Symbiosis between soybean and rhizobia contributes to soybean yield and quality. Although secreted rhizobial type Ⅲ effectors are known to regulate infection and promote nitrogen fixation, much about them remains unk...Symbiosis between soybean and rhizobia contributes to soybean yield and quality. Although secreted rhizobial type Ⅲ effectors are known to regulate infection and promote nitrogen fixation, much about them remains unknown. Mutation of NopC, a type Ⅲ effector from Sinorhizobium fredii HH103, reduced nodule numbers and dry weights in 310 soybean accessions, and expression of NopC in soybean hairy roots promoted symbiosis. Based on observed differences in nodule traits between Suinong 14 and Zyd 00,006inoculated with HH103 and the NopC mutant, 11 QTL associated with rhizobia were identified in chromosome segment substitution lines(CSSLs) derived from Suinong 14 and Zyd 00006. Using chromosome fragment insertion, whole-genome sequencing of Suinong 14 and Zyd 00006, and qRT-PCR,Glyma.19G176300(GmCRP) was identified as a candidate gene associated with NopC, and GmCRP was found to be induced by NopC to positively regulate nodulation. SNPs located in the regulatory regions of GmCRP influenced its expression response to NopC, with SNPs contributing to nodulation having been selected during domestication. Our findings reveal the function of a soybean gene encoding a rhizobial type Ⅲ effector that contributes to symbiosis, and will facilitate the practical application of symbiotic nitrogen fixation in molecular breeding.展开更多
Objective:Spontaneous hepatocellular carcinoma(HCC)rupture can be fatal,and hepatic resection could achieve a favorable long-term survival among all strategies of tumor rupture.However,there is no available prognostic...Objective:Spontaneous hepatocellular carcinoma(HCC)rupture can be fatal,and hepatic resection could achieve a favorable long-term survival among all strategies of tumor rupture.However,there is no available prognostic scoring system for patients with ruptured HCC who underwent partial hepatectomy.Methods:From January 2005 to May 2015,129 patients with spontaneous HCC rupture underwent partial hepatectomy.Preoperative clinical data were collected and analyzed.Independent risk factors affecting overall survival(OS)were used to develop the new scoring system.Harrell’s C statistics,Akaike information criterion(AIC),the relative likelihood,and the log likelihood ratio were calculated to measure the homogeneity and discriminatory ability of a prognostic system.Results:In the multivariable Cox regression analysis,three factors,including tumor size,preoperativeα-fetoprotein level,and alkaline phosphatase level,were chosen for the new tumor-associated antigen(TAA)prognostic scoring system.The 1-year OS rates were 88.1%,43.2%,and 30.2%for TAA scores of 0–5 points(low-risk group),6–9 points(moderate-risk group),and 10–13points(high-risk group),respectively.The TAA scoring system had superior homogeneity and discriminatory ability(Harrell’s C statistics,0.693 vs.0.627 and 0.634;AIC,794.79 vs.817.23 and 820.16;relative likelihood,both<0.001;and log likelihood ratio,45.21 vs.22.77 and 21.84)than the Barcelona Clinic Liver Cancer staging system and the Cancer of the Liver Italian Program in predicting OS.Similar results were found while predicting disease-free survival(DFS).Conclusions:The new prognostic scoring system is simple and effective in predicting both OS and DFS of patients with spontaneous ruptured HCC.展开更多
Three industry-supplied, well-shaped Mo/HZSM-5 catalysts, two binder-added and one binder-free, were tested for the first time in methane dehydroaromatization to benzene at 1073 K and 10000 mL/(g·h) in periodic...Three industry-supplied, well-shaped Mo/HZSM-5 catalysts, two binder-added and one binder-free, were tested for the first time in methane dehydroaromatization to benzene at 1073 K and 10000 mL/(g·h) in periodic CH4-H2 switch operation mode, and their catalytic performances were compared with those of three self-prepared, binder-free powder Mo/HZSM-5 catalysts. XRD, 27Al NMR, SEM, BET and NH3-TPD characterizations of all the catalysts show that the zeolites in the two binder-added catalysts are comparable to those in the three binder-free powder catalysts in crystallinity, crystal size, micropore volume and Br{/o}nsted acidity. The test results, on the other hand, show that the catalytic performances of the two binder-added catalysts are worse than those of the four binder-free catalysts on both catalyst mass and zeolite mass bases. Then, TPO and BET measurements of all spent samples were conducted to get a deep insight into the negative effects of binder addition, and the results suggest that the binder additives functioned mainly to enhance the polyaromatization of formed aromatics to coke on their external surfaces and consequently lower the catalysts' benzene formation activity and selectivity.展开更多
A pilot-scale methane dehydroaromatization–H_2regeneration fluidized bed system(MDARS)was developed.In the MDARS,the catalyst circulation between a fluidized bed reactor and a fluidized bed regenerator with the help ...A pilot-scale methane dehydroaromatization–H_2regeneration fluidized bed system(MDARS)was developed.In the MDARS,the catalyst circulation between a fluidized bed reactor and a fluidized bed regenerator with the help of a catalyst feeder allowed methane dehydroaromatization(MDA)and H_2regeneration to be carried out simultaneously,which is good for maintaining a stable MDA catalytic activity.A fixed bed reactor(FB)and a single fluidized bed reactor(SFB)were also used for a comparative study.The experimental results showed that the catalytic activity in the MDARS was more stable than that in the FB and SFB reactors.The effects of some parameters of MDARS on the CH_4conversion and product selectivity were investigated.To verify the feasibility and reliability of the MDARS,an eight-hour long-term test was carried out,which demonstrated that the operation of the MDARS was stable and that the catalytic activity remained stable throughout the entire experimental period.展开更多
