The bivalve Ruditapes philippinarum is not only one of the main mollusc species in the west Pacific Ocean, but also one of the main species for aquaculture in China. Knowledge of growth of the R. philippinarum shell w...The bivalve Ruditapes philippinarum is not only one of the main mollusc species in the west Pacific Ocean, but also one of the main species for aquaculture in China. Knowledge of growth of the R. philippinarum shell will improve our understanding of the shell as an environmental archive. It is also useful for the aquaculture of R. philippinarum. In this research, a hanging box culture method was introduced in the culture of R. philippinarum. The bivalves were cultured for 126 days, from March 31 to August 3, 2002. The average growth rates of shell width, height, and thickness were 0.069, 0.046, and 0.032 mm/d, respectively. The mean increase of average individual wet mass was 0.028 g/d. The largest growth rates of both shell and average individual wet mass occurred in June, indicating that water temperature and bivalve reproduction were 2 important factors. The shell morphology underwent significant changes with shell growth. The ratio of height to thickness (value of B/C) shifted 1.58 in the first 60 days to 1.54 in the last 30 days, which was resulted from the change in major shell growth direction. Periodic changes in the B/C ratio led to corrugated shell form, which could be used to determine the age of the shell.展开更多
The silk sericin is the main residue in silk production and it is found to be a low cost and efficient bio-sorbent. In this study, sericin was characterized with various techniques including SEM (scanning electron mi...The silk sericin is the main residue in silk production and it is found to be a low cost and efficient bio-sorbent. In this study, sericin was characterized with various techniques including SEM (scanning electron micro- scope), XRD, N2 physisorption, FTIR (Fourier transformed infrared spectroscopy) and XPS (X-ray photoelectron spectroscopy). The nitrogen content of sericin was ca. 8.5 mmol.g-1 according to elemental analysis. Dye adsorption by sericin biosorbent was investigated with the acid yellow (AY), methylene blue (MB) and copper (II) phthalocyanine-3,4'4"4'"-tetrasulfonic acid (CuPc) dyes from water. Sericin displayed large capacity for AY andCuPc adsorption with adsorption capacities of respectively 3.1 and 0.35 mmol.g-1, but it did not adsorbed methyl- ene blue dye. This selectivity is due to the basicity of amide groups in seriein biosorbents.展开更多
[Objective]This study aimed to screen toxin mutant of Dickeya zeae(Erwinia chrysanthemi pv.zeae)and investigate its biological characters.[Method]We obtained a toxin mutant strain D.zeae Ech7-3-42 by using acridine or...[Objective]This study aimed to screen toxin mutant of Dickeya zeae(Erwinia chrysanthemi pv.zeae)and investigate its biological characters.[Method]We obtained a toxin mutant strain D.zeae Ech7-3-42 by using acridine orange as a mutagenic agent and compared their biological characteristics and virulence between the toxin mutant and wild strain.[Result]There was no significant difference in pectin lyase,protease,cellulase and the production of extracellular polysaccharide and lipopolysaccharide,but significant difference in toxin biological activities and virulence.Ech7-3-42 mutant did not produce toxin,as well as the loss of virulence on rice and HR on tobacco,but did not lose the ability to soft rot on potato.Mutant strain Ech7-3-42 can infect rice root and then enriched in the root neck and stalk,but it could not cause rice foot rot.Dickeya zeae(wild and mutant strain)could be detected by PCR in the root neck and below the 1-2 cm long stem area,but could not be detected in the leaves.[Conclusion]We believed that toxin may be one of the important factors for D.zeae virulence on rice.展开更多
Proteins possess many biological functions.However, they can easily degrade or aggregate, thus losing their bioactivity. Therefore, it is very important to develop materials capable of interacting with proteins and fo...Proteins possess many biological functions.However, they can easily degrade or aggregate, thus losing their bioactivity. Therefore, it is very important to develop materials capable of interacting with proteins and forming nanostructures for protein storage and delivery. In this study,we serendipitously found a novel peptide-based supramolecular protein glue(Nap-GFFYK(γE)2-NH2, compound 1) that could co-assemble with proteins into nanofibers and hydrogels. We found that compound 1 rapidly folded into a β-sheet conformation upon contact with many proteins but not with polymers. Total internal reflection fluorescence microscopy(TIRFM) images clearly show the formation of co-assembled nanofibers by proteins and the peptide. The supramolecular protein glue could improve the dispersion of enzymes(lipase and lysozyme) and therefore enhance their catalytic activity,especially at high temperatures. More importantly, the supramolecular protein glue could co-assemble with two enzymes, glucose oxidase/horseradish peroxidase(GOx/HRP)and GOx/cytochrome c(cyt c), to form nanofibers that significantly enhanced the catalytic activity of tandem enzymatic reactions. We envisioned the great potential of our supramolecular protein glue for protein storage, delivery, and bioactivity manipulation.展开更多
