X-ray computed tomography(CT)has been an important technology in paleontology for several decades.It helps researchers to acquire detailed anatomical structures of fossils non-destructively.Despite its widespread appl...X-ray computed tomography(CT)has been an important technology in paleontology for several decades.It helps researchers to acquire detailed anatomical structures of fossils non-destructively.Despite its widespread application,developing an efficient and user-friendly method for segmenting CT data continues to be a formidable challenge in the field.Most CT data segmentation software operates on 2D interfaces,which limits flexibility for real-time adjustments in 3D segmentation.Here,we introduce Curves Mode in Drishti Paint 3.2,an open-source tool for CT data segmentation.Drishti Paint 3.2 allows users to manually or semi-automatically segment the CT data in both 2D and 3D environments,providing a novel solution for revisualizing CT data in paleontological studies.展开更多
BACKGROUND Trastuzumab-targeted therapy is currently the standard of care for advanced human epidermal growth factor receptor 2(HER2)-positive gastric cancer.However,the emergence of resistance to trastuzumab poses si...BACKGROUND Trastuzumab-targeted therapy is currently the standard of care for advanced human epidermal growth factor receptor 2(HER2)-positive gastric cancer.However,the emergence of resistance to trastuzumab poses significant challenges.AIM To identify the key genes associated with trastuzumab resistance.These results provide a basis for the development of interventions to address drug resistance and improve patient outcomes.METHODS High-throughput sequencing and bioinformatics were used to identify the differentially expressed pivotal gene BIRC3 and delineate its potential function and pathway regulation.Tumor samples were collected from patients with HER2-positive gastric cancer to evaluate the correlation between BIRC3 expression and trastuzumab resistance.We established gastric cancer cell lines with both highly expressed and suppressed levels of BIRC3,followed by comprehensive in vitro and in vivo experiments to confirm the involvement of BIRC3 in trastuzumab resistance and to elucidate its underlying mechanisms.RESULTS In patients with HER2-positive gastric cancer,there is a significant correlation between elevated BIRC3 expression in tumor tissues and higher T stage,tumor node metastasis stage,as well as poor overall survival and progressionfree survival.BIRC3 is highly expressed in trastuzumab-resistant gastric cancer cell lines,where it inhibits tumor cell apoptosis and enhances trastuzumab resistance by promoting the phosphorylation and activation of the phosphoinositide 3-kinase-Akt(PI3K-AKT)pathway in HER2-positive gastric cancer cells,both in vivo and in vitro.CONCLUSION This study revealed a robust association between high BIRC3 expression and an unfavorable prognosis in patients with HER2-positive gastric cancer.Thus,the high expression of BIRC3 stimulated PI3K-AKT phosphorylation and activation,stimulating the proliferation of HER2-positive tumor cells and suppressing apoptosis,ultimately leading to trastuzumab resistance.展开更多
