Objective To compare the outcomes after self-expanding metallic stent (SEMS) or transanal drainage tube (TDT) placement in patients with malignant large-bowel obstruction (MLBO). Methods Seventy-three patients with ML...Objective To compare the outcomes after self-expanding metallic stent (SEMS) or transanal drainage tube (TDT) placement in patients with malignant large-bowel obstruction (MLBO). Methods Seventy-three patients with MLBO from the clinical unit underwent SEMS (n = 51) or TDT (n = 22) placement from 2012 to 2017. The success rates of placement, clinical outcomes after decompression, complications, the time to resuming enteral nutrition (EN), Karnofsky performance status (KPS) scoring and the following-up therapeutic options were investigated. Results Technical success were achieved in 100% of patients in both groups. The clinical success rates were 98.0%(50/51) for SEMS and 95.5%(21/22) for TDT. No perforation was found in any group, while 3.9%(2/51) in the SEMS and 18.2%(4/22) in TDT group experienced displacement (P = 0.26). It took 2.1 IQR (0~2) days and 3 IQR (2~5) days to resume EN in the SEMS and TDT groups, respectively (P < 0.001). The KPS scores were significantly higher in patients implanted with SEMS (70, IQR 50~80) than in those with TDT (35, IQR 30~50)(P < 0.001). In the SEMS group, 37.3%(19/51) of patients underwent stenting as a bridge to surgery, 9.8%(5/51) for chemotherapy only and 52.9%(27/51) for palliation, while 40.9%(9/22), 0 and 59.1%(13/22) underwent placement for these reasons in the TDT group, respectively. The majority (6/9) of the patients who underwent TDT placement as a bridge to surgery required stoma creation, while only 31.6%(6/19) of those in the SEMS group needed a stoma (P = 0.080). In addition, anastomotic leakage was only found in the TDT group (2/9)(P = 0.10). Conclusion Both SEMS and TDT placement could provide clinical relief for MLBO. However, SEMS placement is associated with earlier EN, fewer complications, and benefits for the postoperative quality-of-life.展开更多
Background:Chronic obstructive pulmonary disease(COPD)is a prevalent respiratory ailment that has risen to become the foremost cause of mortality globally,and statins are a widely used class of lipid-modifying drugs.D...Background:Chronic obstructive pulmonary disease(COPD)is a prevalent respiratory ailment that has risen to become the foremost cause of mortality globally,and statins are a widely used class of lipid-modifying drugs.Data from some observational studies suggest an association between statins use and COPD.Objectives:The main objective of this study was to investigate whether lipids and apolipoproteins are bidirectionally causally associated with COPD at the genetic level using a Mendelian randomization(MR)design,and to determine the potential role of circulating inflammatory proteins as mediators in this association.Methods:The publicly available Genome-Wide Association Study(GWAS)database was utilised for the purposes of the analysis.The data on high-density lipoprotein(HDL-C),low-density lipoprotein(LDL-C),triglycerides(TG),apolipoprotein A-1(ApoA1),and apolipoprotein B(ApoB)were obtained from the UK BioBank,while the COPD dataset was obtained from the FinnGen BioBank R11(number of cases:21,617,number of controls:372,627).Furthermore,data were gathered on genetic variants linked to inflammatory processes,encompassing 91 circulating inflammatory proteins(n=14,823 individuals).A two-sample MR study was conducted using these data to assess the association between HDL-C,LDL-C,TG,ApoA1,and ApoB with the risk of COPD.Furthermore,in order to investigate the potential mediating influence of inflammatory factor alterations between lipids and COPD,a two-step Mendelian randomization(MR)mediation analysis was conducted.Results:The forward MR methods identified two lipids that were found to have a causal relationship with the development of COPD.An elevated level of LDL-C and ApoB was found to be associated with a diminished risk of COPD.Furthermore,the researchers identified circulating inflammatory factors that were determined to be the causal agents in the development of COPD.Mediation analysis indicated that the inflammatory protein S100-A12 may act as a mediator between the LDL-C and COPD pathways.Conclusion:The present MR study provides genetic evidence for a causal relationship between lipids and apolipoproteins and COPD,as well as identifying the inflammatory protein S100-A12 as a potential mediator of the COPD association.The findings offer valuable insights into the mechanistic studies of statins for COPD and potential targets for disease intervention and treatment.展开更多
