The purpose of this study was to identify and compare the degradation efficiencies of free and entrapped bacterial consortia(Staphylococcus capitis CP053957.1 and Achromobacter marplatensis MT078618.1)to different pol...The purpose of this study was to identify and compare the degradation efficiencies of free and entrapped bacterial consortia(Staphylococcus capitis CP053957.1 and Achromobacter marplatensis MT078618.1)to different polymers such as Sodium Alginate(SA),Sodium Alginate/Poly(Vinyl Alcohol)(SA/PVA),and Bushnell Haas Agar(BHA).In addition to SA and SA/PVA,which are cost-effective,non-toxic and have different functional groups,BHA,which is frequently encountered in laboratory-scale studies but has not been used as an entrapment material until now.Based on these,the polymers with different surface morphologies and chemical compositions were analyzed by SEM and FT-IR.While the petroleum removal efficiency was higher with the entrapped bacterial consortia than with the free one,BHA-entrapped bacterial consortium enhanced the petroleum removal more than SA and SA/PVA.Accordingly,the degradation rate of bacterial consortia entrapped with BHA was 2.039 day^(-1),SA/PVA was 1.560,SA was 0.993,the half-life period of BHA-entrapped bacterial consortia is quite low(t_(1/2)=0.339)compared with SA(t_(1/2)=0.444)and SA/PVA(t_(1/2)=0.697).The effects of the four main factors such as:amount of BHA(0.5,1,1.5,2,2.5,3 g),disc size(4,5,6,7,8 mm),inoculum concentration(1,2.5,5,7.5,10 mL),and incubation period on petroleum removal were also investigated.The maximum petroleum removal(94.5%)was obtained at≥2.5 mL of bacterial consortium entrapped in 2 g BHA with a 7 mm disc size at 168 h and the results were also confirmed by statistical analysis.Although a decrease was observed during the reuse of bacterial consortium entrapped in BHA,the petroleum removal was still above 50%at 10th cycle.Based on GC-MS analysis,the removal capacity of BHA-entrapped consortium was over 90%for short-chain n-alkanes and 80%for medium-chain n-alkanes.Overall,the obtained data are expected to provide a potential guideline in cleaning up the large-scale oil pollution in the future.Since there has been no similar study investigating petroleum removal with the bacterial consortia entrapped with BHA,this novel entrapment material can potentially be used in the treatment of petroleum pollution in advanced remediation studies.展开更多
We developed a new preparation to protect probiotic cells from adverse environmental conditions and improve their livability,which is called Lactobacillus casei-Sodium alginate-Chitosan (LSC).The LSC was prepared by m...We developed a new preparation to protect probiotic cells from adverse environmental conditions and improve their livability,which is called Lactobacillus casei-Sodium alginate-Chitosan (LSC).The LSC was prepared by mixing probiotics with sodium alginate-chitosan sol.The preparation contained complex calcium ions,which were released in the acidic environment of gastric juice,thus crosslinking to form in-situ gel.Different proportions of sodium alginate-chitosan were prepared to add to simulate gastrointestinal fluid to get the best ratio.The optimal ratio of LSC preparation was compared with traditional gel microspheres to observe the survival effect of probiotics in gastrointestinal fluid environment.Compared with sodium alginate sol,the porosity of sodium alginate-chitosan sol is lower,which is beneficial to the protection of probiotics.When the ratio of chitosan to sodium alginate is 1.5:1.5 (w/v),the protective effect is the best.The protective ability of LSC is 64 times that of traditional microspheres,and it has the potential of synergistic anti-tumor.A probiotic preparation with simple preparation process and better protection effect compared with traditional microspheres was prepared,which has joint anti-tumor potential.展开更多
Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of...Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of this type of scaffold to make it a potential template for bone-tissue regeneration.We experimented with adding 0%–15%(volume fraction)gelatin(GE),a protein-based biopolymer known to promote cell adhesion,proliferation,and differentiation.The resulting tri-polymer complex was used as bioink to fabricate SA/CH/GEmatrices by three-dimensional(3D)printing.Morphological studies using scanning electron microscopy revealed the microfibrous porous architecture of all the structures,which had a pore size range of 383–419μm.X-ray diffraction and Fourier-transform infrared spectroscopy analyses revealed the amorphous nature of the scaffold and the strong electrostatic interactions among the functional groups of the polymers,thereby forming polyelectrolyte complexes which were found to improve mechanical properties and structural stability.The scaffolds exhibited a desirable degradation rate,controlled swelling,and hydrophilic characteristics which are favorable for bone-tissue engineering.The tensile strength improved from(386±15)to(693±15)kPa due to the increased stiffness of SA/CH scaffolds upon addition of gelatin.The enhanced protein adsorption and in vitro bioactivity(forming an apatite layer)confirmed the ability of the SA/CH/GE scaffold to offer higher cellular adhesion and a bone-like environment to cells during the process of tissue regeneration.In vitro biological evaluation including the MTT assay,confocal microscopy analysis,and alizarin red S assay showed a significant increase in cell attachment,cell viability,and cell proliferation,which further improved biomineralization over the scaffold surface.In addition,SA/CH containing 15%gelatin designated as SA/CH/GE15 showed superior performance to the other fabricated 3D structures,demonstrating its potential for use in bone-tissue engineering.展开更多
A novel core-shell hydrogel bead was fabricated for effective removal of methylene blue dye from aqueous solutions.The core,made of sodium alginate-g-polyacrylamide and attapulgite nanofibers,was cross-linked by Calci...A novel core-shell hydrogel bead was fabricated for effective removal of methylene blue dye from aqueous solutions.The core,made of sodium alginate-g-polyacrylamide and attapulgite nanofibers,was cross-linked by Calcium ions(Ca^(2+)).The shell,composed of a chitosan/activated carbon mixture,was then coated onto the core.Fourier transform infrared spectroscopy confirmed the grafting polymerization of acrylamide onto sodium alginate.Scanning electron microscopy images showed the core-shell structure.The core exhibited a high water uptake ratio,facilitating the diffusion of methylene blue into the core.During the diffusion process,the methylene blue was first adsorbed by the shell and then further adsorbed by the core.Adsorption tests showed that the coreshell structure had a larger adsorption capacity than the core alone.The shell effectively enhanced the adsorption capacity to methylene blue compared to the single core.Methylene blue was adsorbed by activated carbon and chitosan in the shell,and the residual methylene blue diffused into the core and was further adsorbed.展开更多