Microbe-based cement has been widely reported in recent literatures. It is a new method of consolidating loose fine particles, which relies on the bacterially induced formation of a compatible carbonate precipitation ...Microbe-based cement has been widely reported in recent literatures. It is a new method of consolidating loose fine particles, which relies on the bacterially induced formation of a compatible carbonate precipitation around individual particles and at particle-particle contacts. Materials and cementation procedure are two major factors that influence the cementation performance of microbe-based cement. Besides, there are some other factors related to the performance, such as pH, temperature, metabolism activity, the flushed times of bacterial solution, concentration of substrate and calcium ion, etc., which affect consolidation function. The assessment methods for cementation process are carried out by various techniques. The performance of consolidation loose grains based on microbe-based cement is tested with the help of experiment. In this paper a review is presented on the cementation mechanism of microbe-based cement, techniques utilized to monitor cementation process, the consolidated performance by microbe-based cement and bond factors.展开更多
Wet-resistant flexible electronics have acquired increasing attention on applications in wet environments,such as sweaty skin, rainy weather, biological fluids, and underwater. However, it remains challenging to achie...Wet-resistant flexible electronics have acquired increasing attention on applications in wet environments,such as sweaty skin, rainy weather, biological fluids, and underwater. However, it remains challenging to achieve nonswelling and underwater self-healing hydrogel sensors for the mechanical perception in aqueous solutions. Herein, a selfhealing and non-swellable hydrogel is successfully fabricated,which presents an automatically healing behavior in various aquatic environments, including deionized water, seawater,sweat, alkali and acidic aqueous solutions. Moreover, the hydrogel demonstrates high stretchability and stable electromechanical sensing properties in water. Furthermore, an electronic skin is designed with the features of fast responsiveness, reliability, and high sensitivity for detecting breathing, speaking, coughing, and diverse body movements. The self-healing hydrogel sensors enable a brilliant mechanical sensibility for detecting a series of dynamic stimuli in air and underwater, even after the healing of fracture interface in water. The underwater self-healing and anti-swelling hydrogel would provide enticing potential on various stable electronic devices for aquatic environments, such as implantable electrodes, triboelectric nanogenerators, and underwater soft robotics.展开更多
Biological lung volume reduction (BLVR) using lung sealant has received more attention recently as a new non-surgical approach to emphysema treatment. Many tissue sealants have been studied but only a few have been ...Biological lung volume reduction (BLVR) using lung sealant has received more attention recently as a new non-surgical approach to emphysema treatment. Many tissue sealants have been studied but only a few have been proposed for BLVR. In this work, we prepared in situ forming chitosan-based hydrogels (CSG) using covalent cross-linking of chitosan and genipin in the cooperation of ionic interaction between chitosan and sodium orthophosphate hydrate (Na3PO4.12H20) and characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and rheological methods. CSG showed short gelation time (8 min), high swelling ratio (〉100 %) and non-toxicity (3T3 mouse fibroblast cell viability 〉80 %) under physiological conditions. The application of lung sealant for BLVR was tested in a Chinese dog and evaluated by chest computed tomography. After 3 weeks of the installation of CSG in bronchopulmonary segment, the gel formation was detected at a localized region of bronchi and the local atelectasis occurred. Our findings indicate that this chitosan-based hydrogel is a promising new candidate for use as a lung sealant for BLVR.展开更多