BACKGROUND Computer-aided diagnosis(CAD)may assist endoscopists in identifying and classifying polyps during colonoscopy for detecting colorectal cancer.AIM To build a system using CAD to detect and classify polyps ba...BACKGROUND Computer-aided diagnosis(CAD)may assist endoscopists in identifying and classifying polyps during colonoscopy for detecting colorectal cancer.AIM To build a system using CAD to detect and classify polyps based on the Yamada classification.METHODS A total of 24045 polyp and 72367 nonpolyp images were obtained.We established a computer-aided detection and Yamada classification model based on the YOLOv7 neural network algorithm.Frame-based and image-based evaluation metrics were employed to assess the performance.RESULTS Computer-aided detection and Yamada classification screened polyps with a precision of 96.7%,a recall of 95.8%,and an F1-score of 96.2%,outperforming those of all groups of endoscopists.In regard to the Yamada classification of polyps,the CAD system displayed a precision of 82.3%,a recall of 78.5%,and an F1-score of 80.2%,outper-forming all levels of endoscopists.In addition,according to the image-based method,the CAD had an accuracy of 99.2%,a specificity of 99.5%,a sensitivity of 98.5%,a positive predictive value of 99.0%,a negative predictive value of 99.2%for polyp detection and an accuracy of 97.2%,a specificity of 98.4%,a sensitivity of 79.2%,a positive predictive value of 83.0%,and a negative predictive value of 98.4%for poly Yamada classification.CONCLUSION We developed a novel CAD system based on a deep neural network for polyp detection,and the Yamada classi-fication outperformed that of nonexpert endoscopists.This CAD system could help community-based hospitals enhance their effectiveness in polyp detection and classification.展开更多
The imbalanced allocation of maternal resources to eggs and nestlings may significantly impact the phenotype and fitness of offspring.Moreover,anthropogenic metal pollution has been reported to exert adverse effects o...The imbalanced allocation of maternal resources to eggs and nestlings may significantly impact the phenotype and fitness of offspring.Moreover,anthropogenic metal pollution has been reported to exert adverse effects on avian offspring.Therefore,we herein evaluated the relationships among offspring characteristics,asymmetric sibling rivalry,and the resulting offspring phenotype in a small passerine bird,Tree Sparrow(Passer montanus),at a polluted site(Baiyin,BY)and a relatively unpolluted site(Liujiaxia,LJX).By initiating incubation before the completion of clutch,asymmetric sibling rivalry might create a core and marginal offspring within the brood.In this study,lower egg mass,fewer core offspring,and more marginal offspring were found at the polluted site.Although eggshell speckling and coloration were relatively similar between the two sites,higher eggshell spotting coverage ratio and lower eggshell lightness(L*)and hue(h°)were observed in core eggs than in marginal eggs at the unpolluted site.The clutch size had a positive relationship with egg mass at the polluted site and with brood size at hatching at the unpolluted site.The differences in egg measurements across the laying orders in the samples were relatively large for larger clutch sizes.The core and marginal egg masses had a significant positive effect on the size of early core nestlings and late marginal nestlings at the unpolluted site.Fledgling rate was significantly positively related to the incubation period and nestling period,while negative relationship with mean spotting coverage ratio was found at the polluted site.Marginal nestlings at the polluted site showed a higher mortality rate.Overall,although asymmetric sibling competition strongly determines the variation of marginal offspring size,the effect is less dramatic in metal-polluted environments,providing some respite to wild birds that survive pollution-induced stress.展开更多
Ti-Hf-Zr-Nb-Ta refractory high-entropy alloys(RHEAs)exhibiting a dual-phase structure resulting from martensitic transformation offer significant ductility enhancement,but their design requires precise control of the ...Ti-Hf-Zr-Nb-Ta refractory high-entropy alloys(RHEAs)exhibiting a dual-phase structure resulting from martensitic transformation offer significant ductility enhancement,but their design requires precise control of the phase stability between body-centred cubic(BCC)and hexagonal close-packed(HCP)phases.This study establishes a comprehensive thermodynamic database for the Ti-Hf-Zr-Nb-Ta system using the 3rd-generation Calculation of Phase Diagrams(CALPHAD)model.The reliability of the database is validated by the strong agreement between the calculated