The aim of this study was to prepare silk fibroin/sodium alginate composite film containing curcumin by casting method.Orthogonal test was used to optimize the formulation according to the values of tensile strength a...The aim of this study was to prepare silk fibroin/sodium alginate composite film containing curcumin by casting method.Orthogonal test was used to optimize the formulation according to the values of tensile strength and elongation at break.The release of curcumin in the optimal film was studied in order to explore its application as wound dressing.The results showed that the optimum composition of curcumin/silk fibroin/sodium alginate composite film was as follows:Silk fibroin(70 mg/mL)2.7 g,sodium alginate(24 mg/mL)0.84 g,span 40(5.0 mg/mL)0.4 g,glycerol(3.75%,V/V)3 mL,curcumin(0.2 mg/mL)0.016 g.The optimum film showed the tensile strength and the elongation at break was(0.628±0.032)MPa and(0.794±0.046)%,respectively.展开更多
The discharge of the antibiotic wastewater has increased dramatically in our country with the development of medical science and wide application of antibiotic,resulting in serious harm to human body and ecological en...The discharge of the antibiotic wastewater has increased dramatically in our country with the development of medical science and wide application of antibiotic,resulting in serious harm to human body and ecological environment.In this work,ciprofloxacin(CIP)was selected as one of typical antibiotics and heterogeneous Fenton-like catalysts were prepared for the treatment of ciprofloxacin wastewater.The sodium alginate(SA)gel microspheres catalysts were prepared by polymerization method using double metal ions of Fe^(3+)and Mn^(2+)as cross-linking agents.Preparation conditions such as metal ions concentration,mass fraction of SA,polymerization temperature and dual-metal ions as crosslinking agent were optimized.Moreover,the effects of operating conditions such as initial concentration of CIP,pH value and catalyst dosage on CIP removal were studied.The kinetic equation showed that the effect of the initial concentration of CIP on the degradation rate was in line with second-order kinetics,and the effects of catalyst dosage and pH value on the degradation rate of CIP were in line with first-order kinetics.The SA gel microspheres catalysts prepared by dual-metal ions exhibited a high CIP removal and showed a good reusability after six recycles.The SA gel microspheres catalysts with an easy recovery performance provided an economical and efficient method for the removal of antibiotics in the future.展开更多
Given the gradual increase in the chlorite content of hematite ores, pulp properties seriously deteriorate during flotation. The traditional anion reverse flotation of hematite cannot effectively eliminate the effects...Given the gradual increase in the chlorite content of hematite ores, pulp properties seriously deteriorate during flotation. The traditional anion reverse flotation of hematite cannot effectively eliminate the effects of chlorite, leading to a significant decrease in the total Fe(TFe) grade of the concentrate. In this work, the effect of sodium alginate on the reverse flotation of hematite was systematically investigated. Flotation tests of artificially mixed ores were conducted, and the results showed that sodium alginate can significantly improve the removal rates of quartz and chlorite. The adsorption measurements, infrared spectroscopy, and contact angle tests demonstrated that sodium alginate adsorbs on the quartz surface by chelating with calcium ions, thereby weakening the steric hindrance of oleate ions and increasing the adsorption capacity of sodium oleate to ultimately improve the removal rate of quartz. Furthermore, owing to its lower density and fine particle size, chlorite is easily entrained into the foam layer. Sodium alginate dramatically increases the liquid-to-gas ratio of the foam layer by increasing pulp viscosity, thereby increasing the entrainment rate of chlorite and finally improving its removal rate. The core content of this thesis bears significance in improving the Fe grade in the reverse flotation of chlorite-containing hematite.展开更多
One interpenetrating network hydrogel based on sodium alginate (SA) and polyvinyl alcohol (PVA) was synthesized by combining the raw materials of PVA and SA with the double physical crosslinking methods of freezing th...One interpenetrating network hydrogel based on sodium alginate (SA) and polyvinyl alcohol (PVA) was synthesized by combining the raw materials of PVA and SA with the double physical crosslinking methods of freezing thawing and Ca2+ crosslinking. The PVA-SA composite hydrogel have been characterized by scanning electron microscopy for surface morphology, infrared spectroscopy for investigating the chemical interactions between PVA and SA, X-ray diffraction for studying the PVA-SA composite structure property and thermal gravimetric for understanding the PVA-SA composite thermal stability. The swelling behavior and the degradation rate of the PVA-SA composite hydrogel were studied in simulated gastrointestinal fluid. Using bovine serum albumin (BSA) and salicylic acid as the model drugs, the release behavior of the PVASA composite hydrogel on macromolecular protein drugs and small molecule drug were evaluated. The results showed that the water absorption and degradation ability of the PVA-SA composite hydrogel was much better compared to the pure SA hydrogel or pure PVA hydrogel. The hydrogel exhibited remarkable pH sensitivity and the network was stable in the simulated intestinal fluid for more than 24 h. With the advantages such as mild preparation conditions, simple method, less reagent and none severe reaction, the PVA-SA composite hydrogel is expected to be a new prosperous facile sustained drug delivery carrier.展开更多
Spinal cord injury results in the loss of motor and sensory pathways and spontaneous regeneration of adult mammalian spinal cord neurons is limited. Chitosan and sodium alginate have good biocompatibility, biodegradab...Spinal cord injury results in the loss of motor and sensory pathways and spontaneous regeneration of adult mammalian spinal cord neurons is limited. Chitosan and sodium alginate have good biocompatibility, biodegradability, and are suitable to assist the recovery of damaged tissues, such as skin, bone and nerve. Chitosan scaffolds, sodium alginate scaffolds and chitosan-sodium alginate scaffolds were separately transplanted into rats with spinal cord hemisection. Basso-Beattie-Bresnahan locomotor rating scale scores and electrophysiological results showed that chitosan scaffolds promoted recovery of locomotor capacity and nerve transduction of the experimental rats.Sixty days after surgery, chitosan scaffolds retained the original shape of the spinal cord. Compared with sodium alginate scaffolds- and chitosan-sodium alginate scaffolds-transplanted rats, more neurofilament-H-immunoreactive cells (regenerating nerve fibers) and less glial fibrillary acidic protein-immunoreactive cells (astrocytic scar tissue) were observed at the injury site of experimental rats in chitosan scaffold-transplanted rats. Due to the fast degradation rate of sodium alginate, sodium alginate scaffolds and composite material scaffolds did not have a supporting and bridging effect on the damaged tissue. Above all, compared with sodium alginate and composite material scaffolds, chitosan had better biocompatibility, could promote the regeneration of nerve fibers and prevent the formation of scar tissue,and as such, is more suitable to help the repair of spinal cord injury.展开更多
