Biodegradation usually obscures or even radically alters the original characteristics of oil biomarkers.The mixing of oil from multiple sources makes each source difficult to trace.Identifying the source of biodegrade...Biodegradation usually obscures or even radically alters the original characteristics of oil biomarkers.The mixing of oil from multiple sources makes each source difficult to trace.Identifying the source of biodegraded oil from multiple sources has always been a hard nut to crack.Rising to this challenge,in this study-we carried out a comprehensive investigation of biodegradation impacts,oil-source correlation,and oil charging history to trace the source and reveal the mixing process of biodegraded oil in the Toutunhe Formation(J_(2)t)in the eastern Junggar Basin,NW China.The oil of this area was biodegraded to different extent,consequently,many commonly used biomarker parameters(e.g.Pr/Ph,Pr/n C_(17))became less powerful for oil-source correlation.To address this problem,the resistance of many biomarkers to biodegradation was analyzed,and those of high bio resistance were selected to generate a more reliable oil-source correlation.The results revealed that biodegraded oil was a mixture of oil sourced from Lucaogou Formation(P_(2)l)and Xiaoquangou Formation(T_(2-3)xq).Core sample observation,microscopic fluorescent analysis and fluid inclusion analysis were combined to analyze comprehensively oil charging history.The analysis of accumulation process exhibited that the existing oil in J_(2)t was a mixture originated from the P_(2)l and T_(2-3)xq source rocks in two separate charging stages when it underwent a complicated process of charging,biodegradation,recharging and mixing.展开更多
With a production of 208.2 m3/d, heavy oil was produced by drill stem test (DST) from three shallow reservoirs in Sand Group Nos. Ⅰ and Ⅲ of the Neogene Guantao Formation (NgⅠ and NgⅢ) and the Eogene Dongying Form...With a production of 208.2 m3/d, heavy oil was produced by drill stem test (DST) from three shallow reservoirs in Sand Group Nos. Ⅰ and Ⅲ of the Neogene Guantao Formation (NgⅠ and NgⅢ) and the Eogene Dongying Formation (Ed) in an exploratory well Ban-14-1 within the Qianmiqiao region, Bohai Bay Basin, northern China. Based on the GC and GC-MS data of the NgⅠ and NgⅢ heavy oil samples, all n-alkanes and most isoprenoid hydrocarbons are lost and the GC baseline appears as an evident 'hump', implying a large quantity of unresolved complex mixture (UCM), which typically revealed a result of heavy biodegradation. However, there still is a complete series of C14-C73 n-alkanes in the high-temperature gas chromatograms (HTGC) of the heavy oil, among which, the abundance of C30- n-alkanes are drastically reduced. The C35-C55 high molecular weight (HMW) n-alkanes are at high abundance and show a normal distribution pattern with major peak at C43 and an obvious odd-carbon-number predominance with CPI37-55 and OEP45-49 values of 1.17 and 1.16-1.20, respectively. According to GC-MS analysis, the heavy oil is characterized by dual source inputs of aquatic microbes and terrestrial higher plants. Various steranes and tricyclic terpanes indicate an algal origin, and hopane-type triterpanes, C24 tetracyclic terpane and drimane series show the bacterial contribution. With the odd-carbon-number preference, HMW n-alkanes provide significant information not only on higher plant source input and immaturity, but also on the strong resistibility to biodegradation.展开更多
Natural water absorbent konjac flour participates in synthesizing biodegraded and polyurethane foamed drape, which is used to release urea slowly.The experimental results indicate that the slowly-releasing velocity of...Natural water absorbent konjac flour participates in synthesizing biodegraded and polyurethane foamed drape, which is used to release urea slowly.The experimental results indicate that the slowly-releasing velocity of urea nitrogen and the degrading velocity of the drape can be controlled by regulating the thicknesses of drapes, the amount of konjac flour and the water content. In addition, the biodegradability of the drape was investigated by burying the specimens in earth afterwards,and results show this drape can be degraded naturally.展开更多