As a potential methane efficient conversion process,non-oxidative aromatization of methane in fluidized bed requires a catalyst with good attrition resistance,especially in the states of high temperature,longtime rapi...As a potential methane efficient conversion process,non-oxidative aromatization of methane in fluidized bed requires a catalyst with good attrition resistance,especially in the states of high temperature,longtime rapid movement and chemical reaction.Existing evaluation methods for attrition resistance,such as ASTM D5757 and Jet Cup test,are targeted for fresh catalysts at ambient temperature,which cannot well reflect the real process.In this study,spherical-shaped Mo/HZSM-5 catalyst prepared by dipping and spray drying was placed in a self-made apparatus for attrition testing,in which the catalyst attrition under different system temperatures,running time and process factors was investigated with percent mass loss(PML),particle size-mass distribution(PSMD)and scanning electron microscope(SEM).Carbon deposition on the catalyst before and after activation,aromatization and regeneration was analyzed by thermogravimetry(TG),and the attrited catalysts were evaluated for methane dehydro-aromatization(MDA).The results show that the surface abrasion and body breakage of catalyst particles occur continuously,with the increase of system temperature and running time,and make the PML rise gradually.The process factors of activation,aromatization and regeneration can cause the catalyst attrition and carbon deposits,which broaden the PSMD in varying degrees,and the carbon-substances on catalysts greatly improve their attrition resistance at high temperature.Catalyst attrition has a certain influence on its catalytic performance,and the main reasons point to particle breakage and fine powder escape.展开更多
Mature soybean phenotyping is an important process in soybean breeding;however, the manual process is time-consuming and labor-intensive. Therefore, a novel approach that is rapid, accurate and highly precise is requi...Mature soybean phenotyping is an important process in soybean breeding;however, the manual process is time-consuming and labor-intensive. Therefore, a novel approach that is rapid, accurate and highly precise is required to obtain the phenotypic data of soybean stems, pods and seeds. In this research, we propose a mature soybean phenotype measurement algorithm called Soybean Phenotype Measure-instance Segmentation(SPM-IS). SPM-IS is based on a feature pyramid network, Principal Component Analysis(PCA) and instance segmentation. We also propose a new method that uses PCA to locate and measure the length and width of a target object via image instance segmentation. After 60,000 iterations, the maximum mean Average Precision(m AP) of the mask and box was able to reach 95.7%. The correlation coefficients R^(2) of the manual measurement and SPM-IS measurement of the pod length, pod width, stem length, complete main stem length, seed length and seed width were 0.9755, 0.9872, 0.9692, 0.9803,0.9656, and 0.9716, respectively. The correlation coefficients R^(2) of the manual counting and SPM-IS counting of pods, stems and seeds were 0.9733, 0.9872, and 0.9851, respectively. The above results show that SPM-IS is a robust measurement and counting algorithm that can reduce labor intensity, improve efficiency and speed up the soybean breeding process.展开更多
Objective: Incomplete radiofrequency ablation(ICR) has been proposed as a major cause of recurrence in the treatment of hepatic metastatic tumors.We tried to determine the mechanisms of this progression in colorectal ...Objective: Incomplete radiofrequency ablation(ICR) has been proposed as a major cause of recurrence in the treatment of hepatic metastatic tumors.We tried to determine the mechanisms of this progression in colorectal cancer(CRC) liver metastasis(CRLMs)Methods: We have established a mouse model of radiofrequency ablation(RFA) therapy to demonstrate increased risk of recurrence of CRLMs with ICR.Here we focused on heat shock-induced CRC malignancy.Sub-lethal heat shock(HS) in CRC cell lines provoked cell growth, invasion, and tumor initiation in vitro and in vivo.Results: We found that Fra-1, which lies downstream of PKCα-ERK1/2 signaling, was significantly increased by HS compared with the untreated CRC cells.Silencing Fra-1 reversed the tumor promoting effects of HS.Furthermore, proliferation and tumor initiation inducer c-Myc, together with tumor invasion inducer matrix-metalloprotase 1(MMP-1) expression were up-regulated by AP-1/Fra-1 induced genes transcription.Conclusions: Our study demonstrated that ICR generated HS induces CRC malignancy by targeting Fra-1, which could be a potential prognostic marker and a promising therapeutic strategy to prevent disease recurrence after radiofrequency ablation treatment.展开更多
