Background: Glycine dehydrogenase(GLDC) plays an important role in the initiation and proliferation of several human cancers. In this study, we aimed to detect the methylation status of GLDC promoter and its diagnosti...Background: Glycine dehydrogenase(GLDC) plays an important role in the initiation and proliferation of several human cancers. In this study, we aimed to detect the methylation status of GLDC promoter and its diagnostic value for hepatitis B virus-associated hepatocellular carcinoma(HBV-HCC). Methods: We enrolled 197 patients, 111 with HBV-HCC, 51 with chronic hepatitis B(CHB), and 35 healthy controls(HCs). The methylation status of GLDC promoter in peripheral mononuclear cells(PBMCs) was identified by methylation specific polymerase chain reaction(MSP). The mRNA expression was examined using real-time quantitative polymerase chain reaction(q PCR). Results: The methylation frequency of the GLDC promoter was significantly lower in HBV-HCC patients(27.0%) compared to that in CHB patients(68.6%) and HCs(74.3%)( P < 0.001). The methylated group had lower alanine aminotransferase level( P = 0.035) and lower rates of tumor node metastasis(TNM) Ⅲ/Ⅳ( P = 0.043) and T3/T4( P = 0.026). TNM stage was identified to be an independent factor for GLDC promoter methylation. GLDC mRNA levels in CHB patients and HCs were significantly lower than those in HBV-HCC patients( P = 0.022 and P < 0.001, respectively). GLDC mRNA levels were significantly higher in HBV-HCC patients with unmethylated GLDC promoters than those with methylated GLDC promoters( P = 0.003). The diagnostic accuracy of alpha-fetoprotein(AFP) combined with GLDC promoter methylation for HBV-HCC was improved compared with that of AFP alone(AUC: 0.782 vs. 0.630, P < 0.001). In addition, GLDC promoter methylation was an independent predictor for overall survival of HBV-HCC patients( P = 0.038). Conclusions: The methylation frequency of GLDC promoter was lower in PBMCs from HBV-HCC patients than that from patients with CHB and HCs. The combination of AFP and GLDC promoter hypomethylation significantly improved the diagnostic accuracy of HBV-HCC.展开更多
Chifeng is a concentrated mining area for non-ferrous metal minerals,as well as a key prevention and control area for heavyduty enterprises.This situation necessitates an efective ecological and human health risk asse...Chifeng is a concentrated mining area for non-ferrous metal minerals,as well as a key prevention and control area for heavyduty enterprises.This situation necessitates an efective ecological and human health risk assessment of heavy metal(loid)s driven by the wide distribution of metal ore processing,mining,and smelting factories in Hexigten Banner and Bairin Left Banner.We conducted surveys to assess the levels of heavy metal(loid)s(Cr,As,Pb,Cd,and Hg)in the topsoil and groundwater of the areas.The results indicated that the concentrations of As,Cd,and Pb in partial soil samples exceeded the environmental quality standards of Grade II.Based on contamination assessments,such as geoaccumulation indices and pollution indices,we inferred that Cd,Pb,and As were primary pollutants in topsoil.Potential ecological risks when considered as part of the average risk indices(RI)are up to 1626.40 and 2818.76,respectively,in the two areas.Comparative analysis revealed that Cd posed a very high potential ecological risk,followed by As.Moreover,the evaluation showed that the three exposure pathways of carcinogenic and non-carcinogenic risk followed a descending order:inhalation>ingestion>dermal contact,except for Pb.Arsenic in topsoil posed a potential non-carcinogenic risk to human health,while there were no adverse efects of As in groundwater.In addition,the average total carcinogenic risk for As in the two areas,as well as the risk of Pb in the topsoil of Bairin Left Banner and all the fve heavy metal(loid)s in groundwater,exceeded human tolerance.Pb–Zn mines caused higher human health risks.In addition,the tandem contamination of heavy metal(loid)s in soil and groundwater was not obvious.This research study provides a basis for pollution remediation to control heavy industry-induced ecological and health risks of heavy metal(loid)s.展开更多
The variations of single event transient(SET)pulse width of high-LET heavy ion irradiation in 16-nm-thick bulk silicon fin field-effect transistor(Fin FET)inverter chains with different driven strengths are measured a...The variations of single event transient(SET)pulse width of high-LET heavy ion irradiation in 16-nm-thick bulk silicon fin field-effect transistor(Fin FET)inverter chains with different driven strengths are measured at different temperatures.Three-dimensional(3D)technology computer-aided design simulations are carried out to study the SET pulse width and saturation current varying with temperature.Experimental and simulation results indicate that the increase in temperature will enhance the parasitic bipolar effect of bulk Fin FET technology,resulting in the increase of SET pulse width.On the other hand,the increase of inverter driven strength will change the layout topology,which has a complex influence on the SET temperature effects of Fin FET inverter chains.The experimental and simulation results show that the device with the strongest driven strength has the least dependence on temperature.展开更多