Heavy biodegraded crude oils have larger numbers of coeluting compounds than nonbiodegraded oils, and they are typically not resolved with conventional gas chromatography（GC）. This unresolved complex mixture（UCM） ...Heavy biodegraded crude oils have larger numbers of coeluting compounds than nonbiodegraded oils, and they are typically not resolved with conventional gas chromatography（GC）. This unresolved complex mixture（UCM） has been investigated using comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry（GC×GC-To FMS） within a set of biodegraded petroleums derived from distinct sedimentary basins, including northwestern Sichuan（Neoproterozoic, marine）, Tarim（Early Paleozoic, marine）, Bohai Bay（Eocene, saline/brackish） and Pearl River Mouth（Eocene, freshwater）. In general, the hydrocarbons that constitute the UCM in petroleum saturate fractions can be classified into three catalogues based on the distributions of resolved compounds on two dimensional chromatograms. Group 1 is composed mainly of normal and branched alkanes, isoprenoid alkanes and monocyclic alkanes; Group 2 comprises primarily terpanes ranging from two to five rings, and Group 3 is dominated by monoaromatic hydrocarbons such as tetralins and monoaromatic steranes. In addition, the UCM is source dependent and varies between oil populations. i.e., the UCM of petroleum derived from Precambrian and Early Paleozoic marine, Eocene saline/brackish and freshwater source rocks is specifically rich in higher homologues of A-norsteranes, series of 1,1,3-trimethyl-2-alkylcyclohexanes（carotenoid-derived alkanes）, and tetralin and indane compounds, respectively.展开更多
By aid of gas chromatogram/mass spectrometry(GC-MS),the distributions and the compositions of biomarkers in a set of sequentially biodegraded oils from Liaohe Basin,China,have been quantitatively analyzed,and it has b...By aid of gas chromatogram/mass spectrometry(GC-MS),the distributions and the compositions of biomarkers in a set of sequentially biodegraded oils from Liaohe Basin,China,have been quantitatively analyzed,and it has been found that during the biodegradation process of crude oils,the molecular maturity parameters such as Ts/Tm,homohopane C3122S/(22S+22R)and sterane C2920S/(20S+20R)ratios will be affected to different extent.The results show that except homohopane C3122S/(22S+22R)ratio,Ts/Tm ratio will decrease with increasing biodegradation,but for C2920S/(20S+20R)ratio,it will almost remain constant in slightly and moderately biodegraded oils,and then will increase quickly in severely biodegraded oils.The main reason is that there are some differences in the ability of resistant biodegradation for different isomer of biomarkers with different stereo configuration,resulting in the fact that destroying rate by bacteria for those biomarkers with weak ability will be higher than those with strong ability in resistant biodegradation.For example,18α(H)-22,29,30-trisnorhopanes(Ts)will be destroyed more quickly than 17α(H)-22,29,30-trisnorshopanres(Tm),and 20R isomer is more quickly than 20S isomer for C29 sterane,resulting in the relative ratios changed with increasing biodegradation.Therefore,much more attention should be paid to the biodegradation extent of crude oils and the type of biomarker maturity indicators,when the distributions and the compositions of biomarkers in biodegraded oils are used to determine the maturity of biodegraded oils.展开更多
By the aid of GC-MS technique,a series of sequentially biodegraded oils from Liaohe Basin have been analyzed.The results show that the concentrations and relative compositions of various aromatic compounds in the biod...By the aid of GC-MS technique,a series of sequentially biodegraded oils from Liaohe Basin have been analyzed.The results show that the concentrations and relative compositions of various aromatic compounds in the biodegraded crude oils will change with increasing biodegradation degree.The concentrations of alkyl naphthalenes,alkyl phenanthrenes,alkyl dibenzothiophene are decreased,and the concentration of triaromatic steroids will increase with increasing biodegradation degree in biodegraded oils.Those phenomena indicate that various aromatic compounds are more easily biodegraded by bacteria like other kinds of hydrocarbons such as alkanes,but different series of aromatic compounds have a varied ability to resistant to biodegradation.The ratios of dibenzothiophene to phenenthrene(DBTH/P)and methyl dibenzothiophene to methyl phenanthrene(MDBTH/MP)are related to the features of depositional environment for source rocks such as redox and ancient salinity.However,in biodegraded oils,the two ratios increase quickly with the increase of the biodegradation degree,indicating that they have lost their geochemical significance.In this case,they could not be used to evaluate the features of depositional environment.Methyl phenanthrene index,methyl phenanthrene ratio and methyl dibenzoyhiophene ratio are useful aromatic maturity indicators for the crude oils and the source rocks without vitrinite.But for biodegraded oils,those aromatic maturity indicators will be affected by biodegradation and decrease with the increase of the biodegradation degree.Therefore,those aromatic molecular maturity indicators could not be used for biodegraded oils.展开更多
