Background:Zearalenone(ZEA)is a resorcylic acid lactone derivative derived from various Fusarium species that are widely found in food and feeds.The molecular structure of ZEA resembles that of the mammalian hormone 1...Background:Zearalenone(ZEA)is a resorcylic acid lactone derivative derived from various Fusarium species that are widely found in food and feeds.The molecular structure of ZEA resembles that of the mammalian hormone 17β-oestradiol,thus zearalenone and its metabolites are known to compete with endogenous hormones for estrogen receptors binding sites and to activate transcription of oestrogen-responsive genes.However,the effect of long-term low-dose ZEA exposure on the reproductive response to Bacillus subtilis ANSB01G culture for first-parity gilts has not yet been investigated.This study was conducted to investigate the toxic effects of ZEA as an estrogen receptor selective modulator and the alleviating effects of Bacillus subtilis ANSB01G cultures as ZEA biodegraders in pregnant sows during their first parity.Results:A total of 80 first-parity gilts(Yorkshire×Landrace)were randomly assigned to four dietary treatments during gestation:CO(positive control);MO(negative control,246μg ZEA/kg diet);COA(CO+B.subtilis ANSB01G culture with 2×10^(9)CFU/kg diet);MOA(MO+B.subtilis ANSB01G culture with 2×10^(9)CFU/kg diet).There were 20 replications per treatment with one gilt per replicate.Feeding low-dose ZEA naturally contaminated diets disordered most of reproductive hormones secretion and affected estrogen receptor-αand estrogen receptor-βconcentrations in serum and specific organs and led to moderate histopathological changes of gilts,but did not cause significant detrimental effects on reproductive performance.The addition of Bacillus subtilis ANSB01G culture to the diet can effectively relieve the competence of ZEA to estrogen receptor and the disturbance of reproductive hormones secretion,and then ameliorate toxicosis of ZEA in gilts.Conclusions:Collectively,our study investigated the effects of feeding low-dose ZEA on reproduction in pregnant sows during their first parity.Feeding low-dose ZEA could modulate estrogen receptor-αand-βconcentrations in specific organs,cause disturbance of reproductive hormones and vulva swelling,and damage organ histopathology and up-regulate apoptosis in sow models.Diet with Bacillus subtilis ANSB01G alleviated negative effects of the ZEA on gilts to some extent.展开更多
Crude and used engine oil degrading ability of two white rot fungi Pleurotus ostreatus and P. pulmonarius were investigated for six months. One hundred grams of sterilized soil moistened with 75% distilled water (w/v)...Crude and used engine oil degrading ability of two white rot fungi Pleurotus ostreatus and P. pulmonarius were investigated for six months. One hundred grams of sterilized soil moistened with 75% distilled water (w/v) were weighed into 9 × 9 × 4 cm (350 cm3) jam bottles and mixed thoroughly with bonny light crude oil and used engine oil at different concentrations (0%, 5%, 10%, 15%, 25% and 30%), separately. Each bottle was then inoculated with two agar plugs of a vigorously grown mycelium of P. ostreatus and P. pulmonarius using a sterile cork borer. The bottles were incubated at room temperature for 6 months. The mycelia-ramified waste was separated from soils and analysed for physicochemical parameters such as organic matter, carbon, nitrogen, phosphorus, potassium, pH and total hydrocarbon content, (THC) after drying. The organic carbon, nitrogen and phosphorus contents in contaminated and inoculated soils were increased after six months. However, decrease in potassium, pH and THC occurred in these soils after the period of investigation. P. ostreatus reduced the initial THC to 8% and 9% in soils contaminated with 20% of crude and engine oils, respectively, which was lower than that of P. pulmonarius. The two white rot fungi could be exploited in bioremediation of soils contaminated with bonny light crude and used engine oils.展开更多
Biomedical applications necessitate natural or synthetic biomaterials that can maintain,improve,or even replace damaged tissue or a biological function,facilitating healing for people who have suffered from an injury ...Biomedical applications necessitate natural or synthetic biomaterials that can maintain,improve,or even replace damaged tissue or a biological function,facilitating healing for people who have suffered from an injury or disease.Metallic biomaterials show superior mechanical properties with greater service life than other materials.Biodegradable materials can avoid the inevitable second operation of removing the implant in the case of temporary implantation,reducing the risk of infections,medical complications,healing time,and cost.Magnesium(Mg),zinc(Zn),iron(Fe),and their alloys are potential biodegradable metallic materials.The characteristics of biodegradable metallic materials are variable and depend on many factors,such as alloying elements,microstructure,existing phases,and thermomechanical treatment.The current review emphasizes the impact of alloying element addition on the characteristics of metallic biodegradable materials,with particular attention to the relationships between alloying elements,microstructure,mechanical performance,corrosion,and biocompatibility.Mg alloys show good mechanical and corrosion properties with excellent biocompatibility.Using biocompatible alloying elements can improve Mg alloy mechanical and corrosion properties without af-fecting their biocompatibility.However,critical limitations are still maintained,like rapid degradation and gas bubble formation.Zn alloys could overcome the limitations of Mg alloys with appropriate degradation rates,ease of casting and processing,and good biocompatibility.Alloying,particularly with Mg,Li,and Cu,combined with thermomechanical treatment,can significantly affect the microstructure and mechanical performance of Zn alloys and overcome the problem of unsuitable mechanical properties.Fe alloys have excellent mechanical performance,formability,and biocompatibility with a low degradation rate.Applying surface treatment,using novel structures,alloying with the appropriate amount of alloying elements,and using advanced manufacturing techniques may present a way to solve the problems associated with biodegradable metallic materials,which could open new horizons and increase their applicability in biomedical applications.展开更多
To address the issue of residual pollution caused by polyethylene mulch,this study explored the effects of different mulching methods on the soil environment of the yam field,as well as on yam yield and quality.The ex...To address the issue of residual pollution caused by polyethylene mulch,this study explored the effects of different mulching methods on the soil environment of the yam field,as well as on yam yield and quality.The experiment comprised six treatments in total:one non-mulched treatment served as the control(CK),along with five different film-mulched treatments,namely PE,FZS12,FZS15,FC12,and FC15.The degradation of these films and their effects on soil physicochemical properties,microbial community,yam yield and quality were compared.The results showed that the FZS12 treatment achieved grade 5 degradation by the end of the planting period.Compared with PE treatment,the total soluble sugar content and yield of yam treated with FZS12 were significantly increased by 35.78%and 74.97%,respectively(p<0.05).Compared with CK and PE treatments,FZS12 significantly increased soil available nitrogen by 31.62%and 6.20%,respectively(p<0.05),and significantly increased soil available phosphorus by 8.58%and 4.45%,respectively(p<0.05).Soil pH,available nitrogen,and available phosphorus were the main environmental factors affecting the soil bacterial community.The FZS12 treatment significantly increased the relative abundances of soil bacteria phylum including Acidobacteriota,Myxococcota,Patescibacteria,and Proteobacteria compared with the CK and PE treatments.Functional prediction using Picrust2 revealed that the FZS12 treatment had significantly higher levels of signal transduction and amino acid metabolism than the CK and PE treatments.In conclusion,covering with 12μm PBAT/PLA humic acid biodegradable film enhances yam yield and total soluble sugar content by shaping beneficial soil microbial communities,activating soil nutrients.展开更多
