Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(...Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(III)nanoparticles with the most commonly identified FRB,Geobacter sulfurreducens PCA,remains poorly understood.Herein,we demonstrated that the synergistic role of outer membrane proteins and periplasmic proteins in the EET process for-Fe_(2)O_(3),Fe3O4,and𝛽α-FeOOH nanoparticles by construction of multiple gene knockout strain.oxpG(involved in the type II secretion system)and omcST(outer membrane c-type cytochrome)medi-ated pathways accounted for approximately 67%of the total reduction of𝛼α-Fe_(2)O_(3) nanoparticles.The residual reduction of𝛼α-Fe_(2)O_(3) nanoparticles in∆oxpG-omcST strain was likely caused by redox-active substances in cell supernatant.Conversely,the reduction of dissolved Fe(III)was almost unaffected in∆oxpG-omcST strain at the same concentration.However,at high dissolved Fe(III)concentration,the reduction significantly decreased due to the formation of Fe(III)nanoparticles,suggesting that this EET process is specific to Fe(III)nanoparticles.Overall,our study provided a more comprehensive understanding for the EET pathways between G.sulfurreducens PCA and different Fe(III)species,enriching our knowledge on the role of microorganisms in iron biogeochemical cycles and remediation strategies of pollutants.展开更多
Identification of the most appropriate chemically extractable pool for evaluating Cd and Pb availability remains elusive,hindering accurate assessment on environmental risks and effectiveness of remediation strategies...Identification of the most appropriate chemically extractable pool for evaluating Cd and Pb availability remains elusive,hindering accurate assessment on environmental risks and effectiveness of remediation strategies.This study evaluated the feasibility of European Community Bureau of Reference(BCR)sequential extraction,Ca(NO_(3))_(2)extraction,and water extraction on assessing Cd and Pb availability in agricultural soil amended with slaked lime,magnesium hydroxide,corn stover biochar,and calcium dihydrogen phosphate.Moreover,the enriched isotope tracing technique(^(112)Cd and^(206)Pb)was employed to evaluate the aging process of newly introduced Cd and Pbwithin 56 days’incubation.Results demonstrated that extractable pools by BCR and Ca(NO_(3))_(2)extraction were little impacted by amendments and showed little correlation with soil pH.This is notable because soil pH is closely linked to metal availability,indicating these extraction methods may not adequately reflect metal availability.Conversely,water-soluble concentrations of Cd and Pb were markedly influenced by amendments and exhibited strong correlations with pH(Pearson’s r:-0.908 to-0.825,P<0.001),suggesting water extraction as a more sensitive approach.Furthermore,newly introduced metals underwent a more evident aging process as demonstrated by acid-soluble and water-soluble pools.Additionally,water-soluble concentrations of essential metals were impacted by soil amendments,raising caution on their potential effects on plant growth.These findings suggest water extraction as a promising and attractive method to evaluate Cd and Pb availability,which will help provide assessment guidance for environmental risks caused by heavy metals and develop efficient remediation strategies.展开更多
The removal of highly toxic arsenic(As)and antimony(Sb)contaminants in water by adsorption presents a great challenge worldwide.Conventional adsorbents exhibit insufficient efficacy for removing pentavalent oxyanions,...The removal of highly toxic arsenic(As)and antimony(Sb)contaminants in water by adsorption presents a great challenge worldwide.Conventional adsorbents exhibit insufficient efficacy for removing pentavalent oxyanions,As(Ⅴ)and Sb(Ⅴ),which are predominant compared with the trivalent species,As(Ⅲ)and Sb(Ⅲ),in surface waters.Here,we synthesized a novel composite adsorbent,amine-functionalized polystyrene resin loaded with nano TiO_(2)(Am PSd-Ti).The mm-scale spheres showed outstanding adsorption capacities for As(Ⅲ),As(Ⅴ),Sb(Ⅲ),and Sb(Ⅴ)at 73.85,153.29,86.80,and 123.71 mg/g,respectively.Am PSd-Ti exhibited selective adsorption for As and Sb in the presence of Cl^(-),NO_(3)^(-),SO_(4)^(2-),and F^(-).As and Sb were adsorbed by the nano-sized TiO_(2)confined in the porous resin via forming innersphere complexes.The protonated amine groups enhanced the adsorption of As(Ⅴ)and Sb(Ⅴ)by electrostatic attraction and hydrogen bonding,which was confirmed by experimental results and molecular dynamics simulations.Fixed-bed column tests showed breakthrough curves with adsorption capacities of1.38 mg/g(6600 BV)and 6.65 mg/g(1260 BV)upon treating real As-contaminated groundwater and Sbcontaminated industrial wastewater.Our study highlights a feasible strategy by incorporating inorganic metal oxides into organic polymers to achieve highly efficient removal of As and Sb in real-world scenarios.展开更多
Perfluoroalkyl substances(PFASs)are typical persistent organic pollutants,and their removal is urgently required but challenging.Photocatalysis has shown potential in PFASs degradation due to the redox capabilities of...Perfluoroalkyl substances(PFASs)are typical persistent organic pollutants,and their removal is urgently required but challenging.Photocatalysis has shown potential in PFASs degradation due to the redox capabilities of photoinduced charge carriers in photocatalysts.Herein,hexagonal ZnIn_(2)S_(4)(ZIS)nanosheets were synthesized by a one-pot oil bath method and were well characterized by a series of techniques.In the degradation of sodium p-perfluorous nonenoxybenzenesulfonate(OBS),one kind of representative PFASs,the assynthesized ZIS showed activity superior to P25 TiO_(2) under both simulated sunlight and visible-light irradiation.The good photocatalytic performance was attributed to the enhanced light absorption and facilitated charge separation.The pH conditions were found crucial in the photocatalytic process by influencing the OBS adsorption on the ZIS surface.Photogenerated e−and h+were the main active species involved in OBS degradation in the ZIS system.This work confirmed the feasibility and could provide mechanistic insights into the degradation and defluorination of PFASs by visible-light photocatalysis.展开更多