Hydrogels are a class of special materials that contain a large amount of water and behave like rubber.These materials have found broad applications in tissue engineering,cell culturing,regenerative medicine etc.Recen...Hydrogels are a class of special materials that contain a large amount of water and behave like rubber.These materials have found broad applications in tissue engineering,cell culturing,regenerative medicine etc.Recently,the exploration of peptide-based supramolecular hydrogels has greatly expanded the repertoire of hydrogels suitable for biomedical applications.However,the mechanical properties of peptide-based hydrogels are intrinsically weak.Therefore,it is crucial to develop methods that can improve the mechanical stability of such peptide-based hydrogels.In this review,we explore the factors that determine or influence the mechanical stability of peptide-based hydrogels and summarize several key elements that may guide scientists to achieve mechanically improved hydrogels.In addition,we exemplified several methods that have been successfully developed to prepare hydrogels with enhanced mechanical stability.These mechanically strong peptide-based hydrogels may find broad applications as novel biomaterials.It is still challenging to engineer hydrogels in order to mimic the mechanical properties of biological tissues.More hydrogel materials with optimal mechanical properties suitable for various types of biological applications will be available in the near future.展开更多
The abuse of antibiotics in treating microbial infections has led to the emergence and prevalence of drugresistant bacteria.Thus,the development of novel antibacterial materials is attracting increasing attention.Here...The abuse of antibiotics in treating microbial infections has led to the emergence and prevalence of drugresistant bacteria.Thus,the development of novel antibacterial materials is attracting increasing attention.Here,a series of flexible electrostatic hydrogels with excellent antibacterial ability were constructed using a mixture of nitric oxide(NO)-releasing nitrated chitosan(CSNO)and mesotetra(4-carboxyphenyl)porphine(TCPP)with salmon sperm DNA(ssDNA)solution.When cultured with gram-negative bacteria under solar simulator irradiation,TCPP-CSNO_(m)ssDNA_(n) hydrogels released reactive oxygen species(ROS)and NO to produce peroxynitrite ions(ONOO^(−)).ONOO−is efficient at killing bacteria,thereby improving the antimicrobial ability of photodynamic therapy against gram-negative bacteria.The hydrogels exhibited powerful antibacterial activity in vivo when used to treat skin infections caused by drugresistant bacteria,making them a promising candidate for clinical applications.A string of antibacterial hydrogels that release ROS and NO synergistically can bring new possibilities for effectively killing drug-resistant bacteria and be of great value in anti-infection wound dressings and other applications.展开更多
基金Supported by the Natural Science Foundation of Shandong Province (No. Y2001E02)the National Natural Science Foundation of China (No. 40676035).
文摘The bivalve Ruditapes philippinarum is not only one of the main mollusc species in the west Pacific Ocean, but also one of the main species for aquaculture in China. Knowledge of growth of the R. philippinarum shell will improve our understanding of the shell as an environmental archive. It is also useful for the aquaculture of R. philippinarum. In this research, a hanging box culture method was introduced in the culture of R. philippinarum. The bivalves were cultured for 126 days, from March 31 to August 3, 2002. The average growth rates of shell width, height, and thickness were 0.069, 0.046, and 0.032 mm/d, respectively. The mean increase of average individual wet mass was 0.028 g/d. The largest growth rates of both shell and average individual wet mass occurred in June, indicating that water temperature and bivalve reproduction were 2 important factors. The shell morphology underwent significant changes with shell growth. The ratio of height to thickness (value of B/C) shifted 1.58 in the first 60 days to 1.54 in the last 30 days, which was resulted from the change in major shell growth direction. Periodic changes in the B/C ratio led to corrugated shell form, which could be used to determine the age of the shell.
基金Supported by the Hong Kong Research Grant Council(605009)the Hong Kong Innovation Technology Fund(ITS/108/09FP)the Environment and Conservation Fund(ECWW11EG02)
文摘The silk sericin is the main residue in silk production and it is found to be a low cost and efficient bio-sorbent. In this study, sericin was characterized with various techniques including SEM (scanning electron micro- scope), XRD, N2 physisorption, FTIR (Fourier transformed infrared spectroscopy) and XPS (X-ray photoelectron spectroscopy). The nitrogen content of sericin was ca. 8.5 mmol.g-1 according to elemental analysis. Dye adsorption by sericin biosorbent was investigated with the acid yellow (AY), methylene blue (MB) and copper (II) phthalocyanine-3,4'4"4'"-tetrasulfonic acid (CuPc) dyes from water. Sericin displayed large capacity for AY andCuPc adsorption with adsorption capacities of respectively 3.1 and 0.35 mmol.g-1, but it did not adsorbed methyl- ene blue dye. This selectivity is due to the basicity of amide groups in seriein biosorbents.
