The aim of this work was the synthesis of monodisperse latexes based on methyl methacrylate.To achieve this goal,methyl methacrylate was polymerized in an emulsifier-free static heterogeneous monomer-water system in t...The aim of this work was the synthesis of monodisperse latexes based on methyl methacrylate.To achieve this goal,methyl methacrylate was polymerized in an emulsifier-free static heterogeneous monomer-water system in the presence of hydroquinone and potassium persulfate.The size of the latex particles was determined by electron microscopy.Monodisperse latexes with a diameter of about 100 nm were synthesized as a result.展开更多
Polysiloxane-polystyrene composite latexes were prepared by two-stage emulsionpolymerization. Polymerization of styrene in swollen polysiloxane latex particles were studied.Formation of simple polystyrene particle in ...Polysiloxane-polystyrene composite latexes were prepared by two-stage emulsionpolymerization. Polymerization of styrene in swollen polysiloxane latex particles were studied.Formation of simple polystyrene particle in the 2nd-stage polymerization depends on the particlesize of the lst-stage latex and the polymerization temperature. Polystyrene domains in thevulcanizates reinforce the silicone rubbers effectively.展开更多
In the present investigation antibacterial activity of latexes from ten Indian plant species Spondias dulcis (Amra), Diospyros melanoxylon (Tendu), Terminalia bellirica (Wahera), Ficus glomerata (Gular), Phyllanthus e...In the present investigation antibacterial activity of latexes from ten Indian plant species Spondias dulcis (Amra), Diospyros melanoxylon (Tendu), Terminalia bellirica (Wahera), Ficus glomerata (Gular), Phyllanthus emblica (Awla), Thevetia nerifolia (Kaner), Carica papaya (Papita), Calotropis procera (Ak), Ficus benghalensis (Bargad), Atrocarpus heterophyllus (Kathal) collected from Go-rakhpur, North India were determined in various in vitro systems. MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) values were determined in growth inhibitory bioassays by using different increasing concentrations of various latex extracts. Latex samples were diluted by using serial micro dilution method up to 10-10 method with Luria broth culture medium. These values were obtained significantly 2 - 3 times lower than that of broad spectrum antibiotic drugs. Besides this, inhibition zone diameters were measured in agar disc diffusion assay. A known volume i.e. 0.1 - 20 μg/μl of each latex were coated on separate sterile filter paper discs (Whatman No. 1) measuring 6 mm in size. Latex fractions registered significantly higher growth inhibition than that of broad spectrum antimicrobial drugs. Present study indicates the potential use of shows that both latex and its components and latex as are valuable source of medicinal products/active principles that can be used for treatment of life threatening infectious diseases. Because of higher inhibitory and cidal potential obtained in latexes than the synthetic drugs these that could lead to become efficient phytomedicines mainly to have and develop as complete drug formulations against to control infectious microbes.展开更多
The latexes of the three Euphorbia species, namely E. antiquorum L., E. nerifolia L., and E. tirucalli L., are highly valued in the Indian system of medicine as purgatives, in addition to their specific and distinct t...The latexes of the three Euphorbia species, namely E. antiquorum L., E. nerifolia L., and E. tirucalli L., are highly valued in the Indian system of medicine as purgatives, in addition to their specific and distinct therapeutic activities. In order to distinguish these latexes and develop their diagnostic microscopic and chemical markers, we performed extensive chemical and microscopic studies. The three latexes differ significantly in their microscopic features by exhibiting characteristic starch grain patterns. Although amoebic structures were found to be characteristic of E. antiquorum, dumb-bell and oval structures are characteristic of E. nerifolia and E. tirucalli, respectively. In addition, these latexes showed bone-shaped structures as a common feature, but these differed considerably in their length （10-60, 30-55, and 50-70 μm in length in E. antiquorum, E. nerifolia, and E. tirucalli, respectively）. The chemical markers nerifoliene and euphol were found to be common to both E. antiquorum and E. nerifolia, whereas euphol is the only marker for E. tirucalli. A reverse-phase high-performance thin-layer chromatographic （HPTLC） method was developed to distinguish these three latexes and to generate their standard fingerprinting patterns. Most significantly, the markers nerifoliene and euphol could be resolved by RP-18 F254s precoated aluminium plates and the latexes have been quantitatively estimated with respect to these markers. The developed microscopic, chemical and HPTLC patterns can be used to distinguish the three latexes.展开更多