Pretreatment of Low-Density Polyethylene(LDPE)with physicochemical methods before biodegradation has been demonstrated as an effective strategy.The pretreatment of LDPE exhibited alterations in molecular structure,red...Pretreatment of Low-Density Polyethylene(LDPE)with physicochemical methods before biodegradation has been demonstrated as an effective strategy.The pretreatment of LDPE exhibited alterations in molecular structure,reducing hydrophobicity and decreasing tensile strength.Additionally,pretreating LDPE enhanced microbial biodegradability to improve biofilm formation and significantly reduced the physical weight of LDPE film.AS3–8 consortia exhibited a maximum weight loss of 8.0%±0.5%after 45 days of incubation.While Bacillus sp.AS3 and Sphingobacterium sp.AS8 demonstrated LDPE weight loss of 5.03%±1.6%and 1.6%±0.5%,respectively.The structure of LDPE was altered after incubation with the bacterial strains,resulting in a reduction in the intensity of functional groups,including C=O,C=C,N–H,and C–N.The carbonyl index(CI)of LDPE also decreased by 7.17%after the consortia AS3–8 degradation.Consortia AS3–8 significantly impacted the physical properties of LDPE by reducing the water contact angle(WCA),decreasing to 64.21°±3.69°,and tensile strength(TS),decreasing to 17.97±0.3 MPa.Moreover,the esterase activity was measured through 45 days of incubation.SDS-PAGE analysis of the AS3–8 consortia revealed bands at 35,48,and 70 kDa molecular weights,similar to known enzymes like laccase and esterase.Furthermore,SEM observations showed rough,cracked surfaces on pretreated LDPE,with biofilms present after incubation with the bacterial strains.GC–MS analysis revealed that AS3–8 consortia produced depolymerized chemicals,including alkanes,aldehydes,and esters.The LDPE biodegradation pathway was elucidated.This study addresses critical knowledge gaps in improving plastic degradation efficiency.展开更多
This review draws attention to the innovative use of arrowroot(Maranta arundinacea)fiber as a unique and underutilized biomass source for nanocrystalline cellulose(NCC)-based nanocomposites,presenting a noteworthy alt...This review draws attention to the innovative use of arrowroot(Maranta arundinacea)fiber as a unique and underutilized biomass source for nanocrystalline cellulose(NCC)-based nanocomposites,presenting a noteworthy alternative to extensively researched materials like wood pulp,bacterial cellulose,and chemically modified NCCs.In contrast to traditional sources,arrowroot possesses a naturally elevated cellulose and diminished lignin content,facilitating more effective NCC extraction requiring reduced chemical input and enabling environmentally friendly processing techniques.The review evaluates the performance of arrowroot-derived nanocomposites against systems documented in the literature,including NCC-based shape memory composites and nanoparticle-reinforced films,demonstrating enhanced tensile strength,improved moisture barrier properties,and thermal stability,as well as potential piezoelectric response.This study recognizes arrowroot as a viable option in the biomass-based nanocellulose sector,providing ecological and functional benefits while tackling significant issues such as process scalability and feedstock variability,thereby offering important insights for the advancement of sustainable materials.展开更多
Zn-Mn alloys are regarded as promising biodegradable metals for orthopedic applications owing to their moderate degradation rates and favorable osteogenic properties.However,the presence of a substantial number of sec...Zn-Mn alloys are regarded as promising biodegradable metals for orthopedic applications owing to their moderate degradation rates and favorable osteogenic properties.However,the presence of a substantial number of second-phase particles in Zn-based alloys might induce severe localized degradation via micro-coupling corrosion,thereby compromising the mechanical integrity of the alloy during in vivo tissue regeneration.In this study,high pressure solid solution(HPSS)treatment was conducted at 5 GPa and 380℃ for 1 h to fabricate Zn-0.5 Mn alloys.Microstructural characterization revealed that the HPSS treatment facilitated the formation of a supersaturated solid solution by completely dissolving theζ-MnZn_(13) phase into theα-Zn matrix.The resultant strengthening mechanisms,including supersaturated solid solution strengthening,grain-size strengthening,and dislocation strengthening,collectively enhanced the compressive yield strength(σ_(cys))of the Zn-0.5 Mn alloy to about 183.7 MPa,approximately three times that of the as-cast(AC)Zn-0.5 Mn alloy.Moreover,compared with the AC alloy,the HPSS Zn-0.5 Mn alloy exhibited uniform degradation behavior with a markedly reduced degradation rate.展开更多
Zn's natural degradability and biocompatibility make it a promising candidate for implants,however,its mechanical properties remain insufficient for bone applications.In this study,the performance of Zn was enhanc...Zn's natural degradability and biocompatibility make it a promising candidate for implants,however,its mechanical properties remain insufficient for bone applications.In this study,the performance of Zn was enhanced by developing Zn-Cu alloys via laser powder bed fusion(LPBF).Optimal LPBF parameters for forming stable tracks were achieved by adjusting laser power and scanning speed.Under optimized conditions of 100 W and 100 mm/s,high density(99.58%)Zn-Cu alloys with improved hardness(68.2 HV)and yield strength(160 MPa)were achieved.These improvements are attributed to solid solution strengthening,segregation strengthening,and grain refinement.The Zn-Cu alloys also demonstrated favorable degradation behavior,with a rate of 0.16 mm/year.This degradation is primarily driven by micro-galvanic corrosion between the CuZn 5 phase and Zn matrix,along with refined grains and increased grain boundary density.This work demonstrates a viable strategy for fabricating Zn-based implants with enhanced structural integrity and mechanical performance via LPBF.展开更多
With the increasing accumulation of plastic pollutants in various environments,research on microorganisms(including bacteria,fungi,and algae)with plastic degradation capabilities has gained significant attention.Howev...With the increasing accumulation of plastic pollutants in various environments,research on microorganisms(including bacteria,fungi,and algae)with plastic degradation capabilities has gained significant attention.However,only a limited number of microbial plastic-degrading enzymes have been identified to date.This highlights that the degradation mechanisms employed by many plastic-degrading microorganisms,particularly filamentous fungi,remain insufficiently explored.In this study,we utilized a versatile fungal plasmid(pCT74)to express green fluorescent protein(GFP)in a marine-derived fungus Alternaria alternata strain FB1 with plastic degradation capabilities.Upon evaluating the degradation effect of polyester-type polyurethane(PU)film,we observed that different transformants exhibited three kinds of activities(the same,reduced,or enhanced degradation capability)compared to the FB1 wild-type strain.Further analysis of the plasmid fragment insertion sites in different transformants revealed that pCT74 integrates randomly into the genome of the host fungus.Notably,a direct correlation was found between the plasmid insertion site and the degradation capability of the corresponding transformant.Our findings not only redefine the potential applications of plasmid pCT74 in filamentous fungi but also show a novel research approach to identifying key enzymes involved in plastic degradation by fungi.展开更多