It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower temperature.Herein,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(...It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower temperature.Herein,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(A_(2)B_(2)O_(7)-type)catalysts with disordered defective cubic fluorite phased structure were successfully prepared by a colloidal crystal template method.3DOM structure promotes the accessibility of the gaseous reactants(O2and CH4)to the active sites.The co-doping of Ca and Sr ions in La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts improved the formation of oxygen vacancies,thereby leading to increased density of surface-active oxygen species(O_(2)^(-))for the activation of CH4and the formation of C2products(C2H6and C2H4).3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts exhibit high catalytic activity for OCM at low temperature.3DOM La1.7Sr0.3Ce1.7Ca0.3O7-δcatalyst with the highest density of O_(2)^(-)species exhibited the highest catalytic activity for low-temperature OCM,i.e.,its CH4conversion,selectivity and yield of C2products at 650℃are 32.2%,66.1%and 21.3%,respectively.The mechanism was proposed that the increase in surface oxygen vacancies induced by the co-doping of Ca and Sr ions boosts the key step of C-H bond breaking and C-C bond coupling in catalyzing low-temperature OCM.It is meaningful for the development of the low-temperature and high-efficient catalysts for OCM reaction in practical application.展开更多
Objective:To study the clinical outcomes of complete mesocolic excision(CME)for right-sided colon cancer using 3D(three-dimensional)laparoscopy compared to 2D(two-dimensional)laparoscopy.Methods:From January 2022 to D...Objective:To study the clinical outcomes of complete mesocolic excision(CME)for right-sided colon cancer using 3D(three-dimensional)laparoscopy compared to 2D(two-dimensional)laparoscopy.Methods:From January 2022 to December 2023,58 patients with right-sided colon cancer treated at the Affiliated Hospital of Hebei Engineering University were randomly divided into a 3D laparoscopy group(observation group)and a 2D laparoscopy group(control group),with 29 patients in each group.Intraoperative blood loss,postoperative time to first flatulence,length of hospital stay,and incidence of complications in both groups were recorded.Results:There was a statistically significant difference in intraoperative blood loss between the two groups(P<0.05).There was no statistically significant difference in the time to first flatulence between the groups(P>0.05).However,there was a statistically significant difference in the length of hospital stay(P<0.05)and the incidence of complications(P<0.05)between the two groups.Conclusion:3D laparoscopy for CME can reduce intraoperative blood loss,shorten hospital stay,and decrease postoperative complications,showing significant clinical advantages over traditional 2D laparoscopy.展开更多
Superconducting YBa_(2)Cu_(3)O_(7−x)(YBCO)bulks have promising applications in quasi-permanent magnets,levitation,etc.Recently,a new way of fabricating porous YBCO bulks,named direct-ink-writing(DIW)3D-printing method...Superconducting YBa_(2)Cu_(3)O_(7−x)(YBCO)bulks have promising applications in quasi-permanent magnets,levitation,etc.Recently,a new way of fabricating porous YBCO bulks,named direct-ink-writing(DIW)3D-printing method,has been reported.In this method,the customized precursor paste and programmable shape are two main advantages.Here,we have put forward a new way to customize the YBCO 3D-printing precursor paste which is doped with Al_(2)O_(3)nanoparticles to obtain YBCO with higher thermal conductivity.The great rheological properties of precursor paste after being doped with Al_(2)O_(3)nanoparticles can help the macroscopic YBCO samples with high thermal conductivity fabricated stably with high crystalline and lightweight properties.Test results show that the peak thermal conductivity of Al_(2)O_(3)-doped YBCO can reach twice as much as pure YBCO,which makes a great effort to reduce the quench propagation speed.Based on the microstructure analysis,one can find that the thermal conductivity of Al_(2)O_(3)-doped YBCO has been determined by its components and microstructures.In addition,a macroscopic theoretical