thermodynamic properties and phase equilibria and the experimental data for pure element,as well as for binary and ternary systems.Utilizing this database,the phase stability of various RHEAs within this system was predicted,showing that all RHEAs exhibit a BCC single phase over a wide temperature range.The HCP phase is stable and coexists with BCC phase in both quaternary and quinary RHEAs at lower temepratures.Calculations of the Gibbs energy difference between the BCC and HCP phases(ΔG^(HCP−BCC))in TiHfZrTa_(x) and TiHfZrNb_(x) alloys reveal that both Nb and Ta stabilize the BCC phase,with Nb exerting a stronger influence.Significantly,a metastable BCC+HCP region in the TiHfZrTa_(x) and TiHfZrNb_(x) alloys with ΔG^(HCP−BCC) ranging from 1786 to 2230 J/mol.Utilizing this finding,the critical Nb composition range(0.0367–0.0712)to achieve the metastable BCC+HCP phase is precisely predicted in TiHfZrTa_(0.2)Nb_(x) alloys,enabling targeted design for martensitic transformation.The predictions show excellent agreement with existing experimental measurements.展开更多
Seismic attributes encapsulate substantial reservoir characterization information and can effectively support reservoir prediction.Given the high-dimensional nonlinear between sandbodies and seismic attributes,this st...Seismic attributes encapsulate substantial reservoir characterization information and can effectively support reservoir prediction.Given the high-dimensional nonlinear between sandbodies and seismic attributes,this study employs the RFECV method for seismic attribute selection,inputting the optimized attributes into a LightGBM model to enhance spatial delineation of sandbody identification.By constructing training datasets based on optimized seismic attributes and well logs,followed by class imbalance correction as input variables for machine learning models,with sandbody probability as the output variable,and employing grid search to optimize model parameters,a high-precision sandbody prediction model was established.Taking the 3D seismic data of Block F3 in the North Sea of Holland as an example,this method successfully depicted the three-dimensional spatial distribution of target formation sandstones.The results indicate that even under strong noise conditions,the multi-attribute sandbody identification method based on LightGBM effectively characterizes the distribution features of sandbodies.Compared to unselected attributes,the prediction results using selected attributes have higher vertical resolution and inter-well conformity,with the prediction accuracy for single wells reaching 80.77%,significantly improving the accuracy of sandbody boundary delineation.展开更多
目的研究Notch1信号通路在新生期小鼠肺炎链球菌感染诱导Th1/Th2失衡中的作用。方法12只1周龄Balb/c新生小鼠分为3组(n=4):新生期肺炎链球菌肺炎(Streptococcus pneumoniae pneumonia,S.pp)组、新生期肺炎链球菌肺炎Notch1抑制组[S.pp+D...目的研究Notch1信号通路在新生期小鼠肺炎链球菌感染诱导Th1/Th2失衡中的作用。方法12只1周龄Balb/c新生小鼠分为3组(n=4):新生期肺炎链球菌肺炎(Streptococcus pneumoniae pneumonia,S.pp)组、新生期肺炎链球菌肺炎Notch1抑制组[S.pp+DAPT(γ分泌酶抑制剂)]和对照组。S.pp组、S.pp+DAPT组小鼠鼻腔滴注10μL含有1×10^(7)cfu肺炎链球菌的悬液,对照组同期滴注等量PBS。小鼠感染肺炎链球菌后第7天,S.pp+DAPT组鼻腔滴注0.3 mg/kg的Notch1抑制剂DAPT,S.pp组和对照组鼻腔滴注等量PBS。小鼠发育至6周(成年),检测气道反应性,收集支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)行细胞分类计数,肺组织HE染色病理切片观察组织病理变化;Western blot检测肺组织Notch1蛋白水平;RT-PCR检测肺组织T-bet、GATA3 mRNA水平;流式细胞术检测肺组织Th1、Th2细胞水平并分析Th1/Th2比率。结果S.pp+DAPT组Notch1蛋白表达显著低于S.pp组(0.23±0.09 vs 1.94±0.78,P<0.01)。S.pp+DAPT组BALF细胞总数、中性粒细胞、单核细胞、淋巴细胞计数均明显低于S.pp组(P<0.01);肺组织中细支气管周围炎症(0.55±0.17 vs 1.52±0.27,P<0.01)、血管周围炎症(0.05±0.10 vs 0.88±0.25,P<0.01)、肺间质炎症评分(0.18±0.35 vs 1.57±0.25,P<0.01)、肺部GATA3 mRNA表达(19.11±9.79 vs 177.56±65.95,P<0.01)、Th2细胞水平[(0.16±0.02)%vs(0.28±0.04)%,P<0.01]也显著低于S.pp组;而T-bet mRNA表达、Th1细胞水平与S.pp组比较差异无统计学意义(P>0.05),Th1/Th2比值较S.pp组明显增加(14.67±2.60 vs 7.89±0.82,P<0.01)。S.pp+DAPT组小鼠吸入3.125~50 mg/mL浓度乙酰甲胆碱激发后,气道反应性较S.pp组显著降低(P<0.01)。结论新生期肺炎链球菌肺炎可能通过激活Notch1信号诱导Th1/Th2失衡,促进气道高反应性及气道炎症形成。展开更多
Copper tailings constitute a large proportion of mine wastes. Some of the copper tailings can be recycled to recover valuable minerals. In this paper, a copper tailing was studied through the chemical analysis method,...Copper tailings constitute a large proportion of mine wastes. Some of the copper tailings can be recycled to recover valuable minerals. In this paper, a copper tailing was studied through the chemical analysis method, Xray diffraction and scanning electron microscope-energy dispersive spectrum. It turned out that chalcopyrite(Cu) and pyrite(S) were the main recoverable minerals in the tailing. In order to separate chalcopyrite from pyrite in low pulp pH, ammonium humate(AH) was singled out as the effective regulator. The depression mechanism of AH on the flotation of pyrite was proved by FTIR spectrum and XPS spectrum, demonstrating that there was a chemical adsorption between AH and pyrite. By Response Surface Methodology(RSM), the interaction between AH, pulp pH and iso-butyl ethionine(Z200) was discussed. It was illustrated that the optimal dosage of AH was 1678 g·t^(-1) involving both the recovery of Cu and S. The point prediction by RSM and the closed-circuit flotation displayed that the qualified Cu concentrate and S concentrate could be obtained from the copper tailing.The study indicated that AH was a promising pyrite depressor in the low pulp pH from copper tailings.展开更多
