Poly-3-hydroxybutyrate （PHB） can be produced by various species of bacteria. Among the possible carbon sources, both methane and methanol could be a suitable substrate for the production of PHB. Methane is cheap and...Poly-3-hydroxybutyrate （PHB） can be produced by various species of bacteria. Among the possible carbon sources, both methane and methanol could be a suitable substrate for the production of PHB. Methane is cheap and plentiful not only as natural gas, but also as biogas. Methanol can also maintain methanotrophic activity in some conditions. The methanotrophic strain Methylosinus trichosporium IMV3011 can accumulate PHB with methane and methanol in a brief nonsterile process. Liquid methanol （0.1%） was added to improve the oxidization of methane. The studies were carried out using shake flasks. Cultivation was performed in two stages： a continuous growth phase and a PHB accumulation phase under the conditions short of essential nutrients （ammonium, nitrate, phosphorus, copper, iron （Ⅲ）, magnesium or ethylenediamine tetraacetate （EDTA）） in batch culture. It was found that the most suitable growth time for the cell is 144 h. Then an optimized culture condition for second stage was determined, in which the PHB concentration could be much increased to 0.6 g/L. In order to increase PHB content, citric acid was added as an inhibitor of tricarboxylic acid cycle （TCA）. It was found that citric acid is favorable for the PHB accumulation, and the PHB yield was increased to 40% （w/w） from the initial yield of 12% （w/w） after nutrient deficiency cultivation. The PHB produced is of very high quality with molecular weight up to 1.5 × 10^6Da.展开更多
Biomimetic adsorbent named as PHBBMA was prepared from lipophilic poly-3-hydroxybutyrate （PHB） by a modified double emulsion solvent evaporation method. PHBBMA, characterized by using scanning electron microscope an...Biomimetic adsorbent named as PHBBMA was prepared from lipophilic poly-3-hydroxybutyrate （PHB） by a modified double emulsion solvent evaporation method. PHBBMA, characterized by using scanning electron microscope and nitrogen adsorption/desorption measurements, is porous spherical particles. The characterization with the thermal gravimetric analysis and differential scanning calorimetry, 1 H nuclear magnetic resonance and Fourier transform infrared spectroscopy showed that PHBBMA preparation was a physical process without chemical reaction. The adsorption of PHBBMA for o-nitrochlorobenzene （o-NCB） was fitted better by Langmuir model than by Freundlich model, while the pseudo second-order model fitting was better than the pseudo first-order model fitting. The maximal adsorption capacity of PHBBMA for o-NCB was 57.83 mg/g at 30°C, although its specific surface area （S BET ） was only 8.45 m 2 /g. PHBBMA is a safe and environmental friendly adsorbent with high adsorption capacity because its component is innocuous and biodegradable PHB produced reusing wastes and contaminants, no byproduct can produced, and its ester and hydrocarbyl groups have strong affinity with organochlorine compounds. The further work will focus on the modification and improvement of PHBBMA in order to increase its S BET and adsorption capacity.展开更多
Gene-based therapeutics has emerged as a promising approach for human cancer therapy. Among a variety of non-viral vectors, polymer vectors are particularly attractive due to their safety and multivalent groups on the...Gene-based therapeutics has emerged as a promising approach for human cancer therapy. Among a variety of non-viral vectors, polymer vectors are particularly attractive due to their safety and multivalent groups on their surface. This study focuses on guanidinylated O-carboxymethyl chitosan(GOCMCS) along with poly-β-amino ester(PBAE) for si RNA delivery. Binding efficiency of PBAE/si RNA/GOCMCS nanoparticles were characterized by gel electrophoresis. The si RNA-loaded nanoparticles were found to be stable in the presence of RNase A, serum and BALF respectively. Fine particle fraction(FPF) which was determined by a two-stage impinger(TSI) was 57.8% ± 2.6%. The particle size and zeta potential of the nanoparticles were 153.8 ± 12.54 nm and + 12.2 ± 4.94 m V. In vitro cell transfection studies were carried out with A549 cells. The cellular uptake was significantly increased. When the cells were incubated with si Survivin-loaded nanoparticles, it could induce 26.83% ± 0.59% apoptosis of A549 cells and the gene silencing level of survivin expression in A549 cells were 30.93% ± 2.27%. The results suggested that PBAE/GOCMCS nanoparticle was a very promising gene delivery carrier.展开更多
With the exploitation of rare earth ore, more and more rare earth elements came into groundwater, caused waste of resources and toxicity to the organisms. This study aimed to find an efficient adsorption material to m...With the exploitation of rare earth ore, more and more rare earth elements came into groundwater, caused waste of resources and toxicity to the organisms. This study aimed to find an efficient adsorption material to mitigate the above issue. Through doping polyvinyl alcohol with poly-γ-glutamic acid, an immobilised PSP gel particle was produced and had the adsorption rate of La3＋ up to 97.10%. The factors including initial concentration of La3＋ or Ce3＋, adsorbent dosage, pH and temperature of the solution, which potentially affected the adsorption rate and were studied in batch mode. It was found that the optimum adsorption conditions were composed of 50 mg/L La3 VCe3＋ of initial concentration, 600 mg/L （dry mass） biomass for adsorption, pH 6, temperature 30 ℃, 150 r/min rotational speed, and 1 h adsorption time. The selective adsorption of 15 different rare earth ions in mixed aqueous solu- tions were investigated. However, no significant selective differences were observed. Scanning electron microscopy showed that the morphological characteristic of the novel gel was its porous structure, while polyvinyl alcohol gel had a compact structure. Fourier transform infrared spectroscopy suggested that carboxyl groups in the poly-γ-glutamic acid might played a key role in the adsorption process. The adsorption mechanism forecasted to be cation exchange between -COOH and R3＋. The adsorption kinetic and thermodynamic process for La3＋ and Ce3＋ was consistent with the pseudo-second-order equation and Langmuir adsorption isotherm model. It demonstrated that PSP gels particles were useful for removing REEs from wastewater.展开更多