model has been proposed to assess the thermal conductivity of different microstructures,whose calculated results take good agreement with the experimental results.Meanwhile,a microstructure with high thermal conductivity has been found.Finally,a macroscopic YBCO bulk with the presented high thermal conductivity microstructure has been fabricated by the Al_(2)O_(3)-doped method.Compared with YBCO fabricated by the traditional 3D-printed,the Al_(2)O_(3)-doped structural YBCO bulks present excellent heat transfer performances.Our customized design of 3D-printing precursor pastes and novel concept of structural design for enhancing the thermal conductivity of YBCO superconducting material can be widely used in other DIW 3D-printing materials.展开更多
In the design of building structures,joint efforts must be decided to resolve the depth of competent layers across the intended site to safeguard the durability of civil engineering structures and to avert the disastr...In the design of building structures,joint efforts must be decided to resolve the depth of competent layers across the intended site to safeguard the durability of civil engineering structures and to avert the disastrous consequences of structural failure and collapse.In this study,an integrated methodology that employed DC resistivity tomography involving 2-D and 3-D techniques and geotechnical-soil analysis was used to evaluate subsoil conditions for engineering site investigation at Okerenkoko primary school,in the Warri-southwest area of Delta State,to adduce the phenomena responsible for the visible cracks/structural failure observed in the buildings.The results obtained brought to light the geological structure beneath the subsurface,which consists of four geoelectric layers identified as topsoil,dry/lithified upper sandy layer,wet sand(water-saturated)and peat/clay/sandy clayey soil(highly water-saturated).The deeply-seated peat/clay materials(ρ≤20Ωm)were delineated in the study area to the depths of 17.1 m and 19.8 m from 2-D and 3-D tomography respectively.3-D images presented as horizontal depth slices revealed the dominance of very low resistivity materials i.e.peat/clay/sandy clay within the fourth,fifth and sixth layers at depths ranging from 8.68-12.5 m,12.5-16.9 m and 16.9-21.9 m respectively.The dominance of mechanically unstable peat/clay/sandy clay layers beneath the subsurface,which are highly mobile in response to volumetric changes,is responsible for the noticeable cracks/failure detected on structures within the study site.These observations were validated by a geotechnical test of soil samples in the study area.Atterberg’s limits of the samples revealed plasticity indices of zero.Thus,the soil samples within the depth analyzed were representatives of sandy soil that does not possess any plasticity.The methods justifiably provided relevant information on the subsurface geology beneath the study site and should be appropriated as major tools for engineering site assessment/geotechnical projects.展开更多
On the base of benzimidazole and benzofuran containing heterocyclic system, several derivatives with expected biological activity were synthesized. 2,3-diaminodibenzofuran was the primary substance. Adding various cyc...On the base of benzimidazole and benzofuran containing heterocyclic system, several derivatives with expected biological activity were synthesized. 2,3-diaminodibenzofuran was the primary substance. Adding various cyclic agents, 2-phenil was got, 2-（o-chlorophenil）, 2-（o-oxyphenil）, 2-chlorometyl- and 2-hydroximethyl-3H-benzo[b[furo（3,2-f] benzimidazoles. The aforementioned substances were characterized by IR and NMR spectroscopy.展开更多