The chlorination-volatilization process has been adopted to make full use of gold-bearing and iron-rich pyrite cinder. However, problems of low recovery rate, pulverization of pellets, and ring formation have been enc...The chlorination-volatilization process has been adopted to make full use of gold-bearing and iron-rich pyrite cinder. However, problems of low recovery rate, pulverization of pellets, and ring formation have been encountered during the industrialization of this process. The effects of various parameters on the volatilization rates of valuable metals and on the compressive strength of roasted pellets were investigated in this paper. The parameters include the CaCl_2 dosage, heating temperature, and holding time. The results show that heating temperature is the most important parameter for the recovery of target metals. More CaCl_2 was needed for the recovery of zinc than for the recovery of gold, silver, and lead. CaCl_2 started to react with sulfides/SO_2/SiO_2 at temperatures below the melting point of CaCl_2 to generate Cl_2/HCl. Gaseous CaCl_2 was formed at higher temperatures and could react with any of the components. The compressive strength of roasted CaCl_2-bearing pellets first decreased slowly with increasing temperature at temperatures lower than 873 K, which could result in the pulverization of pellets during heating. Their compressive strength increased dramatically with increasing temperature at temperatures greater than 1273 K. Certain quantities of CaCl_2 and Fe(Ⅱ) could improve the compressive strength of the roasted pellets; however, the addition of excessive CaCl_2 decreased the compressive strength of pellets.展开更多
Hierarchically porous ZSM‐5 (SiO2/Al2O3 ≈ 120) containing phosphorus was prepared by a one‐step post‐synthesis treatment involving controlled desilication and phosphorous modification. The hierarchically porous ZS...Hierarchically porous ZSM‐5 (SiO2/Al2O3 ≈ 120) containing phosphorus was prepared by a one‐step post‐synthesis treatment involving controlled desilication and phosphorous modification. The hierarchically porous ZSM‐5 featured high thermal and hydrothermal stability. The obtained ZSM‐5zeolites were systematically characterized by X‐ray diffraction, scanning electron microscopy,transmission electron microscopy, N2 adsorption‐desorption, NH3 temperature‐programmed desorption,and 27Al and 31P magic‐angle spinning nuclear magnetic resonance spectroscopy. Theprepared ZSM‐5 displayed enhanced activity and prolonged lifetime toward hydrocarbon cracking.The high activity was attributed to improved coke tolerance owing to the presence of the highlystable mesoporous network of ZSM‐5 and acid sites introduced upon phosphorus modification.Additionally a mechanism of the stabilization of the zeolites by phosphorus was proposed and discussed.展开更多
Three-dimensional(3D) ultra-tiny Fe_(2)O_(3) nanoparticles/graphene hydrogels were prepared using a facile and efficient solvothermal reaction, by which the phase of iron oxide, particle size and the morphology of hyd...Three-dimensional(3D) ultra-tiny Fe_(2)O_(3) nanoparticles/graphene hydrogels were prepared using a facile and efficient solvothermal reaction, by which the phase of iron oxide, particle size and the morphology of hydrogels can be precisely controlled by simply adjusting the solvothermal reaction time. Accordingly, the effect of the microstructures of hydrogels on electrochemical performance was systematically studied. It was found that Fe_(2)O_(3)/r GO-50 hydrogels(with a solvothermal reaction time of 50 min) possessed a desirable crystallinity, suitable particle size, decent porous structure, large specific surface area and high electrical conductivity, thus exhibiting a superior electrochemical performance as binder-free anode of supercapacitors: a large potential range of 1.15 V, an ultrahigh specific capacitance of 1090 F·g^(-1) at a current density of 2A·g^(-1) and excellent rate capability (531 F·g^(-1) at 10 A·g^(-1)). The rational design and systematic research of electrode materials will provide new lights for the preparation of advanced electrochemical energy storage devices.展开更多