The production of poly-α-olefins(PAOs)has attracted attention due to their excellent viscosity-temperature dependence,wear characteristics,oxidative properties,and high thermal stability.In this study,indene extracte...The production of poly-α-olefins(PAOs)has attracted attention due to their excellent viscosity-temperature dependence,wear characteristics,oxidative properties,and high thermal stability.In this study,indene extracted during coal tar refining was used as a raw material to synthesize a bis(indenyl)zirconium dichloride metallocene catalyst.A PAO with low viscosity and a high viscosity index was produced via the oligomerization of 1-decene in the presence of both the prepared metallocene and a methylaluminoxane(MAO)co-catalyst.Notably,the effects of different synthesis reaction parameters,such as Al:Zr ratio,amount of catalyst,and reaction temperature,on the conversion ratio and product selectivity were investigated in detail.The produced PAO was thoroughly characterized using Fourier-transform infrared,^(13)C,and^(1)H nuclear magnetic resonance spectroscopies;gas chromatography;and viscosity measurements.At 70℃,the metallocene catalyst created more stable active sites.In addition,the alkylation effect of MAO was noticeable.Interestingly,the obtained catalysis results demonstrated that a high conversion ratio of~93%was achieved at a low reaction temperature of 70℃,with a catalyst dosage of 0.0848 mmol and Al:Zr ratio of 8.48mmol:0.0848mmol.Moreover,under these optimal conditions,the kinematic viscosity of PAO was 4.25 mm2/s at 100℃,and the viscosity index was 139,indicating good viscosity-temperature properties.展开更多
The cobalt and ruthenium bimetallic complex of poly-γ-amino-propylsiloxane( abbr. as Si-CH_2-Co-Ru) was prepared, and it was found that it can catalyze the hydroformylation of cyclobexene effectively with the convers...The cobalt and ruthenium bimetallic complex of poly-γ-amino-propylsiloxane( abbr. as Si-CH_2-Co-Ru) was prepared, and it was found that it can catalyze the hydroformylation of cyclobexene effectively with the conversion amounting to over 90%. Cyclohexanecarboxaldehyde was first formed in the hydroformylation, and then further hydrogenated to form cylcohexanemethanol. The coversion was affected obviously by the Co/Ru ratio.When Co/Ru molar ratio was 100-150, i.e. in the very low content of noble metal Ru, the catalytic activity of Si-NH_2 -Co-Ru was also very high. The product composition was affected by CO/H_2 ratio in the reaction gas. Aldehyde can be got high selectively by controlling CO/H_2 ratio. Compared with other catalyst system, the Si-NH_2-Co-Ru catalyst has higher catalytic activity and efficiency with very low Ru/Co ratio. The total turnover number was more than 28,800 (based on the amount of ruthenium used).展开更多
Biodegradable polymers have been widely used in the field of tissue engineering.The adhesive characteristic of polymer surfaces must be modified for cell seeding and growth before being used.The modified method poly-...Biodegradable polymers have been widely used in the field of tissue engineering.The adhesive characteristic of polymer surfaces must be modified for cell seeding and growth before being used.The modified method poly-β-hybroxybutyric acid (PHB) was introduced and the biocompatibility of modified PHB to adrenocortical cells was studied here,Gelatin was used as a modifier to retrofit PHB and adrenocortical cells were seeded in the modified PHB.The effects of PHB on the proliferation and secreting function of adrenocortical cells were evaluated by MTT and RIA methods.It shows that adrenocortical cells were able to grow and survived in PHB and no influence on the proliferation and secreting function of the cells was observed.The morphology study shows that the modified PHB was easy for cells seeding and growing.The modified PHB is a good biodegradable material as cell carrier for transplantation of adrenocortical cells.展开更多
The purpose of this study was to prepare a poly-γ-glutamic acid hydrogel (PGA gel), to examine its ease of swallowing using texture profile analysis (TPA) and to evaluate its taste-masking effects on basic or acidic ...The purpose of this study was to prepare a poly-γ-glutamic acid hydrogel (PGA gel), to examine its ease of swallowing using texture profile analysis (TPA) and to evaluate its taste-masking effects on basic or acidic drugs using the artificial taste sensor. Using TPA, 0.5% and 1.0% PGA gels, 0.5% and 1.0% agar and 1.0% ι-carrageenan in the absence of drug was examined the hardness, adhesiveness and cohesiveness, ranked according to permission criteria published by the Japanese Consumers Affairs Agency. 0.5% PGA gel and 1.0% agar were classified into grade II. In the taste sensor measurement, the bitterness suppressions by 0.5% PGA gel were larger than that by 1.0% agar in all drugs and the bitterness suppressions of basic drugs in 0.5% PGA gel were more potent than those of acidic drugs in 0.5% PGA gel. 1H-nuclear magnetic resonance spectroscopic analysis was carried out to examine the difference in mechanism of bitterness suppression between basic drugs and acidic drugs mixed with PGA gel. The signals of the proton nearest to the nitrogen atom of basic drugs shifted clearly upfield, suggesting an interaction between the amino group of basic drugs and the carboxyl group of PGA gel. In conclusion, PGA gel is expected to be a useful excipient in formulations contained various drugs, especially basic drugs;it also has advantage for not only increasing ease of swallowing but also masking the bitterness of drugs even though a small amount of a single drug dose might be preferred.展开更多