AIM To prepare 5 FU sodium alginate 125 I bovine serum albumin nanoparticles (BSA NP), to determine the radioactive count in different organs of rats at different time points after oral administration of 5...AIM To prepare 5 FU sodium alginate 125 I bovine serum albumin nanoparticles (BSA NP), to determine the radioactive count in different organs of rats at different time points after oral administration of 5 FU 125 I sodium alginate BSA NP and to calculate the kinetic parameters of its metabolism. METHODS Emulsion solidification method was used to prepare 5 FU 125 I sodium alginate BSA NP, and to determine its diameter under transmission electronic microscope (TEM). Then the rate of NP and external drug releasing velocity were measured. Radioactive counting in different organs of rats was made after oral administration of the NP by GAMA Counter, and the kinetic parameters of drug metabolism were calculated by handling the data with the two department model. RESULTS The average arithmatic diameter of the NP was 166nm ± 34nm , the rate of 5 FU was 32 8% and the cumulative external releasing ratio amounted to 84 0% within 72 hours. The NP was mainly distributed in the liver, spleen, lungs and kidneys after NP oral administration to rats. The micro radioautographic experiment showed that NP was distributed in the Kupffers cells of liver, liver parenchymal cells and the phagocytes of spleen and lungs. The kinetic parameters of matabolism were: T 1/2 =9 42h, C max =2 45×10 7Bq, T max =2 18h, AUC=148×10 9Bq. CONCLUSION NP is difficult to pass through the blood-cerebral barrier,and 125 I sodium alginate-BSA NP enters the body circulation by gastroin testinal passage.展开更多
A novel poly-/-arginine microcapsule was prepared due to its nutritional function and pharmacological efficacy. A high-voltage electrostatic droplet generator was used to make uniform microcapsules. The results show t...A novel poly-/-arginine microcapsule was prepared due to its nutritional function and pharmacological efficacy. A high-voltage electrostatic droplet generator was used to make uniform microcapsules. The results show that the membrane strength and permeating property are both remarkably affected with the changes of sodium alginate concentration. With the sodium alginate concentration increasing, gel beads sizes increase from 233μm to 350μm, release ratio is also higher at the same time, but the membrane strength decreases.展开更多
The resaerch examined the effect of the two oceanic materials as coating materials on the soybean growth.The results showed chitosan and sodium alginate seed coating can enhance the growth of seedling root,increase th...The resaerch examined the effect of the two oceanic materials as coating materials on the soybean growth.The results showed chitosan and sodium alginate seed coating can enhance the growth of seedling root,increase the nodule mumber,root activity and the growth of underground.The suggested coating ratios were 0.5~1.0g/kgseed,the same as chitosan.The two materials could increase the contents of CAT and NR in soybean leaves,decrease the contents of POD in soybean leaves.展开更多
Excess water production has become an important issue in the oil and gas extraction process.Preformed particle gels(PPGs),show the capability to control the conformance and reduce excess water cut.However,conventional...Excess water production has become an important issue in the oil and gas extraction process.Preformed particle gels(PPGs),show the capability to control the conformance and reduce excess water cut.However,conventional PPGs have poor mechanical properties and their swollen particles are easily damaged by shearing force when passing through the fractures in formations,meanwhile PPGs can be also degraded into various byproducts,leading to permanent damage to the reservoir permeability after temporary plugging.Herein,a novel type of dual cross-linked PPGs(dPPGs)was designed and synthesized using sodium alginate(SA)and acrylamide(AAm),cross-linked with N,N’-methylenebisacrylamide(MBA)and Fe^(3+).Results show that dPPGs have excellent mechanical properties with a storage modulus up to 86,445 Pa,which is almost 20 times higher than other reported PPGs.Meanwhile,dPPGs can be completely degraded into liquid without any solid residues or byproducts and the viscosity of dPPGs degraded liquid was found to be lower than 5 mPa·s.A laboratory coreflooding test showed that the plugging efficiency of dPPGs was up to 99.83%on open fractures.The obtained results demonstrated that dPPGs could be used as economical and environment-friendly temporary plugging agent with high-strength,self-degradation,thermal stability,and salt stability,thus making it applicable to a wide range of conformance control to enhance oil recovery.展开更多
Konjac glucomannan (KGM) and sodium alginate were chosen as the research objects, and the hydrogen bond conformation of compound system was studied with the molecular dynamics simulation, which simulated the energy ...Konjac glucomannan (KGM) and sodium alginate were chosen as the research objects, and the hydrogen bond conformation of compound system was studied with the molecular dynamics simulation, which simulated the energy variety in composite process. Combining with Hamiltonian in quantum mechanics calculation, the mechanism of hydrogen bond in KGM and sodium alginate compound system stability was analyzed from a micro angle. The results showed that, the hydrogen bonds occurring between the molecule of KGM and sodium alginate are in large number, and they mainly appeared between the -OH on C(6), C(3) in the mannose residues of KGM and C(2), C(3) of sodium alginate. The formation of hydrogen bonds results in the energy expectation value of the Hamiltonian thermal density matrix of the compound system to be negative, the energy of the system to decrease, and the compounds tending to form stable conformations.展开更多
The synergistic interaction between the cationic guar gum (the ammonium hydroxy-propyl-trimethyl chloride of guar gum) and sodium alginate has been studied. The effects of the mass ratio of them, mixed temperature, ba...The synergistic interaction between the cationic guar gum (the ammonium hydroxy-propyl-trimethyl chloride of guar gum) and sodium alginate has been studied. The effects of the mass ratio of them, mixed temperature, balk salt ion concentration, incubation time and pH value on gelation were investigated. It has been observed that there was a gel strength maximum when the mass ratio was 0.6, the mixed temperature was 70°C, the balk salt ion concentration was 1.0 mol·L?1, the incubation time was 30 min and the pH value was 8. Interaction between molecules of these two polysaccharides was investigated by FT-IR spectrometry. Key words cationic guar gum - sodium alginate - gelation - synergism CLC number O 629.12 Foundation item: Supported by the National Natural Science Foundation of China(29574173)Biography: He Dong-bao (1945-), male, Associate professor, research direction: modifying and gelating of natural polysaccharides.展开更多