Cationic latexes were prepared through emulsion copolymerization of styrene （St） and butyl acrylate （BA） with a cationic surfactant, cetyl trimethyl ammonium bromide （CTAB）. Latex properties, including particle ...Cationic latexes were prepared through emulsion copolymerization of styrene （St） and butyl acrylate （BA） with a cationic surfactant, cetyl trimethyl ammonium bromide （CTAB）. Latex properties, including particle size, size distribution, （ potential, surface tension and monomer conversion, were determined for latexes prepared with different CTAB amounts. Evolution of these properties during emulsion polymerization was followed in order to understand the mechanism of the particles formation. Results showed that both particle size and 6＂ potential were function of polymerization time and latex solids. Parallel emulsion polymerizations with cationic, anionic charged initiator and charge-free initiators were also carried out, the latex properties were determined at different polymerization time. All these results were attentively interpreted based on the mechanisms of emulsion polymerization, surfactant adsorption and latex particle stabilization.展开更多
In the present investigation, various bioassays were conducted to evaluate the alteration in levels of various enzymes i.e. alkaline phosphatase, acid phosphatase, glutamate oxaloacetate transaminase, glutamate pyruva...In the present investigation, various bioassays were conducted to evaluate the alteration in levels of various enzymes i.e. alkaline phosphatase, acid phosphatase, glutamate oxaloacetate transaminase, glutamate pyruvate transaminase and acetylcholinesterase. For this purpose worker termites were treated with sub-lethal doses of 40% and 80% of 24 hrs LD<sub>50</sub> of latex-based combinatorial formulations and observations were taken at 4 hours intervals up to 24 hours. Ficus benghalensis crude latex and its combinatorial mixtures, like C-MLT-A, CU-MLT-A, AQ-MLT, P-MLT and EA-MLT significantly altered the level of enzymes in Odontotermes obesus and this effect found time and dose-dependent. Reduction or increase in enzymes was calculated by using the corresponding control. The maximum decrease in acid phosphatase level was observed at 16 h when termites were treated with 80% of LD<sub>50</sub> of B-MLT-B and P-MLT i.e. 82.84% at 16 h of treatment. A similar dose caused a very slight decrease in glutamate pyruvate transaminase at 4 h of treatment but with the increase in time. Further decrease was noted in other successive treatments that were significant at p > 0.05. Similarly, 40% and 80% of LD<sub>50</sub> of the C-MLT-B mixture caused significant (p > 0.05) decrease in alkaline phosphatase and acid phosphatase level at 16 h treatment i.e. 93.42%, 89.46% and 95.89%, 88.17% respectively. The level of acetylcholinesterase was also found to be decreased when termites were treated with 40% and 80% of LD<sub>50</sub> of C-MLT-B mixture i.e. 92.72% and 97.27% respectively. All the above alterations noted in levels of various enzymes confirm the action of latex ingredients on worker termites that were anti-feedant or deterrent types. These ingredients can be used to control not only termites but also other phytophagous insects.展开更多
In present investigation, various bioassays were conducted to evaluate the alteration in levels of certain biomolecules, such as glycogen, protein, amino acid, DNA, RNA and lipids. For this purpose, worker termites we...In present investigation, various bioassays were conducted to evaluate the alteration in levels of certain biomolecules, such as glycogen, protein, amino acid, DNA, RNA and lipids. For this purpose, worker termites were treated with sub-lethal dose 40% and 80% of 24 hrs LD<sub>50</sub> values and observations were taken at 4 hrs interval up to 24 hrs. Crude latex and its combinatorial mixtures, like S-MLT-A, B-MLT-A, C-MLT-A, CU-MLT-A, AQ-MLT significantly altered level of bio-molecules in Odontotermes obesus. This effect was found time and dose dependent. Reduction or increase in biomolecules was calculated by using corresponding control. Maximum decrease in glycogen level was observed at 16 h when termites were treated with 80% of LD<sub>50</sub> of Ficus benghalensis aqueous extract i.e. 56.88% at 16 h of treatment. A similar dose caused very slight decrease in lipid contents at 4 h of treatment but it was found further significantly (p > 0.05) decreased in other successive treatments. 40% and 80% of LD<sub>50</sub> of C-MLT-B mixture caused significant (p > 0.05) decrease in DNA and RNA level at 16 h treatment. The level of DNA and RNA level was recorded 83.90%, 90.18% and 85.42% and 74.05% respectively. Similarly, total proteins were also found to be decreased with 40% and 80% of LD<sub>50</sub> of C-MLT-B mixture i.e. 71.47% and 66.45% respectively. All these alterations found in levels of various bio-molecules confirm the action of latex ingredients on worker termites that was antifeedant or deterrent types. These ingredients can be used to control not only termites but also other phytophagous insects in a sustainable and eco-friendly way.展开更多