Growing demand for sustainable,high-performance materials is driving research to replace petroleumbased plastics with abundant biomass,especially cellulose.However,the effective modification and functionalization of c...Growing demand for sustainable,high-performance materials is driving research to replace petroleumbased plastics with abundant biomass,especially cellulose.However,the effective modification and functionalization of cellulose is often impeded by complex processing requirements and limited performance tunability.Here,an innovative“active”green medium strategy based on an ethyl cellulose/thymol eutectic system is reported,enabling in situ chemical modification of eutectic components and the construction of dynamic self-adaptive networks without external catalysts or initiators.Through precise molecular design,dynamic boroxine networks and acrylate crosslinking networks are synergistically integrated into the cellulosic bioplastic(CBP)matrix.The resulting CBP-A2B8 exhibits exceptional optical transparency(~85%),superior mechanical properties(tensile strength~30 MPa),facile thermal processability,and closed-loop recyclability.Its chemical structure and mechanical performance remain highly stable even after 20 hot-compression recycling cycles.Complete biodegradation occurs under natural environmental conditions within approximately 100 days.Furthermore,the bioplastic,when combined with silver nanowires,forms high-performance flexible transparent conductive films successfully applied in customizable electroluminescent devices.Post-lifecycle,device components(silver nanowires and CBP matrix)are efficiently separated and recycled using a straightforward solvent-based method.This eutectic system-mediated strategy offers a novel pathway for the development of sustainable,high-performance bioplastics with a closed-loop lifecycle.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
Flexible pressure sensors(FPSs)offer unique benefits for fall detection and rehabilitation training,but conventional FPSs made from synthetic materials have drawbacks,including resource-heavy manufacturing,high costs,...Flexible pressure sensors(FPSs)offer unique benefits for fall detection and rehabilitation training,but conventional FPSs made from synthetic materials have drawbacks,including resource-heavy manufacturing,high costs,and environmental pollution.To address these limitations,this study proposes an innovative fabrication strategy for FPS based on natural materials.The upper and lower electrodes were made by treating a natural wood strip with a flame retardant,converting it into high-quality graphene via a costeffective infrared laser,and transferring it onto starch-based substrates.The dielectric layer was created by electrospinning a composite nanofiber membrane with cyclodextrin and carbon nanotubes.The resulting capacitive FPS shows high sensitivity(2.15 kPa^(-1) within 0-10 kPa),a low detection limit(~6.5 Pa),fast response and recovery times(29 and 39 ms),and excellent long-term stability(over 5000 cycles).It also demonstrates excellent biocompatibility(cell viability>98%)and fully degrades within 6 h.By integrating this sensor with wireless technology,a fall detection and rehabilitation monitoring system was developed.Data processing was handled by a Tiny Machine Learning module on a mobile platform,which transmitted relevant data to a cloud-based platform.The system accurately identified five common fall postures and assisted clinicians in guiding rehabilitation exercises,achieving recognition accuracies of 99%and 100%,respectively,offering a sustainable healthcare solution for the elderly.