Red mud is a type of highly alkaline waste residue produced in the process of alumina smelting by the Bayer process.Based on the idea of medium calcium content,solid wastes such as red mud and fly ash were used to pre...Red mud is a type of highly alkaline waste residue produced in the process of alumina smelting by the Bayer process.Based on the idea of medium calcium content,solid wastes such as red mud and fly ash were used to prepare non-burnt bricks;and the mass ratio of CaO/SiO2 was selected in the range of 0.88–1.42.Mechanical properties and durability were investigated with a compressive strength test.X-ray diffractometry(XRD),scanning electron microscope(SEM),and Fourier transform infrared spectroscopy(FTIR)techniques were used to characterize the hydration characteristic.The environmental performance was analyzed by Inductively Coupled Plasma Mass Spectrometry(ICP).The results indicated that the mechanical properties and the durability were optimal when the mass ratio of CaO/SiO2 was 1.23.The hydration products were mostly C–S–H gel,ettringite,Na4Ca(Si10All6)O32·12H2O and Ca3Al2(SiO4)(OH)8.They were responsible for the strength development,and the CaO/SiO2 mass ratio of 1.23 had the best polymerized structure.The results of an environmental performance test showed that the heavy metals in the raw materials were well-solidified in the brick.Therefore,this paper provides an effective solution for use of solid wastes in building material.展开更多
In order to improve the strength and toughness of Q690 E steel sheets,the effect of rare earth element Ce on the strength and toughness of Q690 E steel was studied by means of transmission electron microscopy,scanning...In order to improve the strength and toughness of Q690 E steel sheets,the effect of rare earth element Ce on the strength and toughness of Q690 E steel was studied by means of transmission electron microscopy,scanning electron microscopy,and metallographic microscope.The results showed that the addition of Ce in steel limited the combination of S with Mn and Ca,transformed Al2O3 inclusion into spherical CeAlO3 inclusion,and modified the precipitate form of some composite inclusions of TiN and sulfide oxides into TiN precipitation alone.The inclusions were spheroidizing.The size of inclusions was decreased from 3–5μm to 1–2μm,and the distribution was dispersed.Ce played a role in purifying molten steel through desulphurization and deoxidization.Meanwhile,the addition of Ce in steel effectively increased the nucleation particles in the liquid phase,improved the nucleation rate,enlarged the equiaxed grain refinement area,and limited the development of columnar crystals.The average grain size of slab decreased from 45.76 to 35.25μm,and the proportion of large grain size(>50μm)decreased from 40.41%to 23.74%.The macrostructural examination of slab was improved from B0.5 to C2.0,which realized the refinement of the solidified structure and reduced the banded structure of hot rolled plate.In addition,due to the inheritance of refined structure in the upstream,the recrystallization of deformed austenite and the growth of grain after recrystallization were restrained,and a refined tempered sorbite structure was obtained.When rare earth element Ce was added,the width of the martensite lath bundle was narrowed from about 500 nm to about 200 nm,which realized a remarkable grain refinement strengthening and toughening effect.Mechanical properties such as tensile,yield,and low-temperature impact toughness were significantly improved.展开更多
AIM:To investigate the potential of promoter methylation of two tumor suppressor genes(TSGs)as biomarkers for hepatocellular carcinoma(HCC).METHODS:A total of 189 subjects were included in this retrospective cohort,wh...AIM:To investigate the potential of promoter methylation of two tumor suppressor genes(TSGs)as biomarkers for hepatocellular carcinoma(HCC).METHODS:A total of 189 subjects were included in this retrospective cohort,which contained 121 HCC patients without any history of curative treatment,37 patients with chronic hepatitis B(CHB),and 31 normal controls(NCs).DNA samples were extracted from 400μL of serum of each subject and then modified using bisulfite treatment.Methylation of the promoters of the TSGs(metallothionein1M,MT1M;and metallothionein 1G,MT1G)was determined using methylation-specific