The remote interaction of polymethacrylic acid hydrogel with a poly-2-methyl-5-vinylpyridine hydrogel was studied. The aim of work was to study the dependence of the swelling coefficient, the conductivity and the pH o...The remote interaction of polymethacrylic acid hydrogel with a poly-2-methyl-5-vinylpyridine hydrogel was studied. The aim of work was to study the dependence of the swelling coefficient, the conductivity and the pH of the water solutions of intergel system at different mass ratios from time were studied. The goal was achieved by using following methods： pH-metry, conductometry and gravimetry.展开更多
The effects of sodium hypochlorite concentration in the recovery of poly-β-hydroxybutyrate (PHB) are investigated. A simple reaction equation and a mathematical model describe the reaction kinetics. Results showed th...The effects of sodium hypochlorite concentration in the recovery of poly-β-hydroxybutyrate (PHB) are investigated. A simple reaction equation and a mathematical model describe the reaction kinetics. Results showed that the stoichiometric coefficient increases with increasing CAO/CBO, where CAO is the concentration of the active chlorine at t = 0 and CBO is the initial concentration of the non-PHB materials.展开更多
Several silica-supported poly-γ-aminopropylsiloxane-monometal and bimetal complexes (Si-NH_2-M,M = Cu or Co ; Si-NH_2-Cu-M', M' =Co, Sn, Mn, Ni or Fe) have been prepared. Their catalytic properties for oxidat...Several silica-supported poly-γ-aminopropylsiloxane-monometal and bimetal complexes (Si-NH_2-M,M = Cu or Co ; Si-NH_2-Cu-M', M' =Co, Sn, Mn, Ni or Fe) have been prepared. Their catalytic properties for oxidative ethoxycarbonylation of aniline to ethyl phenylcarbamate have been investigated.The catalytic reaction was carried out under relatively mild conditions. The catalyst Si-NH_2-Cu-CO had high activity and selectivity, and the turn-over number (molar of aniline converted/molar of metal in Si-NH_2-Cu-CO added) could amount to 450 under the conditions: 150℃ , 4 MPa (CO/O_2 =3) and 40 hours.The results of XPS and IR indicated that the coordination bonds were formed between nitrogen and metals in Si-NH2-Cu, Si-NH_2-Co and Si-NH_2-Cu-Co, and the coordination pattern was not single. In the oxidative ethoxycarbonylation of aniline to ethyl phenylcarbamate, the catalytic property of Si-NH_2-Cu-CO bimetallic complex was better than Si-NH_2-Cu or Si-NH_2-Co monometatlic complex. This indicated that there as synergistic action between different metals in the bimetallic complex.展开更多
The molecular behavior of polyurethane(PU)coating materials during the surface adsorption of poly-α-olefin as a drag reducing polymer was explored by a molecular dynamics simulation.Three different PU capsule wall ma...The molecular behavior of polyurethane(PU)coating materials during the surface adsorption of poly-α-olefin as a drag reducing polymer was explored by a molecular dynamics simulation.Three different PU capsule wall materials were synthesized using two reaction monomers,and a poly-α-olefin/PU drag reducer microcapsule was prepared based on interface polymerization.The structure,morphology,thermal stability,compressive strength,and drag reduction performance of the microcapsules were characterized and compared.The results showed that a non-bonding interaction induced the adsorption of the PU coating material,poly-α-olefin and PU then fused at the interface,and the PU coating material was embedded into the inner grooves of poly-α-olefin in the form of a local mosaic,thereby forming a stable core–shell structure.The morphological characterization indicated that PU and poly-α-olefin could form microcapsule structures.The thermal decomposition temperature of the microcapsule was dependent on the type of capsule wall material.The microcapsule structure had a slight effect on poly-α-olefin drag reduction.The system enabled poly-α-olefin to exist in powdered particles through microcapsulation,and had a good dispersion effect that facilitated storage and transport processes.The method effectively inhibited the accumulation and bonding of poly-α-olefin at room temperature.展开更多
A silica-supported poly-γ- aminopropylsiloxane-rhodium-cobalt bimetallic complex(abbreviated as SiO_2-NH_2-Rh-Co)has been prepared and used as catalyst for hydroformylationof methyl methacrylate. The results showed t...A silica-supported poly-γ- aminopropylsiloxane-rhodium-cobalt bimetallic complex(abbreviated as SiO_2-NH_2-Rh-Co)has been prepared and used as catalyst for hydroformylationof methyl methacrylate. The results showed that the catalyst could catalyze the reaction in95.6% conversion with 92.8% selectivity for the normal aldehyde, methyl β-formylisobu-tyrate. Such catalyst also showed high stability during the reaction and could be used repeat-edly.展开更多
In this paper, a new silica-supported poly-γ-aminopropylsilane Cu2+-Pd2+ complex was studied in Heck vinylation reaction of aryl iodide with olefins. The catalyst is highly active and stereoselective at 70-100℃, and...In this paper, a new silica-supported poly-γ-aminopropylsilane Cu2+-Pd2+ complex was studied in Heck vinylation reaction of aryl iodide with olefins. The catalyst is highly active and stereoselective at 70-100℃, and can be resused after washing without loss in activity.展开更多
In the present study, Fenneropenaeus chinensis individuals were assigned into six groups, and fed with a diet supplemented with 0 （Control）, 0.5% （Group Eos）, 1.0% （Group E1.0）, 2.0% （Group E2.0）, 3.0% （Group...In the present study, Fenneropenaeus chinensis individuals were assigned into six groups, and fed with a diet supplemented with 0 （Control）, 0.5% （Group Eos）, 1.0% （Group E1.0）, 2.0% （Group E2.0）, 3.0% （Group E3.0） or 5.0% （Group E5.0） of poly-13-hydroxybutyrate （PHB） during their growth and spawning periods, to explore the effect of PHB on the reproductive performance of parents and the development of larvae. The experi- ment was lasted for 192 d to measure the mortality rate, relative percentage of survival（RPS）, weight gain rate（WGR）, specific growth rate （SGR） and cycle of gonadal development of parental shrimps, number of eggs, number of nauplii, stages of larval development and metamorphosis. The results indicated that PHB had an obvious effect on the fecundity of parental shrimps and growth