The aim of the present work is fabrication of dual cross linked sodium alginate(SA)/montmorillonite(MMT) microbeads as a potential drug vehicle for extended release of curcumin(CUR). The microbeads were prepared using...The aim of the present work is fabrication of dual cross linked sodium alginate(SA)/montmorillonite(MMT) microbeads as a potential drug vehicle for extended release of curcumin(CUR). The microbeads were prepared using in situ ion-exchange followed by simple ionotropic gelation technique. The developed beads were characterized by Fourier transform infrared spectroscopy(FTIR), differential scanning calorimetry(DSC), thermogravimetric analysis(TGA), X-ray diffraction(X-RD) and scanning electron microscopy(SEM). The effect of MMT on encapsulation efficiency of CUR and intercalation kinetics was investigated. Dynamic swelling study and in vitro release study were investigated in simulated intestinal fluid(pH 7.4) and simulated gastric fluid(pH 1.2) at 37 ℃. Results suggested that both the swelling and in vitro release studies were influenced by the pH of test media, which might be suitable for intestinal drug delivery. The release mechanism was analyzed by fitting the release data into KorsmeyerPeppas equation.展开更多
The miniature pig is an optimal animal model for studying nervous system disease because of its physiologic and pathologic features. However, the rete mirabile composed of arteries and veins at the skull base limits t...The miniature pig is an optimal animal model for studying nervous system disease because of its physiologic and pathologic features. However, the rete mirabile composed of arteries and veins at the skull base limits their application as a model of ischemic stroke by middle cerebral artery occlusion. The present study investigated the possibility of establishing an ischemic stroke model in the miniature pig by blocking the skull base retia with sodium alginate microspheres. Three Bama miniature pigs were used. Using the monitor of C-arm X-ray machine, sodium aiginate microspheres (100-300 pm), a novel embolic material, were injected through the femoral artery, aortic arch, common carotid artery, ascending pharyngeal artery and the retia. Results were evaluated using carotid arteriography, MRI, behavior observation and histology. The unilateral rete mirabile was completely blocked, resulting in disturbance in blood supply to the basal ganglia, astasia of the dght hind limb and salivation. MRI and hematoxylin-eosin staining showed an evident infarction focus in the basal ganglia. These findings indicate that sodium alginate microspheres are a suitable embolic material for blocking the skull base retia in miniature pigs to establish an ischemic stroke models.展开更多
Recently,an emerging category green of energetic material ammonium dinitramide(ADN)has exhibited promising application in propellants due to its outstanding merits in energy release and environmental friendliness.It c...Recently,an emerging category green of energetic material ammonium dinitramide(ADN)has exhibited promising application in propellants due to its outstanding merits in energy release and environmental friendliness.It can be considered to substitute traditional oxidizer of ammonium perchlorate(AP)in military systems and aerospace.In this paper,a novel spherical energetic composite ADN/copper alginate(CA)with a microporous structure was designed and prepared by the W/O gel emulsion method,and a desirable porous microsphere structure was obtained.Multiple characterization techniques were used to investigate the structure and properties of ADN/CA composites.The results showed that ADN crystals were homogeneously encapsulated in an alginate-gel matrix.Thermal decomposition temperature was reduced to 151.7℃compared to ADN,while the activation energy of them was reduced from 129.73 k J/mol(ADN)to 107.50 k J/mol(ADN/CA-4).In addition,as-prepared samples had lower impact and frictional sensitivity than ADN.The mechanism of sensitivity reduction and decomposition are also discussed.Constant-volume combustion tests show that peak pressure of the ADN/CA-4 achieves 253.4 k Pa and pressurization rate of 2750.4 k Pa/s.Hence,this has a promising application in improving the combustion performance and safety performance of solid propellants.展开更多
To expand the future clinic applications of biodegradable magnesium alloy,polymer coatings with excellent biocompatibility are the keys to solve the local alkalinity and rapid hydrogen release.Natural-organic silk fib...To expand the future clinic applications of biodegradable magnesium alloy,polymer coatings with excellent biocompatibility are the keys to solve the local alkalinity and rapid hydrogen release.Natural-organic silk fibroin provides an approach to fabricate a protective coating on biomedical Mg-Zn-Ca alloy,however,the adhesion force and mechanical properties of the coating on substrates are ought to be further improved without any chemical conversion/intermediate layer.Hereby,based on VUV/O;surface activation,a hybrid of silk fibroin and sodium alginate is proposed to enhance the adhesion force and mechanical properties of the composite coatings on hydrophilic Mg-Zn-Ca alloy surfaces.Various mass ratios of sodium alginate addition were investigated to achieve the optimum coating strategy.The nanoscratch test and nanoindentation test confirmed that the adhesion force was tripled and mechanical properties index was significantly improved when the mass ratio of silk fibroin/sodium alginate was 70/30 compared to pure silk fibroin or sodium alginate coatings.Meanwhile,the corrosion rate of the coated Mg-Zn-Ca alloy was significantly delayed with the addition of sodium alginate,resulting in a reaction layer during corrosion process.Furthermore,the mechanisms for both adhesion and corrosion processes were discussed in detail.Our findings offer more possibilities for the controllable surface performance of degradable metals.展开更多
The membrane-based CO2 separation process has an advantage compared to traditional CO2 separation technologies. The membrane is the key of the membrane separation process. In this paper, preparation, characterization ...The membrane-based CO2 separation process has an advantage compared to traditional CO2 separation technologies. The membrane is the key of the membrane separation process. In this paper, preparation, characterization and laboratory testing of the membrane, which was prepared from sodium alginate, hydrogen bond cross-linked with sodium tartrate and used for CO2/N2 separation, were reported. The resistance to SO2 of the membrane was also investigated. The experimental results demonstrate that the membrane possesses a high resistance to SO2.Finally,based on experimental results, the economic feasibility of the membrane used for CO2/N2 separation was evaluated,indicating the two-stage membrane process can compete with the traditional chemical absorption method.展开更多