polymerase chain reaction.The diagnostic value of combined MT1M and MT1G promoter methylation was evaluated using the area under the receiver operating characteristic curves.RESULTS:Our results indicated that the methylation status of serum MT1M(48.8%,59/121)and MT1G(70.2%,85/121)promoters in the HCC group was significantly higher than that in the CHB group(MT1M 5.4%,2/37,P<0.001;MT1G 16.2%,6/37,P<0.001)and NC group(MT1M 6.5%,2/31,P<0.001;MT1G 12.9%,4/27,P<0.001).Aberrant serum MT1M promoter methylation gave higher specificity to discriminate HCC from CHB(94.6%)and NCs(93.5%),whereas combined methylation of serum MT1M and MT1G promoters showed higher diagnostic sensitivity(90.9%),suggesting that they are potential markers for noninvasive detection of HCC.Furthermore,MT1M promoter methylation was positively correlated with tumor size(rs=0.321,P<0.001),and HCC patients with both MT1M and MT1G promoter methylation tended to show a higher incidence of vascular invasion or metastasis(P=0.018).CONCLUSION:MT1M and MT1G promoter methylation may be used as serum biomarkers for noninvasive detection of HCC.展开更多
For ultra-low-carbon(ULC)steel production,the higher oxygen content before Ruhrstahl-Heraeus(RH)decarburization(de-C)treatment could shorten the de-C time in the RH degasser.However,this would lead to oxidation rates ...For ultra-low-carbon(ULC)steel production,the higher oxygen content before Ruhrstahl-Heraeus(RH)decarburization(de-C)treatment could shorten the de-C time in the RH degasser.However,this would lead to oxidation rates being exceeded by molten steel production,affecting ULC steel surface quality.In this work,a carbon powder addition(CPA)process was proposed to reduce the dissolved oxygen content at the end of RH de-C through addition of carbon powder to molten steel in the vacuum vessel.Carbon and oxygen behavior during the CPA and conventional process was then studied.The results demonstrated that the de-C rate with CPA was lower compared to the conventional process,but the carbon content at the end of de-C presented no difference.The de-C reaction for CPA process took place in the four reaction sites:(1)within the bulk steel where the spontaneous CO bubbles form;(2)splashing area on the liquid steel surface;(3)Ar bubble surface;(4)molten steel surface.The CPA process could significantly reduce the dissolved oxygen content at the end of de-C,the sum content of FeO and MnO in the slag,the aluminum consumption,and the defect rate of rolled products.This was beneficial in improving ULC steel cleanliness.展开更多
A dual double interlocked storage cell(DICE)interleaving layout static random-access memory(SRAM)is designed and manufactured based on 65 nm bulk complementary metal oxide semiconductor technology.The single event ups...A dual double interlocked storage cell(DICE)interleaving layout static random-access memory(SRAM)is designed and manufactured based on 65 nm bulk complementary metal oxide semiconductor technology.The single event upset(SEU)cross sections of this memory are obtained via heavy ion irradiation with a linear energy transfer(LET)value ranging from 1.7 to 83.4 MeV/(mg/cm^(2)).Experimental results show that the upset threshold(LETth)of a 4 KB block is approximately 6 MeV/(mg/cm^(2)),which is much better than that of a standard unhardened SRAM with an identical technology node.A 1 KB block has a higher LETth of 25 MeV/(mg/cm^(2))owing to the use of the error detection and correction(EDAC)code.For a Ta ion irradiation test with the highest LET value(83.4 MeV/(mg/cm^(2))),the benefit of the EDAC code is reduced significantly because the multi-bit upset proportion in the SEU is increased remarkably.Compared with normal incident ions,the memory exhibits a higher SEU sensitivity in the tilt angle irradiation test.Moreover,the SEU cross section indicates a significant dependence on the data pattern.When comprehensively considering HSPICE simulation results and the sensitive area distributions of the DICE cell,it is shown that the data pattern dependence is primarily associated with the arrangement of sensitive transistor pairs in the layout.Finally,some suggestions are provided to further improve the radiation resistance of the memory.By implementing a particular design at the layout level,the SEU tolerance of the memory is improved significantly at a low area cost.Therefore,the designed 65 nm SRAM is suitable for electronic systems operating in serious radiation environments.展开更多