A sol-gel tandem with a solid-phase modification procedure was developed to synthesize Li_(2)TiO_(3)-doped LiCoO_(2) together with phosphate coatings(denoted as LCO-Ti/P),which possesses excellent high-voltage perform...A sol-gel tandem with a solid-phase modification procedure was developed to synthesize Li_(2)TiO_(3)-doped LiCoO_(2) together with phosphate coatings(denoted as LCO-Ti/P),which possesses excellent high-voltage performance in the range of 3.0-4.6 V.The characterizations of X-ray diffraction,high-resolution transmission electron microscopy,and X-ray photoelectron spectroscopy illustrated that the modified sample LCO-Ti/P had the dopant of monoclinic Li_(2)TiO_(3) and amorphous Li3PO4 coating layers.LCO-Ti/P has an initial discharge capacity of 211.6 mAh/g at 0.1 C and a retention of 85.7%after 100 cycles at 1 C and 25±1°C between 3.0 and 4.6 V.Nyquist plots reflect that the charge transfer resistance of LCO-Ti/P after 100 cycles at 1 C is much lower than that of the spent LCO,which benefits Li-ion diffusion.Density functional theory calculations disclose the superior lattice-matching property of major crystal planes for Li_(2)TiO_(3) and LiCoO_(2),the lower energy barriers for Li-ion diffusion in Li_(2)TiO_(3),and the suppressed oxygen release performance resulting from phosphate adsorption.This work provides useful guidance on the rational design of the high-voltage performance of modified LiCoO_(2) materials in terms of lattice-matching properties aside from the phosphate coating to reduce the energy barriers of Li-ion diffusion and enhance cycling stability.展开更多
The Co2O3-doping effect on the formation of 3CaO · 3A12O3· CaSO from CaCO3-A12O3-CaSO4, 2H20 mixtures was investigated by means of SO2 emission behavior, chemical analysis, X-ray diffraction, differential th...The Co2O3-doping effect on the formation of 3CaO · 3A12O3· CaSO from CaCO3-A12O3-CaSO4, 2H20 mixtures was investigated by means of SO2 emission behavior, chemical analysis, X-ray diffraction, differential thermal analysis and scanning electron microscopy. The experimental results show that CO2O3 addition increases the reactivity of the CaCO3-A12O3-CaSO4·2H2O system significantly, by reducing SO2 emissions in combustion andf-CaO contents in the clinkers, promoting the nucleation and growth of 3CaO·3A12O3-CaSO4, and intensifying the formation of 3CaO·3A12O3·CaSO4. Moreover, CO2O3 addition lowers the formation temperature of 3CaO·3A12O3·CaSO4 by 18 ℃, and similarly increases the thermal stability of it at a wider temperature range.展开更多
目的:研究MRI 3D CUBE T_(2)序列检查在踝关节外伤患者韧带损伤诊断中的价值。方法:选择2020年4月—2023年4月于白银市第一人民医院就诊的226例踝关节外伤拟行手术术前患者作为研究对象,按照不同检查方式将患者分为观察组(n=126)与对照...目的:研究MRI 3D CUBE T_(2)序列检查在踝关节外伤患者韧带损伤诊断中的价值。方法:选择2020年4月—2023年4月于白银市第一人民医院就诊的226例踝关节外伤拟行手术术前患者作为研究对象,按照不同检查方式将患者分为观察组(n=126)与对照组(n=100)。观察组采用MRI 3D CUBE T_(2)序列检查,对照组采取常规MRI检查。比较两组患侧、健侧距腓前韧带测量结果、诊断效能。结果:两组患侧、健侧距腓前韧带宽度及厚度比较,差异无统计学意义(P>0.05)。观察组Ⅰ级踝关节外伤患者韧带损伤诊断准确度、敏感度、特异度、阳性预测值、阴性预测值高于对照组,Ⅱ级患者准确度、敏感度、阴性预测值高于对照组,Ⅲ级患者准确度、特异度、阳性预测值高于对照组,差异有统计学意义(P<0.05)。结论:MRI 3D CUBE T_(2)序列检查踝关节外伤患者韧带损伤诊断效能高于常规MRI检查,可作为治疗效果评价及康复治疗的重要依据。展开更多
A new coordination polymer {[Cd（C_（21）H_（14）N_6）（C_8H_4O_4）]·H_2O}_n（1） was synthesized by an elaborate design via the reaction of 3-（2,6-di（pyrazin-2-yl）pyridin-4-yl）-1H-indole（bppi）,1,4-benzene-...A new coordination polymer {[Cd（C_（21）H_（14）N_6）（C_8H_4O_4）]·H_2O}_n（1） was synthesized by an elaborate design via the reaction of 3-（2,6-di（pyrazin-2-yl）pyridin-4-yl）-1H-indole（bppi）,1,4-benzene-dicarboxylic acid（H2bdc） and cadmium（Ⅱ） nitrate in CH_3OH/H_2O mixed solvents. Complex 1 crystallizes in orthorhombic,space group Ccca with a = 20.012（4）,b = 31.881（6）,c = 19.808（4） ？,V = 12638（4） ？