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(ester amide)s(PEAs)represent promising biomaterials because of their well-balanced mechanical properties,biodegradability,and biocompatibility.However,practical applications of PEAs are still limited by challenge...Poly(ester amide)s(PEAs)represent promising biomaterials because of their well-balanced mechanical properties,biodegradability,and biocompatibility.However,practical applications of PEAs are still limited by challenges in functional versatility and environmental adaptability.Here,we present the first synthesis of periodic selenium-incorporated PEAs(Se-PEAs)via a rapid,catalyst-free selenol-yne click polymerization process.By harnessing the versatility of selenium,we achieved precise modulation of material properties.The resulting Se-PEAs demonstrated tunable mechanical behavior,spanning rigid plastics to elastomers,alongside exceptional thermal stability and high optical clarity.Programmable degradation profiles ensure long-term stability in physiological environments while facilitating rapid oxidative degradation at the end of the lifecycle.Surface selenoniumization further conferred robust antibacterial efficacy without compromising mechanical integrity.This multifunctionality positions Se-PEAs as transformative materials for biomedical implants,sustainable packaging,and high-refractiveindex optics.Our work advanced functional polymer design and underscored the potential of selenium chemistry in addressing global challenges in terms of plastic waste and ecological sustainability.展开更多
With wax content of 1.62%, heavy oil has been produced from the sandstone reservoirs of Neogene Guantao Formation (Ng1m). In the GC and GC-MS RIC profiles of its aliphatic fraction, n-alkanes are totally lost, which s...With wax content of 1.62%, heavy oil has been produced from the sandstone reservoirs of Neogene Guantao Formation (Ng1m). In the GC and GC-MS RIC profiles of its aliphatic fraction, n-alkanes are totally lost, which shows the result of heavy biodegradedation. However, the remaining trace C13-C36 n-alkanes can be still seen from its mlz 85 mass chromatogram. In addition, a complete series of C35-C73 high molecular weight (HMW) n-alkanes was detected by high-temperature gas chromatography (HTGC). The HMW R-alkane series shows a normal distribution pattern, a major peak at nC43, obvious odd-carbon-number predominance, CPI37-55 and OEP45-49 values up to 1.17 and 1.16-1.20 respectively. The present study not only has conformed the strong resistibility of HMW n-alkanes to biodegradation in crude oils as concluded by previous researchers, but also has provided some significant information on source input and maturity for the heavily biodegraded oil in the Qianmiqiao region.展开更多
Secondary variation of reservoir is a hot problem in petroleum geochemistry field. Several kinds of secondary variations have taken place after the formation of bituminous sandstones in the Tarim Basin including biode...Secondary variation of reservoir is a hot problem in petroleum geochemistry field. Several kinds of secondary variations have taken place after the formation of bituminous sandstones in the Tarim Basin including biodegra-dation, washing, dissipation and secondary thermal stress. Biodegraded bituminous sandstones were used in the experiment. Pyrolysis experiment has been performed in a closed system, simulating secondary thermal stress with continual burial of Silurian bituminous sandstones which may cause the changes in molecular compositions, carbon isotope and physical properties of bituminous sandstones. The results are as follows: (i) Gases are mainly product during the experiment and carbon isotope of gas is lighter. (ii) Yield of C6+ hydrocarbon is relative smaller, and yielded oil is mainly light oil. (iii) Chromatogram character of biodegraded oil-sand is similar to that of saturated hydrocarbon in extracts from present-day bituminous sandstones, (iv) Porosity of bituminous sandstones gradually展开更多
It is demonstrated by various geochemical indexes that the Zhengjia-Wangzhuang Oilfield with viscous crude oil in the Jiyang Depression has been sourced from the contribution of matured source rocks in the upper Es4. ...It is demonstrated by various geochemical indexes that the Zhengjia-Wangzhuang Oilfield with viscous crude oil in the Jiyang Depression has been sourced from the contribution of matured source rocks in the upper Es4. The principal cause leading to the densification of crude oils would be biodegradation, with the degradation level of crude oils being ranked as 2-8; vertically, the biodegradation level increases from the top to bottom of the oil column, with a distinctive biodegradation gradient occurring. Calculated parameters of sterane, terpane and methyl-phenanthrene have indicated that the source-rock’s maturity of crude oils and asphaltic sands ranges from 0.7 to 0.9, and based on the calculation of Easy Ro model, the temperature of hydrocarbon generation in the source rock would be within 120-140℃, which coincides with the measurements of reservoir inclusions. The measured homogenization temperature would represent the generation temperature of the source rock, and be fairly different from that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