In plants,glycerol-3-phosphate dehydrogenase(GPDH)catalyzes the interconversion of glycerol-3-phosphate(G3P)and dihydroxyacetone phosphate(DHAP)coupled to the reduction/oxidation of the nicotinamide adenine dinucleoti...In plants,glycerol-3-phosphate dehydrogenase(GPDH)catalyzes the interconversion of glycerol-3-phosphate(G3P)and dihydroxyacetone phosphate(DHAP)coupled to the reduction/oxidation of the nicotinamide adenine dinucleotide(NADH)pool,and plays a central role in glycerolipid metabolism and stress response.Previous studies have focused mainly on the NAD+-dependent GPDH isoforms,neglecting the role of flavin adenine dinucleotide(FAD)-dependent GPDHs.We isolated and characterized three mitochondrialtargeted FAD-GPDHs in soybean,of which one isoform(GmGPDH12)showed a significant transcriptional response to NaCl and mannitol treatments,suggesting the existence of a major FAD-GPDH isoform acting in soybean responses to salt and osmotic stress.An enzyme kinetic assay showed that the purified GmGPDH12 protein possessed the capacity to oxidize G3P to DHAP in the presence of FAD.Overexpression and RNA interference of GmGPDH12 in soybean hairy roots resulted in elevated tolerance and sensitivity to salt and osmotic stress,respectively.G3P contents were significantly lower in GmGPDH12-overexpressing hair roots and higher in knockdown hair roots,indicating that GmGPDH12 was essential for G3P catabolism.A significant perturbation in redox status of NADH,ascorbic acid(ASA)and glutathione(GSH)pools was observed in GmGPDH12-knockdown plants under stress conditions.The impaired redox balance was manifested by higher reactive oxygen species generation and consequent cell damage or death;however,overexpressing plants showed the opposite results for these traits.GmGPDH12 overexpression contributed to maintaining constant respiration rates under salt or osmotic stress by regulating mRNA levels of key mitochondrial respiratory enzymes.This study provides new evidence for the roles of mitochondria-localized GmGPDH12 in conferring resistance to salt or osmotic stress by maintaining cellular redox homeostasis,protecting cells and respiration from oxidative injury.展开更多
Biliary tract cancers(BTCs)are a group of malignant neoplasms that have recently increased in incidence and have a poor prognosis.Surgery is the only curative therapy.However,most patients are only indicated for palli...Biliary tract cancers(BTCs)are a group of malignant neoplasms that have recently increased in incidence and have a poor prognosis.Surgery is the only curative therapy.However,most patients are only indicated for palliative therapy because of advanced-stage disease at diagnosis and rapid progression.The current first-line treatment for advanced BTC is gemcitabine and cisplatin chemotherapy.Nonetheless,many patients develop resistance to this regimen.Over the years,few chemotherapy regimens have managed to improve the overall survival of patients.Accordingly,novel therapies such as targeted therapy have been introduced to treat this patient population.Extensive research on tumorigenesis and the genetic profiling of BTC have revealed the heterogenicity and potential target pathways,such as EGFR,VEGF,MEK/ERK,PI3K and mTOR.Moreover,mutational analysis has documented the presence of IDH1,FGFR2,HER2,PRKACA,PRKACB,BRAF,and KRAS gene aberrations.The emergence of immunotherapy in recent years has expanded the treatment landscape for this group of malignancies.Cancer vaccines,adoptive cell transfer,and immune checkpoint inhibitors have been extensively investigated in trials of BTC.Therefore,patient stratification and a combination of various therapies have become a reasonable and important clinical strategy to improve patient outcomes.This review elaborates the literature on combined treatment strategies for advanced BTC from the past few years and ongoing clinical trials to provide new inspiration for the treatment of advanced BTC.展开更多
There is growing interest in expanding the production of soybean oils(mainly triacylglycerol, or TAG) to meet rising feed demand and address global energy concerns. We report that a plastidlocalized glycerol-3-phospha...There is growing interest in expanding the production of soybean oils(mainly triacylglycerol, or TAG) to meet rising feed demand and address global energy concerns. We report that a plastidlocalized glycerol-3-phosphate dehydrogenase(GPDH), encoded by GmGPDHp1 gene, catalyzes the formation of glycerol-3-phosphate(G3 P), an obligate substrate required for TAG biosynthesis.Overexpression of GmGPDHp1 increases soybean seed oil content with high levels of unsaturated fatty acids(FAs), especially oleic acid(C18:1), without detectably affecting growth or seed protein content or seed weight. Based on the lipidomic analyses, we found that the increase in G3 P content led to an elevated diacylglycerol(DAG) pool, in which the Kennedy pathwayderived DAG was mostly increased, followed by PC-derived DAG, thereby promoting the synthesis of TAG containing relatively high proportion of C18:1. The increased G3 P levels induced several transcriptional alterations of genes involved in the glycerolipid pathways. In particular, genes encoding the enzymes responsible for de novo glycerolipid synthesis were largely upregulated in the transgenic lines, in-line with the identified biochemical phenotype. These results reveal a key role for GmGPDHp1-mediated G3 P metabolism in enhancing TAG synthesis and demonstrate a strategy to modify the FA compositions of soybean oils for improved nutrition and biofuel.展开更多