~3,Z = 16,C_（29）H_（20）CdN_6O_5,M_r = 644.91,D_c = 1.356 g·cm^（-3）,μ = 0.735 mm^（-1）,F（000） = 5184,GOOF = 1.046,the final R = 0.0405 and wR = 0.1063 for 6870 observed reflections（I 〉 2σ（I））. The Cd（Ⅱ） centre is hepta-coordinated by three N and four O atoms from one bppi terminal ligand and two bdc2– ligands,respectively,displaying a capped trigonal prism geometry. Structure extension gives coordination polymeric chains,in which the bdc2– linkers connect Cd（Ⅱ） cations into a one-dimensional（1D） coordination polymer along the c axis,giving zigzag chains with the Cd···Cd separation of 11.178（1） ？. The adjacent bppi terminal ligands in the chains are anti-periplanar conformation. The three-dimensional（3D） structure is stabilized by π···π stacking and hydrogen-bonding interactions to form a supramolecular self-penetrating network with 1D channels. In 1,there are voids 2999.7 ？~3 with 23.7% of per unit cell volume. Thermal analysis indicates that the framework of 1 is stable until 651 K and the photoluminescence of 1 in the solid shows very weak fluorescence at 382 and 560 nm upon excitation at 310 nm.展开更多
文摘X-ray computed tomography(CT)has been an important technology in paleontology for several decades.It helps researchers to acquire detailed anatomical structures of fossils non-destructively.Despite its widespread application,developing an efficient and user-friendly method for segmenting CT data continues to be a formidable challenge in the field.Most CT data segmentation software operates on 2D interfaces,which limits flexibility for real-time adjustments in 3D segmentation.Here,we introduce Curves Mode in Drishti Paint 3.2,an open-source tool for CT data segmentation.Drishti Paint 3.2 allows users to manually or semi-automatically segment the CT data in both 2D and 3D environments,providing a novel solution for revisualizing CT data in paleontological studies.
文摘BACKGROUND Trastuzumab-targeted therapy is currently the standard of care for advanced human epidermal growth factor receptor 2(HER2)-positive gastric cancer.However,the emergence of resistance to trastuzumab poses significant challenges.AIM To identify the key genes associated with trastuzumab resistance.These results provide a basis for the development of interventions to address drug resistance and improve patient outcomes.METHODS High-throughput sequencing and bioinformatics were used to identify the differentially expressed pivotal gene BIRC3 and delineate its potential function and pathway regulation.Tumor samples were collected from patients with HER2-positive gastric cancer to evaluate the correlation between BIRC3 expression and trastuzumab resistance.We established gastric cancer cell lines with both highly expressed and suppressed levels of BIRC3,followed by comprehensive in vitro and in vivo experiments to confirm the involvement of BIRC3 in trastuzumab resistance and to elucidate its underlying mechanisms.RESULTS In patients with HER2-positive gastric cancer,there is a significant correlation between elevated BIRC3 expression in tumor tissues and higher T stage,tumor node metastasis stage,as well as poor overall survival and progressionfree survival.BIRC3 is highly expressed in trastuzumab-resistant gastric cancer cell lines,where it inhibits tumor cell apoptosis and enhances trastuzumab resistance by promoting the phosphorylation and activation of the phosphoinositide 3-kinase-Akt(PI3K-AKT)pathway in HER2-positive gastric cancer cells,both in vivo and in vitro.CONCLUSION This study revealed a robust association between high BIRC3 expression and an unfavorable prognosis in patients with HER2-positive gastric cancer.Thus,the high expression of BIRC3 stimulated PI3K-AKT phosphorylation and activation,stimulating the proliferation of HER2-positive tumor cells and suppressing apoptosis,ultimately leading to trastuzumab resistance.