文摘Objective To compare the outcomes after self-expanding metallic stent (SEMS) or transanal drainage tube (TDT) placement in patients with malignant large-bowel obstruction (MLBO). Methods Seventy-three patients with MLBO from the clinical unit underwent SEMS (n = 51) or TDT (n = 22) placement from 2012 to 2017. The success rates of placement, clinical outcomes after decompression, complications, the time to resuming enteral nutrition (EN), Karnofsky performance status (KPS) scoring and the following-up therapeutic options were investigated. Results Technical success were achieved in 100% of patients in both groups. The clinical success rates were 98.0%(50/51) for SEMS and 95.5%(21/22) for TDT. No perforation was found in any group, while 3.9%(2/51) in the SEMS and 18.2%(4/22) in TDT group experienced displacement (P = 0.26). It took 2.1 IQR (0~2) days and 3 IQR (2~5) days to resume EN in the SEMS and TDT groups, respectively (P < 0.001). The KPS scores were significantly higher in patients implanted with SEMS (70, IQR 50~80) than in those with TDT (35, IQR 30~50)(P < 0.001). In the SEMS group, 37.3%(19/51) of patients underwent stenting as a bridge to surgery, 9.8%(5/51) for chemotherapy only and 52.9%(27/51) for palliation, while 40.9%(9/22), 0 and 59.1%(13/22) underwent placement for these reasons in the TDT group, respectively. The majority (6/9) of the patients who underwent TDT placement as a bridge to surgery required stoma creation, while only 31.6%(6/19) of those in the SEMS group needed a stoma (P = 0.080). In addition, anastomotic leakage was only found in the TDT group (2/9)(P = 0.10). Conclusion Both SEMS and TDT placement could provide clinical relief for MLBO. However, SEMS placement is associated with earlier EN, fewer complications, and benefits for the postoperative quality-of-life.
基金supported by the Key Support Project of Regional Innovation and Development Joint Fund of National Natural Science Foundation of China(U20A20398)the National Natural Science Foundation of China(82104454,82374399)+1 种基金the Clinical Medical Research Transformation Project of Anhui Province(202304295107020111)the Natural Science Research Key Project of Anhui Provincial Department of Education(KJ2021A0542).
文摘Background:Chronic obstructive pulmonary disease(COPD)is a prevalent respiratory ailment that has risen to become the foremost cause of mortality globally,and statins are a widely used class of lipid-modifying drugs.Data from some observational studies suggest an association between statins use and COPD.Objectives:The main objective of this study was to investigate whether lipids and apolipoproteins are bidirectionally causally associated with COPD at the genetic level using a Mendelian randomization(MR)design,and to determine the potential role of circulating inflammatory proteins as mediators in this association.Methods:The publicly available Genome-Wide Association Study(GWAS)database was utilised for the purposes of the analysis.The data on high-density lipoprotein(HDL-C),low-density lipoprotein(LDL-C),triglycerides(TG),apolipoprotein A-1(ApoA1),and apolipoprotein B(ApoB)were obtained from the UK BioBank,while the COPD dataset was obtained from the FinnGen BioBank R11(number of cases:21,617,number of controls:372,627).Furthermore,data were gathered on genetic variants linked to inflammatory processes,encompassing 91 circulating inflammatory proteins(n=14,823 individuals).A two-sample MR study was conducted using these data to assess the association between HDL-C,LDL-C,TG,ApoA1,and ApoB with the risk of COPD.Furthermore,in order to investigate the potential mediating influence of inflammatory factor alterations between lipids and COPD,a two-step Mendelian randomization(MR)mediation analysis was conducted.Results:The forward MR methods identified two lipids that were found to have a causal relationship with the development of COPD.An elevated level of LDL-C and ApoB was found to be associated with a diminished risk of COPD.Furthermore,the researchers identified circulating inflammatory factors that were determined to be the causal agents in the development of COPD.Mediation analysis indicated that the inflammatory protein S100-A12 may act as a mediator between the LDL-C and COPD pathways.Conclusion:The present MR study provides genetic evidence for a causal relationship between lipids and apolipoproteins and COPD,as well as identifying the inflammatory protein S100-A12 as a potential mediator of the COPD association.The findings offer valuable insights into the mechanistic studies of statins for COPD and potential targets for disease intervention and treatment.