performance of larva. Compared with control group, the mortality rate of broodstock in experimental groups decreased initially and increased subsequently with the increase of PHB concentration, while RPS showed an opposite pattern. The mortality rate of group E2.0 was the lowest among all groups, showing significant difference from that of other groups（P 〈 0.05） except group E1.0 （P 〉 0.05）. WGR of all experimental groups was higher than that of the control group, among which, group E2.0 and group E5.0 had significantly higher WGR than the control （P〈0.05）. However, there was no significant difference in the cycle of gonadal development between the experimental groups and the control group （P 〉 0.05）. The numbers of eggs and nauplii in the experimental groups were higher than those of the control group. And the numbers of eggs and nauplii in group E2.0 were significantly higher than those of the control （P 〈 0.05）, bud showed no significant difference from those of other groups （P 〉 0.05）. However, there was no significant difference in the duration of larval development and metamorphosis among all the groups. In summary, PHB is capable of improving the reproductive performance of parents and the survival and development of larva in F. chinensis, and 2.0% is the optimal concentration of PHB supplemented to the diet.展开更多
An economical and environmental sustainability of bioplastic production is dependent on the use of low cost and waste C-sources as raw materials. OMW （Olive Mill Wastewater） with its high organic load represents a d...An economical and environmental sustainability of bioplastic production is dependent on the use of low cost and waste C-sources as raw materials. OMW （Olive Mill Wastewater） with its high organic load represents a dangerous polluting waste. Herein the authors present an integrated process for the simultaneous recovery of polyphenols, high value natural antioxidants, production of PHAs （polyhydroxyalkanotes）, thermoplastic bio-polymers, in particular of PHB （poly-3-hydroxybutyrate） starting from OMW. The combination of membrane filtration and bacterial digestion of OMW resulted in very high yields of polyphenols （3 2.5 g/L） and PHB （31.4 mg/L.h） if compared with the state of the art. These results make the technical approach described here effective for reducing the polluting effect of OMW and maximizing the valuable product yield. Moreover the process is readily suitable for an industrial scale PHB production from OMW.展开更多
[Objective] This study was carried out to explore the effect of poly-β-hydroxybutyrate（PHB） on the performance of the nonspecific immune system in Fenneropenaeus chinensis. [Method] F. chinensis individuals were as...[Objective] This study was carried out to explore the effect of poly-β-hydroxybutyrate（PHB） on the performance of the nonspecific immune system in Fenneropenaeus chinensis. [Method] F. chinensis individuals were assigned into six groups, and each group was fed with a diet containing 0（Control）, 0.5%（Group E0.5）, 1.0%（Group E1.0）, 2.5%（Group E2.5）, 5.0%（Group E5.0） or 10.0% PHB（Group E10.0）. The mortality rate and relative percent of survival（RPS） of each group were calculated after 6 weeks. Meanwhile, the total antioxidant capacity（T-AOC）, the activity of acid phosphatase（ACP）, peroxidase（POD） and catalase（CAT）, and the content of malondialdehyde（MDA） in hepatopancreas and serum were measured,and their correlation with PHB concentration was analyzed. [Result] The RPS in PHB treated shrimps increased initially and decreased subsequently with increasing PHB concentration. RPS of Group E1.0 was the highest, showing significant difference from that of other groups（ P 〈0.05）.With the increase in PHB concentration, the activity of immunity related enzymes changed in a similar pattern with RPS： increasing at first and decreasing subsequently. In addition, the activity of the enzymes was elevated in the 2nd and 3rd weeks of PHB administration. Among them, T-AOC in serum of groups E1.0 and E2.5, T-AOC in hepatopancreas of Group E1.0, ACP activity in serum of groups E1.0 and E2.5, ACP activity in hepatopancreas of Group E1.0, CAT activity in groups E0.5, E1.0 and E2.5, CAT activity in hepatopancreas of groups E0.5, E1.0 and E10.0, POD activity in both serum and hepatopancreas of groups E0.5, E1.0 and E2.5, SOD activity in both serum and hepatopancreas of Group E1.0, MDA content in serum of Group E1.0 and MDA content in hepatopancreas of groups E0.5 and E1.0 showed significant difference from those of other groups（P〈0.05）. [Conclusion] PHB can improve the immunity of F. chinensis, 1.0% in feed has the best effect, and the total enzyme activity reaches the highest level in the 2nd and 3rd weeks of PHB administration.展开更多
In order to improve poly-β-hydroxybutyrate（PHB） production in activated sludge, the anaerobic/aerobic alternative operating sequencing batch reactor（SBR） process was applied in this paper to accumulate PHB. Effec...In order to improve poly-β-hydroxybutyrate（PHB） production in activated sludge, the anaerobic/aerobic alternative operating sequencing batch reactor（SBR） process was applied in this paper to accumulate PHB. Effects of nutritional conditions and carbon concentration on PHB accumulation were studied. Results indicated that PHB accumulation reached the highest level and accounted for 11.2 % under anaerobic condition for phosphate limitation and 20.84 % under aerobic condition for nitrogen and phosphate limitation of mixed liquor suspended solid（MLSS）, respectively. In addition, 4 g/L was proved to be the optimum carbon concentration in both anaerobic and aerobic experiments, and the PHB accumulation reached 17.1 %（anaerobic, phosphorus limitation） and 60.4 %（aerobic, nitrogen and phosphorus limitation） of MLSS, respectively. PHB could be successfully extracted with sodium hypochlorite and chloroform method from the activated sludge. In addition, the infrared spectrum showed that the PHB sample extracted was of high purity.展开更多