基金supported by the National Key Research and Development Program of China(Nos.2022YFB3504100,2022YFB3506200)the National Natural Science Foundation of China(Nos.22208373,22376217)+1 种基金the Beijing Nova Program(No.20220484215)the Science Foundation of China University of Petroleum,Beijing(No.2462023YJRC030)。
文摘It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower temperature.Herein,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(A_(2)B_(2)O_(7)-type)catalysts with disordered defective cubic fluorite phased structure were successfully prepared by a colloidal crystal template method.3DOM structure promotes the accessibility of the gaseous reactants(O2and CH4)to the active sites.The co-doping of Ca and Sr ions in La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts improved the formation of oxygen vacancies,thereby leading to increased density of surface-active oxygen species(O_(2)^(-))for the activation of CH4and the formation of C2products(C2H6and C2H4).3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts exhibit high catalytic activity for OCM at low temperature.3DOM La1.7Sr0.3Ce1.7Ca0.3O7-δcatalyst with the highest density of O_(2)^(-)species exhibited the highest catalytic activity for low-temperature OCM,i.e.,its CH4conversion,selectivity and yield of C2products at 650℃are 32.2%,66.1%and 21.3%,respectively.The mechanism was proposed that the increase in surface oxygen vacancies induced by the co-doping of Ca and Sr ions boosts the key step of C-H bond breaking and C-C bond coupling in catalyzing low-temperature OCM.It is meaningful for the development of the low-temperature and high-efficient catalysts for OCM reaction in practical application.
文摘Objective:To study the clinical outcomes of complete mesocolic excision(CME)for right-sided colon cancer using 3D(three-dimensional)laparoscopy compared to 2D(two-dimensional)laparoscopy.Methods:From January 2022 to December 2023,58 patients with right-sided colon cancer treated at the Affiliated Hospital of Hebei Engineering University were randomly divided into a 3D laparoscopy group(observation group)and a 2D laparoscopy group(control group),with 29 patients in each group.Intraoperative blood loss,postoperative time to first flatulence,length of hospital stay,and incidence of complications in both groups were recorded.Results:There was a statistically significant difference in intraoperative blood loss between the two groups(P<0.05).There was no statistically significant difference in the time to first flatulence between the groups(P>0.05).However,there was a statistically significant difference in the length of hospital stay(P<0.05)and the incidence of complications(P<0.05)between the two groups.Conclusion:3D laparoscopy for CME can reduce intraoperative blood loss,shorten hospital stay,and decrease postoperative complications,showing significant clinical advantages over traditional 2D laparoscopy.
基金supported by the Fund of Natural Science Foundation of China(No.11872196,12232005)supported by the Outstanding Postgraduate‘Innovation Star’Fund for Distinguished of Gansu Province(No.2021CXZX-032).
文摘Superconducting YBa_(2)Cu_(3)O_(7−x)(YBCO)bulks have promising applications in quasi-permanent magnets,levitation,etc.Recently,a new way of fabricating porous YBCO bulks,named direct-ink-writing(DIW)3D-printing method,has been reported.In this method,the customized precursor paste and programmable shape are two main advantages.Here,we have put forward a new way to customize the YBCO 3D-printing precursor paste which is doped with Al_(2)O_(3)nanoparticles to obtain YBCO with higher thermal conductivity.The great rheological properties of precursor paste after being doped with Al_(2)O_(3)nanoparticles can help the macroscopic YBCO samples with high thermal conductivity fabricated stably with high crystalline and lightweight properties.Test results show that the peak thermal conductivity of Al_(2)O_(3)-doped YBCO can reach twice as much as pure YBCO,which makes a great effort to reduce the quench propagation speed.Based on the microstructure analysis,one can find that the thermal conductivity of Al_(2)O_(3)-doped YBCO has been determined by its components and microstructures.In addition,a macroscopic theoretical model has been proposed to assess the thermal conductivity of different microstructures,whose calculated results take good agreement with the experimental results.Meanwhile,a microstructure with high thermal conductivity has been found.Finally,a macroscopic YBCO bulk with the presented high thermal conductivity microstructure has been fabricated by the Al_(2)O_(3)-doped method.Compared with YBCO fabricated by the traditional 3D-printed,the Al_(2)O_(3)-doped structural YBCO bulks present excellent heat transfer performances.Our customized design of 3D-printing precursor pastes and novel concept of structural design for enhancing the thermal conductivity of YBCO superconducting material can be widely used in other DIW 3D-printing materials.