Mercury(Hg),especially methylmercury(MeHg),accumulation in rice grain due to rice paddy possessing conditions conducive to Hg methylation has led to human Hg exposure through consumption of rice-based daily meals.In a...Mercury(Hg),especially methylmercury(MeHg),accumulation in rice grain due to rice paddy possessing conditions conducive to Hg methylation has led to human Hg exposure through consumption of rice-based daily meals.In addition to being a food staple,rice is widely used as a raw material to produce a vast variety of processed food products.Little is known about Hg levels in snacking rice-food products and potential Hg exposure from consumption of them,besides previous studies on infant rice cereals.Aiming to provide complementary information for a more complete assessment on Hg exposure risk originated from Hgcontaining rice,this study determined total Hg(THg)and MeHg levels in 195 rice-containing and rice-free processed food products covering all major types of snack foods marketed in China and the estimated daily intake(EDI)of dietary Hg from the consumption of these foods.The results clearly showed THg and MeHg contents in rice-containing foods were significantly higher than rice-free products,suggesting the transfer of Hg and MeHg from the rice to the end products,even after manufacturing processes.Moreover,significant positive correlations were observed between THg,MeHg,or MeHg/THg ratio and rice content for samples containing multiple grains as ingredients,further indicating the deciding role of rice for Hg levels in the end food products.Although the EDI of THg and MeHg via ricebased food products were relatively low compared to the reference dose,it should be considered these snacking food products would contribute additive Hg intake outside of the daily regular meals.展开更多
Considerable levels of methylmercury(MeHg)have been found rice-based infant cereals as a result of MeHg transfer from the rice as a raw material to the products,hence consumption of rice products may pose a potential ...Considerable levels of methylmercury(MeHg)have been found rice-based infant cereals as a result of MeHg transfer from the rice as a raw material to the products,hence consumption of rice products may pose a potential health risk to infants who may receive cereals as the major diets and are susceptible to toxicity of MeHg.Determination of bioaccessibility of MeHg would provide a more accurate assessment of MeHg exposure through consumption of rice-based cereals,yet this information remains lacking.Further,the re-adsorption of methylmercury on the residual food will affect the accurate assessment of its bioaccessibility.Our goals in this work were 1)to determine the bioaccessibility of MeHg in infant rice cereals commonly available on the market by using a typical in vitro artificial gastrointestinal digestionmodel and 2)to evaluate the effects of MeHg re-adsorption on the in vitro assessment of MeHg bioaccessibility.The determined bioaccessibility of MeHg in the studied rice cereals after the standard dual-step(using gastric followed by intestinal juice)protocol ranged from 25%to 74%,a wide range comparable to that of fish samples observed here and in previous studies.The surprisingly higher bioaccessibility of MeHg in fish and rice cereals after the gastric step only,in comparison to after the complete two-step gastrointestinal digestion,suggests the re-adsorption of MeHg on the residual food.Separate experiments with spiked MeHg standards confirmed that the MeHg released by the acetic gastric juice was re-adsorbed on the residues during the intestinal step at neutral pH.This study provided first-hand data on the bioaccessibility of MeHg in infant rice cereals and methodological implications on using in vitro digestion to evaluate the bioaccessibility of MeHg and metal contaminants in general.展开更多
AIM: To evaluate the effect of multidisciplinary team (MDT) treatment modality on outcomes of patients with gastrointestinal malignancy in China. METHODS: Data about patients with gastric and colorectal cancer treated...AIM: To evaluate the effect of multidisciplinary team (MDT) treatment modality on outcomes of patients with gastrointestinal malignancy in China. METHODS: Data about patients with gastric and colorectal cancer treated in our center during the past 10 years were collected and divided into two parts. Part 1 consisted of the data collected from 516 consecutive complicated cases discussed at MDT meetings in Peking University School of Oncology (PKUSO) from December 2005 to July 2009. Part 2 consisted of the data collected from 263 consecutive cases of resect-able locally advanced rectal cancer from January 2001 to January 2005. These 263 patients were divided into neoadjuvant therapy (NT) group and control group. Patients in NT group received MDT treatment, namely neoadjuvant therapy + surgery + postoperative adjuvant therapy. Patients in control group underwent direct surgery + postoperative adjuvant therapy. The outcomes in two groups were compared. RESULTS: The treatment strategy was altered after discussed at MDT meeting in 76.81% of gastric cancer patients and in 58.33% of colorectal cancer patients before operation. The sphincter-preservation and local control of tumor were better in NT group than in control group. The 5-year overall survival rate was also higher in NT group than in control group (77.23% vs 69.75%, P = 0.049). CONCLUSION: MDT treatment modality can significantly improve the outcomes of patients with gastrointestinal malignancy in China.展开更多