基金Supported by Science and Technology Projects in Guangzhou,No.2023A04J2282。
文摘BACKGROUND Computer-aided diagnosis(CAD)may assist endoscopists in identifying and classifying polyps during colonoscopy for detecting colorectal cancer.AIM To build a system using CAD to detect and classify polyps based on the Yamada classification.METHODS A total of 24045 polyp and 72367 nonpolyp images were obtained.We established a computer-aided detection and Yamada classification model based on the YOLOv7 neural network algorithm.Frame-based and image-based evaluation metrics were employed to assess the performance.RESULTS Computer-aided detection and Yamada classification screened polyps with a precision of 96.7%,a recall of 95.8%,and an F1-score of 96.2%,outperforming those of all groups of endoscopists.In regard to the Yamada classification of polyps,the CAD system displayed a precision of 82.3%,a recall of 78.5%,and an F1-score of 80.2%,outper-forming all levels of endoscopists.In addition,according to the image-based method,the CAD had an accuracy of 99.2%,a specificity of 99.5%,a sensitivity of 98.5%,a positive predictive value of 99.0%,a negative predictive value of 99.2%for polyp detection and an accuracy of 97.2%,a specificity of 98.4%,a sensitivity of 79.2%,a positive predictive value of 83.0%,and a negative predictive value of 98.4%for poly Yamada classification.CONCLUSION We developed a novel CAD system based on a deep neural network for polyp detection,and the Yamada classi-fication outperformed that of nonexpert endoscopists.This CAD system could help community-based hospitals enhance their effectiveness in polyp detection and classification.
基金supported by the National Natural Science Foundation of China (No.32370508 and 32201266)the China Postdoctoral Science Foundation (No.GZC20230731)。
文摘The imbalanced allocation of maternal resources to eggs and nestlings may significantly impact the phenotype and fitness of offspring.Moreover,anthropogenic metal pollution has been reported to exert adverse effects on avian offspring.Therefore,we herein evaluated the relationships among offspring characteristics,asymmetric sibling rivalry,and the resulting offspring phenotype in a small passerine bird,Tree Sparrow(Passer montanus),at a polluted site(Baiyin,BY)and a relatively unpolluted site(Liujiaxia,LJX).By initiating incubation before the completion of clutch,asymmetric sibling rivalry might create a core and marginal offspring within the brood.In this study,lower egg mass,fewer core offspring,and more marginal offspring were found at the polluted site.Although eggshell speckling and coloration were relatively similar between the two sites,higher eggshell spotting coverage ratio and lower eggshell lightness(L*)and hue(h°)were observed in core eggs than in marginal eggs at the unpolluted site.The clutch size had a positive relationship with egg mass at the polluted site and with brood size at hatching at the unpolluted site.The differences in egg measurements across the laying orders in the samples were relatively large for larger clutch sizes.The core and marginal egg masses had a significant positive effect on the size of early core nestlings and late marginal nestlings at the unpolluted site.Fledgling rate was significantly positively related to the incubation period and nestling period,while negative relationship with mean spotting coverage ratio was found at the polluted site.Marginal nestlings at the polluted site showed a higher mortality rate.Overall,although asymmetric sibling competition strongly determines the variation of marginal offspring size,the effect is less dramatic in metal-polluted environments,providing some respite to wild birds that survive pollution-induced stress.
基金financially supported by the Natural Science Foundation of Hebei Province,China(No.E202302154).
文摘Ti-Hf-Zr-Nb-Ta refractory high-entropy alloys(RHEAs)exhibiting a dual-phase structure resulting from martensitic transformation offer significant ductility enhancement,but their design requires precise control of the phase stability between body-centred cubic(BCC)and hexagonal close-packed(HCP)phases.This study establishes a comprehensive thermodynamic database for the Ti-Hf-Zr-Nb-Ta system using the 3rd-generation Calculation of Phase Diagrams(CALPHAD)model.The reliability of the database is validated by the strong agreement between the calculated thermodynamic properties and phase equilibria and the experimental data for pure element,as well as for binary and ternary systems.Utilizing this database,the phase stability of various RHEAs within this system was predicted,showing that all RHEAs exhibit a BCC single phase over a wide temperature range.The HCP phase is stable and coexists with BCC phase in both quaternary and quinary RHEAs at lower temepratures.Calculations of the Gibbs energy difference between the BCC and HCP phases(ΔG^(HCP−BCC))in TiHfZrTa_(x) and TiHfZrNb_(x) alloys reveal that both Nb and Ta stabilize the BCC phase,with Nb exerting a stronger influence.Significantly,a metastable BCC+HCP region in the TiHfZrTa_(x) and TiHfZrNb_(x) alloys with ΔG^(HCP−BCC) ranging from 1786 to 2230 J/mol.Utilizing this finding,the critical Nb composition range(0.0367–0.0712)to achieve the metastable BCC+HCP phase is precisely predicted in TiHfZrTa_(0.2)Nb_(x) alloys,enabling targeted design for martensitic transformation.The predictions show excellent agreement with existing experimental measurements.