Latex wastewater is a kind of refractory organic wastewater containing high concentrations of organics and ammonia nitrogen.In this work,the combined process of forward osmosis(FO)and reverse osmosis(RO)was designed t...Latex wastewater is a kind of refractory organic wastewater containing high concentrations of organics and ammonia nitrogen.In this work,the combined process of forward osmosis(FO)and reverse osmosis(RO)was designed to treat the latex wastewater in the whole process,achieving the water recovery rate of 99%and basically no waste discharge after the catalytic oxidation process.The turbidity of the latex wastewater was decreased to below 1 NTU by microfiltration pretreatment,and then using MgCl_2 worked as the draw solution for FO process to treat the latex wastewater.Different operation conditions including adding acid or scale inhibitor as the pretreatment methods were conducted to improve the treatment performance of the combined process.After the treatment of the whole process,the concentration of COD was less than 20 mg·L^(-1),the concentration of NH_3-N was less than 10 mg·L^(-1),and the concentration of TP was less than 0.5 mg·L^(-1)for the treated latex wastewater.The water quality met standards of industrial water reuse after the complete analysis of the treated latex wastewater,meanwhile,useful substances of L-Quebrachitol(L-Q)were successfully extracted from the concentrated solution.Therefore,the combined process of FO and RO could realize the efficient treatment and reuse of latex wastewater,which provided with some important guidance on the industrial application.展开更多
Over 350 million years have passed since the documentation of the first interaction between plants and insects. Numerous plant defense qualities and associated counter-adaptive features have developed as a result of t...Over 350 million years have passed since the documentation of the first interaction between plants and insects. Numerous plant defense qualities and associated counter-adaptive features have developed as a result of these interactions between insects and plants. These characteristics might be either morphological or biological in nature. One of the most significant and useful biochemical characteristics in plants is latex. Latex has a sticky property due to presence of secondary metabolites in it, which aids in entangling or sealing the mouthparts of small insects. These metabolites also chemically interact with the insects interfering with crucial bodily processes. Plant latex has amazing properties that help protect plants from insects and inhibit them in general. It may be possible to control insect pests in a natural, secure, and long-lasting manner by correctly identifying plant latex with strong insecticidal properties and developing formulations of plant latex.展开更多
This work focuses on the development of carpets from sand, fabrics of cotton fiber and mosquito nets and rubber latex. Following a study on the choice of the best formulations, the quantity of rubber latex used for sh...This work focuses on the development of carpets from sand, fabrics of cotton fiber and mosquito nets and rubber latex. Following a study on the choice of the best formulations, the quantity of rubber latex used for shaping varies between 14% and 18% (latex/sand + latex ratio) for the carpet with the fabric of mosquito nets and between 16% and 18% for the one made with the fabric of cotton fiber. Thus, with a mixture of sand, fiber fabrics (cotton and mosquito nets) and rubber latex, carpets were developed. In addition, the wear test carried out on these samples indicates that it is possible to produce carpets with the new material made of rubber sand and latex: SABLATEX At room temperature. Following the characterization test, it resorts to only 16% latex with cotton fiber fabric, allowing to have carpets with good mechanical characteristics.展开更多
文摘The aim of this work was the synthesis of monodisperse latexes based on methyl methacrylate.To achieve this goal,methyl methacrylate was polymerized in an emulsifier-free static heterogeneous monomer-water system in the presence of hydroquinone and potassium persulfate.The size of the latex particles was determined by electron microscopy.Monodisperse latexes with a diameter of about 100 nm were synthesized as a result.