基金Supported by the National Natural Science Foundation of China(31071658)
文摘[Objective]This study aimed to screen toxin mutant of Dickeya zeae(Erwinia chrysanthemi pv.zeae)and investigate its biological characters.[Method]We obtained a toxin mutant strain D.zeae Ech7-3-42 by using acridine orange as a mutagenic agent and compared their biological characteristics and virulence between the toxin mutant and wild strain.[Result]There was no significant difference in pectin lyase,protease,cellulase and the production of extracellular polysaccharide and lipopolysaccharide,but significant difference in toxin biological activities and virulence.Ech7-3-42 mutant did not produce toxin,as well as the loss of virulence on rice and HR on tobacco,but did not lose the ability to soft rot on potato.Mutant strain Ech7-3-42 can infect rice root and then enriched in the root neck and stalk,but it could not cause rice foot rot.Dickeya zeae(wild and mutant strain)could be detected by PCR in the root neck and below the 1-2 cm long stem area,but could not be detected in the leaves.[Conclusion]We believed that toxin may be one of the important factors for D.zeae virulence on rice.
基金supported by the National Science Fund for Distinguished Young Scholars(31825012)the National Key Research and Development Program of China(2017YFC1103502)+4 种基金the National Natural Science Foundation of China(NSFC,51773097,51873156 and 21876116)Tianjin Science Fund for Distinguished Young Scholars(17JCJQJC44900)the National Program for Support of Topnotch Young Professionalsthe Fundamental Research Funds for the Central Universitiesthe Young Elite Scientists Sponsorship Program by Tianjin(TJSQNTJ-2017-16)
文摘Proteins possess many biological functions.However, they can easily degrade or aggregate, thus losing their bioactivity. Therefore, it is very important to develop materials capable of interacting with proteins and forming nanostructures for protein storage and delivery. In this study,we serendipitously found a novel peptide-based supramolecular protein glue(Nap-GFFYK(γE)2-NH2, compound 1) that could co-assemble with proteins into nanofibers and hydrogels. We found that compound 1 rapidly folded into a β-sheet conformation upon contact with many proteins but not with polymers. Total internal reflection fluorescence microscopy(TIRFM) images clearly show the formation of co-assembled nanofibers by proteins and the peptide. The supramolecular protein glue could improve the dispersion of enzymes(lipase and lysozyme) and therefore enhance their catalytic activity,especially at high temperatures. More importantly, the supramolecular protein glue could co-assemble with two enzymes, glucose oxidase/horseradish peroxidase(GOx/HRP)and GOx/cytochrome c(cyt c), to form nanofibers that significantly enhanced the catalytic activity of tandem enzymatic reactions. We envisioned the great potential of our supramolecular protein glue for protein storage, delivery, and bioactivity manipulation.
基金supported by the National Natural Science Foundation of China (Grant No. 51072035)
文摘Microbe-based cement has been widely reported in recent literatures. It is a new method of consolidating loose fine particles, which relies on the bacterially induced formation of a compatible carbonate precipitation around individual particles and at particle-particle contacts. Materials and cementation procedure are two major factors that influence the cementation performance of microbe-based cement. Besides, there are some other factors related to the performance, such as pH, temperature, metabolism activity, the flushed times of bacterial solution, concentration of substrate and calcium ion, etc., which affect consolidation function. The assessment methods for cementation process are carried out by various techniques. The performance of consolidation loose grains based on microbe-based cement is tested with the help of experiment. In this paper a review is presented on the cementation mechanism of microbe-based cement, techniques utilized to monitor cementation process, the consolidated performance by microbe-based cement and bond factors.
基金supported by the National Natural Science Foundation of China (51873024)the grant from Science and Technology Department of Jilin Province (20200708102YY)。
文摘Wet-resistant flexible electronics have acquired increasing attention on applications in wet environments,such as sweaty skin, rainy weather, biological fluids, and underwater. However, it remains challenging to achieve nonswelling and underwater self-healing hydrogel sensors for the mechanical perception in aqueous solutions. Herein, a selfhealing and non-swellable hydrogel is successfully fabricated,which presents an automatically healing behavior in various aquatic environments, including deionized water, seawater,sweat, alkali and acidic aqueous solutions. Moreover, the hydrogel demonstrates high stretchability and stable electromechanical sensing properties in water. Furthermore, an electronic skin is designed with the features of fast responsiveness, reliability, and high sensitivity for detecting breathing, speaking, coughing, and diverse body movements. The self-healing hydrogel sensors enable a brilliant mechanical sensibility for detecting a series of dynamic stimuli in air and underwater, even after the healing of fracture interface in water. The underwater self-healing and anti-swelling hydrogel would provide enticing potential on various stable electronic devices for aquatic environments, such as implantable electrodes, triboelectric nanogenerators, and underwater soft robotics.