Poly(butylene adipate-terephthalate)(PBAT),as one of the most common and promising biodegradable plastics,has been widely used in agriculture,packaging,and other industries due to its strong biodegradability propertie...Poly(butylene adipate-terephthalate)(PBAT),as one of the most common and promising biodegradable plastics,has been widely used in agriculture,packaging,and other industries due to its strong biodegradability properties.It is well known that PBAT suffers a series of natural weathering,mechanical wear,hydrolysis,photochemical transformation,and other abiotic degradation processes before being biodegraded.Therefore,it is particularly important to understand the role of abiotic degradation in the life cycle of PBAT.Since the abiotic degradation of PBAT has not been systematically summarized,this review aims to summarize the mechanisms and main factors of the three major abiotic degradation pathways(hydrolysis,photochemical transformation,and thermochemical degradation)of PBAT.It was found that all of them preferentially destroy the chemical bonds with higher energy(especially C-O and C=O)of PBAT,which eventually leads to the shortening of the polymer chain and then leads to reduction in molecular weight.The main factors affecting these abiotic degradations are closely related to the energy or PBAT structure.These findings provide important theoretical and practical guidance for identifying effective methods for PBAT waste management and proposing advanced schemes to regulate the degradation rate of PBAT.展开更多
BACKGROUND Proximal bile duct injury(BDI),which often occurs after laparoscopic cholecystectomy(LC),can lead to complex biliary stricture and recurrent cholangitis.This case report presented a 39-year-old woman who ex...BACKGROUND Proximal bile duct injury(BDI),which often occurs after laparoscopic cholecystectomy(LC),can lead to complex biliary stricture and recurrent cholangitis.This case report presented a 39-year-old woman who experienced proximal BDI during LC in 2017,leading to multiple episodes of cholangitis and subsequent hepaticojejunostomy in 2018.Despite these interventions,persistent biliary complications necessitated repeated hospital admissions and antibiotic treatment.Imaging studies revealed persistent stricture at the site of hepaticojejunostomy,prompting a series of percutaneous procedures,including balloon dilatation and biliary drainage.In August 2024,she underwent biodegradable biliary stenting,which significantly improved her condition.Subsequently,she remained clinically stable for 5 months without further episodes of cholangitis and had improved liver function tests.This case highlighted the complexities of managing postinjury biliary stricture,underscored the potential of biodegradable stents as an effective treatment option,and emphasized the need for a multidisciplinary approach in managing such complications.Long-term follow-up is essential for monitoring treatment effectiveness and preventing recurrence.CASE SUMMARY A 39-year-old female had a routine LC in 2017.The patient sustained a proximal BDI during the surgery.In the months that followed,recurrent bouts of cholangitis occurred.A hepaticojejunostomy biliary reconstruction was performed in 2018.However,hepatic cholangitis persisted.In 2021 and 2022,MRCP scans revealed biliary stasis,duct dilation,and a stricture at the hepaticojejunostomy site.A subsequent percutaneous transhepatic cholangiography(PTC)confirmed these findings and led to drain placement.The treatment included internal and external biliary drain placements,repeated balloon dilations of the stricture,percutaneous transhepatic cholangioscopy to extract intrahepatic lithiasis,and insertion of a biodegradable biliary stent.Since the first PTC intervention,there have been no hospital admissions for cholangitis.Liver function tests showed improvement,and for five months following the biodegradable stenting,the condition remained stable.Long-term surveillance with regular imaging and blood work has been emphasized.The final diagnosis is recurrent biliary stricture secondary to proximal BDI.Treatment,including hepaticojejunostomy,repeated PTC with balloon dilation,and biodegradable biliary stenting,has led to complete drainage of the biliary system.Ongoing follow-up remains crucial for monitoring the patient's progress and maintaining their health.CONCLUSION This case demonstrated how strictures and recurrent cholangitis complicate the management of BDI after LC.A customized and multidisciplinary approach to control chronic biliary disease was proven effective,as shown by the patient’s good outcome.This was achieved by integrating balloon dilatation sessions,biliary drainage,stone clearing,and biodegradable stent placement.Long-term follow-up and continued monitoring remain essential to ensure patient stability and prevent further complications.展开更多
Oxytetracycline(OTC)is used extensively in animal husbandry and enters the soil in different forms,causing severe environmental pollution.Previous studies have shown that the genus Pseudomonas can potentially degrade ...Oxytetracycline(OTC)is used extensively in animal husbandry and enters the soil in different forms,causing severe environmental pollution.Previous studies have shown that the genus Pseudomonas can potentially degrade antibiotics in the soil environment.Environmental conditions,such as the initial concentration of antibiotics,incubation temperature and others,have significant impacts on the activity of antibiotic-degrading bacteria.However,few reports have clarified the environmental impacts on the effectiveness of Pseudomonas spp.In the present study,we investigated the effects of different initial concentrations of OTC and incubation temperatures,as well as soil sterilization,on OTC degradation by Pseudomonas strain T4.We also focused on the microbial degradation pathways of OTC,and variations in both antibiotic resistance genes(ARGs)and microbial communities with T4 functioning under optimal conditions.The results showed that the most effective degradation occurred under an initial OTC concentration of 2.5 mg kg^(-1)at 30℃in unsterilized soil spiked with T4.These conditions yielded an OTC degradation rate of 69.53%within 63 days.The putative degradation pathways of OTC in the presence of T4 included dehydration,demethylation,deamination,hydroxylation,oxidation and ring opening.Bacteroidetes,Proteobacteria and Acidobacteria played key roles in the biodegradation of OTC with T4 in the soil.The results also showed that tet(G)was the most frequently detected ARGs among the 13 common tetracycline ARGs that were investigated.The bacterial community shift observed in this study may provide new insights into the microbial degradation of OTC in soil.展开更多
Amid the escalating plastic pollution issue, the development of biodegradable and recyclable polymeric materials has become a focus within the scientific community. Chain extenders, which are an important class of com...Amid the escalating plastic pollution issue, the development of biodegradable and recyclable polymeric materials has become a focus within the scientific community. Chain extenders, which are an important class of compounds, facilitate the elongation of polymer chains through reactive functional groups, thereby enhancing the performance of the materials. Epoxy-based chain extenders, due to their cost-effectiveness, low toxicity, high reaction efficiency, and effective reactivity with hydroxyl and carboxyl groups, have emerged as a promising class of chain extenders. This manuscript comprehensively elaborates on the varieties, structural characteristics, and performance of chain extenders, the challenges they face, and the methods for their modification. Special emphasis is placed on the application of epoxy-based chain extenders in biodegradable polymers, such as polylactic acid (PLA), and their subsequent influence on the structural and performance properties of these materials.展开更多