For modern scaling devices,multiple cell upsets(MCUs)have become a major threat to high-reliability field-programmable gate array(FPGA)-based systems.Thus,both performing the worst-case irradiation tests to provide th...For modern scaling devices,multiple cell upsets(MCUs)have become a major threat to high-reliability field-programmable gate array(FPGA)-based systems.Thus,both performing the worst-case irradiation tests to provide the actual MCU response of devices and proposing an effective MCU distinction method are urgently needed.In this study,high-and medium-energy heavy-ion irradiations for the configuration random-access memory of 28 nm FPGAs are performed.An MCU extraction method supported by theoretical predictions is proposed to study the MCU sizes,shapes,and frequencies in detail.Based on the extraction method,the different percentages,and orientations of the large MCUs in both the azimuth and zenith directions determine the worse irradiation response of the FPGAs.The extracted largest 9-bit MCUs indicate that high-energy heavy ions can induce more severe failures than medium-energy ones.The results show that both the use of high-energy heavy ions during MCU evaluations and effective protection for the application of high-density 28 nm FPGAs in space are extremely necessary.展开更多
AIM: To evaluate tumor necrosis factor-α converting enzyme(TACE) methylation status in patients with chronic hepatitis B(CHB).METHODS: Eighty patients with hepatitis B e antigen(HBe Ag)-positive CHB, 80 with HBe Ag-n...AIM: To evaluate tumor necrosis factor-α converting enzyme(TACE) methylation status in patients with chronic hepatitis B(CHB).METHODS: Eighty patients with hepatitis B e antigen(HBe Ag)-positive CHB, 80 with HBe Ag-negative CHB, and 40 healthy controls(HCs) were randomly enrolled in this study. Genomic DNA was extracted from peripheral blood mononuclear cells and methylation status of TACE promoter was determined by methylation-specific polymerase chain reaction. The clinical and laboratory parameters were collected.RESULTS: One hundred and thirty of 160 patients with CHB(81.25%) and 38 of 40 HCs(95%) displayed TACE promoter methylation. The difference was significant(χ2 = 4.501, P < 0.05). TACE promoter methylation frequency in HBe Ag-positive CHB(58/80, 72.5%) was significantly lower than that in HBe Ag-negative CHB(72/80, 90%; χ2 = 8.041, P < 0.01) and HCs(χ2 = 8.438, P < 0.01). However, no significant difference was observed in the methylation frequency between HBe Agnegative CHB and HCs(χ2 = 0.873, P > 0.05). In the HBe Ag-positive group, TACE methylation frequency was significantly negatively correlated with HBe Ag(r =-0.602, P < 0.01), alanine aminotransferase(r =-0.461, P < 0.01) and aspartate aminotransferase(r =-0.329, P < 0.01). CONCLUSION: Patients with HBe Ag-positive CHB have aberrant demethylation of the TACE promoter, which may potentially serve as a biomarker for HBe Ag seroconversion.展开更多
Groundwater of Luohe Formation is the main water source for industrial and agricultural and residential use in Binchang mining area,which is one of the key elements to water conservation coal mining.However,few studie...Groundwater of Luohe Formation is the main water source for industrial and agricultural and residential use in Binchang mining area,which is one of the key elements to water conservation coal mining.However,few studies are available to document the enrichment characteristics and influence of underground coal mining on groundwater for the Luohe Formation.This study evaluates the changes of groundwater levels and spring flow caused by mining activities to explore the influence mechanism of coal mining on groundwater by comparatively analysing existing mining data and survey data combined with a series of mapping methods.The results show that the aquifer of Luohe Formation are gradually thinning south-eastwards,disappeared at the mining boundary.In the vertical direction,the lithological structure is distinct,due to alternative sedimentation of meandering river facies and braided river facies.According to the yielding property,the aquifer is divided into three sections,namely,strong water-rich section,medium water-rich section,and weak water-rich section,which are located in northwest and central part,southwest,and the rest part of the mining area,respectively.Mining of Tingnan Coal Mine since 2004 has caused a 3.16 to 194.87 meters drop in groundwater level of Luohe Formation.Until 2015,70.10%of the mining area undergoes a groundwater level drop larger than 10.00 meters.Another influence of underground mining is that the total flow from 34 springs in 8 southern coal mines of the area has decreased by 286.48 L/s with a rate of decrease at 46.95%from 2007 to 2017.The areas that groundwater level falls or spring flow declines are manly located in the mine gob areas.Results also indicate that the ratio of the height of water conducted fracture zone to the mining height in Binchang mining area is between 16.85 and 27.92.This may increase ground water flow in vertical direction,causing a water level in the aquifer system to drop and ultimately decreasing the flow from the springs.The research results will provide data and theoretical support for the protection of groundwater resources and water conservation coal mining of Luohe Formation in Binchang mining area.展开更多