基金co-funded by the China National Nuclear Corporation-State Key Laboratory of Nuclear Resources and Environment(East ChinaUniversity of Technology)Joint Innovation Fund Project(No.2023NRE-LH-08)the Natural Science Foundation of Jiangxi Province,China(No.20252BAC240270)+1 种基金the Funding of National Key Laboratory of Uranium Resources Exploration-Mining and Nuclear Remote Sensing(2025QZ-YZZ-08)the National Major Science and Technology Project on Deep Earth of China(No.2024ZD 1003300)。
文摘Seismic attributes encapsulate substantial reservoir characterization information and can effectively support reservoir prediction.Given the high-dimensional nonlinear between sandbodies and seismic attributes,this study employs the RFECV method for seismic attribute selection,inputting the optimized attributes into a LightGBM model to enhance spatial delineation of sandbody identification.By constructing training datasets based on optimized seismic attributes and well logs,followed by class imbalance correction as input variables for machine learning models,with sandbody probability as the output variable,and employing grid search to optimize model parameters,a high-precision sandbody prediction model was established.Taking the 3D seismic data of Block F3 in the North Sea of Holland as an example,this method successfully depicted the three-dimensional spatial distribution of target formation sandstones.The results indicate that even under strong noise conditions,the multi-attribute sandbody identification method based on LightGBM effectively characterizes the distribution features of sandbodies.Compared to unselected attributes,the prediction results using selected attributes have higher vertical resolution and inter-well conformity,with the prediction accuracy for single wells reaching 80.77%,significantly improving the accuracy of sandbody boundary delineation.
文摘目的研究Notch1信号通路在新生期小鼠肺炎链球菌感染诱导Th1/Th2失衡中的作用。方法12只1周龄Balb/c新生小鼠分为3组(n=4):新生期肺炎链球菌肺炎(Streptococcus pneumoniae pneumonia,S.pp)组、新生期肺炎链球菌肺炎Notch1抑制组[S.pp+DAPT(γ分泌酶抑制剂)]和对照组。S.pp组、S.pp+DAPT组小鼠鼻腔滴注10μL含有1×10^(7)cfu肺炎链球菌的悬液,对照组同期滴注等量PBS。小鼠感染肺炎链球菌后第7天,S.pp+DAPT组鼻腔滴注0.3 mg/kg的Notch1抑制剂DAPT,S.pp组和对照组鼻腔滴注等量PBS。小鼠发育至6周(成年),检测气道反应性,收集支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)行细胞分类计数,肺组织HE染色病理切片观察组织病理变化;Western blot检测肺组织Notch1蛋白水平;RT-PCR检测肺组织T-bet、GATA3 mRNA水平;流式细胞术检测肺组织Th1、Th2细胞水平并分析Th1/Th2比率。结果S.pp+DAPT组Notch1蛋白表达显著低于S.pp组(0.23±0.09 vs 1.94±0.78,P<0.01)。S.pp+DAPT组BALF细胞总数、中性粒细胞、单核细胞、淋巴细胞计数均明显低于S.pp组(P<0.01);肺组织中细支气管周围炎症(0.55±0.17 vs 1.52±0.27,P<0.01)、血管周围炎症(0.05±0.10 vs 0.88±0.25,P<0.01)、肺间质炎症评分(0.18±0.35 vs 1.57±0.25,P<0.01)、肺部GATA3 mRNA表达(19.11±9.79 vs 177.56±65.95,P<0.01)、Th2细胞水平[(0.16±0.02)%vs(0.28±0.04)%,P<0.01]也显著低于S.pp组;而T-bet mRNA表达、Th1细胞水平与S.pp组比较差异无统计学意义(P>0.05),Th1/Th2比值较S.pp组明显增加(14.67±2.60 vs 7.89±0.82,P<0.01)。S.pp+DAPT组小鼠吸入3.125~50 mg/mL浓度乙酰甲胆碱激发后,气道反应性较S.pp组显著降低(P<0.01)。结论新生期肺炎链球菌肺炎可能通过激活Notch1信号诱导Th1/Th2失衡,促进气道高反应性及气道炎症形成。
基金Supported by the National Natural Science Foundation of China(51202249)the National High Technology Research and Development Program of China(2011AA06A104)the National Science&Technology Pillar Program during the 12th Five-year Plan Period(2012BAB08B04)
文摘Copper tailings constitute a large proportion of mine wastes. Some of the copper tailings can be recycled to recover valuable minerals. In this paper, a copper tailing was studied through the chemical analysis method, Xray diffraction and scanning electron microscope-energy dispersive spectrum. It turned out that chalcopyrite(Cu) and pyrite(S) were the main recoverable minerals in the tailing. In order to separate chalcopyrite from pyrite in low pulp pH, ammonium humate(AH) was singled out as the effective regulator. The depression mechanism of AH on the flotation of pyrite was proved by FTIR spectrum and XPS spectrum, demonstrating that there was a chemical adsorption between AH and pyrite. By Response Surface Methodology(RSM), the interaction between AH, pulp pH and iso-butyl ethionine(Z200) was discussed. It was illustrated that the optimal dosage of AH was 1678 g·t^(-1) involving both the recovery of Cu and S. The point prediction by RSM and the closed-circuit flotation displayed that the qualified Cu concentrate and S concentrate could be obtained from the copper tailing.The study indicated that AH was a promising pyrite depressor in the low pulp pH from copper tailings.