基金supported by a grant from National Science Foundation for Young Scientists of China(Grant No.41702143)Natural Science Foundation of Shandong Province of China(ZR2016DL06+3 种基金ZR2017LD005)the Fundamental Research Funds for the Central Universities(17CX02006A)the Foundation of Shandong Provincial Key Laboratory of Depositional Mineralization&Sedimentary Mineral(DMSM2017063)the major science and technology project of Xinjiang Petroleum Administration Bureau of CNPC(2017E-0401)。
文摘Biodegradation usually obscures or even radically alters the original characteristics of oil biomarkers.The mixing of oil from multiple sources makes each source difficult to trace.Identifying the source of biodegraded oil from multiple sources has always been a hard nut to crack.Rising to this challenge,in this study-we carried out a comprehensive investigation of biodegradation impacts,oil-source correlation,and oil charging history to trace the source and reveal the mixing process of biodegraded oil in the Toutunhe Formation(J_(2)t)in the eastern Junggar Basin,NW China.The oil of this area was biodegraded to different extent,consequently,many commonly used biomarker parameters(e.g.Pr/Ph,Pr/n C_(17))became less powerful for oil-source correlation.To address this problem,the resistance of many biomarkers to biodegradation was analyzed,and those of high bio resistance were selected to generate a more reliable oil-source correlation.The results revealed that biodegraded oil was a mixture of oil sourced from Lucaogou Formation(P_(2)l)and Xiaoquangou Formation(T_(2-3)xq).Core sample observation,microscopic fluorescent analysis and fluid inclusion analysis were combined to analyze comprehensively oil charging history.The analysis of accumulation process exhibited that the existing oil in J_(2)t was a mixture originated from the P_(2)l and T_(2-3)xq source rocks in two separate charging stages when it underwent a complicated process of charging,biodegradation,recharging and mixing.
基金Th is study was supported by the National Natural Science Foundation of China(NSFC,no.40172056)the Research Fund for the Doctoral Program of Higher Education,China(RFDP,no.2000042506).
文摘With a production of 208.2 m3/d, heavy oil was produced by drill stem test (DST) from three shallow reservoirs in Sand Group Nos. Ⅰ and Ⅲ of the Neogene Guantao Formation (NgⅠ and NgⅢ) and the Eogene Dongying Formation (Ed) in an exploratory well Ban-14-1 within the Qianmiqiao region, Bohai Bay Basin, northern China. Based on the GC and GC-MS data of the NgⅠ and NgⅢ heavy oil samples, all n-alkanes and most isoprenoid hydrocarbons are lost and the GC baseline appears as an evident 'hump', implying a large quantity of unresolved complex mixture (UCM), which typically revealed a result of heavy biodegradation. However, there still is a complete series of C14-C73 n-alkanes in the high-temperature gas chromatograms (HTGC) of the heavy oil, among which, the abundance of C30- n-alkanes are drastically reduced. The C35-C55 high molecular weight (HMW) n-alkanes are at high abundance and show a normal distribution pattern with major peak at C43 and an obvious odd-carbon-number predominance with CPI37-55 and OEP45-49 values of 1.17 and 1.16-1.20, respectively. According to GC-MS analysis, the heavy oil is characterized by dual source inputs of aquatic microbes and terrestrial higher plants. Various steranes and tricyclic terpanes indicate an algal origin, and hopane-type triterpanes, C24 tetracyclic terpane and drimane series show the bacterial contribution. With the odd-carbon-number preference, HMW n-alkanes provide significant information not only on higher plant source input and immaturity, but also on the strong resistibility to biodegradation.
文摘Natural water absorbent konjac flour participates in synthesizing biodegraded and polyurethane foamed drape, which is used to release urea slowly.The experimental results indicate that the slowly-releasing velocity of urea nitrogen and the degrading velocity of the drape can be controlled by regulating the thicknesses of drapes, the amount of konjac flour and the water content. In addition, the biodegradability of the drape was investigated by burying the specimens in earth afterwards,and results show this drape can be degraded naturally.