In the accompanying paper (Part 1), we showed that the fatty acid moiety and the acidity of the polysaccharide-backbone of a fatty acid-containing polysaccharide might be involved in its emul-sification, moisture abso...In the accompanying paper (Part 1), we showed that the fatty acid moiety and the acidity of the polysaccharide-backbone of a fatty acid-containing polysaccharide might be involved in its emul-sification, moisture absorption, and moisture retention abilities. In this study, we synthesized alkyl esterified poly-γ-glutamic acid (PGA) with various chain lengths and degrees of substitution of the alkyl moieties to examine how hydrophobic groups incorporated in the anionic polymer contribute to enhanced emulsification, moisture absorption, and moisture retention. With a low degree of alkylation of PGA, these abilities were drastically improved. To improve the moisture absorption of PGA, alkylation with a short chain length is effective in forming interspaces between PGA chains to trap water molecules. Hydrophobic-hydrophilic balance may also be important to improve the emulsification and moisture retention abilities of PGA alkylates. To the best of our knowledge, this is the first report of the relationship between the structure and the multifunctional abilities of an anionic polymer incorporated with a small amount of hydrophobic residue. PGA alkylates, as well as fatty acid-containing polysaccharides, have potential use as multifunctional surfactants throughout various industries.展开更多
基金New Century Excellent Talents in University of China(NCET-05-0358)the National Natural Science Foundation of China(20625308)
文摘Poly-3-hydroxybutyrate （PHB） can be produced by various species of bacteria. Among the possible carbon sources, both methane and methanol could be a suitable substrate for the production of PHB. Methane is cheap and plentiful not only as natural gas, but also as biogas. Methanol can also maintain methanotrophic activity in some conditions. The methanotrophic strain Methylosinus trichosporium IMV3011 can accumulate PHB with methane and methanol in a brief nonsterile process. Liquid methanol （0.1%） was added to improve the oxidization of methane. The studies were carried out using shake flasks. Cultivation was performed in two stages： a continuous growth phase and a PHB accumulation phase under the conditions short of essential nutrients （ammonium, nitrate, phosphorus, copper, iron （Ⅲ）, magnesium or ethylenediamine tetraacetate （EDTA）） in batch culture. It was found that the most suitable growth time for the cell is 144 h. Then an optimized culture condition for second stage was determined, in which the PHB concentration could be much increased to 0.6 g/L. In order to increase PHB content, citric acid was added as an inhibitor of tricarboxylic acid cycle （TCA）. It was found that citric acid is favorable for the PHB accumulation, and the PHB yield was increased to 40% （w/w） from the initial yield of 12% （w/w） after nutrient deficiency cultivation. The PHB produced is of very high quality with molecular weight up to 1.5 × 10^6Da.
基金supported by the National Hi-Tech Research and Development Program (863) ofChina (No. 2006AA06Z378)the National Natural Science Foundation of China (No. 20777018, 20977035)+1 种基金the National Key Technology R&D Program of China(No. 2008BAC32B06-1)the Science and Technology Plan Project of Guangdong Province, China (No.2007B030103011)
文摘Biomimetic adsorbent named as PHBBMA was prepared from lipophilic poly-3-hydroxybutyrate （PHB） by a modified double emulsion solvent evaporation method. PHBBMA, characterized by using scanning electron microscope and nitrogen adsorption/desorption measurements, is porous spherical particles. The characterization with the thermal gravimetric analysis and differential scanning calorimetry, 1 H nuclear magnetic resonance and Fourier transform infrared spectroscopy showed that PHBBMA preparation was a physical process without chemical reaction. The adsorption of PHBBMA for o-nitrochlorobenzene （o-NCB） was fitted better by Langmuir model than by Freundlich model, while the pseudo second-order model fitting was better than the pseudo first-order model fitting. The maximal adsorption capacity of PHBBMA for o-NCB was 57.83 mg/g at 30°C, although its specific surface area （S BET ） was only 8.45 m 2 /g. PHBBMA is a safe and environmental friendly adsorbent with high adsorption capacity because its component is innocuous and biodegradable PHB produced reusing wastes and contaminants, no byproduct can produced, and its ester and hydrocarbyl groups have strong affinity with organochlorine compounds. The further work will focus on the modification and improvement of PHBBMA in order to increase its S BET and adsorption capacity.
基金This work was supported by the 3rd Jiangsu Overseas Research&Training Program for University Prominent Young&Middleaged Teachers and Presidentsthe College Students Innovation Project for the R&D of Novel Drugs[No.J1310032]And we would like to thank cell and molecular biology experiment platform of China Pharmaceutical University for the assistance with relevant test items.
文摘Gene-based therapeutics has emerged as a promising approach for human cancer therapy. Among a variety of non-viral vectors, polymer vectors are particularly attractive due to their safety and multivalent groups on their surface. This study focuses on guanidinylated O-carboxymethyl chitosan(GOCMCS) along with poly-β-amino ester(PBAE) for si RNA delivery. Binding efficiency of PBAE/si RNA/GOCMCS nanoparticles were characterized by gel electrophoresis. The si RNA-loaded nanoparticles were found to be stable in the presence of RNase A, serum and BALF respectively. Fine particle fraction(FPF) which was determined by a two-stage impinger(TSI) was 57.8% ± 2.6%. The particle size and zeta potential of the nanoparticles were 153.8 ± 12.54 nm and + 12.2 ± 4.94 m V. In vitro cell transfection studies were carried out with A549 cells. The cellular uptake was significantly increased. When the cells were incubated with si Survivin-loaded nanoparticles, it could induce 26.83% ± 0.59% apoptosis of A549 cells and the gene silencing level of survivin expression in A549 cells were 30.93% ± 2.27%. The results suggested that PBAE/GOCMCS nanoparticle was a very promising gene delivery carrier.