文摘Polysiloxane-polystyrene composite latexes were prepared by two-stage emulsionpolymerization. Polymerization of styrene in swollen polysiloxane latex particles were studied.Formation of simple polystyrene particle in the 2nd-stage polymerization depends on the particlesize of the lst-stage latex and the polymerization temperature. Polystyrene domains in thevulcanizates reinforce the silicone rubbers effectively.
文摘In the present investigation antibacterial activity of latexes from ten Indian plant species Spondias dulcis (Amra), Diospyros melanoxylon (Tendu), Terminalia bellirica (Wahera), Ficus glomerata (Gular), Phyllanthus emblica (Awla), Thevetia nerifolia (Kaner), Carica papaya (Papita), Calotropis procera (Ak), Ficus benghalensis (Bargad), Atrocarpus heterophyllus (Kathal) collected from Go-rakhpur, North India were determined in various in vitro systems. MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) values were determined in growth inhibitory bioassays by using different increasing concentrations of various latex extracts. Latex samples were diluted by using serial micro dilution method up to 10-10 method with Luria broth culture medium. These values were obtained significantly 2 - 3 times lower than that of broad spectrum antibiotic drugs. Besides this, inhibition zone diameters were measured in agar disc diffusion assay. A known volume i.e. 0.1 - 20 μg/μl of each latex were coated on separate sterile filter paper discs (Whatman No. 1) measuring 6 mm in size. Latex fractions registered significantly higher growth inhibition than that of broad spectrum antimicrobial drugs. Present study indicates the potential use of shows that both latex and its components and latex as are valuable source of medicinal products/active principles that can be used for treatment of life threatening infectious diseases. Because of higher inhibitory and cidal potential obtained in latexes than the synthetic drugs these that could lead to become efficient phytomedicines mainly to have and develop as complete drug formulations against to control infectious microbes.
基金Publication of this paper is supported by the National Natural Science Foundation of China （30424813） and Science Publication Foundation of the Chinese Academy of Sciences. Supported by the Regional Research Laboratory, Bhubaneswar. Acknowledgements The authors thank Dr Vibhuti N. Misra, Director, Regional Research Laboratory, Bhubaneswar, for encouragement and also Dr S. N. Padhy, State Forensic Laboratory, Bhubaneswar, for help running some of the HPTLC chromatograms.