The organic compound composition ofwastewater,serves as a crucial indicator for the operational performance of activated sludge processes and has a major influence on the development of filamentous bulking in activate...The organic compound composition ofwastewater,serves as a crucial indicator for the operational performance of activated sludge processes and has a major influence on the development of filamentous bulking in activated sludge.This study focused on the impact of typical soluble and slowly-biodegradable organic compounds,investigating the pathways through which these substrates affect the occurrence of filamentous bulking in systems operated under both high-and low-oxygen conditions.Results showed that slowly-biodegradable organic compounds lead to a concentrated distribution of microorganisms within flocs,with inward growth of filamentous bacteria.Both Tween-80 and granular starch treated systems exhibited a significant increase in protein content.The glucose system,utilizing soluble substrates,exhibited a markedly higher total polysaccharide content.Microbial communities in the Tween-80 and granular starch treated systems were characterized by a higher abundance of bacteria known to enhance sludge flocculation and settling,such as Competibacter,Xanthomonadaceae and Zoogloea.These findings are of high significance for controlling the operational performance and stability of activated sludge systems,deepening our understanding and providing a novel perspective for the improvement of wastewater treatment processes.展开更多
Benzo[a]pyrene(B[a]P)is a carcinogenic environmental pollutant widely present in the environment and can enter the human body through the food chain.It is therefore essential to treat and remediate the B[a]P-contamina...Benzo[a]pyrene(B[a]P)is a carcinogenic environmental pollutant widely present in the environment and can enter the human body through the food chain.It is therefore essential to treat and remediate the B[a]P-contaminated environment.Microbial remediation of B[a]Pcontaminated environments is considered to be one of the most effective strategies,and the addition of biostimulants is a feasible method to further improve the effectiveness of microbial remediation.In this study,we used Bacillus subtilis MSC4 to screen for the stimulation of sodium gluconate,which promoted B[a]P degradation.Based on biochemical and transcriptomic analyses,Sodium gluconate was found to significantly increase the biomass of MSC4 and the expression of most genes involved in B[a]P degradation.Activities of central carbon metabolism,fatty acidβ-oxidation and oxidative phosphorylation were all promoted.The significant increase in acid-induced oxalate decarboxylase expression indicates a decrease in intracellular pH,which promoted the synthesis of acetoin and lactate.Genes involved in the nitrogen cycle,especially nitrification and denitrification,were significantly up-regulated,contributing to B[a]P degradation.Genes involved in the synthesis of enzyme cofactors,including thiamine,molybdenum cofactors,NAD and heme,were up-regulated,which contributes to increasing enzyme activity in metabolic pathways.Up-regulation of genes in flagella assembly,chemotaxis,and lipopeptide synthesis is beneficial for the dissolution and uptake of B[a]P.Genes related to the sugar transport system were upregulated,which facilitates the transport and absorption of monosaccharides and oligosaccharides by MSC4.This study provides a theoretical basis for the further application of sodium gluconate in the treatment of PAH-contaminated sites.展开更多
In the realm of biomedical materials,biomedical magnesium(Mg)alloy materials are progressively emerging as a highly salient research focal point,capitalizing on their distinctive advantages.Mg,as a unique metallic ele...In the realm of biomedical materials,biomedical magnesium(Mg)alloy materials are progressively emerging as a highly salient research focal point,capitalizing on their distinctive advantages.Mg,as a unique metallic element,by virtue of its specific properties,has ushered in novel development opportunities for the biomedical domain[1-3].Firstly,Mg manifests outstanding biodegradability.展开更多
Zinc-based alloys are promising biodegradable materials for application in the intestinal environment due to their appropriate degradation rates and favorable biocompatibility.However,the corrosion and degradation of ...Zinc-based alloys are promising biodegradable materials for application in the intestinal environment due to their appropriate degradation rates and favorable biocompatibility.However,the corrosion and degradation of biodegradable zinc alloys in the presence of intestinal microorganisms are seldom investigated.In this study,binary Zn-Mn alloys with 0.4 and 0.8 wt.%Mn content were fabricated using the extrusion process.The corrosion behaviors of pure zinc and Zn-Mn alloys with the existence of Lactobacillus acidophilus,a representative microorganism in the intestinal tract,were systematically investigated.In comparison to pure zinc,both Zn-Mn alloys exhibited enhanced strength and ductility.L.acidophilus significantly accelerated the corrosion of both pure zinc and Zn-Mn alloys by generating acidic agents.The presence of L.acidophilus increased the icorr values for pure zinc,Zn-0.4Mn,and Zn-0.8Mn from 68.7±9.9,33.9±2.3 and 17.1±0.1µA cm^(-2) to 253.5±26.7,167.6±8.7 and 30.6±2.2µA cm^(-2),respectively.The addition of Mn mitigated corrosion by refining grains and reducing the local surface potential difference.Compared to pure zinc,the surface potential difference of Zn-0.8Mn decreased from 31.8±1.7 mV to 11.8±0.9 mV.This study points out the existence of microbiologically influenced corrosion in the intestinal environment and emphasizes its importance in the comprehensive design of biodegradable zinc alloys.展开更多
Axonal regeneration following surgical nerve repair is slow and often incomplete,resulting in poor functional recovery which sometimes contributes to lifelong disability.Currently,there are no FDA-approved therapies a...Axonal regeneration following surgical nerve repair is slow and often incomplete,resulting in poor functional recovery which sometimes contributes to lifelong disability.Currently,there are no FDA-approved therapies available to promote nerve regeneration.Tacrolimus accelerates axonal regeneration,but systemic side effects presently outweigh its potential benefits for peripheral nerve surgery.The authors describe herein a biodegradable polyurethane-based drug delivery system for the sustained local release of tacrolimus at the nerve repair site,with suitable properties for scalable production and clinical application,aiming to promote nerve regeneration and functional recovery with minimal systemic drug exposure.Tacrolimus is encapsulated into co-axially electrospun polycarbonate-urethane nanofibers to generate an implantable nerve wrap that releases therapeutic doses of bioactive tacrolimus over 31 days.Size and drug loading are adjustable for applications in small and large caliber nerves,and the wrap degrades within 120 days into biocompatible byproducts.Tacrolimus released from the nerve wrap promotes axon elongation in vitro and accelerates nerve regeneration and functional recovery in preclinical nerve repair models while off-target systemic drug exposure is reduced by 80%compared with systemic delivery.Given its surgical suitability and preclinical efficacy and safety,this system may provide a readily translatable approach to support axonal regeneration and recovery in patients undergoing nerve surgery.展开更多
In this study,composite films consisting of polylactic acid(PLA),ethyl cellulose(EC),and zein were prepared by solution casting method,and their performance and application in chilled fresh meat preservation were inve...In this study,composite films consisting of polylactic acid(PLA),ethyl cellulose(EC),and zein were prepared by solution casting method,and their performance and application in chilled fresh meat preservation were investigated.The results showed that the three materials had satisfactory compatibility in the composite film.Addition of EC and zein effectively improved the mechanical properties,thermodynamic properties,surface hydrophilicity,oxygen permeability,and degradation properties of PLA films.When the ratio of PLA to EC was 3:7,the tensile strength and elongation at break reached maximum values of 16.6 MPa and 30.5%,respectively.Moreover,under different conditions,the composite film exhibited better degradability than the PLA film.The composite film with a 3:7 ratio of PLA to EC had the best performance,with a degradation rate of 21.75%after 84 days.Chilled fresh meat wrapped with the composite film showed significantly improved antioxidant,antibacterial,and water-holding properties.展开更多
A type of novel biodegradable fibers,made from magnetic particles and the patient’s own blood,promises an immune-evading brain cancer therapy with minimal invasion.