文摘The purpose of this study was to identify and compare the degradation efficiencies of free and entrapped bacterial consortia(Staphylococcus capitis CP053957.1 and Achromobacter marplatensis MT078618.1)to different polymers such as Sodium Alginate(SA),Sodium Alginate/Poly(Vinyl Alcohol)(SA/PVA),and Bushnell Haas Agar(BHA).In addition to SA and SA/PVA,which are cost-effective,non-toxic and have different functional groups,BHA,which is frequently encountered in laboratory-scale studies but has not been used as an entrapment material until now.Based on these,the polymers with different surface morphologies and chemical compositions were analyzed by SEM and FT-IR.While the petroleum removal efficiency was higher with the entrapped bacterial consortia than with the free one,BHA-entrapped bacterial consortium enhanced the petroleum removal more than SA and SA/PVA.Accordingly,the degradation rate of bacterial consortia entrapped with BHA was 2.039 day^(-1),SA/PVA was 1.560,SA was 0.993,the half-life period of BHA-entrapped bacterial consortia is quite low(t_(1/2)=0.339)compared with SA(t_(1/2)=0.444)and SA/PVA(t_(1/2)=0.697).The effects of the four main factors such as:amount of BHA(0.5,1,1.5,2,2.5,3 g),disc size(4,5,6,7,8 mm),inoculum concentration(1,2.5,5,7.5,10 mL),and incubation period on petroleum removal were also investigated.The maximum petroleum removal(94.5%)was obtained at≥2.5 mL of bacterial consortium entrapped in 2 g BHA with a 7 mm disc size at 168 h and the results were also confirmed by statistical analysis.Although a decrease was observed during the reuse of bacterial consortium entrapped in BHA,the petroleum removal was still above 50%at 10th cycle.Based on GC-MS analysis,the removal capacity of BHA-entrapped consortium was over 90%for short-chain n-alkanes and 80%for medium-chain n-alkanes.Overall,the obtained data are expected to provide a potential guideline in cleaning up the large-scale oil pollution in the future.Since there has been no similar study investigating petroleum removal with the bacterial consortia entrapped with BHA,this novel entrapment material can potentially be used in the treatment of petroleum pollution in advanced remediation studies.
基金Funded by the National Natural Science Foundation of China(No.52003211)。
文摘We developed a new preparation to protect probiotic cells from adverse environmental conditions and improve their livability,which is called Lactobacillus casei-Sodium alginate-Chitosan (LSC).The LSC was prepared by mixing probiotics with sodium alginate-chitosan sol.The preparation contained complex calcium ions,which were released in the acidic environment of gastric juice,thus crosslinking to form in-situ gel.Different proportions of sodium alginate-chitosan were prepared to add to simulate gastrointestinal fluid to get the best ratio.The optimal ratio of LSC preparation was compared with traditional gel microspheres to observe the survival effect of probiotics in gastrointestinal fluid environment.Compared with sodium alginate sol,the porosity of sodium alginate-chitosan sol is lower,which is beneficial to the protection of probiotics.When the ratio of chitosan to sodium alginate is 1.5:1.5 (w/v),the protective effect is the best.The protective ability of LSC is 64 times that of traditional microspheres,and it has the potential of synergistic anti-tumor.A probiotic preparation with simple preparation process and better protection effect compared with traditional microspheres was prepared,which has joint anti-tumor potential.
基金The authors are thankful to Ministry of Human Resource Development(presently Ministry of Education),Government of India,New Delhi,for providing research facility by sanctioning Center of Excellence(F.No.5-6/2013-TS VII)in Tissue Engineering and Center of Excellence in Orthopedic Tissue Engineering and Rehabilitation funded by World Bank under TEQIP-II.
文摘Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of this type of scaffold to make it a potential template for bone-tissue regeneration.We experimented with adding 0%–15%(volume fraction)gelatin(GE),a protein-based biopolymer known to promote cell adhesion,proliferation,and differentiation.The resulting tri-polymer complex was used as bioink to fabricate SA/CH/GEmatrices by three-dimensional(3D)printing.Morphological studies using scanning electron microscopy revealed the microfibrous porous architecture of all the structures,which had a pore size range of 383–419μm.X-ray diffraction and Fourier-transform infrared spectroscopy analyses revealed the amorphous nature of the scaffold and the strong electrostatic interactions among the functional groups of the polymers,thereby forming polyelectrolyte complexes which were found to improve mechanical properties and structural stability.The scaffolds exhibited a desirable degradation rate,controlled swelling,and hydrophilic characteristics which are favorable for bone-tissue engineering.The tensile strength improved from(386±15)to(693±15)kPa due to the increased stiffness of SA/CH scaffolds upon addition of gelatin.The enhanced protein adsorption and in vitro bioactivity(forming an apatite layer)confirmed the ability of the SA/CH/GE scaffold to offer higher cellular adhesion and a bone-like environment to cells during the process of tissue regeneration.In vitro biological evaluation including the MTT assay,confocal microscopy analysis,and alizarin red S assay showed a significant increase in cell attachment,cell viability,and cell proliferation,which further improved biomineralization over the scaffold surface.In addition,SA/CH containing 15%gelatin designated as SA/CH/GE15 showed superior performance to the other fabricated 3D structures,demonstrating its potential for use in bone-tissue engineering.
文摘A novel core-shell hydrogel bead was fabricated for effective removal of methylene blue dye from aqueous solutions.The core,made of sodium alginate-g-polyacrylamide and attapulgite nanofibers,was cross-linked by Calcium ions(Ca^(2+)).The shell,composed of a chitosan/activated carbon mixture,was then coated onto the core.Fourier transform infrared spectroscopy confirmed the grafting polymerization of acrylamide onto sodium alginate.Scanning electron microscopy images showed the core-shell structure.The core exhibited a high water uptake ratio,facilitating the diffusion of methylene blue into the core.During the diffusion process,the methylene blue was first adsorbed by the shell and then further adsorbed by the core.Adsorption tests showed that the coreshell structure had a larger adsorption capacity than the core alone.The shell effectively enhanced the adsorption capacity to methylene blue compared to the single core.Methylene blue was adsorbed by activated carbon and chitosan in the shell,and the residual methylene blue diffused into the core and was further adsorbed.