AIM: To investigate the meaning of lymphovascular invasion (LVI) in rectal cancer after neoadjuvant radiotherapy. METHODS: A total of 325 patients who underwent radical resection using total mesorectal excision (TME) ...AIM: To investigate the meaning of lymphovascular invasion (LVI) in rectal cancer after neoadjuvant radiotherapy. METHODS: A total of 325 patients who underwent radical resection using total mesorectal excision (TME) from January 2000 to January 2005 in Beijing cancer hospital were included retrospectively, divided into a preoperative radiotherapy (PRT) group and a control group, according to whether or not they underwent preoperative radiation. Histological assessments of tumor specimens were made and the correlation of LVI and prognosis were evaluated by univariate and multivariate analysis. RESULTS: The occurrence of LVI in the PRT and control groups was 21.4% and 26.1% respectively. In the control group, LVI was signifi cantly associated with histological differentiation and pathologic TNM stage, whereas these associations were not observed in the PRT group. LVI was closely correlated to disease progression and 5-year overall survival (OS) in both groups. Among the patients with disease progression, LVI positive patients in the PRT group had a signifi cantly longer median disease-free period (22.5 mo vs 11.5 mo, P = 0.023) and overall survival time (42.5 mo vs 26.5 mo, P = 0.035) compared to those in the control group, despite the fact that no signifi cant difference in 5-year OS rate was observed (54.4% vs 48.3%, P = 0.137). Multivariate analysis showed the distance of tumor from the anal verge, pretreatment serum carcinoembryonic antigen level, pathologic TNM stage and LVI were the major factors affecting OS. CONCLUSION: Neoadjuvant radiotherapy does not reduce LVI significantly; however, the prognostic meaning of LVI has changed. Patients with LVI may benefi t from neoadjuvant radiotherapy.展开更多
Rhenium diselenide(ReSe2) has caused considerable concerns in the field of energy storage because the compound and its composites still suffer from low specific capacity and inferior cyclic stability.In this study,ReS...Rhenium diselenide(ReSe2) has caused considerable concerns in the field of energy storage because the compound and its composites still suffer from low specific capacity and inferior cyclic stability.In this study,ReSe2 nanoparticles encapsulated in carbon nanofibers were synthesized successfully with simple electrospinning and heat treatment.It was found that graphene modifications could affect considerably the microstructure and electrochemical properties of ReSe2–carbon nanofibers.Accordingly,the modified compound maintained a capacity of 227 mAhg-1 after 500cycles at 200 mAg-1 for Na+storage,230 mAh g-1 after 200 cycles at 200 mAg-1,212 mAh g-1 after 150 cycles at 500 mAg-1 for K+ storage,which corresponded to the capacity retention ratios of 89%,97%,and 86%,respectively.Even in Na+full cells,its capacity was maintained to 82% after 200 cycles at 1 C(117 mAg-1).The superior stability of ReSe2–carbon nanofibers benefitted from the extremely weak van der Waals interactions and large interlayer spacing of ReSe2,in association with the role of graphene-modified carbon nanofibers,in terms of the shortening of electron/ion transport paths and the improvement of structural support.This study may provide a new route for a broadened range of applications of other rhenium-based compounds.展开更多
High-entropy alloys(HEAs) are of great interest in materials science and engineering communities owing to their unique phase structure.HEAs are constructed with five or more principal alloying elements in equimolar or...High-entropy alloys(HEAs) are of great interest in materials science and engineering communities owing to their unique phase structure.HEAs are constructed with five or more principal alloying elements in equimolar or near-equimolar ratios.Therefore,they can derive their performance from multiple principal elements ratherthan a single element.In this work,three-dimensional printing laser cladding was applied to produce an Al_(0.4)CoCu_(0.6)NiSi_(0.2)Ti_(0.25) HEA coating.The experimental results confirmed that the laser cladding could be used to produce a thin coating of 120 μm in thickness.In the high-temperature laser cladding process,some Fe elements diffused from the substrate to the coating,forming a combination of face-centred cubic and body-centred cubic phase structures.The HEA coating metallurgically bonded well with the substrate.Owing to the increased dislocation density and number of grain boundaries,the HEA coating was harder and had a stronger hydrophobicity than X70 steel.The electrochemistry results showed that the HEA coating had better corrosion resistance than X70 steel.Aluminium oxides formed on the surface of the HEA coating had a certain protective effect.However,because of the laser cladding,the HEA coating generated cracks.In future work,the laser cladding technology will be improved and heat treatment will be implemented to prevent formation of cracks.展开更多
As anode materials of electrochemical energy storage system,metal sulfides with high theoretical capacities suffer from issues of materials smashing and deactivation due to huge volume change,resulting in the inferior...As anode materials of electrochemical energy storage system,metal sulfides with high theoretical capacities suffer from issues of materials smashing and deactivation due to huge volume change,resulting in the inferior cycle stability.In this paper,a new strategy of adding sulfur powder into the electrospinning precursor instead of employing sulfur powder during the sulfurizing treatment is proposed to prepare Fe_(9)S_(10)composites(CNF@G-Fe_(9)S_(10)-1).In those composites,most of Fe_(9)S_(10)particles are embedded in the graphene-carbon fibers with multiple protection.As anodes for potassium-ion batteries,CNF@G-Fe_(9)S_(10)-1 display higher rate capacities and more excellent stability(103.2 mAh·g^(-1)at 1000 mA·g^(-1)after 892 cycles)than Fe_(9)S_(10)composites synthesized by the traditional method.In addition,as anodes for potassiumion hybrid capacitors,they also deliver high capacities of102.8 mAh·g^(-1)at 1000 mA·g^(-1)after 100 cycles.The morphology characterization evidences indicate that the surface and integrity of CNF@G-Fe_(9)S_(10)-1 are more smooth and complete than the Fe_(9)S_(10)composites fabricated using a common method without sulfur power in electrospinning precursor.The excellent stability and high capacity of CNF@G-Fe_(9)S_(10)-1 can be attributed to nearly full-wrapped structure of Fe_(9)S_(10)in the carbon matrix arising from the new strategy.Owing to the formation of the structure,Fe_(9)S_(10)particles are protected from the pulverization,and the structure stability of hybrid carbon fibers is enhanced.This study may provide a new strategy for the controllable synthesis of metal sulfide-CNFs and their application for high stability energy storage.展开更多