基金supported by National Natural Science Foundation of China(Grant No. 31772637, 31301981)a Special Fund for Agro-scientific Research in the Public Interest (201403047)
文摘Background:Zearalenone(ZEA)is a resorcylic acid lactone derivative derived from various Fusarium species that are widely found in food and feeds.The molecular structure of ZEA resembles that of the mammalian hormone 17β-oestradiol,thus zearalenone and its metabolites are known to compete with endogenous hormones for estrogen receptors binding sites and to activate transcription of oestrogen-responsive genes.However,the effect of long-term low-dose ZEA exposure on the reproductive response to Bacillus subtilis ANSB01G culture for first-parity gilts has not yet been investigated.This study was conducted to investigate the toxic effects of ZEA as an estrogen receptor selective modulator and the alleviating effects of Bacillus subtilis ANSB01G cultures as ZEA biodegraders in pregnant sows during their first parity.Results:A total of 80 first-parity gilts(Yorkshire×Landrace)were randomly assigned to four dietary treatments during gestation:CO(positive control);MO(negative control,246μg ZEA/kg diet);COA(CO+B.subtilis ANSB01G culture with 2×10^(9)CFU/kg diet);MOA(MO+B.subtilis ANSB01G culture with 2×10^(9)CFU/kg diet).There were 20 replications per treatment with one gilt per replicate.Feeding low-dose ZEA naturally contaminated diets disordered most of reproductive hormones secretion and affected estrogen receptor-αand estrogen receptor-βconcentrations in serum and specific organs and led to moderate histopathological changes of gilts,but did not cause significant detrimental effects on reproductive performance.The addition of Bacillus subtilis ANSB01G culture to the diet can effectively relieve the competence of ZEA to estrogen receptor and the disturbance of reproductive hormones secretion,and then ameliorate toxicosis of ZEA in gilts.Conclusions:Collectively,our study investigated the effects of feeding low-dose ZEA on reproduction in pregnant sows during their first parity.Feeding low-dose ZEA could modulate estrogen receptor-αand-βconcentrations in specific organs,cause disturbance of reproductive hormones and vulva swelling,and damage organ histopathology and up-regulate apoptosis in sow models.Diet with Bacillus subtilis ANSB01G alleviated negative effects of the ZEA on gilts to some extent.
文摘Crude and used engine oil degrading ability of two white rot fungi Pleurotus ostreatus and P. pulmonarius were investigated for six months. One hundred grams of sterilized soil moistened with 75% distilled water (w/v) were weighed into 9 × 9 × 4 cm (350 cm3) jam bottles and mixed thoroughly with bonny light crude oil and used engine oil at different concentrations (0%, 5%, 10%, 15%, 25% and 30%), separately. Each bottle was then inoculated with two agar plugs of a vigorously grown mycelium of P. ostreatus and P. pulmonarius using a sterile cork borer. The bottles were incubated at room temperature for 6 months. The mycelia-ramified waste was separated from soils and analysed for physicochemical parameters such as organic matter, carbon, nitrogen, phosphorus, potassium, pH and total hydrocarbon content, (THC) after drying. The organic carbon, nitrogen and phosphorus contents in contaminated and inoculated soils were increased after six months. However, decrease in potassium, pH and THC occurred in these soils after the period of investigation. P. ostreatus reduced the initial THC to 8% and 9% in soils contaminated with 20% of crude and engine oils, respectively, which was lower than that of P. pulmonarius. The two white rot fungi could be exploited in bioremediation of soils contaminated with bonny light crude and used engine oils.
文摘Biomedical applications necessitate natural or synthetic biomaterials that can maintain,improve,or even replace damaged tissue or a biological function,facilitating healing for people who have suffered from an injury or disease.Metallic biomaterials show superior mechanical properties with greater service life than other materials.Biodegradable materials can avoid the inevitable second operation of removing the implant in the case of temporary implantation,reducing the risk of infections,medical complications,healing time,and cost.Magnesium(Mg),zinc(Zn),iron(Fe),and their alloys are potential biodegradable metallic materials.The characteristics of biodegradable metallic materials are variable and depend on many factors,such as alloying elements,microstructure,existing phases,and thermomechanical treatment.The current review emphasizes the impact of alloying element addition on the characteristics of metallic biodegradable materials,with particular attention to the relationships between alloying elements,microstructure,mechanical performance,corrosion,and biocompatibility.Mg alloys show good mechanical and corrosion properties with excellent biocompatibility.Using biocompatible alloying elements can improve Mg alloy mechanical and corrosion properties without af-fecting their biocompatibility.However,critical limitations are still maintained,like rapid degradation and gas bubble formation.Zn alloys could overcome the limitations of Mg alloys with appropriate degradation rates,ease of casting and processing,and good biocompatibility.Alloying,particularly with Mg,Li,and Cu,combined with thermomechanical treatment,can significantly affect the microstructure and mechanical performance of Zn alloys and overcome the problem of unsuitable mechanical properties.Fe alloys have excellent mechanical performance,formability,and biocompatibility with a low degradation rate.Applying surface treatment,using novel structures,alloying with the appropriate amount of alloying elements,and using advanced manufacturing techniques may present a way to solve the problems associated with biodegradable metallic materials,which could open new horizons and increase their applicability in biomedical applications.
基金supported by the Wencheng County Science and Technology Plan Project(2023NKY03)Earmarked Fund for Modern Agro-industry Technology Research System(Grant Number CARS-24-B04,CARS-23-B05)Additional support was provided by Key Laboratory of Biology and Genetic Improvement of Horticultural Crops(Vegetables),Ministry of Agriculture and Rural Affairs,China.
文摘To address the issue of residual pollution caused by polyethylene mulch,this study explored the effects of different mulching methods on the soil environment of the yam field,as well as on yam yield and quality.The experiment comprised six treatments in total:one non-mulched treatment served as the control(CK),along with five different film-mulched treatments,namely PE,FZS12,FZS15,FC12,and FC15.The degradation of these films and their effects on soil physicochemical properties,microbial community,yam yield and quality were compared.The results showed that the FZS12 treatment achieved grade 5 degradation by the end of the planting period.Compared with PE treatment,the total soluble sugar content and yield of yam treated with FZS12 were significantly increased by 35.78%and 74.97%,respectively(p<0.05).Compared with CK and PE treatments,FZS12 significantly increased soil available nitrogen by 31.62%and 6.20%,respectively(p<0.05),and significantly increased soil available phosphorus by 8.58%and 4.45%,respectively(p<0.05).Soil pH,available nitrogen,and available phosphorus were the main environmental factors affecting the soil bacterial community.The FZS12 treatment significantly increased the relative abundances of soil bacteria phylum including Acidobacteriota,Myxococcota,Patescibacteria,and Proteobacteria compared with the CK and PE treatments.Functional prediction using Picrust2 revealed that the FZS12 treatment had significantly higher levels of signal transduction and amino acid metabolism than the CK and PE treatments.In conclusion,covering with 12μm PBAT/PLA humic acid biodegradable film enhances yam yield and total soluble sugar content by shaping beneficial soil microbial communities,activating soil nutrients.