基金financially supported by the National NaturalScience Foundation of China (No. 51202249)the National High-Tech Research and Development Program of China (No. 2011AA06A104)the Projects in the National Science & Technology Pillar Program during the 12th Five-year Plan Period (No. 2012BAB08B04)
文摘The chlorination-volatilization process has been adopted to make full use of gold-bearing and iron-rich pyrite cinder. However, problems of low recovery rate, pulverization of pellets, and ring formation have been encountered during the industrialization of this process. The effects of various parameters on the volatilization rates of valuable metals and on the compressive strength of roasted pellets were investigated in this paper. The parameters include the CaCl_2 dosage, heating temperature, and holding time. The results show that heating temperature is the most important parameter for the recovery of target metals. More CaCl_2 was needed for the recovery of zinc than for the recovery of gold, silver, and lead. CaCl_2 started to react with sulfides/SO_2/SiO_2 at temperatures below the melting point of CaCl_2 to generate Cl_2/HCl. Gaseous CaCl_2 was formed at higher temperatures and could react with any of the components. The compressive strength of roasted CaCl_2-bearing pellets first decreased slowly with increasing temperature at temperatures lower than 873 K, which could result in the pulverization of pellets during heating. Their compressive strength increased dramatically with increasing temperature at temperatures greater than 1273 K. Certain quantities of CaCl_2 and Fe(Ⅱ) could improve the compressive strength of the roasted pellets; however, the addition of excessive CaCl_2 decreased the compressive strength of pellets.
基金supported by the National Natural Science Foundation of China (21403070, 21573073)National Key Technology Research and De-velopment Program (2012BAE05B02)Shanghai Leading Academic Discipline Project (B409)~~
文摘Hierarchically porous ZSM‐5 (SiO2/Al2O3 ≈ 120) containing phosphorus was prepared by a one‐step post‐synthesis treatment involving controlled desilication and phosphorous modification. The hierarchically porous ZSM‐5 featured high thermal and hydrothermal stability. The obtained ZSM‐5zeolites were systematically characterized by X‐ray diffraction, scanning electron microscopy,transmission electron microscopy, N2 adsorption‐desorption, NH3 temperature‐programmed desorption,and 27Al and 31P magic‐angle spinning nuclear magnetic resonance spectroscopy. Theprepared ZSM‐5 displayed enhanced activity and prolonged lifetime toward hydrocarbon cracking.The high activity was attributed to improved coke tolerance owing to the presence of the highlystable mesoporous network of ZSM‐5 and acid sites introduced upon phosphorus modification.Additionally a mechanism of the stabilization of the zeolites by phosphorus was proposed and discussed.
基金financially supported by the National Natural Science Foundation of China (Nos. 21603019,51772034 and 12075224)the Opening Project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure(No. SKL201807SIC)The Fundamental Research Funds for the Central Universities (No. 2019CDJGFCL004)。
文摘Three-dimensional(3D) ultra-tiny Fe_(2)O_(3) nanoparticles/graphene hydrogels were prepared using a facile and efficient solvothermal reaction, by which the phase of iron oxide, particle size and the morphology of hydrogels can be precisely controlled by simply adjusting the solvothermal reaction time. Accordingly, the effect of the microstructures of hydrogels on electrochemical performance was systematically studied. It was found that Fe_(2)O_(3)/r GO-50 hydrogels(with a solvothermal reaction time of 50 min) possessed a desirable crystallinity, suitable particle size, decent porous structure, large specific surface area and high electrical conductivity, thus exhibiting a superior electrochemical performance as binder-free anode of supercapacitors: a large potential range of 1.15 V, an ultrahigh specific capacitance of 1090 F·g^(-1) at a current density of 2A·g^(-1) and excellent rate capability (531 F·g^(-1) at 10 A·g^(-1)). The rational design and systematic research of electrode materials will provide new lights for the preparation of advanced electrochemical energy storage devices.