Monolith SCR catalysts coated with V2Os- WO3/TiO2 were prepared by varying binder and coating thickness. Comparing with a monolith extruded with 100% V2O5-WO3/TiO2 powder, a coated monolith with a catalyst-coating lay...Monolith SCR catalysts coated with V2Os- WO3/TiO2 were prepared by varying binder and coating thickness. Comparing with a monolith extruded with 100% V2O5-WO3/TiO2 powder, a coated monolith with a catalyst-coating layer of 260 μm in thickness exhibited the similar initial NOx reduction activity at 250℃. After 4 h abrasion (attrition) in an air stream containing 300 g. m^-3 fine sands (50-100μm) at a superficial gas velocity of 10m·s^-1, the catalyst still has the activity as a 100% molded monolith does in a 24-h activity test and it retains about 92% of its initial activity at 250℃. Estimation of the equivalent durable hours at a fly ash concentration of 1.0 g.m^-3 in flue gas and a gas velocity of 5 m.s^-1 demonstrated that this coated monolith catalyst is capable of resisting abrasion for 13 months without losing more than 8% of its initial activity. The result suggests the great potential of the coated monolith for application to de-NOx of flue gases with low fly ash concentrations from, such as glass and ceramics manufacturing processes.展开更多
A comprehensive overview is presented to summarize the research works since 1982 on oxidative coupling of methane(OCM),a complex reaction network combining heterogeneous and homogeneous reaction steps.Fundamentals on ...A comprehensive overview is presented to summarize the research works since 1982 on oxidative coupling of methane(OCM),a complex reaction network combining heterogeneous and homogeneous reaction steps.Fundamentals on reaction mechanisms and thermodynamics have revealed that the OCM process is highly exothermic and its C2+selectivity and yield is critical in evaluating its commercial viability.Catalytic strategies have been put to enhance C2+selectivity,improve C2+yield and lower reaction temperature.The catalyst MnNa2WO4/SiO2 enables methane activation at a temperature of 800◦C and simultaneously a high C2+selectivity of 70–80%,while the nanowire and La2O3-based catalysts enable to lower the reaction temperature to 200–300◦C and 500◦C,respectively.Reaction engineering aspects have also been dealt in many investigations in order to make the process technically feasible.Particularly,research works on reaction kinetics,reactor selection and reactor operating mode choice have been addressed.Intermediate cooling and distributed oxygen feed have been integrated into a multi-stage adiabatic fixed-bed reactor system to suppress the side oxidation reactions and improve the performance of the catalysts towards CH4 conversion and C2+yield.This review paper proposes employing a circulating reactor system coupled with catalyst fine particles but having little internal diffusion resistance to maximize one-pass C2+selectivity and yield of the OCM reaction and evaluate its industrial application potential.展开更多
Background and Aims:The expression of discoidin domain receptor 1(DDR1)is commonly up-regulated and undergoes collagen-induced ectodomain(N-terminal)shedding during the progression of liver fibrosis.This study aimed t...Background and Aims:The expression of discoidin domain receptor 1(DDR1)is commonly up-regulated and undergoes collagen-induced ectodomain(N-terminal)shedding during the progression of liver fibrosis.This study aimed to evaluate the clinical utility of N-terminal DDR1 as a diagnostic biomarker for liver fibrosis.Methods:N-terminal DDR1 shedding was evaluated using cell lines,liver fibrosis mouse models,clinical data of 298 patients collected from February 2019 to June 2020.The clinical data were divided into test and validation cohorts to evaluate the diagnostic performance of serum N-terminal DDR1.Results:Timeand dosage-dependent N-terminal DDR1 shedding stimulated by collagen I was observed in a hepatocyte cell line model.The type I collagen deposition and serum N-terminal DDR1 levels concurrently increased in the development of liver fibrosis in mouse models.Clinical data demonstrated a significant diagnostic power of serum N-terminal DDR1 levels as an accurate biomarker of liver fibrosis and cirrhosis.The diagnostic performance was further increased when applying N-DDR1/albumin ratio,achieving area under the curve of 0.790,0.802,0.879,and 0.865 for detecting histological fibrosis stages F≥2,F≥3,F 4 with liver biopsy as a reference method,and cirrhosis according to imaging techniques,respectively.With a cut-off of 55.6,a sensitivity,specificity,positive predictive value,and negative predictive value of 82.7%,76.6%,67.4%,and 88.3%were achieved for the detection of cirrhosis.Conclusions:Serum N-terminal DDR1 appears to be a novel diagnostic marker for liver fibrosis.展开更多
Ultra-thin Pd-Ag alloy membranes were prepared initially by cold rolling, and it was found that there exist a large number of defects such as pinholes or cracks in the as-rolled membranes. Subsequently, these defects ...Ultra-thin Pd-Ag alloy membranes were prepared initially by cold rolling, and it was found that there exist a large number of defects such as pinholes or cracks in the as-rolled membranes. Subsequently, these defects were repaired using electroless plating technique. The morphologies of the membranes have been examined by scanning electron microscopy (SEM). It was observed in some as-repaired membranes that the defects were disappeared. A hydrogen permeation study has demonstrated that the as-repaired Pd-Ag alloy membranes were of high hydrogen permeation flux and hydrogen selectivity.展开更多
基金supported by the China Postdoctoral Science Foundation(2020M681072)the National Natural Science Foundation of China(32072014,U20A2027,and 31771882)‘Hundred-thousand and million project of Heilongjiang province for engineering and technology science’soybean breeding technology innovation and new cultivar breeding(2019ZX16B01).