The performance of an iodine radio ion thruster with a 4 cm diameter(IRIT4)was studied experimentally in this paper.Regulation of the mass flow rates of the iodine propellant is achieved by using a temperature control...The performance of an iodine radio ion thruster with a 4 cm diameter(IRIT4)was studied experimentally in this paper.Regulation of the mass flow rates of the iodine propellant is achieved by using a temperature control method of the iodine reservoir.Performance of the thruster using iodine as propellants is obtained at different total thruster powers of 40.6–128.8 W,different grid voltages of 1000–1800 V and the iodine flow rate of 100μgs^(-1).Results show that thrust and specific impulse increase approximately linearly with the increasing total thruster power and the screen grid voltage.The thrust of 2.32 mN and the specific impulse of 2361 s are obtained at the nominal total thruster power of 95.8 W and the screen grid voltage of 1800 V.It is also indicated that performance of the iodine propellant is comparable to that of the xenon propellant;and a difference between them is that the iodine thrust is slightly higher than xenon when the total thruster power is more than 62 W.At the nominal 95.8 W total thruster power,the thrust values of them are 2.32 m N and 2.15 mN respectively,and the thrust-to-power ratios of them are 24.2 mN kW^(-1)and 23.5 mN kW^(-1),respectively.展开更多
Manganese-based material is a prospective cathode material for aqueous zinc ion batteries(ZIBs)by virtue of its high theoretical capacity,high operating voltage,and low price.However,the manganese dissolution during t...Manganese-based material is a prospective cathode material for aqueous zinc ion batteries(ZIBs)by virtue of its high theoretical capacity,high operating voltage,and low price.However,the manganese dissolution during the electrochemical reaction causes its electrochemical cycling stability to be undesirable.In this work,heterointerface engineering-induced oxygen defects are introduced into heterostructure MnO_(2)(δa-MnO_(2))by in situ electrochemical activation to inhibit manganese dissolution for aqueous zinc ion batteries.Meanwhile,the heterointerface between the disordered amorphous and the crystalline MnO_(2)ofδa-MnO_(2)is decisive for the formation of oxygen defects.And the experimental results indicate that the manganese dissolution ofδa-MnO_(2)is considerably inhibited during the charge/discharge cycle.Theoretical analysis indicates that the oxygen defect regulates the electronic and band structure and the Mn-O bonding state of the electrode material,thereby promoting electron transport kinetics as well as inhibiting Mn dissolution.Consequently,the capacity ofδa-MnO_(2)does not degrade after 100 cycles at a current density of 0.5 Ag^(-1)and also 91%capacity retention after 500cycles at 1 Ag^(-1).This study provides a promising insight into the development of high-performance manganese-based cathode materials through a facile and low-cost strategy.展开更多
Objective： In this study, we examine the effects of recombinant adenovirus-p53 （rAd-p53） on the pancreatic carcinoma cell line SW1990. Specifically, we determine if expression of rAd-p53 sensitizes these cells to r...Objective： In this study, we examine the effects of recombinant adenovirus-p53 （rAd-p53） on the pancreatic carcinoma cell line SW1990. Specifically, we determine if expression of rAd-p53 sensitizes these cells to radiation. Methods： Following transfection of SW1990 cells with rAd-p53, we measured expression of P53, P21 and Bax by immunocytochemistry. Both transfected and control cell lines were irradiated with a range of doses, and the survival fractions （SF） were calculated. Dose survival cttrves were constructed and modeled for comparison. Results： Transfection of SW1990 cells with rAd-p53 resulted in increased expression of P53, P21 and Bax in a time-dependent manner. At 96 h after transfection, 89.92% of cells expressed P53, 56.8% expressed P21, and 76.50% expressed Bax. The SF following radiation was lower in the rAd-p53 transfected cells compared to the control cells, suggesting that rAd-p53 sensitizes SW1990 cells to radiation （Do for the experimental and control groups was 2.199 and 2.462, respectively）. Conclusions： Use of the adenoviral vector is an effective means of transfecting SW1990 cells with wild-type P53, and this sensitizes the cell line to irradiation. This work suggests that combining rAd-p53 with radiation therapy in pancreatic cancer may be therapeutically beneficial.展开更多
Li-S batteries have shown great potential as secondary energy batteries.However,the side reaction between Li anodes and polysulfides seriously limited their practical application.Herein,the artificial protective film,...Li-S batteries have shown great potential as secondary energy batteries.However,the side reaction between Li anodes and polysulfides seriously limited their practical application.Herein,the artificial protective film,which is consisted of Li-Nafion and TiO_(2),was designed and successfully prepared to achieve a corrosion-resistant Li anode in Li-S battery.In the composite protective film,the Li-Nafion could efficiently prevent the contact between Li anodes and polysulfides,and the incorporation of TiO_(2)nanoparticles into the Nafion could significantly increase the ionic conductivity and mechanical strength of the protective film.Li-Li symmetric cells with an optimal artificial protective film exhibited an extended cycle-life of 750 h at a current density of 1 mA/cm^(2)in Li_(2)S_(8)electrolyte.Moreover,the Li-S full battery with an optimal protective Li anode exhibited higher capacity retention of 777.4 mAh/g after 100 cycles at 0.1 C as well as better rate performance than the cell with a pure Li anode.This work provides alternative insights to suppress the side reaction for Li-S batteries with high capacity retention.展开更多
基金supported by the National Key Research and Development Project(No.2020YFA0907500)the National Natural Science Foundation of China(No.22476206)+1 种基金the supports from the National Young Top-Notch Talents(No.W03070030)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y202011).