Multiple-bit upsets(MBUs)have become a threat to modern advanced field-programmable gate arrays(FPGAs)applications in radiation environments.Hence,many investigations have been conducted using mediumenergy heavy ions ...Multiple-bit upsets(MBUs)have become a threat to modern advanced field-programmable gate arrays(FPGAs)applications in radiation environments.Hence,many investigations have been conducted using mediumenergy heavy ions to study the effects of MBU radiation.However,high-energy heavy ions(HEHIs)greatly affect the size and percentage of MBUs because their ionizationtrack structures differ from those of medium-energy heavy ions.In this study,the different impacts of high-energy and medium-energy heavy ions on MBUs in 28 nm FPGAs as well as their mechanisms are thoroughly investigated.With the Geant4 calculation,more serious energy effects of HEHIs on MBU scales were successfully demonstrated.In addition,we identified worse MBU responses resulting from lowered voltages.The MBU orientation effect was observed in the radiation of different dimensions.The broadened ionization tracks for tilted tests in different dimensions could result in different MBU sizes.The results also revealed that the ionization tracks of tilted HEHIs have more severe impacts on the MBU scales than mediumenergy heavy ions with much higher linear energy transfer.Therefore,comprehensive radiation with HEHIs is indispensable for effective hardened designs to apply highdensity 28 nm FPGAs in deep space exploration.展开更多
The root system is fundamental for maize growth and yield.Characterizing its heterogeneity and cell type-specific response to nitrate at the single-cell level will shed light on root development and nutrient uptake.We...The root system is fundamental for maize growth and yield.Characterizing its heterogeneity and cell type-specific response to nitrate at the single-cell level will shed light on root development and nutrient uptake.We profiled the transcriptomes of>7000 cells derived from root tips of maize seedlings grown on media with or without nitrate,and identified 11 major cell types or tissues and 85 cell type-specific nitrate-response genes,including several known nitrate metabolic genes.A pseudotime analysis showed a continuous pseudotime series with the beginning at meristematic zone cells and showed that the root hair cell was derived by differentiation of a subset of epidermal cells.Interspecies comparison of root cells between maize and rice revealed the conservation and divergence of the root cell types and identified 57,216,and 80 conserved orthologous genes in root hair,endodermis,and phloem cells respectively.This study provides a global view of maize root tip developmental processes and responses to nitrate at the single-cell level.The genes described in the present work could serve as targets for further genetic analyses and accurate regulation of gene expression and phenotypic variation in specific cell types or tissues.展开更多
Magnesium alloys,the lightest structural metal,are used in the field of aeronautics and astronautics more and more,however they are still limited for the poor corrosion resistant and high temperature property.In order...Magnesium alloys,the lightest structural metal,are used in the field of aeronautics and astronautics more and more,however they are still limited for the poor corrosion resistant and high temperature property.In order to satisfy the need of long time store and short time operation at elevated temperature,coating with excellent corrosion resistance and thermal resistance was prepared on the surface of Mg alloy AZ31B.The cathodic electrophoretic deposition was applied for the preparation of coating.The bonding of organic electrophoretic deposition coating with substrate was improved using silane pretreatment.Nano-ZrO_(2) powder treated by silane was added into electrophoretic deposition solution.The corrosion resistance property of electrophoretic coating was evaluated using Machu test,and thermal characteristic using the thermal shock experiment and DTA respectively.The morphology of the coating was examined by SEM.It is found that both the corrosion resistant and thermal shock resistant properties can be improved by modifying the Mg specimen with APS silane,while adding nano-ZrO_(2)powder treated by GPS silane to the coating has the optimal effect.And the results also show that the main reason of the coating damage after thermal shock at 400°C or 500°C is mainly for the thermal stress.展开更多