基金funded by Livelihood Plan Project of Department of Science and Technology of Liaoning Province(2021JH2/10300069,2019-ZD-0845)Department of Education of Liaoning Province(LJKZ0918)National College Students’Innovation and Entrepreneurship Training Program(202210163013).
文摘The aim of this study was to prepare silk fibroin/sodium alginate composite film containing curcumin by casting method.Orthogonal test was used to optimize the formulation according to the values of tensile strength and elongation at break.The release of curcumin in the optimal film was studied in order to explore its application as wound dressing.The results showed that the optimum composition of curcumin/silk fibroin/sodium alginate composite film was as follows:Silk fibroin(70 mg/mL)2.7 g,sodium alginate(24 mg/mL)0.84 g,span 40(5.0 mg/mL)0.4 g,glycerol(3.75%,V/V)3 mL,curcumin(0.2 mg/mL)0.016 g.The optimum film showed the tensile strength and the elongation at break was(0.628±0.032)MPa and(0.794±0.046)%,respectively.
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The discharge of the antibiotic wastewater has increased dramatically in our country with the development of medical science and wide application of antibiotic,resulting in serious harm to human body and ecological environment.In this work,ciprofloxacin(CIP)was selected as one of typical antibiotics and heterogeneous Fenton-like catalysts were prepared for the treatment of ciprofloxacin wastewater.The sodium alginate(SA)gel microspheres catalysts were prepared by polymerization method using double metal ions of Fe^(3+)and Mn^(2+)as cross-linking agents.Preparation conditions such as metal ions concentration,mass fraction of SA,polymerization temperature and dual-metal ions as crosslinking agent were optimized.Moreover,the effects of operating conditions such as initial concentration of CIP,pH value and catalyst dosage on CIP removal were studied.The kinetic equation showed that the effect of the initial concentration of CIP on the degradation rate was in line with second-order kinetics,and the effects of catalyst dosage and pH value on the degradation rate of CIP were in line with first-order kinetics.The SA gel microspheres catalysts prepared by dual-metal ions exhibited a high CIP removal and showed a good reusability after six recycles.The SA gel microspheres catalysts with an easy recovery performance provided an economical and efficient method for the removal of antibiotics in the future.
基金financially supported by the National Natural Science Foundation of China(Nos.51504053 and 51374079)the Fundamental Research Funds for the Central Universities(No.N170107013)
文摘Given the gradual increase in the chlorite content of hematite ores, pulp properties seriously deteriorate during flotation. The traditional anion reverse flotation of hematite cannot effectively eliminate the effects of chlorite, leading to a significant decrease in the total Fe(TFe) grade of the concentrate. In this work, the effect of sodium alginate on the reverse flotation of hematite was systematically investigated. Flotation tests of artificially mixed ores were conducted, and the results showed that sodium alginate can significantly improve the removal rates of quartz and chlorite. The adsorption measurements, infrared spectroscopy, and contact angle tests demonstrated that sodium alginate adsorbs on the quartz surface by chelating with calcium ions, thereby weakening the steric hindrance of oleate ions and increasing the adsorption capacity of sodium oleate to ultimately improve the removal rate of quartz. Furthermore, owing to its lower density and fine particle size, chlorite is easily entrained into the foam layer. Sodium alginate dramatically increases the liquid-to-gas ratio of the foam layer by increasing pulp viscosity, thereby increasing the entrainment rate of chlorite and finally improving its removal rate. The core content of this thesis bears significance in improving the Fe grade in the reverse flotation of chlorite-containing hematite.
基金Funded by the National Natural Science Foundation of China(No.81401510)Hubei Provincial Natural Science Foundation of China(No.2017CFB414)+1 种基金the Fundamental Research Funds for the Central Universities,South-Central University for Nationalities(No.CZY19030)the National College Students Innovation and Entrepreneurship Training Project(No.GCX16034)
文摘One interpenetrating network hydrogel based on sodium alginate (SA) and polyvinyl alcohol (PVA) was synthesized by combining the raw materials of PVA and SA with the double physical crosslinking methods of freezing thawing and Ca2+ crosslinking. The PVA-SA composite hydrogel have been characterized by scanning electron microscopy for surface morphology, infrared spectroscopy for investigating the chemical interactions between PVA and SA, X-ray diffraction for studying the PVA-SA composite structure property and thermal gravimetric for understanding the PVA-SA composite thermal stability. The swelling behavior and the degradation rate of the PVA-SA composite hydrogel were studied in simulated gastrointestinal fluid. Using bovine serum albumin (BSA) and salicylic acid as the model drugs, the release behavior of the PVASA composite hydrogel on macromolecular protein drugs and small molecule drug were evaluated. The results showed that the water absorption and degradation ability of the PVA-SA composite hydrogel was much better compared to the pure SA hydrogel or pure PVA hydrogel. The hydrogel exhibited remarkable pH sensitivity and the network was stable in the simulated intestinal fluid for more than 24 h. With the advantages such as mild preparation conditions, simple method, less reagent and none severe reaction, the PVA-SA composite hydrogel is expected to be a new prosperous facile sustained drug delivery carrier.