文摘Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(III)nanoparticles with the most commonly identified FRB,Geobacter sulfurreducens PCA,remains poorly understood.Herein,we demonstrated that the synergistic role of outer membrane proteins and periplasmic proteins in the EET process for-Fe_(2)O_(3),Fe3O4,and𝛽α-FeOOH nanoparticles by construction of multiple gene knockout strain.oxpG(involved in the type II secretion system)and omcST(outer membrane c-type cytochrome)medi-ated pathways accounted for approximately 67%of the total reduction of𝛼α-Fe_(2)O_(3) nanoparticles.The residual reduction of𝛼α-Fe_(2)O_(3) nanoparticles in∆oxpG-omcST strain was likely caused by redox-active substances in cell supernatant.Conversely,the reduction of dissolved Fe(III)was almost unaffected in∆oxpG-omcST strain at the same concentration.However,at high dissolved Fe(III)concentration,the reduction significantly decreased due to the formation of Fe(III)nanoparticles,suggesting that this EET process is specific to Fe(III)nanoparticles.Overall,our study provided a more comprehensive understanding for the EET pathways between G.sulfurreducens PCA and different Fe(III)species,enriching our knowledge on the role of microorganisms in iron biogeochemical cycles and remediation strategies of pollutants.
基金supported by the National Natural Science Foundation of Shandong(No.ZR2020ZD20)the National Natural Science Foundation of China(No.22193051)+1 种基金the National Young Top-Notch Talents(No.W03070030)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y202011).
文摘Identification of the most appropriate chemically extractable pool for evaluating Cd and Pb availability remains elusive,hindering accurate assessment on environmental risks and effectiveness of remediation strategies.This study evaluated the feasibility of European Community Bureau of Reference(BCR)sequential extraction,Ca(NO_(3))_(2)extraction,and water extraction on assessing Cd and Pb availability in agricultural soil amended with slaked lime,magnesium hydroxide,corn stover biochar,and calcium dihydrogen phosphate.Moreover,the enriched isotope tracing technique(^(112)Cd and^(206)Pb)was employed to evaluate the aging process of newly introduced Cd and Pbwithin 56 days’incubation.Results demonstrated that extractable pools by BCR and Ca(NO_(3))_(2)extraction were little impacted by amendments and showed little correlation with soil pH.This is notable because soil pH is closely linked to metal availability,indicating these extraction methods may not adequately reflect metal availability.Conversely,water-soluble concentrations of Cd and Pb were markedly influenced by amendments and exhibited strong correlations with pH(Pearson’s r:-0.908 to-0.825,P<0.001),suggesting water extraction as a more sensitive approach.Furthermore,newly introduced metals underwent a more evident aging process as demonstrated by acid-soluble and water-soluble pools.Additionally,water-soluble concentrations of essential metals were impacted by soil amendments,raising caution on their potential effects on plant growth.These findings suggest water extraction as a promising and attractive method to evaluate Cd and Pb availability,which will help provide assessment guidance for environmental risks caused by heavy metals and develop efficient remediation strategies.
基金supported by the National Natural Science Foundation of China (No.52271107)the Bintech-IMR R&D Program,China (No.GYY-JSBU-2022-012)+1 种基金the Natural Science Foundation of Shandong Province,China (No.ZR2021ME241)the Natural Science Foundation of Liaoning Province,China (No.2020-MS-004).
基金financial support of the National Natural Science Foundation of China(No.42230706)the Outstanding Youth Science Fund(Overseas)of Shandong Provincial Natural Science Foundation(No.2022HWYQ-015)+1 种基金the Taishan Scholars Project Special Fund(No.tsqn202211039)Qilu Youth Talent Program of Shandong University(No.61440082163171)。
文摘The removal of highly toxic arsenic(As)and antimony(Sb)contaminants in water by adsorption presents a great challenge worldwide.Conventional adsorbents exhibit insufficient efficacy for removing pentavalent oxyanions,As(Ⅴ)and Sb(Ⅴ),which are predominant compared with the trivalent species,As(Ⅲ)and Sb(Ⅲ),in surface waters.Here,we synthesized a novel composite adsorbent,amine-functionalized polystyrene resin loaded with nano TiO_(2)(Am PSd-Ti).The mm-scale spheres showed outstanding adsorption capacities for As(Ⅲ),As(Ⅴ),Sb(Ⅲ),and Sb(Ⅴ)at 73.85,153.29,86.80,and 123.71 mg/g,respectively.Am PSd-Ti exhibited selective adsorption for As and Sb in the presence of Cl^(-),NO_(3)^(-),SO_(4)^(2-),and F^(-).As and Sb were adsorbed by the nano-sized TiO_(2)confined in the porous resin via forming innersphere complexes.The protonated amine groups enhanced the adsorption of As(Ⅴ)and Sb(Ⅴ)by electrostatic attraction and hydrogen bonding,which was confirmed by experimental results and molecular dynamics simulations.Fixed-bed column tests showed breakthrough curves with adsorption capacities of1.38 mg/g(6600 BV)and 6.65 mg/g(1260 BV)upon treating real As-contaminated groundwater and Sbcontaminated industrial wastewater.Our study highlights a feasible strategy by incorporating inorganic metal oxides into organic polymers to achieve highly efficient removal of As and Sb in real-world scenarios.
基金supported by the National Natural Science Foundation of China (Nos.22206113 and 22376124)the Outstanding Youth Science Fund (Overseas)of Shandong Provincial Natural Science Foundation (No.2022HWYQ-015)+2 种基金the Taishan Scholars Project Special Fund (No.tsqn202211039)the Guangdong Basic and Applied Basic Research Foundation (No.2021A1515111137)Qilu Youth Talent Program of Shandong University (No.61440082163171).