文摘In the design of building structures,joint efforts must be decided to resolve the depth of competent layers across the intended site to safeguard the durability of civil engineering structures and to avert the disastrous consequences of structural failure and collapse.In this study,an integrated methodology that employed DC resistivity tomography involving 2-D and 3-D techniques and geotechnical-soil analysis was used to evaluate subsoil conditions for engineering site investigation at Okerenkoko primary school,in the Warri-southwest area of Delta State,to adduce the phenomena responsible for the visible cracks/structural failure observed in the buildings.The results obtained brought to light the geological structure beneath the subsurface,which consists of four geoelectric layers identified as topsoil,dry/lithified upper sandy layer,wet sand(water-saturated)and peat/clay/sandy clayey soil(highly water-saturated).The deeply-seated peat/clay materials(ρ≤20Ωm)were delineated in the study area to the depths of 17.1 m and 19.8 m from 2-D and 3-D tomography respectively.3-D images presented as horizontal depth slices revealed the dominance of very low resistivity materials i.e.peat/clay/sandy clay within the fourth,fifth and sixth layers at depths ranging from 8.68-12.5 m,12.5-16.9 m and 16.9-21.9 m respectively.The dominance of mechanically unstable peat/clay/sandy clay layers beneath the subsurface,which are highly mobile in response to volumetric changes,is responsible for the noticeable cracks/failure detected on structures within the study site.These observations were validated by a geotechnical test of soil samples in the study area.Atterberg’s limits of the samples revealed plasticity indices of zero.Thus,the soil samples within the depth analyzed were representatives of sandy soil that does not possess any plasticity.The methods justifiably provided relevant information on the subsurface geology beneath the study site and should be appropriated as major tools for engineering site assessment/geotechnical projects.
文摘On the base of benzimidazole and benzofuran containing heterocyclic system, several derivatives with expected biological activity were synthesized. 2,3-diaminodibenzofuran was the primary substance. Adding various cyclic agents, 2-phenil was got, 2-（o-chlorophenil）, 2-（o-oxyphenil）, 2-chlorometyl- and 2-hydroximethyl-3H-benzo[b[furo（3,2-f] benzimidazoles. The aforementioned substances were characterized by IR and NMR spectroscopy.
基金partially supported by the Major Program of the National Natural Science Foundation of China (No.22090034)the Haihe Laboratory of Sustainable Chemical Transformations for financial support (CYZC202108)
文摘A sol-gel tandem with a solid-phase modification procedure was developed to synthesize Li_(2)TiO_(3)-doped LiCoO_(2) together with phosphate coatings(denoted as LCO-Ti/P),which possesses excellent high-voltage performance in the range of 3.0-4.6 V.The characterizations of X-ray diffraction,high-resolution transmission electron microscopy,and X-ray photoelectron spectroscopy illustrated that the modified sample LCO-Ti/P had the dopant of monoclinic Li_(2)TiO_(3) and amorphous Li3PO4 coating layers.LCO-Ti/P has an initial discharge capacity of 211.6 mAh/g at 0.1 C and a retention of 85.7%after 100 cycles at 1 C and 25±1°C between 3.0 and 4.6 V.Nyquist plots reflect that the charge transfer resistance of LCO-Ti/P after 100 cycles at 1 C is much lower than that of the spent LCO,which benefits Li-ion diffusion.Density functional theory calculations disclose the superior lattice-matching property of major crystal planes for Li_(2)TiO_(3) and LiCoO_(2),the lower energy barriers for Li-ion diffusion in Li_(2)TiO_(3),and the suppressed oxygen release performance resulting from phosphate adsorption.This work provides useful guidance on the rational design of the high-voltage performance of modified LiCoO_(2) materials in terms of lattice-matching properties aside from the phosphate coating to reduce the energy barriers of Li-ion diffusion and enhance cycling stability.