Objective:This study aimed to analyze and evaluate the results of mid-term follow-up after fetal pulmonary valvuloplasty(FPV)in fetuses with pulmonary atresia with intact ventricular septum(PA/IVS).Methods:From August...Objective:This study aimed to analyze and evaluate the results of mid-term follow-up after fetal pulmonary valvuloplasty(FPV)in fetuses with pulmonary atresia with intact ventricular septum(PA/IVS).Methods:From August 31,2018,to May 31,2019,seven fetuses with PA/IVS and hypoplastic right heart were included in this study.All underwent echocardiography by the same specialist and were operated on by the same team.Intervention and echocardiography data were collected,and changes in the associated indices noted during follow-up were analyzed.Results:All seven fetuses successfully underwent FPV.The median gestational age at FPV was 27.54 weeks.The average FPV procedural time was 6 min.Persistent bradycardia requiring treatment occurred in 4/7 procedures.Finally,five pregnancies were successfully delivered,and the other two were aborted.Compared to data before fetal cardiac interventions(FCI),tricuspid valve annulus diameter/mitral valve annulus diameter(TV/MV)and right ventricle diameter/left ventricle diameter(RV/LV)of all fetuses had progressively improved.The maximum tricuspid regurgitation velocity decreased from 4.60 m/s to 3.64 m/s.The average follow-up time was 30.40±2.05 months.During the follow-up period,the diameter of the tricuspid valve ring in five children continued to improve,and the development rate of the tricuspid valve was relatively obvious from 6 months to 1 year after birth.However,the development of the right ventricle after birth was relatively slow.It was discovered that there were individual variations in the development of the right ventricle during follow-up.Conclusion:The findings support the potential for the development of the right ventricle and tricuspid valve in fetuses with PA/IVS who underwent FCI.Development of the right ventricle and tricuspid valve does not occur synchronously during pregnancy.The right ventricle develops rapidly in utero,but the development of tricuspid valve is more apparent after birth than in utero.展开更多
Recently, growing evidences show that the combination of epigenetic and genetic abnormalities contribute together to the development of liver diseases. DNA methylation is a very important epigenetic mechanism in human...Recently, growing evidences show that the combination of epigenetic and genetic abnormalities contribute together to the development of liver diseases. DNA methylation is a very important epigenetic mechanism in human beings. It refers to addition of the methyl groups to DNA and mainly occurs at cytosine adjacent to guanine. DNA methylation is prevalent across human genome and is essential for the normal human development, while its dysfunction is associated with many human diseases. A deep understanding of DNA methylation may provide us deep insight into the origination of liver diseases. Also, it may provide us new tools for diseases diagnosis and prognosis prediction. This review summarized recent progress of DNA methylation study and provided an overview of DNA methylation and liver diseases. Meanwhile, the association between DNA methylation and liver diseases including hepatocellular carcinoma, liver fibrosis, nonalcoholic steatohepatitis and liver failure were extensively discussed. Finally, we discussed the potential of DNA methylationtherapeutics for liver diseases and the value of DNA methylation as biomarkers for liver diseases diagnosis and prognosis prediction. This review aimed to provide the emerging DNA methylation information about liver diseases. It might provide essential information for managing and care of these patients.展开更多
The high porosity and interconnectivity of scaffolds are critical for nutrient transmission in bone tis-sue engineering but usually lead to poor mechanical properties.Herein,a novel method that combines acid etching(A...The high porosity and interconnectivity of scaffolds are critical for nutrient transmission in bone tis-sue engineering but usually lead to poor mechanical properties.Herein,a novel method that combines acid etching(AE)with selective laser sintering(SLS)and reaction bonding(RB)of Al particles is pro-posed to realize highly improved porosity,interconnectivity,mechanical strength,and in vitro bioactivity in 3D Al_(2)O_(3) scaffolds.By controlling the oxidation and etching behaviors of Al particles,a tunable hol-low spherical feature can be obtained,which brings about the distinction in compressive response and fracture path.The prevention of microcrack propagation on the in situ formed hollow spheres results in unique near elastic buckling rather than traditional brittle fracture,allowing an unparalleled compressive strength of 3.72±0.17 MPa at a high porosity of 87.7%±0.4%and pore interconnectivity of 94.7%±0.4%.Furthermore,scaffolds with an optimized pore structure and superhydrophilic surface show excellent cell proliferation and adhesion properties.Our findings offer a promising strategy for the coexistence of out-standing mechanical and biological properties,with great potential for tissue engineering applications.展开更多