文摘Symbiosis between soybean and rhizobia contributes to soybean yield and quality. Although secreted rhizobial type Ⅲ effectors are known to regulate infection and promote nitrogen fixation, much about them remains unknown. Mutation of NopC, a type Ⅲ effector from Sinorhizobium fredii HH103, reduced nodule numbers and dry weights in 310 soybean accessions, and expression of NopC in soybean hairy roots promoted symbiosis. Based on observed differences in nodule traits between Suinong 14 and Zyd 00,006inoculated with HH103 and the NopC mutant, 11 QTL associated with rhizobia were identified in chromosome segment substitution lines(CSSLs) derived from Suinong 14 and Zyd 00006. Using chromosome fragment insertion, whole-genome sequencing of Suinong 14 and Zyd 00006, and qRT-PCR,Glyma.19G176300(GmCRP) was identified as a candidate gene associated with NopC, and GmCRP was found to be induced by NopC to positively regulate nodulation. SNPs located in the regulatory regions of GmCRP influenced its expression response to NopC, with SNPs contributing to nodulation having been selected during domestication. Our findings reveal the function of a soybean gene encoding a rhizobial type Ⅲ effector that contributes to symbiosis, and will facilitate the practical application of symbiotic nitrogen fixation in molecular breeding.
文摘Objective:Spontaneous hepatocellular carcinoma(HCC)rupture can be fatal,and hepatic resection could achieve a favorable long-term survival among all strategies of tumor rupture.However,there is no available prognostic scoring system for patients with ruptured HCC who underwent partial hepatectomy.Methods:From January 2005 to May 2015,129 patients with spontaneous HCC rupture underwent partial hepatectomy.Preoperative clinical data were collected and analyzed.Independent risk factors affecting overall survival(OS)were used to develop the new scoring system.Harrell’s C statistics,Akaike information criterion(AIC),the relative likelihood,and the log likelihood ratio were calculated to measure the homogeneity and discriminatory ability of a prognostic system.Results:In the multivariable Cox regression analysis,three factors,including tumor size,preoperativeα-fetoprotein level,and alkaline phosphatase level,were chosen for the new tumor-associated antigen(TAA)prognostic scoring system.The 1-year OS rates were 88.1%,43.2%,and 30.2%for TAA scores of 0–5 points(low-risk group),6–9 points(moderate-risk group),and 10–13points(high-risk group),respectively.The TAA scoring system had superior homogeneity and discriminatory ability(Harrell’s C statistics,0.693 vs.0.627 and 0.634;AIC,794.79 vs.817.23 and 820.16;relative likelihood,both<0.001;and log likelihood ratio,45.21 vs.22.77 and 21.84)than the Barcelona Clinic Liver Cancer staging system and the Cancer of the Liver Italian Program in predicting OS.Similar results were found while predicting disease-free survival(DFS).Conclusions:The new prognostic scoring system is simple and effective in predicting both OS and DFS of patients with spontaneous ruptured HCC.
文摘Three industry-supplied, well-shaped Mo/HZSM-5 catalysts, two binder-added and one binder-free, were tested for the first time in methane dehydroaromatization to benzene at 1073 K and 10000 mL/(g·h) in periodic CH4-H2 switch operation mode, and their catalytic performances were compared with those of three self-prepared, binder-free powder Mo/HZSM-5 catalysts. XRD, 27Al NMR, SEM, BET and NH3-TPD characterizations of all the catalysts show that the zeolites in the two binder-added catalysts are comparable to those in the three binder-free powder catalysts in crystallinity, crystal size, micropore volume and Br{/o}nsted acidity. The test results, on the other hand, show that the catalytic performances of the two binder-added catalysts are worse than those of the four binder-free catalysts on both catalyst mass and zeolite mass bases. Then, TPO and BET measurements of all spent samples were conducted to get a deep insight into the negative effects of binder addition, and the results suggest that the binder additives functioned mainly to enhance the polyaromatization of formed aromatics to coke on their external surfaces and consequently lower the catalysts' benzene formation activity and selectivity.
基金Supported by Hydrocarbon High-efficiency Utilization Technology Research Center of Yanchang Petroleum(Group)Co.Ltd,China(Contract No.HCRC-C13-010)by the National Natural Science Foundation of China(21536009)
文摘A pilot-scale methane dehydroaromatization–H_2regeneration fluidized bed system(MDARS)was developed.In the MDARS,the catalyst circulation between a fluidized bed reactor and a fluidized bed regenerator with the help of a catalyst feeder allowed methane dehydroaromatization(MDA)and H_2regeneration to be carried out simultaneously,which is good for maintaining a stable MDA catalytic activity.A fixed bed reactor(FB)and a single fluidized bed reactor(SFB)were also used for a comparative study.The experimental results showed that the catalytic activity in the MDARS was more stable than that in the FB and SFB reactors.The effects of some parameters of MDARS on the CH_4conversion and product selectivity were investigated.To verify the feasibility and reliability of the MDARS,an eight-hour long-term test was carried out,which demonstrated that the operation of the MDARS was stable and that the catalytic activity remained stable throughout the entire experimental period.