基金supported by Key Scientific and Technological Project in Henan Province(122102110120)
文摘With the exploitation of rare earth ore, more and more rare earth elements came into groundwater, caused waste of resources and toxicity to the organisms. This study aimed to find an efficient adsorption material to mitigate the above issue. Through doping polyvinyl alcohol with poly-γ-glutamic acid, an immobilised PSP gel particle was produced and had the adsorption rate of La3＋ up to 97.10%. The factors including initial concentration of La3＋ or Ce3＋, adsorbent dosage, pH and temperature of the solution, which potentially affected the adsorption rate and were studied in batch mode. It was found that the optimum adsorption conditions were composed of 50 mg/L La3 VCe3＋ of initial concentration, 600 mg/L （dry mass） biomass for adsorption, pH 6, temperature 30 ℃, 150 r/min rotational speed, and 1 h adsorption time. The selective adsorption of 15 different rare earth ions in mixed aqueous solu- tions were investigated. However, no significant selective differences were observed. Scanning electron microscopy showed that the morphological characteristic of the novel gel was its porous structure, while polyvinyl alcohol gel had a compact structure. Fourier transform infrared spectroscopy suggested that carboxyl groups in the poly-γ-glutamic acid might played a key role in the adsorption process. The adsorption mechanism forecasted to be cation exchange between -COOH and R3＋. The adsorption kinetic and thermodynamic process for La3＋ and Ce3＋ was consistent with the pseudo-second-order equation and Langmuir adsorption isotherm model. It demonstrated that PSP gels particles were useful for removing REEs from wastewater.
基金supported by the Chinese Academy of Sciences Strategic Pilot Science and Technology Special (Class A)(XDA21020000)the National Natural Science Foundation of China (22072175,21673272)support from the Ulam program,awarded by the Polish National Agency for Academic Exchange (NAWA),Poland,under project No.PPN/ULM/2020/1/00006/DEC/1
文摘The production of poly-α-olefins(PAOs)has attracted attention due to their excellent viscosity-temperature dependence,wear characteristics,oxidative properties,and high thermal stability.In this study,indene extracted during coal tar refining was used as a raw material to synthesize a bis(indenyl)zirconium dichloride metallocene catalyst.A PAO with low viscosity and a high viscosity index was produced via the oligomerization of 1-decene in the presence of both the prepared metallocene and a methylaluminoxane(MAO)co-catalyst.Notably,the effects of different synthesis reaction parameters,such as Al:Zr ratio,amount of catalyst,and reaction temperature,on the conversion ratio and product selectivity were investigated in detail.The produced PAO was thoroughly characterized using Fourier-transform infrared,^(13)C,and^(1)H nuclear magnetic resonance spectroscopies;gas chromatography;and viscosity measurements.At 70℃,the metallocene catalyst created more stable active sites.In addition,the alkylation effect of MAO was noticeable.Interestingly,the obtained catalysis results demonstrated that a high conversion ratio of~93%was achieved at a low reaction temperature of 70℃,with a catalyst dosage of 0.0848 mmol and Al:Zr ratio of 8.48mmol:0.0848mmol.Moreover,under these optimal conditions,the kinematic viscosity of PAO was 4.25 mm2/s at 100℃,and the viscosity index was 139,indicating good viscosity-temperature properties.
文摘The cobalt and ruthenium bimetallic complex of poly-γ-amino-propylsiloxane( abbr. as Si-CH_2-Co-Ru) was prepared, and it was found that it can catalyze the hydroformylation of cyclobexene effectively with the conversion amounting to over 90%. Cyclohexanecarboxaldehyde was first formed in the hydroformylation, and then further hydrogenated to form cylcohexanemethanol. The coversion was affected obviously by the Co/Ru ratio.When Co/Ru molar ratio was 100-150, i.e. in the very low content of noble metal Ru, the catalytic activity of Si-NH_2 -Co-Ru was also very high. The product composition was affected by CO/H_2 ratio in the reaction gas. Aldehyde can be got high selectively by controlling CO/H_2 ratio. Compared with other catalyst system, the Si-NH_2-Co-Ru catalyst has higher catalytic activity and efficiency with very low Ru/Co ratio. The total turnover number was more than 28,800 (based on the amount of ruthenium used).
文摘Biodegradable polymers have been widely used in the field of tissue engineering.The adhesive characteristic of polymer surfaces must be modified for cell seeding and growth before being used.The modified method poly-β-hybroxybutyric acid (PHB) was introduced and the biocompatibility of modified PHB to adrenocortical cells was studied here,Gelatin was used as a modifier to retrofit PHB and adrenocortical cells were seeded in the modified PHB.The effects of PHB on the proliferation and secreting function of adrenocortical cells were evaluated by MTT and RIA methods.It shows that adrenocortical cells were able to grow and survived in PHB and no influence on the proliferation and secreting function of the cells was observed.The morphology study shows that the modified PHB was easy for cells seeding and growing.The modified PHB is a good biodegradable material as cell carrier for transplantation of adrenocortical cells.
文摘The purpose of this study was to prepare a poly-γ-glutamic acid hydrogel (PGA gel), to examine its ease of swallowing using texture profile analysis (TPA) and to evaluate its taste-masking effects on basic or acidic drugs using the artificial taste sensor. Using TPA, 0.5% and 1.0% PGA gels, 0.5% and 1.0% agar and 1.0% ι-carrageenan in the absence of drug was examined the hardness, adhesiveness and cohesiveness, ranked according to permission criteria published by the Japanese Consumers Affairs Agency. 0.5% PGA gel and 1.0% agar were classified into grade II. In the taste sensor measurement, the bitterness suppressions by 0.5% PGA gel were larger than that by 1.0% agar in all drugs and the bitterness suppressions of basic drugs in 0.5% PGA gel were more potent than those of acidic drugs in 0.5% PGA gel. 1H-nuclear magnetic resonance spectroscopic analysis was carried out to examine the difference in mechanism of bitterness suppression between basic drugs and acidic drugs mixed with PGA gel. The signals of the proton nearest to the nitrogen atom of basic drugs shifted clearly upfield, suggesting an interaction between the amino group of basic drugs and the carboxyl group of PGA gel. In conclusion, PGA gel is expected to be a useful excipient in formulations contained various drugs, especially basic drugs;it also has advantage for not only increasing ease of swallowing but also masking the bitterness of drugs even though a small amount of a single drug dose might be preferred.