基金supported by the National Natural Science Foundation of China,No.81671243 and 81373429
文摘Spinal cord injury results in the loss of motor and sensory pathways and spontaneous regeneration of adult mammalian spinal cord neurons is limited. Chitosan and sodium alginate have good biocompatibility, biodegradability, and are suitable to assist the recovery of damaged tissues, such as skin, bone and nerve. Chitosan scaffolds, sodium alginate scaffolds and chitosan-sodium alginate scaffolds were separately transplanted into rats with spinal cord hemisection. Basso-Beattie-Bresnahan locomotor rating scale scores and electrophysiological results showed that chitosan scaffolds promoted recovery of locomotor capacity and nerve transduction of the experimental rats.Sixty days after surgery, chitosan scaffolds retained the original shape of the spinal cord. Compared with sodium alginate scaffolds- and chitosan-sodium alginate scaffolds-transplanted rats, more neurofilament-H-immunoreactive cells (regenerating nerve fibers) and less glial fibrillary acidic protein-immunoreactive cells (astrocytic scar tissue) were observed at the injury site of experimental rats in chitosan scaffold-transplanted rats. Due to the fast degradation rate of sodium alginate, sodium alginate scaffolds and composite material scaffolds did not have a supporting and bridging effect on the damaged tissue. Above all, compared with sodium alginate and composite material scaffolds, chitosan had better biocompatibility, could promote the regeneration of nerve fibers and prevent the formation of scar tissue,and as such, is more suitable to help the repair of spinal cord injury.
文摘AIM To prepare 5 FU sodium alginate 125 I bovine serum albumin nanoparticles (BSA NP), to determine the radioactive count in different organs of rats at different time points after oral administration of 5 FU 125 I sodium alginate BSA NP and to calculate the kinetic parameters of its metabolism. METHODS Emulsion solidification method was used to prepare 5 FU 125 I sodium alginate BSA NP, and to determine its diameter under transmission electronic microscope (TEM). Then the rate of NP and external drug releasing velocity were measured. Radioactive counting in different organs of rats was made after oral administration of the NP by GAMA Counter, and the kinetic parameters of drug metabolism were calculated by handling the data with the two department model. RESULTS The average arithmatic diameter of the NP was 166nm ± 34nm , the rate of 5 FU was 32 8% and the cumulative external releasing ratio amounted to 84 0% within 72 hours. The NP was mainly distributed in the liver, spleen, lungs and kidneys after NP oral administration to rats. The micro radioautographic experiment showed that NP was distributed in the Kupffers cells of liver, liver parenchymal cells and the phagocytes of spleen and lungs. The kinetic parameters of matabolism were: T 1/2 =9 42h, C max =2 45×10 7Bq, T max =2 18h, AUC=148×10 9Bq. CONCLUSION NP is difficult to pass through the blood-cerebral barrier,and 125 I sodium alginate-BSA NP enters the body circulation by gastroin testinal passage.
文摘A novel poly-/-arginine microcapsule was prepared due to its nutritional function and pharmacological efficacy. A high-voltage electrostatic droplet generator was used to make uniform microcapsules. The results show that the membrane strength and permeating property are both remarkably affected with the changes of sodium alginate concentration. With the sodium alginate concentration increasing, gel beads sizes increase from 233μm to 350μm, release ratio is also higher at the same time, but the membrane strength decreases.
文摘The resaerch examined the effect of the two oceanic materials as coating materials on the soybean growth.The results showed chitosan and sodium alginate seed coating can enhance the growth of seedling root,increase the nodule mumber,root activity and the growth of underground.The suggested coating ratios were 0.5~1.0g/kgseed,the same as chitosan.The two materials could increase the contents of CAT and NR in soybean leaves,decrease the contents of POD in soybean leaves.
基金supported by Shanxi Provincial Key Research and Development Project(No.20201102002)the Science Foundation of China University of Petroleum,Beijing(No.2462020BJRC007,2462020YXZZ003)State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(No.PRP/DX-2216)
文摘Excess water production has become an important issue in the oil and gas extraction process.Preformed particle gels(PPGs),show the capability to control the conformance and reduce excess water cut.However,conventional PPGs have poor mechanical properties and their swollen particles are easily damaged by shearing force when passing through the fractures in formations,meanwhile PPGs can be also degraded into various byproducts,leading to permanent damage to the reservoir permeability after temporary plugging.Herein,a novel type of dual cross-linked PPGs(dPPGs)was designed and synthesized using sodium alginate(SA)and acrylamide(AAm),cross-linked with N,N’-methylenebisacrylamide(MBA)and Fe^(3+).Results show that dPPGs have excellent mechanical properties with a storage modulus up to 86,445 Pa,which is almost 20 times higher than other reported PPGs.Meanwhile,dPPGs can be completely degraded into liquid without any solid residues or byproducts and the viscosity of dPPGs degraded liquid was found to be lower than 5 mPa·s.A laboratory coreflooding test showed that the plugging efficiency of dPPGs was up to 99.83%on open fractures.The obtained results demonstrated that dPPGs could be used as economical and environment-friendly temporary plugging agent with high-strength,self-degradation,thermal stability,and salt stability,thus making it applicable to a wide range of conformance control to enhance oil recovery.
基金supported by the National Natural Science Foundation of China(31471704 and 31271837)Specialized Research Fund for the Doctoral Program of Higher Education jointly funded by Ministry of Education(20113515110010)Major projects of industries,university and research in Fujian Province(2013N5003)
文摘Konjac glucomannan (KGM) and sodium alginate were chosen as the research objects, and the hydrogen bond conformation of compound system was studied with the molecular dynamics simulation, which simulated the energy variety in composite process. Combining with Hamiltonian in quantum mechanics calculation, the mechanism of hydrogen bond in KGM and sodium alginate compound system stability was analyzed from a micro angle. The results showed that, the hydrogen bonds occurring between the molecule of KGM and sodium alginate are in large number, and they mainly appeared between the -OH on C(6), C(3) in the mannose residues of KGM and C(2), C(3) of sodium alginate. The formation of hydrogen bonds results in the energy expectation value of the Hamiltonian thermal density matrix of the compound system to be negative, the energy of the system to decrease, and the compounds tending to form stable conformations.
文摘The synergistic interaction between the cationic guar gum (the ammonium hydroxy-propyl-trimethyl chloride of guar gum) and sodium alginate has been studied. The effects of the mass ratio of them, mixed temperature, balk salt ion concentration, incubation time and pH value on gelation were investigated. It has been observed that there was a gel strength maximum when the mass ratio was 0.6, the mixed temperature was 70°C, the balk salt ion concentration was 1.0 mol·L?1, the incubation time was 30 min and the pH value was 8. Interaction between molecules of these two polysaccharides was investigated by FT-IR spectrometry. Key words cationic guar gum - sodium alginate - gelation - synergism CLC number O 629.12 Foundation item: Supported by the National Natural Science Foundation of China(29574173)Biography: He Dong-bao (1945-), male, Associate professor, research direction: modifying and gelating of natural polysaccharides.