文摘The latexes of the three Euphorbia species, namely E. antiquorum L., E. nerifolia L., and E. tirucalli L., are highly valued in the Indian system of medicine as purgatives, in addition to their specific and distinct therapeutic activities. In order to distinguish these latexes and develop their diagnostic microscopic and chemical markers, we performed extensive chemical and microscopic studies. The three latexes differ significantly in their microscopic features by exhibiting characteristic starch grain patterns. Although amoebic structures were found to be characteristic of E. antiquorum, dumb-bell and oval structures are characteristic of E. nerifolia and E. tirucalli, respectively. In addition, these latexes showed bone-shaped structures as a common feature, but these differed considerably in their length （10-60, 30-55, and 50-70 μm in length in E. antiquorum, E. nerifolia, and E. tirucalli, respectively）. The chemical markers nerifoliene and euphol were found to be common to both E. antiquorum and E. nerifolia, whereas euphol is the only marker for E. tirucalli. A reverse-phase high-performance thin-layer chromatographic （HPTLC） method was developed to distinguish these three latexes and to generate their standard fingerprinting patterns. Most significantly, the markers nerifoliene and euphol could be resolved by RP-18 F254s precoated aluminium plates and the latexes have been quantitatively estimated with respect to these markers. The developed microscopic, chemical and HPTLC patterns can be used to distinguish the three latexes.
基金supported by the Natural Science Foundation of Shandong Province,China(No.Z2008B07)the National Natural Science Foundation of China(No.20874040)
文摘Cationic latexes were prepared through emulsion copolymerization of styrene （St） and butyl acrylate （BA） with a cationic surfactant, cetyl trimethyl ammonium bromide （CTAB）. Latex properties, including particle size, size distribution, （ potential, surface tension and monomer conversion, were determined for latexes prepared with different CTAB amounts. Evolution of these properties during emulsion polymerization was followed in order to understand the mechanism of the particles formation. Results showed that both particle size and 6＂ potential were function of polymerization time and latex solids. Parallel emulsion polymerizations with cationic, anionic charged initiator and charge-free initiators were also carried out, the latex properties were determined at different polymerization time. All these results were attentively interpreted based on the mechanisms of emulsion polymerization, surfactant adsorption and latex particle stabilization.
文摘In the present investigation, various bioassays were conducted to evaluate the alteration in levels of various enzymes i.e. alkaline phosphatase, acid phosphatase, glutamate oxaloacetate transaminase, glutamate pyruvate transaminase and acetylcholinesterase. For this purpose worker termites were treated with sub-lethal doses of 40% and 80% of 24 hrs LD<sub>50</sub> of latex-based combinatorial formulations and observations were taken at 4 hours intervals up to 24 hours. Ficus benghalensis crude latex and its combinatorial mixtures, like C-MLT-A, CU-MLT-A, AQ-MLT, P-MLT and EA-MLT significantly altered the level of enzymes in Odontotermes obesus and this effect found time and dose-dependent. Reduction or increase in enzymes was calculated by using the corresponding control. The maximum decrease in acid phosphatase level was observed at 16 h when termites were treated with 80% of LD<sub>50</sub> of B-MLT-B and P-MLT i.e. 82.84% at 16 h of treatment. A similar dose caused a very slight decrease in glutamate pyruvate transaminase at 4 h of treatment but with the increase in time. Further decrease was noted in other successive treatments that were significant at p > 0.05. Similarly, 40% and 80% of LD<sub>50</sub> of the C-MLT-B mixture caused significant (p > 0.05) decrease in alkaline phosphatase and acid phosphatase level at 16 h treatment i.e. 93.42%, 89.46% and 95.89%, 88.17% respectively. The level of acetylcholinesterase was also found to be decreased when termites were treated with 40% and 80% of LD<sub>50</sub> of C-MLT-B mixture i.e. 92.72% and 97.27% respectively. All the above alterations noted in levels of various enzymes confirm the action of latex ingredients on worker termites that were anti-feedant or deterrent types. These ingredients can be used to control not only termites but also other phytophagous insects.