基金supported by the University of Chinese Academy of Sciences(UCAS)and Royal Thai Government(Office of The Civil Service Commission,OCSC)Scholarship(27012552)
文摘Biological lung volume reduction (BLVR) using lung sealant has received more attention recently as a new non-surgical approach to emphysema treatment. Many tissue sealants have been studied but only a few have been proposed for BLVR. In this work, we prepared in situ forming chitosan-based hydrogels (CSG) using covalent cross-linking of chitosan and genipin in the cooperation of ionic interaction between chitosan and sodium orthophosphate hydrate (Na3PO4.12H20) and characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and rheological methods. CSG showed short gelation time (8 min), high swelling ratio (〉100 %) and non-toxicity (3T3 mouse fibroblast cell viability 〉80 %) under physiological conditions. The application of lung sealant for BLVR was tested in a Chinese dog and evaluated by chest computed tomography. After 3 weeks of the installation of CSG in bronchopulmonary segment, the gel formation was detected at a localized region of bronchi and the local atelectasis occurred. Our findings indicate that this chitosan-based hydrogel is a promising new candidate for use as a lung sealant for BLVR.
基金supported by the National Natural Science Foundation of China(Grant Nos.11304156,11334004,91127026,31170813 and 11074115)China Postdoctoral Science Foundation(Grant No.2013M531312)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Program for New Century Excellent Talents in University
文摘Hydrogels are a class of special materials that contain a large amount of water and behave like rubber.These materials have found broad applications in tissue engineering,cell culturing,regenerative medicine etc.Recently,the exploration of peptide-based supramolecular hydrogels has greatly expanded the repertoire of hydrogels suitable for biomedical applications.However,the mechanical properties of peptide-based hydrogels are intrinsically weak.Therefore,it is crucial to develop methods that can improve the mechanical stability of such peptide-based hydrogels.In this review,we explore the factors that determine or influence the mechanical stability of peptide-based hydrogels and summarize several key elements that may guide scientists to achieve mechanically improved hydrogels.In addition,we exemplified several methods that have been successfully developed to prepare hydrogels with enhanced mechanical stability.These mechanically strong peptide-based hydrogels may find broad applications as novel biomaterials.It is still challenging to engineer hydrogels in order to mimic the mechanical properties of biological tissues.More hydrogel materials with optimal mechanical properties suitable for various types of biological applications will be available in the near future.
基金supported by the National Key R&D Program of China(2021YFB3800900)the National Natural Science Foundation of China(22122501,21875014 and 52073013)Beijing Outstanding Young Scientist Program(BJJWZYJH01201910010024)。
文摘The abuse of antibiotics in treating microbial infections has led to the emergence and prevalence of drugresistant bacteria.Thus,the development of novel antibacterial materials is attracting increasing attention.Here,a series of flexible electrostatic hydrogels with excellent antibacterial ability were constructed using a mixture of nitric oxide(NO)-releasing nitrated chitosan(CSNO)and mesotetra(4-carboxyphenyl)porphine(TCPP)with salmon sperm DNA(ssDNA)solution.When cultured with gram-negative bacteria under solar simulator irradiation,TCPP-CSNO_(m)ssDNA_(n) hydrogels released reactive oxygen species(ROS)and NO to produce peroxynitrite ions(ONOO^(−)).ONOO−is efficient at killing bacteria,thereby improving the antimicrobial ability of photodynamic therapy against gram-negative bacteria.The hydrogels exhibited powerful antibacterial activity in vivo when used to treat skin infections caused by drugresistant bacteria,making them a promising candidate for clinical applications.A string of antibacterial hydrogels that release ROS and NO synergistically can bring new possibilities for effectively killing drug-resistant bacteria and be of great value in anti-infection wound dressings and other applications.