文摘Perfluoroalkyl substances(PFASs)are typical persistent organic pollutants,and their removal is urgently required but challenging.Photocatalysis has shown potential in PFASs degradation due to the redox capabilities of photoinduced charge carriers in photocatalysts.Herein,hexagonal ZnIn_(2)S_(4)(ZIS)nanosheets were synthesized by a one-pot oil bath method and were well characterized by a series of techniques.In the degradation of sodium p-perfluorous nonenoxybenzenesulfonate(OBS),one kind of representative PFASs,the assynthesized ZIS showed activity superior to P25 TiO_(2) under both simulated sunlight and visible-light irradiation.The good photocatalytic performance was attributed to the enhanced light absorption and facilitated charge separation.The pH conditions were found crucial in the photocatalytic process by influencing the OBS adsorption on the ZIS surface.Photogenerated e−and h+were the main active species involved in OBS degradation in the ZIS system.This work confirmed the feasibility and could provide mechanistic insights into the degradation and defluorination of PFASs by visible-light photocatalysis.
基金supported by the Shandong Provincial Natural Science Foundation (No.ZR2022QB242)the National Natural Science Foundation of China (No.22306111 and 22306108)+1 种基金the Shandong Provincial Natural Science Foundation (No.ZR2020ZD20)the Chinese Postdoctoral Science Foundation (No.2023M732059).
文摘Mercury(Hg),especially methylmercury(MeHg),accumulation in rice grain due to rice paddy possessing conditions conducive to Hg methylation has led to human Hg exposure through consumption of rice-based daily meals.In addition to being a food staple,rice is widely used as a raw material to produce a vast variety of processed food products.Little is known about Hg levels in snacking rice-food products and potential Hg exposure from consumption of them,besides previous studies on infant rice cereals.Aiming to provide complementary information for a more complete assessment on Hg exposure risk originated from Hgcontaining rice,this study determined total Hg(THg)and MeHg levels in 195 rice-containing and rice-free processed food products covering all major types of snack foods marketed in China and the estimated daily intake(EDI)of dietary Hg from the consumption of these foods.The results clearly showed THg and MeHg contents in rice-containing foods were significantly higher than rice-free products,suggesting the transfer of Hg and MeHg from the rice to the end products,even after manufacturing processes.Moreover,significant positive correlations were observed between THg,MeHg,or MeHg/THg ratio and rice content for samples containing multiple grains as ingredients,further indicating the deciding role of rice for Hg levels in the end food products.Although the EDI of THg and MeHg via ricebased food products were relatively low compared to the reference dose,it should be considered these snacking food products would contribute additive Hg intake outside of the daily regular meals.
基金supported by the National Natural Science Foundation of China(No.22306111)Shandong Provincial Natural Science Foundation of China(Nos.ZR2022QB242 and ZR2020ZD20).
文摘Considerable levels of methylmercury(MeHg)have been found rice-based infant cereals as a result of MeHg transfer from the rice as a raw material to the products,hence consumption of rice products may pose a potential health risk to infants who may receive cereals as the major diets and are susceptible to toxicity of MeHg.Determination of bioaccessibility of MeHg would provide a more accurate assessment of MeHg exposure through consumption of rice-based cereals,yet this information remains lacking.Further,the re-adsorption of methylmercury on the residual food will affect the accurate assessment of its bioaccessibility.Our goals in this work were 1)to determine the bioaccessibility of MeHg in infant rice cereals commonly available on the market by using a typical in vitro artificial gastrointestinal digestionmodel and 2)to evaluate the effects of MeHg re-adsorption on the in vitro assessment of MeHg bioaccessibility.The determined bioaccessibility of MeHg in the studied rice cereals after the standard dual-step(using gastric followed by intestinal juice)protocol ranged from 25%to 74%,a wide range comparable to that of fish samples observed here and in previous studies.The surprisingly higher bioaccessibility of MeHg in fish and rice cereals after the gastric step only,in comparison to after the complete two-step gastrointestinal digestion,suggests the re-adsorption of MeHg on the residual food.Separate experiments with spiked MeHg standards confirmed that the MeHg released by the acetic gastric juice was re-adsorbed on the residues during the intestinal step at neutral pH.This study provided first-hand data on the bioaccessibility of MeHg in infant rice cereals and methodological implications on using in vitro digestion to evaluate the bioaccessibility of MeHg and metal contaminants in general.
基金National Natural Science Foundation of China(No.52271107)Natural Science Foundation of Liaoning Province,China(No.2020-MS-004)Natural Science Foundation of Shandong Province,China(No.ZR2021ME241)。
文摘AIM: To evaluate the effect of multidisciplinary team (MDT) treatment modality on outcomes of patients with gastrointestinal malignancy in China. METHODS: Data about patients with gastric and colorectal cancer treated in our center during the past 10 years were collected and divided into two parts. Part 1 consisted of the data collected from 516 consecutive complicated cases discussed at MDT meetings in Peking University School of Oncology (PKUSO) from December 2005 to July 2009. Part 2 consisted of the data collected from 263 consecutive cases of resect-able locally advanced rectal cancer from January 2001 to January 2005. These 263 patients were divided into neoadjuvant therapy (NT) group and control group. Patients in NT group received MDT treatment, namely neoadjuvant therapy + surgery + postoperative adjuvant therapy. Patients in control group underwent direct surgery + postoperative adjuvant therapy. The outcomes in two groups were compared. RESULTS: The treatment strategy was altered after discussed at MDT meeting in 76.81% of gastric cancer patients and in 58.33% of colorectal cancer patients before operation. The sphincter-preservation and local control of tumor were better in NT group than in control group. The 5-year overall survival rate was also higher in NT group than in control group (77.23% vs 69.75%, P = 0.049). CONCLUSION: MDT treatment modality can significantly improve the outcomes of patients with gastrointestinal malignancy in China.