文摘Pretreatment of Low-Density Polyethylene(LDPE)with physicochemical methods before biodegradation has been demonstrated as an effective strategy.The pretreatment of LDPE exhibited alterations in molecular structure,reducing hydrophobicity and decreasing tensile strength.Additionally,pretreating LDPE enhanced microbial biodegradability to improve biofilm formation and significantly reduced the physical weight of LDPE film.AS3–8 consortia exhibited a maximum weight loss of 8.0%±0.5%after 45 days of incubation.While Bacillus sp.AS3 and Sphingobacterium sp.AS8 demonstrated LDPE weight loss of 5.03%±1.6%and 1.6%±0.5%,respectively.The structure of LDPE was altered after incubation with the bacterial strains,resulting in a reduction in the intensity of functional groups,including C=O,C=C,N–H,and C–N.The carbonyl index(CI)of LDPE also decreased by 7.17%after the consortia AS3–8 degradation.Consortia AS3–8 significantly impacted the physical properties of LDPE by reducing the water contact angle(WCA),decreasing to 64.21°±3.69°,and tensile strength(TS),decreasing to 17.97±0.3 MPa.Moreover,the esterase activity was measured through 45 days of incubation.SDS-PAGE analysis of the AS3–8 consortia revealed bands at 35,48,and 70 kDa molecular weights,similar to known enzymes like laccase and esterase.Furthermore,SEM observations showed rough,cracked surfaces on pretreated LDPE,with biofilms present after incubation with the bacterial strains.GC–MS analysis revealed that AS3–8 consortia produced depolymerized chemicals,including alkanes,aldehydes,and esters.The LDPE biodegradation pathway was elucidated.This study addresses critical knowledge gaps in improving plastic degradation efficiency.
基金the financial support provided by Universiti Putra Malaysiasupported by the Matching Grant(9300489).
文摘This review draws attention to the innovative use of arrowroot(Maranta arundinacea)fiber as a unique and underutilized biomass source for nanocrystalline cellulose(NCC)-based nanocomposites,presenting a noteworthy alternative to extensively researched materials like wood pulp,bacterial cellulose,and chemically modified NCCs.In contrast to traditional sources,arrowroot possesses a naturally elevated cellulose and diminished lignin content,facilitating more effective NCC extraction requiring reduced chemical input and enabling environmentally friendly processing techniques.The review evaluates the performance of arrowroot-derived nanocomposites against systems documented in the literature,including NCC-based shape memory composites and nanoparticle-reinforced films,demonstrating enhanced tensile strength,improved moisture barrier properties,and thermal stability,as well as potential piezoelectric response.This study recognizes arrowroot as a viable option in the biomass-based nanocellulose sector,providing ecological and functional benefits while tackling significant issues such as process scalability and feedstock variability,thereby offering important insights for the advancement of sustainable materials.
基金Project(52401064)supported by the National Natural Science Foundation of ChinaProject(24B0172)supported by the Scientific Research Fund of Hunan Provincial Education Department,ChinaProject(XDCX2024Y273)supported by the Postgraduate Scientific Research Innovation Project of Xiangtan University,China。
文摘Zn-Mn alloys are regarded as promising biodegradable metals for orthopedic applications owing to their moderate degradation rates and favorable osteogenic properties.However,the presence of a substantial number of second-phase particles in Zn-based alloys might induce severe localized degradation via micro-coupling corrosion,thereby compromising the mechanical integrity of the alloy during in vivo tissue regeneration.In this study,high pressure solid solution(HPSS)treatment was conducted at 5 GPa and 380℃ for 1 h to fabricate Zn-0.5 Mn alloys.Microstructural characterization revealed that the HPSS treatment facilitated the formation of a supersaturated solid solution by completely dissolving theζ-MnZn_(13) phase into theα-Zn matrix.The resultant strengthening mechanisms,including supersaturated solid solution strengthening,grain-size strengthening,and dislocation strengthening,collectively enhanced the compressive yield strength(σ_(cys))of the Zn-0.5 Mn alloy to about 183.7 MPa,approximately three times that of the as-cast(AC)Zn-0.5 Mn alloy.Moreover,compared with the AC alloy,the HPSS Zn-0.5 Mn alloy exhibited uniform degradation behavior with a markedly reduced degradation rate.
基金Projects(52571276,52275395,U24A20120,52475362)supported by the National Natural Science Foundation of ChinaProject(2025JJ30015)supported by the Hunan Provincial Natural Science Foundation,China+3 种基金Project(2023RC3046)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProject(2023YFB4605800)supported by National Key Research and Development Program of ChinaProject(2023CXQD023)supported by the Central South University Innovation-Driven Research Programme,ChinaProject supported by the State Key Laboratory of Precision Manufacturing for Extreme Service Performance,Central South University,China。
文摘Zn's natural degradability and biocompatibility make it a promising candidate for implants,however,its mechanical properties remain insufficient for bone applications.In this study,the performance of Zn was enhanced by developing Zn-Cu alloys via laser powder bed fusion(LPBF).Optimal LPBF parameters for forming stable tracks were achieved by adjusting laser power and scanning speed.Under optimized conditions of 100 W and 100 mm/s,high density(99.58%)Zn-Cu alloys with improved hardness(68.2 HV)and yield strength(160 MPa)were achieved.These improvements are attributed to solid solution strengthening,segregation strengthening,and grain refinement.The Zn-Cu alloys also demonstrated favorable degradation behavior,with a rate of 0.16 mm/year.This degradation is primarily driven by micro-galvanic corrosion between the CuZn 5 phase and Zn matrix,along with refined grains and increased grain boundary density.This work demonstrates a viable strategy for fabricating Zn-based implants with enhanced structural integrity and mechanical performance via LPBF.
基金Supported by the Science and Technology Innovation Project of Laoshan Laboratory(Nos.2022QNLM030004-3,LSKJ202203103)the NSFC Innovative Group Grant(No.42221005)+5 种基金the Key Collaborative Research Program of the Alliance of International Science Organizations(No.ANSO-CR-KP-2022-08)the Shandong Provincial Natural Science Foundation(No.ZR2021ZD28)the Major Research Plan of the National Natural Science Foundation(No.92351301)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA22050301)the Taishan Scholars Program(No.tstp20230637)the Qingdao Natural Science Foundation(No.23-2-1-182-zyyd-jch)。
文摘With the increasing accumulation of plastic pollutants in various environments,research on microorganisms(including bacteria,fungi,and algae)with plastic degradation capabilities has gained significant attention.However,only a limited number of microbial plastic-degrading enzymes have been identified to date.This highlights that the degradation mechanisms employed by many plastic-degrading microorganisms,particularly filamentous fungi,remain insufficiently explored.In this study,we utilized a versatile fungal plasmid(pCT74)to express green fluorescent protein(GFP)in a marine-derived fungus Alternaria alternata strain FB1 with plastic degradation capabilities.Upon evaluating the degradation effect of polyester-type polyurethane(PU)film,we observed that different transformants exhibited three kinds of activities(the same,reduced,or enhanced degradation capability)compared to the FB1 wild-type strain.Further analysis of the plasmid fragment insertion sites in different transformants revealed that pCT74 integrates randomly into the genome of the host fungus.Notably,a direct correlation was found between the plasmid insertion site and the degradation capability of the corresponding transformant.Our findings not only redefine the potential applications of plasmid pCT74 in filamentous fungi but also show a novel research approach to identifying key enzymes involved in plastic degradation by fungi.