基金supported by Hydrocarbon High-efficiency Utilization Technology Research Center of Shaanxi Yanchang Petroleum(Group)Co.,Ltd.,China(Contract No.HCRC-C13-010)the National Natural Science Foundation of China(No.21536009)。
文摘As a potential methane efficient conversion process,non-oxidative aromatization of methane in fluidized bed requires a catalyst with good attrition resistance,especially in the states of high temperature,longtime rapid movement and chemical reaction.Existing evaluation methods for attrition resistance,such as ASTM D5757 and Jet Cup test,are targeted for fresh catalysts at ambient temperature,which cannot well reflect the real process.In this study,spherical-shaped Mo/HZSM-5 catalyst prepared by dipping and spray drying was placed in a self-made apparatus for attrition testing,in which the catalyst attrition under different system temperatures,running time and process factors was investigated with percent mass loss(PML),particle size-mass distribution(PSMD)and scanning electron microscope(SEM).Carbon deposition on the catalyst before and after activation,aromatization and regeneration was analyzed by thermogravimetry(TG),and the attrited catalysts were evaluated for methane dehydro-aromatization(MDA).The results show that the surface abrasion and body breakage of catalyst particles occur continuously,with the increase of system temperature and running time,and make the PML rise gradually.The process factors of activation,aromatization and regeneration can cause the catalyst attrition and carbon deposits,which broaden the PSMD in varying degrees,and the carbon-substances on catalysts greatly improve their attrition resistance at high temperature.Catalyst attrition has a certain influence on its catalytic performance,and the main reasons point to particle breakage and fine powder escape.
基金supported by the National Natural Science Foundation of China (31400074, 31471516, 31271747, and 30971809)the Natural Science Foundation of Heilongjiang Province of China(ZD201213)the Heilongjiang Postdoctoral Science Foundation(LBH-Q18025)。
文摘Mature soybean phenotyping is an important process in soybean breeding;however, the manual process is time-consuming and labor-intensive. Therefore, a novel approach that is rapid, accurate and highly precise is required to obtain the phenotypic data of soybean stems, pods and seeds. In this research, we propose a mature soybean phenotype measurement algorithm called Soybean Phenotype Measure-instance Segmentation(SPM-IS). SPM-IS is based on a feature pyramid network, Principal Component Analysis(PCA) and instance segmentation. We also propose a new method that uses PCA to locate and measure the length and width of a target object via image instance segmentation. After 60,000 iterations, the maximum mean Average Precision(m AP) of the mask and box was able to reach 95.7%. The correlation coefficients R^(2) of the manual measurement and SPM-IS measurement of the pod length, pod width, stem length, complete main stem length, seed length and seed width were 0.9755, 0.9872, 0.9692, 0.9803,0.9656, and 0.9716, respectively. The correlation coefficients R^(2) of the manual counting and SPM-IS counting of pods, stems and seeds were 0.9733, 0.9872, and 0.9851, respectively. The above results show that SPM-IS is a robust measurement and counting algorithm that can reduce labor intensity, improve efficiency and speed up the soybean breeding process.
基金supported by the State Key Project on Infection Disease of China (Grant No.2018ZX10723204-003)National Natural Science Foundation of China (Grant No.81502530, 81874149, 81572427, 81874189)
文摘Objective: Incomplete radiofrequency ablation(ICR) has been proposed as a major cause of recurrence in the treatment of hepatic metastatic tumors.We tried to determine the mechanisms of this progression in colorectal cancer(CRC) liver metastasis(CRLMs)Methods: We have established a mouse model of radiofrequency ablation(RFA) therapy to demonstrate increased risk of recurrence of CRLMs with ICR.Here we focused on heat shock-induced CRC malignancy.Sub-lethal heat shock(HS) in CRC cell lines provoked cell growth, invasion, and tumor initiation in vitro and in vivo.Results: We found that Fra-1, which lies downstream of PKCα-ERK1/2 signaling, was significantly increased by HS compared with the untreated CRC cells.Silencing Fra-1 reversed the tumor promoting effects of HS.Furthermore, proliferation and tumor initiation inducer c-Myc, together with tumor invasion inducer matrix-metalloprotase 1(MMP-1) expression were up-regulated by AP-1/Fra-1 induced genes transcription.Conclusions: Our study demonstrated that ICR generated HS induces CRC malignancy by targeting Fra-1, which could be a potential prognostic marker and a promising therapeutic strategy to prevent disease recurrence after radiofrequency ablation treatment.