文摘AIM: To investigate the meaning of lymphovascular invasion (LVI) in rectal cancer after neoadjuvant radiotherapy. METHODS: A total of 325 patients who underwent radical resection using total mesorectal excision (TME) from January 2000 to January 2005 in Beijing cancer hospital were included retrospectively, divided into a preoperative radiotherapy (PRT) group and a control group, according to whether or not they underwent preoperative radiation. Histological assessments of tumor specimens were made and the correlation of LVI and prognosis were evaluated by univariate and multivariate analysis. RESULTS: The occurrence of LVI in the PRT and control groups was 21.4% and 26.1% respectively. In the control group, LVI was signifi cantly associated with histological differentiation and pathologic TNM stage, whereas these associations were not observed in the PRT group. LVI was closely correlated to disease progression and 5-year overall survival (OS) in both groups. Among the patients with disease progression, LVI positive patients in the PRT group had a signifi cantly longer median disease-free period (22.5 mo vs 11.5 mo, P = 0.023) and overall survival time (42.5 mo vs 26.5 mo, P = 0.035) compared to those in the control group, despite the fact that no signifi cant difference in 5-year OS rate was observed (54.4% vs 48.3%, P = 0.137). Multivariate analysis showed the distance of tumor from the anal verge, pretreatment serum carcinoembryonic antigen level, pathologic TNM stage and LVI were the major factors affecting OS. CONCLUSION: Neoadjuvant radiotherapy does not reduce LVI significantly; however, the prognostic meaning of LVI has changed. Patients with LVI may benefi t from neoadjuvant radiotherapy.
基金supported by the National Natural Science Foundation of China(Grants51772082,51574117,and 51804106)the Research Projects of Degree and Graduate Education Teaching Reformation in Hunan Province(JG2018B031,JG2018A007)+1 种基金the Natural Science Foundation of Hunan Province(2019JJ30002,2019JJ50061)project funded by the China Postdoctoral Science Foundation(2017M610495,2018T110822)
文摘Rhenium diselenide(ReSe2) has caused considerable concerns in the field of energy storage because the compound and its composites still suffer from low specific capacity and inferior cyclic stability.In this study,ReSe2 nanoparticles encapsulated in carbon nanofibers were synthesized successfully with simple electrospinning and heat treatment.It was found that graphene modifications could affect considerably the microstructure and electrochemical properties of ReSe2–carbon nanofibers.Accordingly,the modified compound maintained a capacity of 227 mAhg-1 after 500cycles at 200 mAg-1 for Na+storage,230 mAh g-1 after 200 cycles at 200 mAg-1,212 mAh g-1 after 150 cycles at 500 mAg-1 for K+ storage,which corresponded to the capacity retention ratios of 89%,97%,and 86%,respectively.Even in Na+full cells,its capacity was maintained to 82% after 200 cycles at 1 C(117 mAg-1).The superior stability of ReSe2–carbon nanofibers benefitted from the extremely weak van der Waals interactions and large interlayer spacing of ReSe2,in association with the role of graphene-modified carbon nanofibers,in terms of the shortening of electron/ion transport paths and the improvement of structural support.This study may provide a new route for a broadened range of applications of other rhenium-based compounds.
基金supported by the National Natural Science Foundation of China(Grant Nos.51701055)Science Foundation of China University of Petroleum,Beijing(Nos.2462018YJRC021)+2 种基金the Fundamental Research Funds for the Central Universities(21619401)National Science and Technology Major Project of the Miristry of Science and Technology of China(2016ZX05057001)National Environmental Corrosion Platform。
文摘High-entropy alloys(HEAs) are of great interest in materials science and engineering communities owing to their unique phase structure.HEAs are constructed with five or more principal alloying elements in equimolar or near-equimolar ratios.Therefore,they can derive their performance from multiple principal elements ratherthan a single element.In this work,three-dimensional printing laser cladding was applied to produce an Al_(0.4)CoCu_(0.6)NiSi_(0.2)Ti_(0.25) HEA coating.The experimental results confirmed that the laser cladding could be used to produce a thin coating of 120 μm in thickness.In the high-temperature laser cladding process,some Fe elements diffused from the substrate to the coating,forming a combination of face-centred cubic and body-centred cubic phase structures.The HEA coating metallurgically bonded well with the substrate.Owing to the increased dislocation density and number of grain boundaries,the HEA coating was harder and had a stronger hydrophobicity than X70 steel.The electrochemistry results showed that the HEA coating had better corrosion resistance than X70 steel.Aluminium oxides formed on the surface of the HEA coating had a certain protective effect.However,because of the laser cladding,the HEA coating generated cracks.In future work,the laser cladding technology will be improved and heat treatment will be implemented to prevent formation of cracks.
基金financially supported by the National Natural Science Foundation of China(Nos.51772082 and 51804106)the Natural Science Foundation of Hunan Province(Nos.2019JJ30002 and 2019JJ50061)。
文摘As anode materials of electrochemical energy storage system,metal sulfides with high theoretical capacities suffer from issues of materials smashing and deactivation due to huge volume change,resulting in the inferior cycle stability.In this paper,a new strategy of adding sulfur powder into the electrospinning precursor instead of employing sulfur powder during the sulfurizing treatment is proposed to prepare Fe_(9)S_(10)composites(CNF@G-Fe_(9)S_(10)-1).In those composites,most of Fe_(9)S_(10)particles are embedded in the graphene-carbon fibers with multiple protection.As anodes for potassium-ion batteries,CNF@G-Fe_(9)S_(10)-1 display higher rate capacities and more excellent stability(103.2 mAh·g^(-1)at 1000 mA·g^(-1)after 892 cycles)than Fe_(9)S_(10)composites synthesized by the traditional method.In addition,as anodes for potassiumion hybrid capacitors,they also deliver high capacities of102.8 mAh·g^(-1)at 1000 mA·g^(-1)after 100 cycles.The morphology characterization evidences indicate that the surface and integrity of CNF@G-Fe_(9)S_(10)-1 are more smooth and complete than the Fe_(9)S_(10)composites fabricated using a common method without sulfur power in electrospinning precursor.The excellent stability and high capacity of CNF@G-Fe_(9)S_(10)-1 can be attributed to nearly full-wrapped structure of Fe_(9)S_(10)in the carbon matrix arising from the new strategy.Owing to the formation of the structure,Fe_(9)S_(10)particles are protected from the pulverization,and the structure stability of hybrid carbon fibers is enhanced.This study may provide a new strategy for the controllable synthesis of metal sulfide-CNFs and their application for high stability energy storage.