基金supported by the National Key R&D Program of China(No.2022YFC3901800)the National Natural Science Foundation of China(No.22176041)Guangzhou Science and Technology Planning Project(No.2023A04J0918)。
文摘Poly(butylene adipate-terephthalate)(PBAT),as one of the most common and promising biodegradable plastics,has been widely used in agriculture,packaging,and other industries due to its strong biodegradability properties.It is well known that PBAT suffers a series of natural weathering,mechanical wear,hydrolysis,photochemical transformation,and other abiotic degradation processes before being biodegraded.Therefore,it is particularly important to understand the role of abiotic degradation in the life cycle of PBAT.Since the abiotic degradation of PBAT has not been systematically summarized,this review aims to summarize the mechanisms and main factors of the three major abiotic degradation pathways(hydrolysis,photochemical transformation,and thermochemical degradation)of PBAT.It was found that all of them preferentially destroy the chemical bonds with higher energy(especially C-O and C=O)of PBAT,which eventually leads to the shortening of the polymer chain and then leads to reduction in molecular weight.The main factors affecting these abiotic degradations are closely related to the energy or PBAT structure.These findings provide important theoretical and practical guidance for identifying effective methods for PBAT waste management and proposing advanced schemes to regulate the degradation rate of PBAT.
文摘BACKGROUND Proximal bile duct injury(BDI),which often occurs after laparoscopic cholecystectomy(LC),can lead to complex biliary stricture and recurrent cholangitis.This case report presented a 39-year-old woman who experienced proximal BDI during LC in 2017,leading to multiple episodes of cholangitis and subsequent hepaticojejunostomy in 2018.Despite these interventions,persistent biliary complications necessitated repeated hospital admissions and antibiotic treatment.Imaging studies revealed persistent stricture at the site of hepaticojejunostomy,prompting a series of percutaneous procedures,including balloon dilatation and biliary drainage.In August 2024,she underwent biodegradable biliary stenting,which significantly improved her condition.Subsequently,she remained clinically stable for 5 months without further episodes of cholangitis and had improved liver function tests.This case highlighted the complexities of managing postinjury biliary stricture,underscored the potential of biodegradable stents as an effective treatment option,and emphasized the need for a multidisciplinary approach in managing such complications.Long-term follow-up is essential for monitoring treatment effectiveness and preventing recurrence.CASE SUMMARY A 39-year-old female had a routine LC in 2017.The patient sustained a proximal BDI during the surgery.In the months that followed,recurrent bouts of cholangitis occurred.A hepaticojejunostomy biliary reconstruction was performed in 2018.However,hepatic cholangitis persisted.In 2021 and 2022,MRCP scans revealed biliary stasis,duct dilation,and a stricture at the hepaticojejunostomy site.A subsequent percutaneous transhepatic cholangiography(PTC)confirmed these findings and led to drain placement.The treatment included internal and external biliary drain placements,repeated balloon dilations of the stricture,percutaneous transhepatic cholangioscopy to extract intrahepatic lithiasis,and insertion of a biodegradable biliary stent.Since the first PTC intervention,there have been no hospital admissions for cholangitis.Liver function tests showed improvement,and for five months following the biodegradable stenting,the condition remained stable.Long-term surveillance with regular imaging and blood work has been emphasized.The final diagnosis is recurrent biliary stricture secondary to proximal BDI.Treatment,including hepaticojejunostomy,repeated PTC with balloon dilation,and biodegradable biliary stenting,has led to complete drainage of the biliary system.Ongoing follow-up remains crucial for monitoring the patient's progress and maintaining their health.CONCLUSION This case demonstrated how strictures and recurrent cholangitis complicate the management of BDI after LC.A customized and multidisciplinary approach to control chronic biliary disease was proven effective,as shown by the patient’s good outcome.This was achieved by integrating balloon dilatation sessions,biliary drainage,stone clearing,and biodegradable stent placement.Long-term follow-up and continued monitoring remain essential to ensure patient stability and prevent further complications.
基金funded by the earmarked fund for China Agriculture Research System(CARS-29-zp-10)。
文摘Oxytetracycline(OTC)is used extensively in animal husbandry and enters the soil in different forms,causing severe environmental pollution.Previous studies have shown that the genus Pseudomonas can potentially degrade antibiotics in the soil environment.Environmental conditions,such as the initial concentration of antibiotics,incubation temperature and others,have significant impacts on the activity of antibiotic-degrading bacteria.However,few reports have clarified the environmental impacts on the effectiveness of Pseudomonas spp.In the present study,we investigated the effects of different initial concentrations of OTC and incubation temperatures,as well as soil sterilization,on OTC degradation by Pseudomonas strain T4.We also focused on the microbial degradation pathways of OTC,and variations in both antibiotic resistance genes(ARGs)and microbial communities with T4 functioning under optimal conditions.The results showed that the most effective degradation occurred under an initial OTC concentration of 2.5 mg kg^(-1)at 30℃in unsterilized soil spiked with T4.These conditions yielded an OTC degradation rate of 69.53%within 63 days.The putative degradation pathways of OTC in the presence of T4 included dehydration,demethylation,deamination,hydroxylation,oxidation and ring opening.Bacteroidetes,Proteobacteria and Acidobacteria played key roles in the biodegradation of OTC with T4 in the soil.The results also showed that tet(G)was the most frequently detected ARGs among the 13 common tetracycline ARGs that were investigated.The bacterial community shift observed in this study may provide new insights into the microbial degradation of OTC in soil.
文摘Amid the escalating plastic pollution issue, the development of biodegradable and recyclable polymeric materials has become a focus within the scientific community. Chain extenders, which are an important class of compounds, facilitate the elongation of polymer chains through reactive functional groups, thereby enhancing the performance of the materials. Epoxy-based chain extenders, due to their cost-effectiveness, low toxicity, high reaction efficiency, and effective reactivity with hydroxyl and carboxyl groups, have emerged as a promising class of chain extenders. This manuscript comprehensively elaborates on the varieties, structural characteristics, and performance of chain extenders, the challenges they face, and the methods for their modification. Special emphasis is placed on the application of epoxy-based chain extenders in biodegradable polymers, such as polylactic acid (PLA), and their subsequent influence on the structural and performance properties of these materials.
基金supported by the Opening Project of National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology,and the National Natural Science Foundation of China(No.52270017).