基金funded by the National Natural Science Foundation of China(Grant No.41172126)the State Key Laboratory of Petroleum Resources and Prospecting(PRP/indep-2-1402)
文摘Heavy biodegraded crude oils have larger numbers of coeluting compounds than nonbiodegraded oils, and they are typically not resolved with conventional gas chromatography（GC）. This unresolved complex mixture（UCM） has been investigated using comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry（GC×GC-To FMS） within a set of biodegraded petroleums derived from distinct sedimentary basins, including northwestern Sichuan（Neoproterozoic, marine）, Tarim（Early Paleozoic, marine）, Bohai Bay（Eocene, saline/brackish） and Pearl River Mouth（Eocene, freshwater）. In general, the hydrocarbons that constitute the UCM in petroleum saturate fractions can be classified into three catalogues based on the distributions of resolved compounds on two dimensional chromatograms. Group 1 is composed mainly of normal and branched alkanes, isoprenoid alkanes and monocyclic alkanes; Group 2 comprises primarily terpanes ranging from two to five rings, and Group 3 is dominated by monoaromatic hydrocarbons such as tetralins and monoaromatic steranes. In addition, the UCM is source dependent and varies between oil populations. i.e., the UCM of petroleum derived from Precambrian and Early Paleozoic marine, Eocene saline/brackish and freshwater source rocks is specifically rich in higher homologues of A-norsteranes, series of 1,1,3-trimethyl-2-alkylcyclohexanes（carotenoid-derived alkanes）, and tetralin and indane compounds, respectively.
基金Supported by Key Technologies R&D Programme(Grant No.2004BA616A02-04-02-01)
文摘By aid of gas chromatogram/mass spectrometry(GC-MS),the distributions and the compositions of biomarkers in a set of sequentially biodegraded oils from Liaohe Basin,China,have been quantitatively analyzed,and it has been found that during the biodegradation process of crude oils,the molecular maturity parameters such as Ts/Tm,homohopane C3122S/(22S+22R)and sterane C2920S/(20S+20R)ratios will be affected to different extent.The results show that except homohopane C3122S/(22S+22R)ratio,Ts/Tm ratio will decrease with increasing biodegradation,but for C2920S/(20S+20R)ratio,it will almost remain constant in slightly and moderately biodegraded oils,and then will increase quickly in severely biodegraded oils.The main reason is that there are some differences in the ability of resistant biodegradation for different isomer of biomarkers with different stereo configuration,resulting in the fact that destroying rate by bacteria for those biomarkers with weak ability will be higher than those with strong ability in resistant biodegradation.For example,18α(H)-22,29,30-trisnorhopanes(Ts)will be destroyed more quickly than 17α(H)-22,29,30-trisnorshopanres(Tm),and 20R isomer is more quickly than 20S isomer for C29 sterane,resulting in the relative ratios changed with increasing biodegradation.Therefore,much more attention should be paid to the biodegradation extent of crude oils and the type of biomarker maturity indicators,when the distributions and the compositions of biomarkers in biodegraded oils are used to determine the maturity of biodegraded oils.
基金Supported by Key Technologies R&D Programme(Grant No.2004BA616A02-04-02-01)
文摘By the aid of GC-MS technique,a series of sequentially biodegraded oils from Liaohe Basin have been analyzed.The results show that the concentrations and relative compositions of various aromatic compounds in the biodegraded crude oils will change with increasing biodegradation degree.The concentrations of alkyl naphthalenes,alkyl phenanthrenes,alkyl dibenzothiophene are decreased,and the concentration of triaromatic steroids will increase with increasing biodegradation degree in biodegraded oils.Those phenomena indicate that various aromatic compounds are more easily biodegraded by bacteria like other kinds of hydrocarbons such as alkanes,but different series of aromatic compounds have a varied ability to resistant to biodegradation.The ratios of dibenzothiophene to phenenthrene(DBTH/P)and methyl dibenzothiophene to methyl phenanthrene(MDBTH/MP)are related to the features of depositional environment for source rocks such as redox and ancient salinity.However,in biodegraded oils,the two ratios increase quickly with the increase of the biodegradation degree,indicating that they have lost their geochemical significance.In this case,they could not be used to evaluate the features of depositional environment.Methyl phenanthrene index,methyl phenanthrene ratio and methyl dibenzoyhiophene ratio are useful aromatic maturity indicators for the crude oils and the source rocks without vitrinite.But for biodegraded oils,those aromatic maturity indicators will be affected by biodegradation and decrease with the increase of the biodegradation degree.Therefore,those aromatic molecular maturity indicators could not be used for biodegraded oils.