基金UGCe BSR, New Delhi, India, for the financial support provided。
文摘The aim of the present work is fabrication of dual cross linked sodium alginate(SA)/montmorillonite(MMT) microbeads as a potential drug vehicle for extended release of curcumin(CUR). The microbeads were prepared using in situ ion-exchange followed by simple ionotropic gelation technique. The developed beads were characterized by Fourier transform infrared spectroscopy(FTIR), differential scanning calorimetry(DSC), thermogravimetric analysis(TGA), X-ray diffraction(X-RD) and scanning electron microscopy(SEM). The effect of MMT on encapsulation efficiency of CUR and intercalation kinetics was investigated. Dynamic swelling study and in vitro release study were investigated in simulated intestinal fluid(pH 7.4) and simulated gastric fluid(pH 1.2) at 37 ℃. Results suggested that both the swelling and in vitro release studies were influenced by the pH of test media, which might be suitable for intestinal drug delivery. The release mechanism was analyzed by fitting the release data into KorsmeyerPeppas equation.
基金supported by the Science and Technology Support Program of Beijing Science and Technology Committee,No.Z101107052210004
文摘The miniature pig is an optimal animal model for studying nervous system disease because of its physiologic and pathologic features. However, the rete mirabile composed of arteries and veins at the skull base limits their application as a model of ischemic stroke by middle cerebral artery occlusion. The present study investigated the possibility of establishing an ischemic stroke model in the miniature pig by blocking the skull base retia with sodium alginate microspheres. Three Bama miniature pigs were used. Using the monitor of C-arm X-ray machine, sodium aiginate microspheres (100-300 pm), a novel embolic material, were injected through the femoral artery, aortic arch, common carotid artery, ascending pharyngeal artery and the retia. Results were evaluated using carotid arteriography, MRI, behavior observation and histology. The unilateral rete mirabile was completely blocked, resulting in disturbance in blood supply to the basal ganglia, astasia of the dght hind limb and salivation. MRI and hematoxylin-eosin staining showed an evident infarction focus in the basal ganglia. These findings indicate that sodium alginate microspheres are a suitable embolic material for blocking the skull base retia in miniature pigs to establish an ischemic stroke models.
基金supported by the National Natural Science Foundation of China(Grant No.22005253)。
文摘Recently,an emerging category green of energetic material ammonium dinitramide(ADN)has exhibited promising application in propellants due to its outstanding merits in energy release and environmental friendliness.It can be considered to substitute traditional oxidizer of ammonium perchlorate(AP)in military systems and aerospace.In this paper,a novel spherical energetic composite ADN/copper alginate(CA)with a microporous structure was designed and prepared by the W/O gel emulsion method,and a desirable porous microsphere structure was obtained.Multiple characterization techniques were used to investigate the structure and properties of ADN/CA composites.The results showed that ADN crystals were homogeneously encapsulated in an alginate-gel matrix.Thermal decomposition temperature was reduced to 151.7℃compared to ADN,while the activation energy of them was reduced from 129.73 k J/mol(ADN)to 107.50 k J/mol(ADN/CA-4).In addition,as-prepared samples had lower impact and frictional sensitivity than ADN.The mechanism of sensitivity reduction and decomposition are also discussed.Constant-volume combustion tests show that peak pressure of the ADN/CA-4 achieves 253.4 k Pa and pressurization rate of 2750.4 k Pa/s.Hence,this has a promising application in improving the combustion performance and safety performance of solid propellants.
基金supported by the National Natural Science Foundation of China(Grant No.51975151)the China Postdoctoral Science Foundation(Grant No.2017M610207)+1 种基金the Heilongjiang Provincial Natural Science Foundation of China(Grant No.LH2019E041)the Fundamental Research Funds for Central Universities(Grant No.HIT.NSRIF.2019005)。
文摘To expand the future clinic applications of biodegradable magnesium alloy,polymer coatings with excellent biocompatibility are the keys to solve the local alkalinity and rapid hydrogen release.Natural-organic silk fibroin provides an approach to fabricate a protective coating on biomedical Mg-Zn-Ca alloy,however,the adhesion force and mechanical properties of the coating on substrates are ought to be further improved without any chemical conversion/intermediate layer.Hereby,based on VUV/O;surface activation,a hybrid of silk fibroin and sodium alginate is proposed to enhance the adhesion force and mechanical properties of the composite coatings on hydrophilic Mg-Zn-Ca alloy surfaces.Various mass ratios of sodium alginate addition were investigated to achieve the optimum coating strategy.The nanoscratch test and nanoindentation test confirmed that the adhesion force was tripled and mechanical properties index was significantly improved when the mass ratio of silk fibroin/sodium alginate was 70/30 compared to pure silk fibroin or sodium alginate coatings.Meanwhile,the corrosion rate of the coated Mg-Zn-Ca alloy was significantly delayed with the addition of sodium alginate,resulting in a reaction layer during corrosion process.Furthermore,the mechanisms for both adhesion and corrosion processes were discussed in detail.Our findings offer more possibilities for the controllable surface performance of degradable metals.
基金Supported by the National Natural Science Foundation of China (20836006), the National Basic Research Program (2009CB623405), the Science & Technology Pillar Program of Tianjin (10ZCKFSH01700), the Programme of Introducing Talents of Discipline to Universities (B06006) and the Cheung Kong Scholar Program for Innovative Teams of the Ministry of Education (IRT064.1).
文摘The membrane-based CO2 separation process has an advantage compared to traditional CO2 separation technologies. The membrane is the key of the membrane separation process. In this paper, preparation, characterization and laboratory testing of the membrane, which was prepared from sodium alginate, hydrogen bond cross-linked with sodium tartrate and used for CO2/N2 separation, were reported. The resistance to SO2 of the membrane was also investigated. The experimental results demonstrate that the membrane possesses a high resistance to SO2.Finally,based on experimental results, the economic feasibility of the membrane used for CO2/N2 separation was evaluated,indicating the two-stage membrane process can compete with the traditional chemical absorption method.