文摘The organic compound composition ofwastewater,serves as a crucial indicator for the operational performance of activated sludge processes and has a major influence on the development of filamentous bulking in activated sludge.This study focused on the impact of typical soluble and slowly-biodegradable organic compounds,investigating the pathways through which these substrates affect the occurrence of filamentous bulking in systems operated under both high-and low-oxygen conditions.Results showed that slowly-biodegradable organic compounds lead to a concentrated distribution of microorganisms within flocs,with inward growth of filamentous bacteria.Both Tween-80 and granular starch treated systems exhibited a significant increase in protein content.The glucose system,utilizing soluble substrates,exhibited a markedly higher total polysaccharide content.Microbial communities in the Tween-80 and granular starch treated systems were characterized by a higher abundance of bacteria known to enhance sludge flocculation and settling,such as Competibacter,Xanthomonadaceae and Zoogloea.These findings are of high significance for controlling the operational performance and stability of activated sludge systems,deepening our understanding and providing a novel perspective for the improvement of wastewater treatment processes.
基金supported by the National Key R&D Program of China(No.2020YFC1808803).
文摘Benzo[a]pyrene(B[a]P)is a carcinogenic environmental pollutant widely present in the environment and can enter the human body through the food chain.It is therefore essential to treat and remediate the B[a]P-contaminated environment.Microbial remediation of B[a]Pcontaminated environments is considered to be one of the most effective strategies,and the addition of biostimulants is a feasible method to further improve the effectiveness of microbial remediation.In this study,we used Bacillus subtilis MSC4 to screen for the stimulation of sodium gluconate,which promoted B[a]P degradation.Based on biochemical and transcriptomic analyses,Sodium gluconate was found to significantly increase the biomass of MSC4 and the expression of most genes involved in B[a]P degradation.Activities of central carbon metabolism,fatty acidβ-oxidation and oxidative phosphorylation were all promoted.The significant increase in acid-induced oxalate decarboxylase expression indicates a decrease in intracellular pH,which promoted the synthesis of acetoin and lactate.Genes involved in the nitrogen cycle,especially nitrification and denitrification,were significantly up-regulated,contributing to B[a]P degradation.Genes involved in the synthesis of enzyme cofactors,including thiamine,molybdenum cofactors,NAD and heme,were up-regulated,which contributes to increasing enzyme activity in metabolic pathways.Up-regulation of genes in flagella assembly,chemotaxis,and lipopeptide synthesis is beneficial for the dissolution and uptake of B[a]P.Genes related to the sugar transport system were upregulated,which facilitates the transport and absorption of monosaccharides and oligosaccharides by MSC4.This study provides a theoretical basis for the further application of sodium gluconate in the treatment of PAH-contaminated sites.
文摘In the realm of biomedical materials,biomedical magnesium(Mg)alloy materials are progressively emerging as a highly salient research focal point,capitalizing on their distinctive advantages.Mg,as a unique metallic element,by virtue of its specific properties,has ushered in novel development opportunities for the biomedical domain[1-3].Firstly,Mg manifests outstanding biodegradability.
基金financially supported by the National Natural Science Foundation of China(No.52231010).
文摘Zinc-based alloys are promising biodegradable materials for application in the intestinal environment due to their appropriate degradation rates and favorable biocompatibility.However,the corrosion and degradation of biodegradable zinc alloys in the presence of intestinal microorganisms are seldom investigated.In this study,binary Zn-Mn alloys with 0.4 and 0.8 wt.%Mn content were fabricated using the extrusion process.The corrosion behaviors of pure zinc and Zn-Mn alloys with the existence of Lactobacillus acidophilus,a representative microorganism in the intestinal tract,were systematically investigated.In comparison to pure zinc,both Zn-Mn alloys exhibited enhanced strength and ductility.L.acidophilus significantly accelerated the corrosion of both pure zinc and Zn-Mn alloys by generating acidic agents.The presence of L.acidophilus increased the icorr values for pure zinc,Zn-0.4Mn,and Zn-0.8Mn from 68.7±9.9,33.9±2.3 and 17.1±0.1µA cm^(-2) to 253.5±26.7,167.6±8.7 and 30.6±2.2µA cm^(-2),respectively.The addition of Mn mitigated corrosion by refining grains and reducing the local surface potential difference.Compared to pure zinc,the surface potential difference of Zn-0.8Mn decreased from 31.8±1.7 mV to 11.8±0.9 mV.This study points out the existence of microbiologically influenced corrosion in the intestinal environment and emphasizes its importance in the comprehensive design of biodegradable zinc alloys.
基金supported by the German Research Foundation(DA 2255/1-1to SCD)+4 种基金a SickKids Research Training Competition(RESTRACOMP)Graduate Scholarship(to KJWS)an Ontario Graduate Scholarship(to KJWS)a grant from Natural Sciences and Engineering Research Council of Canada(NSERC)(to KJWS)a Kickstarter grant from the Institute of Biomedical Engineering(BME)at the University of Toronto(to KJWS)the Abe Frank Fund from the Riley’s Children Foundation(GHB)。
文摘Axonal regeneration following surgical nerve repair is slow and often incomplete,resulting in poor functional recovery which sometimes contributes to lifelong disability.Currently,there are no FDA-approved therapies available to promote nerve regeneration.Tacrolimus accelerates axonal regeneration,but systemic side effects presently outweigh its potential benefits for peripheral nerve surgery.The authors describe herein a biodegradable polyurethane-based drug delivery system for the sustained local release of tacrolimus at the nerve repair site,with suitable properties for scalable production and clinical application,aiming to promote nerve regeneration and functional recovery with minimal systemic drug exposure.Tacrolimus is encapsulated into co-axially electrospun polycarbonate-urethane nanofibers to generate an implantable nerve wrap that releases therapeutic doses of bioactive tacrolimus over 31 days.Size and drug loading are adjustable for applications in small and large caliber nerves,and the wrap degrades within 120 days into biocompatible byproducts.Tacrolimus released from the nerve wrap promotes axon elongation in vitro and accelerates nerve regeneration and functional recovery in preclinical nerve repair models while off-target systemic drug exposure is reduced by 80%compared with systemic delivery.Given its surgical suitability and preclinical efficacy and safety,this system may provide a readily translatable approach to support axonal regeneration and recovery in patients undergoing nerve surgery.
文摘In this study,composite films consisting of polylactic acid(PLA),ethyl cellulose(EC),and zein were prepared by solution casting method,and their performance and application in chilled fresh meat preservation were investigated.The results showed that the three materials had satisfactory compatibility in the composite film.Addition of EC and zein effectively improved the mechanical properties,thermodynamic properties,surface hydrophilicity,oxygen permeability,and degradation properties of PLA films.When the ratio of PLA to EC was 3:7,the tensile strength and elongation at break reached maximum values of 16.6 MPa and 30.5%,respectively.Moreover,under different conditions,the composite film exhibited better degradability than the PLA film.The composite film with a 3:7 ratio of PLA to EC had the best performance,with a degradation rate of 21.75%after 84 days.Chilled fresh meat wrapped with the composite film showed significantly improved antioxidant,antibacterial,and water-holding properties.
文摘A type of novel biodegradable fibers,made from magnetic particles and the patient’s own blood,promises an immune-evading brain cancer therapy with minimal invasion.
