursor for Ag°;and the commercial nanoparticle ZnO/Ag.For the study of application of the nanoparticles,they were processed in the form of films and the polymer utilized was the blend of HMSPP(high melt strength polypropylene)and styrene-ethylene/butadiene-styrene.For the study of nanoparticles,they were submitted to biocide tests against Staphylococcus aureus(ATCC 6538)and Escherichia coli(ATCC8739)and XRD(X-Ray Diffraction).The XRD analysis results indicated,in both of nanoparticles,with the presence of wurtzite phase of ZnO,being that on the commercial nanoparticles the intensity of peak was higher than that of synthesized one,on other hand,the peaks attributed to Ag°,were more intense in the synthesized nanoparticle.
文摘Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. <em>Spodoptera frugiperda</em> is a pest that affects corn crops among others and has a great capacity to develop resistance to traditional insecticides, which represents sufficient reasons for the search for new alternatives for their control. The objective of this study was to determine the appropriate concentration and screening new natural insecticides against second instar larvae of <em>S. frugiperda</em>, under glasshouse conditions on <em>Zea mays</em> L. Natural products such as annonaceous acetogenins and some acetylated and methoxy methylated ACG derivatives and the commercial product Lambda-cyhalotrin (LC) were evaluated. The percent mortalities of <em>S. frugiperda </em>larvae in glasshouse conditions were recorded after 24, 48 and 72 h of treatment application. The results showed that the acetogenins tested were significantly (P < 0.05) different in relation to pest mortality than untreated check. After 72 h of treatment application the highest percent mortalities were obtained with the mixture of two natural products, rolliniastatin-2 (<strong>5</strong>) (100 μg/mL) + squamocin (<strong>6</strong>) (100 μg/mL) + LC (50 μg/mL) that proved the most effective and gave (100%), while rolliniastatin-2 (<strong>5</strong>) at 100 μg/mL alone, gave lowest percent mortality (65%), followed by squamocin (<strong>6</strong>) at 100 μg/mL (55%) and LC at 50 μg/mL (30%). The acetylated and methoxy methylated ACGs derivatives caused very low mortality (25% - 35%). It is recommended the mixture as a management option of <em>S. frugiperda</em> as a component of integrated pest management. The results allow us to infer that the addition of natural ACGs synergizes the insecticidal activity of the commercial product. Finding a new ecological alternative for insect control.
文摘Emulsive polymerization of mono- and dy(meth)acrylates of butandiol, decid(meth)acrylate, methyl-α-alkilacrylates with industrial acrylic monomers—butylacrylate, methylacrylate, methacrylic acid, methyl(meth)acrylate has been investigated. Structurization of copolymers using dy(meth)acrylates of butandiol, braking of emulsive polymerization using water insoluble biocides, dy(meth)acrylates of butandiol and methyl-α-alkilacrylates have been determined. The mechanism of emulsive polymerization of (meth)acrylic monomers using methyl-α-alkilacrylates has been investigated.