文摘The remote interaction of polymethacrylic acid hydrogel with a poly-2-methyl-5-vinylpyridine hydrogel was studied. The aim of work was to study the dependence of the swelling coefficient, the conductivity and the pH of the water solutions of intergel system at different mass ratios from time were studied. The goal was achieved by using following methods： pH-metry, conductometry and gravimetry.
文摘The effects of sodium hypochlorite concentration in the recovery of poly-β-hydroxybutyrate (PHB) are investigated. A simple reaction equation and a mathematical model describe the reaction kinetics. Results showed that the stoichiometric coefficient increases with increasing CAO/CBO, where CAO is the concentration of the active chlorine at t = 0 and CBO is the initial concentration of the non-PHB materials.
文摘Several silica-supported poly-γ-aminopropylsiloxane-monometal and bimetal complexes (Si-NH_2-M,M = Cu or Co ; Si-NH_2-Cu-M', M' =Co, Sn, Mn, Ni or Fe) have been prepared. Their catalytic properties for oxidative ethoxycarbonylation of aniline to ethyl phenylcarbamate have been investigated.The catalytic reaction was carried out under relatively mild conditions. The catalyst Si-NH_2-Cu-CO had high activity and selectivity, and the turn-over number (molar of aniline converted/molar of metal in Si-NH_2-Cu-CO added) could amount to 450 under the conditions: 150℃ , 4 MPa (CO/O_2 =3) and 40 hours.The results of XPS and IR indicated that the coordination bonds were formed between nitrogen and metals in Si-NH2-Cu, Si-NH_2-Co and Si-NH_2-Cu-Co, and the coordination pattern was not single. In the oxidative ethoxycarbonylation of aniline to ethyl phenylcarbamate, the catalytic property of Si-NH_2-Cu-CO bimetallic complex was better than Si-NH_2-Cu or Si-NH_2-Co monometatlic complex. This indicated that there as synergistic action between different metals in the bimetallic complex.
基金This paper is supported by the Shandong Provincial Key Research and Development Program(Project No.2020CXGC010403)the Key Projects of New and Old Kinetic Energy Conversion(No.[2020]1220)the scientific research project of SINOPEC Corporation(CLY19005).
文摘The molecular behavior of polyurethane(PU)coating materials during the surface adsorption of poly-α-olefin as a drag reducing polymer was explored by a molecular dynamics simulation.Three different PU capsule wall materials were synthesized using two reaction monomers,and a poly-α-olefin/PU drag reducer microcapsule was prepared based on interface polymerization.The structure,morphology,thermal stability,compressive strength,and drag reduction performance of the microcapsules were characterized and compared.The results showed that a non-bonding interaction induced the adsorption of the PU coating material,poly-α-olefin and PU then fused at the interface,and the PU coating material was embedded into the inner grooves of poly-α-olefin in the form of a local mosaic,thereby forming a stable core–shell structure.The morphological characterization indicated that PU and poly-α-olefin could form microcapsule structures.The thermal decomposition temperature of the microcapsule was dependent on the type of capsule wall material.The microcapsule structure had a slight effect on poly-α-olefin drag reduction.The system enabled poly-α-olefin to exist in powdered particles through microcapsulation,and had a good dispersion effect that facilitated storage and transport processes.The method effectively inhibited the accumulation and bonding of poly-α-olefin at room temperature.
文摘A silica-supported poly-γ- aminopropylsiloxane-rhodium-cobalt bimetallic complex(abbreviated as SiO_2-NH_2-Rh-Co)has been prepared and used as catalyst for hydroformylationof methyl methacrylate. The results showed that the catalyst could catalyze the reaction in95.6% conversion with 92.8% selectivity for the normal aldehyde, methyl β-formylisobu-tyrate. Such catalyst also showed high stability during the reaction and could be used repeat-edly.
文摘In this paper, a new silica-supported poly-γ-aminopropylsilane Cu2+-Pd2+ complex was studied in Heck vinylation reaction of aryl iodide with olefins. The catalyst is highly active and stereoselective at 70-100℃, and can be resused after washing without loss in activity.
基金Supported by Central Public-interest Scientific Institution Basal Research Fund,Yellow Sea Fisheries Research Institute,CAFS(20603022017001)National Natural Science Foundation of China(41676148)Taishan Scholar Program for Seed Industry and China Agriculture Research System(CARS-48)
文摘In the present study, Fenneropenaeus chinensis individuals were assigned into six groups, and fed with a diet supplemented with 0 （Control）, 0.5% （Group Eos）, 1.0% （Group E1.0）, 2.0% （Group E2.0）, 3.0% （Group E3.0） or 5.0% （Group E5.0） of poly-13-hydroxybutyrate （PHB） during their growth and spawning periods, to explore the effect of PHB on the reproductive performance of parents and the development of larvae. The experi- ment was lasted for 192 d to measure the mortality rate, relative percentage of survival（RPS）, weight gain rate（WGR）, specific growth rate （SGR） and cycle of gonadal development of parental shrimps, number of eggs, number of nauplii, stages of larval development and metamorphosis. The results indicated that PHB had an obvious effect on the fecundity of parental shrimps and growth performance of larva. Compared with control group, the mortality rate of broodstock in experimental groups decreased initially and increased subsequently with the increase of PHB concentration, while RPS showed an opposite pattern. The mortality rate of group E2.0 was the lowest among all groups, showing significant difference from that of other groups（P 〈 0.05） except group E1.0 （P 〉 0.05）. WGR of all experimental groups was higher than that of the control group, among which, group E2.0 and group E5.0 had significantly higher WGR than the control （P〈0.05）. However, there was no significant difference in the cycle of gonadal development between the experimental groups and the control group （P 〉 0.05）. The numbers of eggs and nauplii in the experimental groups were higher than those of the control group. And the numbers of eggs and nauplii in group E2.0 were significantly higher than those of the control （P 〈 0.05）, bud showed no significant difference from those of other groups （P 〉 0.05）. However, there was no significant difference in the duration of larval development and metamorphosis among all the groups. In summary, PHB is capable of improving the reproductive performance of parents and the survival and development of larva in F. chinensis, and 2.0% is the optimal concentration of PHB supplemented to the diet.