基金Funded by the National Natural Science Foundation of China(No.50972116)
文摘The Co2O3-doping effect on the formation of 3CaO · 3A12O3· CaSO from CaCO3-A12O3-CaSO4, 2H20 mixtures was investigated by means of SO2 emission behavior, chemical analysis, X-ray diffraction, differential thermal analysis and scanning electron microscopy. The experimental results show that CO2O3 addition increases the reactivity of the CaCO3-A12O3-CaSO4·2H2O system significantly, by reducing SO2 emissions in combustion andf-CaO contents in the clinkers, promoting the nucleation and growth of 3CaO·3A12O3-CaSO4, and intensifying the formation of 3CaO·3A12O3·CaSO4. Moreover, CO2O3 addition lowers the formation temperature of 3CaO·3A12O3·CaSO4 by 18 ℃, and similarly increases the thermal stability of it at a wider temperature range.
文摘目的:研究MRI 3D CUBE T_(2)序列检查在踝关节外伤患者韧带损伤诊断中的价值。方法:选择2020年4月—2023年4月于白银市第一人民医院就诊的226例踝关节外伤拟行手术术前患者作为研究对象,按照不同检查方式将患者分为观察组(n=126)与对照组(n=100)。观察组采用MRI 3D CUBE T_(2)序列检查,对照组采取常规MRI检查。比较两组患侧、健侧距腓前韧带测量结果、诊断效能。结果:两组患侧、健侧距腓前韧带宽度及厚度比较,差异无统计学意义(P>0.05)。观察组Ⅰ级踝关节外伤患者韧带损伤诊断准确度、敏感度、特异度、阳性预测值、阴性预测值高于对照组,Ⅱ级患者准确度、敏感度、阴性预测值高于对照组,Ⅲ级患者准确度、特异度、阳性预测值高于对照组,差异有统计学意义(P<0.05)。结论:MRI 3D CUBE T_(2)序列检查踝关节外伤患者韧带损伤诊断效能高于常规MRI检查,可作为治疗效果评价及康复治疗的重要依据。
基金supported by the National Natural Science Foundation of China(Nos.21571118&21271121)
文摘A new coordination polymer {[Cd（C_（21）H_（14）N_6）（C_8H_4O_4）]·H_2O}_n（1） was synthesized by an elaborate design via the reaction of 3-（2,6-di（pyrazin-2-yl）pyridin-4-yl）-1H-indole（bppi）,1,4-benzene-dicarboxylic acid（H2bdc） and cadmium（Ⅱ） nitrate in CH_3OH/H_2O mixed solvents. Complex 1 crystallizes in orthorhombic,space group Ccca with a = 20.012（4）,b = 31.881（6）,c = 19.808（4） ？,V = 12638（4） ？~3,Z = 16,C_（29）H_（20）CdN_6O_5,M_r = 644.91,D_c = 1.356 g·cm^（-3）,μ = 0.735 mm^（-1）,F（000） = 5184,GOOF = 1.046,the final R = 0.0405 and wR = 0.1063 for 6870 observed reflections（I 〉 2σ（I））. The Cd（Ⅱ） centre is hepta-coordinated by three N and four O atoms from one bppi terminal ligand and two bdc2– ligands,respectively,displaying a capped trigonal prism geometry. Structure extension gives coordination polymeric chains,in which the bdc2– linkers connect Cd（Ⅱ） cations into a one-dimensional（1D） coordination polymer along the c axis,giving zigzag chains with the Cd···Cd separation of 11.178（1） ？. The adjacent bppi terminal ligands in the chains are anti-periplanar conformation. The three-dimensional（3D） structure is stabilized by π···π stacking and hydrogen-bonding interactions to form a supramolecular self-penetrating network with 1D channels. In 1,there are voids 2999.7 ？~3 with 23.7% of per unit cell volume. Thermal analysis indicates that the framework of 1 is stable until 651 K and the photoluminescence of 1 in the solid shows very weak fluorescence at 382 and 560 nm upon excitation at 310 nm.