文摘In present investigation, various bioassays were conducted to evaluate the alteration in levels of certain biomolecules, such as glycogen, protein, amino acid, DNA, RNA and lipids. For this purpose, worker termites were treated with sub-lethal dose 40% and 80% of 24 hrs LD<sub>50</sub> values and observations were taken at 4 hrs interval up to 24 hrs. Crude latex and its combinatorial mixtures, like S-MLT-A, B-MLT-A, C-MLT-A, CU-MLT-A, AQ-MLT significantly altered level of bio-molecules in Odontotermes obesus. This effect was found time and dose dependent. Reduction or increase in biomolecules was calculated by using corresponding control. Maximum decrease in glycogen level was observed at 16 h when termites were treated with 80% of LD<sub>50</sub> of Ficus benghalensis aqueous extract i.e. 56.88% at 16 h of treatment. A similar dose caused very slight decrease in lipid contents at 4 h of treatment but it was found further significantly (p > 0.05) decreased in other successive treatments. 40% and 80% of LD<sub>50</sub> of C-MLT-B mixture caused significant (p > 0.05) decrease in DNA and RNA level at 16 h treatment. The level of DNA and RNA level was recorded 83.90%, 90.18% and 85.42% and 74.05% respectively. Similarly, total proteins were also found to be decreased with 40% and 80% of LD<sub>50</sub> of C-MLT-B mixture i.e. 71.47% and 66.45% respectively. All these alterations found in levels of various bio-molecules confirm the action of latex ingredients on worker termites that was antifeedant or deterrent types. These ingredients can be used to control not only termites but also other phytophagous insects in a sustainable and eco-friendly way.
基金supported by the National Natural Science Foundation of China (22125802 and 22108012)Natural Science Foundation of Beijing Municipality (2222017)Fundamental Research Funds for the Central Universities (BUCTRC-202109)。
文摘Latex wastewater is a kind of refractory organic wastewater containing high concentrations of organics and ammonia nitrogen.In this work,the combined process of forward osmosis(FO)and reverse osmosis(RO)was designed to treat the latex wastewater in the whole process,achieving the water recovery rate of 99%and basically no waste discharge after the catalytic oxidation process.The turbidity of the latex wastewater was decreased to below 1 NTU by microfiltration pretreatment,and then using MgCl_2 worked as the draw solution for FO process to treat the latex wastewater.Different operation conditions including adding acid or scale inhibitor as the pretreatment methods were conducted to improve the treatment performance of the combined process.After the treatment of the whole process,the concentration of COD was less than 20 mg·L^(-1),the concentration of NH_3-N was less than 10 mg·L^(-1),and the concentration of TP was less than 0.5 mg·L^(-1)for the treated latex wastewater.The water quality met standards of industrial water reuse after the complete analysis of the treated latex wastewater,meanwhile,useful substances of L-Quebrachitol(L-Q)were successfully extracted from the concentrated solution.Therefore,the combined process of FO and RO could realize the efficient treatment and reuse of latex wastewater,which provided with some important guidance on the industrial application.
文摘Over 350 million years have passed since the documentation of the first interaction between plants and insects. Numerous plant defense qualities and associated counter-adaptive features have developed as a result of these interactions between insects and plants. These characteristics might be either morphological or biological in nature. One of the most significant and useful biochemical characteristics in plants is latex. Latex has a sticky property due to presence of secondary metabolites in it, which aids in entangling or sealing the mouthparts of small insects. These metabolites also chemically interact with the insects interfering with crucial bodily processes. Plant latex has amazing properties that help protect plants from insects and inhibit them in general. It may be possible to control insect pests in a natural, secure, and long-lasting manner by correctly identifying plant latex with strong insecticidal properties and developing formulations of plant latex.
文摘This work focuses on the development of carpets from sand, fabrics of cotton fiber and mosquito nets and rubber latex. Following a study on the choice of the best formulations, the quantity of rubber latex used for shaping varies between 14% and 18% (latex/sand + latex ratio) for the carpet with the fabric of mosquito nets and between 16% and 18% for the one made with the fabric of cotton fiber. Thus, with a mixture of sand, fiber fabrics (cotton and mosquito nets) and rubber latex, carpets were developed. In addition, the wear test carried out on these samples indicates that it is possible to produce carpets with the new material made of rubber sand and latex: SABLATEX At room temperature. Following the characterization test, it resorts to only 16% latex with cotton fiber fabric, allowing to have carpets with good mechanical characteristics.