文摘An economical and environmental sustainability of bioplastic production is dependent on the use of low cost and waste C-sources as raw materials. OMW （Olive Mill Wastewater） with its high organic load represents a dangerous polluting waste. Herein the authors present an integrated process for the simultaneous recovery of polyphenols, high value natural antioxidants, production of PHAs （polyhydroxyalkanotes）, thermoplastic bio-polymers, in particular of PHB （poly-3-hydroxybutyrate） starting from OMW. The combination of membrane filtration and bacterial digestion of OMW resulted in very high yields of polyphenols （3 2.5 g/L） and PHB （31.4 mg/L.h） if compared with the state of the art. These results make the technical approach described here effective for reducing the polluting effect of OMW and maximizing the valuable product yield. Moreover the process is readily suitable for an industrial scale PHB production from OMW.
基金Supported by Central Public-interest Scientific Institution Basal Research Fund,Yellow Sea Fisheries Research Institute,CAFS(20603022017001)National Natural Science Foundation of China(41676148)+1 种基金Taishan Scholar Program for Seed IndustryChina Agriculture Research System(CARS-48)
文摘[Objective] This study was carried out to explore the effect of poly-β-hydroxybutyrate（PHB） on the performance of the nonspecific immune system in Fenneropenaeus chinensis. [Method] F. chinensis individuals were assigned into six groups, and each group was fed with a diet containing 0（Control）, 0.5%（Group E0.5）, 1.0%（Group E1.0）, 2.5%（Group E2.5）, 5.0%（Group E5.0） or 10.0% PHB（Group E10.0）. The mortality rate and relative percent of survival（RPS） of each group were calculated after 6 weeks. Meanwhile, the total antioxidant capacity（T-AOC）, the activity of acid phosphatase（ACP）, peroxidase（POD） and catalase（CAT）, and the content of malondialdehyde（MDA） in hepatopancreas and serum were measured,and their correlation with PHB concentration was analyzed. [Result] The RPS in PHB treated shrimps increased initially and decreased subsequently with increasing PHB concentration. RPS of Group E1.0 was the highest, showing significant difference from that of other groups（ P 〈0.05）.With the increase in PHB concentration, the activity of immunity related enzymes changed in a similar pattern with RPS： increasing at first and decreasing subsequently. In addition, the activity of the enzymes was elevated in the 2nd and 3rd weeks of PHB administration. Among them, T-AOC in serum of groups E1.0 and E2.5, T-AOC in hepatopancreas of Group E1.0, ACP activity in serum of groups E1.0 and E2.5, ACP activity in hepatopancreas of Group E1.0, CAT activity in groups E0.5, E1.0 and E2.5, CAT activity in hepatopancreas of groups E0.5, E1.0 and E10.0, POD activity in both serum and hepatopancreas of groups E0.5, E1.0 and E2.5, SOD activity in both serum and hepatopancreas of Group E1.0, MDA content in serum of Group E1.0 and MDA content in hepatopancreas of groups E0.5 and E1.0 showed significant difference from those of other groups（P〈0.05）. [Conclusion] PHB can improve the immunity of F. chinensis, 1.0% in feed has the best effect, and the total enzyme activity reaches the highest level in the 2nd and 3rd weeks of PHB administration.
基金Funded by the Fundamental Research Funds for the Central Universities(No.2572014CA23)the National Natural Science Foundation of China(No.51678120)
文摘In order to improve poly-β-hydroxybutyrate（PHB） production in activated sludge, the anaerobic/aerobic alternative operating sequencing batch reactor（SBR） process was applied in this paper to accumulate PHB. Effects of nutritional conditions and carbon concentration on PHB accumulation were studied. Results indicated that PHB accumulation reached the highest level and accounted for 11.2 % under anaerobic condition for phosphate limitation and 20.84 % under aerobic condition for nitrogen and phosphate limitation of mixed liquor suspended solid（MLSS）, respectively. In addition, 4 g/L was proved to be the optimum carbon concentration in both anaerobic and aerobic experiments, and the PHB accumulation reached 17.1 %（anaerobic, phosphorus limitation） and 60.4 %（aerobic, nitrogen and phosphorus limitation） of MLSS, respectively. PHB could be successfully extracted with sodium hypochlorite and chloroform method from the activated sludge. In addition, the infrared spectrum showed that the PHB sample extracted was of high purity.
文摘In the accompanying paper (Part 1), we showed that the fatty acid moiety and the acidity of the polysaccharide-backbone of a fatty acid-containing polysaccharide might be involved in its emul-sification, moisture absorption, and moisture retention abilities. In this study, we synthesized alkyl esterified poly-γ-glutamic acid (PGA) with various chain lengths and degrees of substitution of the alkyl moieties to examine how hydrophobic groups incorporated in the anionic polymer contribute to enhanced emulsification, moisture absorption, and moisture retention. With a low degree of alkylation of PGA, these abilities were drastically improved. To improve the moisture absorption of PGA, alkylation with a short chain length is effective in forming interspaces between PGA chains to trap water molecules. Hydrophobic-hydrophilic balance may also be important to improve the emulsification and moisture retention abilities of PGA alkylates. To the best of our knowledge, this is the first report of the relationship between the structure and the multifunctional abilities of an anionic polymer incorporated with a small amount of hydrophobic residue. PGA alkylates, as well as fatty acid-containing polysaccharides, have potential use as multifunctional surfactants throughout various industries.