基金financially supported by National Natural Science Foundation of China(31701449,31971968,31971899,31501332)National Key Research and Development Program of China(2016YFD 0100500,2016YFD0100300,2016YFD0100201-21,JFYS2016ZY03003792-01-21)+7 种基金China Postdoctoral Science Foundation(2019M661243)Postdoctoral Project of Northeast Agricultural University(NEAUBH-19002)EUCLEG(727312,2017YFE0111000)Natural Science Foundation of Heilongjiang Province(QC2017013)Special Financial Aid to Post-doctor Research Fellow in Heilongjiang(LBH-TZ1714)Heilongjiang Academy of Agricultural Sciences Funds(2019YYYF019)International Postdoctoral Exchange Fellowship Program of China Postdoctoral Council(20180004)Heilongjiang Funds for Distinguished Young Scientists(JC2016004,JC2017006)。
文摘In plants,glycerol-3-phosphate dehydrogenase(GPDH)catalyzes the interconversion of glycerol-3-phosphate(G3P)and dihydroxyacetone phosphate(DHAP)coupled to the reduction/oxidation of the nicotinamide adenine dinucleotide(NADH)pool,and plays a central role in glycerolipid metabolism and stress response.Previous studies have focused mainly on the NAD+-dependent GPDH isoforms,neglecting the role of flavin adenine dinucleotide(FAD)-dependent GPDHs.We isolated and characterized three mitochondrialtargeted FAD-GPDHs in soybean,of which one isoform(GmGPDH12)showed a significant transcriptional response to NaCl and mannitol treatments,suggesting the existence of a major FAD-GPDH isoform acting in soybean responses to salt and osmotic stress.An enzyme kinetic assay showed that the purified GmGPDH12 protein possessed the capacity to oxidize G3P to DHAP in the presence of FAD.Overexpression and RNA interference of GmGPDH12 in soybean hairy roots resulted in elevated tolerance and sensitivity to salt and osmotic stress,respectively.G3P contents were significantly lower in GmGPDH12-overexpressing hair roots and higher in knockdown hair roots,indicating that GmGPDH12 was essential for G3P catabolism.A significant perturbation in redox status of NADH,ascorbic acid(ASA)and glutathione(GSH)pools was observed in GmGPDH12-knockdown plants under stress conditions.The impaired redox balance was manifested by higher reactive oxygen species generation and consequent cell damage or death;however,overexpressing plants showed the opposite results for these traits.GmGPDH12 overexpression contributed to maintaining constant respiration rates under salt or osmotic stress by regulating mRNA levels of key mitochondrial respiratory enzymes.This study provides new evidence for the roles of mitochondria-localized GmGPDH12 in conferring resistance to salt or osmotic stress by maintaining cellular redox homeostasis,protecting cells and respiration from oxidative injury.
基金funded by National Natural Science Foundation of China (No.81502530,No.82172976)。
文摘Biliary tract cancers(BTCs)are a group of malignant neoplasms that have recently increased in incidence and have a poor prognosis.Surgery is the only curative therapy.However,most patients are only indicated for palliative therapy because of advanced-stage disease at diagnosis and rapid progression.The current first-line treatment for advanced BTC is gemcitabine and cisplatin chemotherapy.Nonetheless,many patients develop resistance to this regimen.Over the years,few chemotherapy regimens have managed to improve the overall survival of patients.Accordingly,novel therapies such as targeted therapy have been introduced to treat this patient population.Extensive research on tumorigenesis and the genetic profiling of BTC have revealed the heterogenicity and potential target pathways,such as EGFR,VEGF,MEK/ERK,PI3K and mTOR.Moreover,mutational analysis has documented the presence of IDH1,FGFR2,HER2,PRKACA,PRKACB,BRAF,and KRAS gene aberrations.The emergence of immunotherapy in recent years has expanded the treatment landscape for this group of malignancies.Cancer vaccines,adoptive cell transfer,and immune checkpoint inhibitors have been extensively investigated in trials of BTC.Therefore,patient stratification and a combination of various therapies have become a reasonable and important clinical strategy to improve patient outcomes.This review elaborates the literature on combined treatment strategies for advanced BTC from the past few years and ongoing clinical trials to provide new inspiration for the treatment of advanced BTC.
基金financially supported by National Key R&D Program of China(2016YFD0100201,2016YFD0100500,2016YFD0100300)National Natural Science Foundation of China(U20A2027,31971899,31971968,32070274)+7 种基金Hundred-thousand and million project of“Heilongjiang province for engineering and technology science”soybean breeding technology innovation and new cultivar breeding(2019ZX16B01)Natural Science Foundation of Heilongjiang(ZD2020C007)China Postdoctoral Science Foundation(2019M661243)Postdoctoral Project of Northeast Agricultural University(NEAUBH-19002)International Postdoctoral Exchange Fellowship Program of China Postdoctoral Council(20180004)Heilongjiang Funds for Distinguished Young Scientists(JC2016004,JC2017006)Dongnongxue zhe Project(to Chen Qingshan)Backbone of Young Talent Scholar Project(to Qi Zhaoming,18XG01)of Northeast Agricultural University。
文摘There is growing interest in expanding the production of soybean oils(mainly triacylglycerol, or TAG) to meet rising feed demand and address global energy concerns. We report that a plastidlocalized glycerol-3-phosphate dehydrogenase(GPDH), encoded by GmGPDHp1 gene, catalyzes the formation of glycerol-3-phosphate(G3 P), an obligate substrate required for TAG biosynthesis.Overexpression of GmGPDHp1 increases soybean seed oil content with high levels of unsaturated fatty acids(FAs), especially oleic acid(C18:1), without detectably affecting growth or seed protein content or seed weight. Based on the lipidomic analyses, we found that the increase in G3 P content led to an elevated diacylglycerol(DAG) pool, in which the Kennedy pathwayderived DAG was mostly increased, followed by PC-derived DAG, thereby promoting the synthesis of TAG containing relatively high proportion of C18:1. The increased G3 P levels induced several transcriptional alterations of genes involved in the glycerolipid pathways. In particular, genes encoding the enzymes responsible for de novo glycerolipid synthesis were largely upregulated in the transgenic lines, in-line with the identified biochemical phenotype. These results reveal a key role for GmGPDHp1-mediated G3 P metabolism in enhancing TAG synthesis and demonstrate a strategy to modify the FA compositions of soybean oils for improved nutrition and biofuel.