基金supported by the Jiangsu Provincial Natural Science Foundation(BK20240685)the Opening Project of Key Laboratory of Optoelectronic Chemical Materials and Devices,Ministry of Education,Jianghan University(JDGD202309)。
文摘Growing demand for sustainable,high-performance materials is driving research to replace petroleumbased plastics with abundant biomass,especially cellulose.However,the effective modification and functionalization of cellulose is often impeded by complex processing requirements and limited performance tunability.Here,an innovative“active”green medium strategy based on an ethyl cellulose/thymol eutectic system is reported,enabling in situ chemical modification of eutectic components and the construction of dynamic self-adaptive networks without external catalysts or initiators.Through precise molecular design,dynamic boroxine networks and acrylate crosslinking networks are synergistically integrated into the cellulosic bioplastic(CBP)matrix.The resulting CBP-A2B8 exhibits exceptional optical transparency(~85%),superior mechanical properties(tensile strength~30 MPa),facile thermal processability,and closed-loop recyclability.Its chemical structure and mechanical performance remain highly stable even after 20 hot-compression recycling cycles.Complete biodegradation occurs under natural environmental conditions within approximately 100 days.Furthermore,the bioplastic,when combined with silver nanowires,forms high-performance flexible transparent conductive films successfully applied in customizable electroluminescent devices.Post-lifecycle,device components(silver nanowires and CBP matrix)are efficiently separated and recycled using a straightforward solvent-based method.This eutectic system-mediated strategy offers a novel pathway for the development of sustainable,high-performance bioplastics with a closed-loop lifecycle.
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.
基金supported by the National Natural Science Foundation of China(62301291,61904092,and 62181240278)Natural Science Foundation of Shandong Province(ZR2025MS1072)+1 种基金Youth Innovation Team Project of Shandong Provincial Education Department(2022KJ141)Taishan Scholars Project Special Funds(tsqn202312035)。
文摘Flexible pressure sensors(FPSs)offer unique benefits for fall detection and rehabilitation training,but conventional FPSs made from synthetic materials have drawbacks,including resource-heavy manufacturing,high costs,and environmental pollution.To address these limitations,this study proposes an innovative fabrication strategy for FPS based on natural materials.The upper and lower electrodes were made by treating a natural wood strip with a flame retardant,converting it into high-quality graphene via a costeffective infrared laser,and transferring it onto starch-based substrates.The dielectric layer was created by electrospinning a composite nanofiber membrane with cyclodextrin and carbon nanotubes.The resulting capacitive FPS shows high sensitivity(2.15 kPa^(-1) within 0-10 kPa),a low detection limit(~6.5 Pa),fast response and recovery times(29 and 39 ms),and excellent long-term stability(over 5000 cycles).It also demonstrates excellent biocompatibility(cell viability>98%)and fully degrades within 6 h.By integrating this sensor with wireless technology,a fall detection and rehabilitation monitoring system was developed.Data processing was handled by a Tiny Machine Learning module on a mobile platform,which transmitted relevant data to a cloud-based platform.The system accurately identified five common fall postures and assisted clinicians in guiding rehabilitation exercises,achieving recognition accuracies of 99%and 100%,respectively,offering a sustainable healthcare solution for the elderly.