基金financial support from National Natural Science Foundation of China(No.11805265)Key Laboratory of Micro-Satellites,Chinese Academy of Sciences(No.KFKT201903)。
文摘The performance of an iodine radio ion thruster with a 4 cm diameter(IRIT4)was studied experimentally in this paper.Regulation of the mass flow rates of the iodine propellant is achieved by using a temperature control method of the iodine reservoir.Performance of the thruster using iodine as propellants is obtained at different total thruster powers of 40.6–128.8 W,different grid voltages of 1000–1800 V and the iodine flow rate of 100μgs^(-1).Results show that thrust and specific impulse increase approximately linearly with the increasing total thruster power and the screen grid voltage.The thrust of 2.32 mN and the specific impulse of 2361 s are obtained at the nominal total thruster power of 95.8 W and the screen grid voltage of 1800 V.It is also indicated that performance of the iodine propellant is comparable to that of the xenon propellant;and a difference between them is that the iodine thrust is slightly higher than xenon when the total thruster power is more than 62 W.At the nominal 95.8 W total thruster power,the thrust values of them are 2.32 m N and 2.15 mN respectively,and the thrust-to-power ratios of them are 24.2 mN kW^(-1)and 23.5 mN kW^(-1),respectively.
基金funds from the National Natural Science Foundation of China(51772082 and 51804106)the Natural Science Foundation of Hunan Province(2023JJ10005)
文摘Manganese-based material is a prospective cathode material for aqueous zinc ion batteries(ZIBs)by virtue of its high theoretical capacity,high operating voltage,and low price.However,the manganese dissolution during the electrochemical reaction causes its electrochemical cycling stability to be undesirable.In this work,heterointerface engineering-induced oxygen defects are introduced into heterostructure MnO_(2)(δa-MnO_(2))by in situ electrochemical activation to inhibit manganese dissolution for aqueous zinc ion batteries.Meanwhile,the heterointerface between the disordered amorphous and the crystalline MnO_(2)ofδa-MnO_(2)is decisive for the formation of oxygen defects.And the experimental results indicate that the manganese dissolution ofδa-MnO_(2)is considerably inhibited during the charge/discharge cycle.Theoretical analysis indicates that the oxygen defect regulates the electronic and band structure and the Mn-O bonding state of the electrode material,thereby promoting electron transport kinetics as well as inhibiting Mn dissolution.Consequently,the capacity ofδa-MnO_(2)does not degrade after 100 cycles at a current density of 0.5 Ag^(-1)and also 91%capacity retention after 500cycles at 1 Ag^(-1).This study provides a promising insight into the development of high-performance manganese-based cathode materials through a facile and low-cost strategy.
基金supported by Fujian Province Natural Science Foundation(No.2012J05139)Beijing Municipal Science & Technology Commission(No.Z111107058811021)
文摘Objective： In this study, we examine the effects of recombinant adenovirus-p53 （rAd-p53） on the pancreatic carcinoma cell line SW1990. Specifically, we determine if expression of rAd-p53 sensitizes these cells to radiation. Methods： Following transfection of SW1990 cells with rAd-p53, we measured expression of P53, P21 and Bax by immunocytochemistry. Both transfected and control cell lines were irradiated with a range of doses, and the survival fractions （SF） were calculated. Dose survival cttrves were constructed and modeled for comparison. Results： Transfection of SW1990 cells with rAd-p53 resulted in increased expression of P53, P21 and Bax in a time-dependent manner. At 96 h after transfection, 89.92% of cells expressed P53, 56.8% expressed P21, and 76.50% expressed Bax. The SF following radiation was lower in the rAd-p53 transfected cells compared to the control cells, suggesting that rAd-p53 sensitizes SW1990 cells to radiation （Do for the experimental and control groups was 2.199 and 2.462, respectively）. Conclusions： Use of the adenoviral vector is an effective means of transfecting SW1990 cells with wild-type P53, and this sensitizes the cell line to irradiation. This work suggests that combining rAd-p53 with radiation therapy in pancreatic cancer may be therapeutically beneficial.
基金partially supported by grants from the National Natural Science Foundation of China(Nos.51772069 and 52072099)。
文摘Li-S batteries have shown great potential as secondary energy batteries.However,the side reaction between Li anodes and polysulfides seriously limited their practical application.Herein,the artificial protective film,which is consisted of Li-Nafion and TiO_(2),was designed and successfully prepared to achieve a corrosion-resistant Li anode in Li-S battery.In the composite protective film,the Li-Nafion could efficiently prevent the contact between Li anodes and polysulfides,and the incorporation of TiO_(2)nanoparticles into the Nafion could significantly increase the ionic conductivity and mechanical strength of the protective film.Li-Li symmetric cells with an optimal artificial protective film exhibited an extended cycle-life of 750 h at a current density of 1 mA/cm^(2)in Li_(2)S_(8)electrolyte.Moreover,the Li-S full battery with an optimal protective Li anode exhibited higher capacity retention of 777.4 mAh/g after 100 cycles at 0.1 C as well as better rate performance than the cell with a pure Li anode.This work provides alternative insights to suppress the side reaction for Li-S batteries with high capacity retention.