文摘Monolith SCR catalysts coated with V2Os- WO3/TiO2 were prepared by varying binder and coating thickness. Comparing with a monolith extruded with 100% V2O5-WO3/TiO2 powder, a coated monolith with a catalyst-coating layer of 260 μm in thickness exhibited the similar initial NOx reduction activity at 250℃. After 4 h abrasion (attrition) in an air stream containing 300 g. m^-3 fine sands (50-100μm) at a superficial gas velocity of 10m·s^-1, the catalyst still has the activity as a 100% molded monolith does in a 24-h activity test and it retains about 92% of its initial activity at 250℃. Estimation of the equivalent durable hours at a fly ash concentration of 1.0 g.m^-3 in flue gas and a gas velocity of 5 m.s^-1 demonstrated that this coated monolith catalyst is capable of resisting abrasion for 13 months without losing more than 8% of its initial activity. The result suggests the great potential of the coated monolith for application to de-NOx of flue gases with low fly ash concentrations from, such as glass and ceramics manufacturing processes.
基金the Fund of National Key Research and Development Projects(Intergovernmental International Cooperation in Science and Technology Innovation Program,No.2018YFE0103400),China.
文摘A comprehensive overview is presented to summarize the research works since 1982 on oxidative coupling of methane(OCM),a complex reaction network combining heterogeneous and homogeneous reaction steps.Fundamentals on reaction mechanisms and thermodynamics have revealed that the OCM process is highly exothermic and its C2+selectivity and yield is critical in evaluating its commercial viability.Catalytic strategies have been put to enhance C2+selectivity,improve C2+yield and lower reaction temperature.The catalyst MnNa2WO4/SiO2 enables methane activation at a temperature of 800◦C and simultaneously a high C2+selectivity of 70–80%,while the nanowire and La2O3-based catalysts enable to lower the reaction temperature to 200–300◦C and 500◦C,respectively.Reaction engineering aspects have also been dealt in many investigations in order to make the process technically feasible.Particularly,research works on reaction kinetics,reactor selection and reactor operating mode choice have been addressed.Intermediate cooling and distributed oxygen feed have been integrated into a multi-stage adiabatic fixed-bed reactor system to suppress the side oxidation reactions and improve the performance of the catalysts towards CH4 conversion and C2+yield.This review paper proposes employing a circulating reactor system coupled with catalyst fine particles but having little internal diffusion resistance to maximize one-pass C2+selectivity and yield of the OCM reaction and evaluate its industrial application potential.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.81502530 and 81874149).
文摘Background and Aims:The expression of discoidin domain receptor 1(DDR1)is commonly up-regulated and undergoes collagen-induced ectodomain(N-terminal)shedding during the progression of liver fibrosis.This study aimed to evaluate the clinical utility of N-terminal DDR1 as a diagnostic biomarker for liver fibrosis.Methods:N-terminal DDR1 shedding was evaluated using cell lines,liver fibrosis mouse models,clinical data of 298 patients collected from February 2019 to June 2020.The clinical data were divided into test and validation cohorts to evaluate the diagnostic performance of serum N-terminal DDR1.Results:Timeand dosage-dependent N-terminal DDR1 shedding stimulated by collagen I was observed in a hepatocyte cell line model.The type I collagen deposition and serum N-terminal DDR1 levels concurrently increased in the development of liver fibrosis in mouse models.Clinical data demonstrated a significant diagnostic power of serum N-terminal DDR1 levels as an accurate biomarker of liver fibrosis and cirrhosis.The diagnostic performance was further increased when applying N-DDR1/albumin ratio,achieving area under the curve of 0.790,0.802,0.879,and 0.865 for detecting histological fibrosis stages F≥2,F≥3,F 4 with liver biopsy as a reference method,and cirrhosis according to imaging techniques,respectively.With a cut-off of 55.6,a sensitivity,specificity,positive predictive value,and negative predictive value of 82.7%,76.6%,67.4%,and 88.3%were achieved for the detection of cirrhosis.Conclusions:Serum N-terminal DDR1 appears to be a novel diagnostic marker for liver fibrosis.
基金financially supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Ultra-thin Pd-Ag alloy membranes were prepared initially by cold rolling, and it was found that there exist a large number of defects such as pinholes or cracks in the as-rolled membranes. Subsequently, these defects were repaired using electroless plating technique. The morphologies of the membranes have been examined by scanning electron microscopy (SEM). It was observed in some as-repaired membranes that the defects were disappeared. A hydrogen permeation study has demonstrated that the as-repaired Pd-Ag alloy membranes were of high hydrogen permeation flux and hydrogen selectivity.