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 Natural Science Foundation of China(21971177)the Natural Science Foundation of the Jiangsu Higher Education Institution of China(22KJA150004)+3 种基金the Suzhou Science and Technology Bureau(SZM2021008)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutionsthe Jiangsu Key Laboratory of Advanced Functional Polymers Design and Application,Soochow University,Suzhou Medical and Industrial Cooperation Innovation Project(SZM2022011)the Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis and the Program of Innovative Research Team of Soochow University。
文摘Poly(ester amide)s(PEAs)represent promising biomaterials because of their well-balanced mechanical properties,biodegradability,and biocompatibility.However,practical applications of PEAs are still limited by challenges in functional versatility and environmental adaptability.Here,we present the first synthesis of periodic selenium-incorporated PEAs(Se-PEAs)via a rapid,catalyst-free selenol-yne click polymerization process.By harnessing the versatility of selenium,we achieved precise modulation of material properties.The resulting Se-PEAs demonstrated tunable mechanical behavior,spanning rigid plastics to elastomers,alongside exceptional thermal stability and high optical clarity.Programmable degradation profiles ensure long-term stability in physiological environments while facilitating rapid oxidative degradation at the end of the lifecycle.Surface selenoniumization further conferred robust antibacterial efficacy without compromising mechanical integrity.This multifunctionality positions Se-PEAs as transformative materials for biomedical implants,sustainable packaging,and high-refractiveindex optics.Our work advanced functional polymer design and underscored the potential of selenium chemistry in addressing global challenges in terms of plastic waste and ecological sustainability.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 40172056)the Research Found for the Doctoral Program of High Education (RFDP No. 2000042506)the Geological Research Institute, Dagang Oilfield (Group) Co. Ltd.
文摘With wax content of 1.62%, heavy oil has been produced from the sandstone reservoirs of Neogene Guantao Formation (Ng1m). In the GC and GC-MS RIC profiles of its aliphatic fraction, n-alkanes are totally lost, which shows the result of heavy biodegradedation. However, the remaining trace C13-C36 n-alkanes can be still seen from its mlz 85 mass chromatogram. In addition, a complete series of C35-C73 high molecular weight (HMW) n-alkanes was detected by high-temperature gas chromatography (HTGC). The HMW R-alkane series shows a normal distribution pattern, a major peak at nC43, obvious odd-carbon-number predominance, CPI37-55 and OEP45-49 values up to 1.17 and 1.16-1.20 respectively. The present study not only has conformed the strong resistibility of HMW n-alkanes to biodegradation in crude oils as concluded by previous researchers, but also has provided some significant information on source input and maturity for the heavily biodegraded oil in the Qianmiqiao region.
文摘Secondary variation of reservoir is a hot problem in petroleum geochemistry field. Several kinds of secondary variations have taken place after the formation of bituminous sandstones in the Tarim Basin including biodegra-dation, washing, dissipation and secondary thermal stress. Biodegraded bituminous sandstones were used in the experiment. Pyrolysis experiment has been performed in a closed system, simulating secondary thermal stress with continual burial of Silurian bituminous sandstones which may cause the changes in molecular compositions, carbon isotope and physical properties of bituminous sandstones. The results are as follows: (i) Gases are mainly product during the experiment and carbon isotope of gas is lighter. (ii) Yield of C6+ hydrocarbon is relative smaller, and yielded oil is mainly light oil. (iii) Chromatogram character of biodegraded oil-sand is similar to that of saturated hydrocarbon in extracts from present-day bituminous sandstones, (iv) Porosity of bituminous sandstones gradually
文摘It is demonstrated by various geochemical indexes that the Zhengjia-Wangzhuang Oilfield with viscous crude oil in the Jiyang Depression has been sourced from the contribution of matured source rocks in the upper Es4. The principal cause leading to the densification of crude oils would be biodegradation, with the degradation level of crude oils being ranked as 2-8; vertically, the biodegradation level increases from the top to bottom of the oil column, with a distinctive biodegradation gradient occurring. Calculated parameters of sterane, terpane and methyl-phenanthrene have indicated that the source-rock’s maturity of crude oils and asphaltic sands ranges from 0.7 to 0.9, and based on the calculation of Easy Ro model, the temperature of hydrocarbon generation in the source rock would be within 120-140℃, which coincides with the measurements of reservoir inclusions. The measured homogenization temperature would represent the generation temperature of the source rock, and be fairly different from that
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.