The term“over-skidding”indicates that the cage rotational speed ratio exceeds the theoretical value as ball purely rolls on the raceway.Different from the skidding phenomenon that occurs in low-load and high-speed b...The term“over-skidding”indicates that the cage rotational speed ratio exceeds the theoretical value as ball purely rolls on the raceway.Different from the skidding phenomenon that occurs in low-load and high-speed bearing,over-skidding usually occurs in large-size angular contact bearings,and it is still difficult to suppress under high load conditions.The main forms of damage to the raceway by over-skidding are spinning and gyro slip.To further explore the vibration characteristics and thermal effects of this phenomenon,a set of over-skidding tests of an angular contact bearing with a bore diameter of 220 mm were conducted on an industrial-size test bench.Through the experiment,the influence of axial load,rotational speed,and lubrication conditions on the occurrence of over-skidding were determined.Based on a previous dynamics model,the heat generation and thermal network models were integrated in the present study to predict the over-skidding and its thermal behavior.The model was validated in terms of the measured degree of over-skidding and temperature rise.The results showed that the degree of over-skidding reaches up to 12%of the theoretical value,and the friction power loss of the ball-pocket accounts for 30%of the total power loss.The analysis of the vibration signal showed a strong correlation between the bearing vibration characteristics and over-skidding behavior,thereby providing a way to indirectly measure the degree of over-skidding.展开更多
Photocatalytic fuel cell (PFC) holds great potential for the sustainable production of electricity and degradation of organic pollutants for solving global energy and environmental problems.However,the efficient photo...Photocatalytic fuel cell (PFC) holds great potential for the sustainable production of electricity and degradation of organic pollutants for solving global energy and environmental problems.However,the efficient photodegradation of organic dyes and antibiotic drugs,such as ciprofloxacin (CIP) and methylene blue(MB),remains challenging.Aiming at improving the separation efficiency of hole and electron for electricity generation in the PFC system,TiO_(2)-NPs@NF-x photoanode was fabricated by a cost-effective and laborsaving hydrothermal approach.The as-fabricated photoanode demonstrated abundant active sites,enhanced light harvesting capacity and photogenerated charge carrier separation.At a CIP-HCl concentration of 10 mg/L and p H value of about 7,85%of CIP-HCl can be efficiently removed after 3 h irradiation by 300 W Xe lamp.TiO_(2)-NPs@NF-20 photoelectrode based PFC system exhibited an impressed ability to simultaneously degrade ciprofloxacin and generate electricity under light irradiation with an open circuit voltage of 1.021 V,short circuit current density and maximum power density of 2.4 mA/cm^(2),0.357 mW/cm^(2),respectively.This work provided a cost-effective method for the treatment of organic waste and generation of electrical power.展开更多
基金This study was supported by grants from the Key Project of the Chinese Ministry of Science and Technology(2017ZX102022022)National Key Research and Development Program of China(2021YFC2301801).
文摘Background: Glycine dehydrogenase(GLDC) plays an important role in the initiation and proliferation of several human cancers. In this study, we aimed to detect the methylation status of GLDC promoter and its diagnostic value for hepatitis B virus-associated hepatocellular carcinoma(HBV-HCC). Methods: We enrolled 197 patients, 111 with HBV-HCC, 51 with chronic hepatitis B(CHB), and 35 healthy controls(HCs). The methylation status of GLDC promoter in peripheral mononuclear cells(PBMCs) was identified by methylation specific polymerase chain reaction(MSP). The mRNA expression was examined using real-time quantitative polymerase chain reaction(q PCR). Results: The methylation frequency of the GLDC promoter was significantly lower in HBV-HCC patients(27.0%) compared to that in CHB patients(68.6%) and HCs(74.3%)( P < 0.001). The methylated group had lower alanine aminotransferase level( P = 0.035) and lower rates of tumor node metastasis(TNM) Ⅲ/Ⅳ( P = 0.043) and T3/T4( P = 0.026). TNM stage was identified to be an independent factor for GLDC promoter methylation. GLDC mRNA levels in CHB patients and HCs were significantly lower than those in HBV-HCC patients( P = 0.022 and P < 0.001, respectively). GLDC mRNA levels were significantly higher in HBV-HCC patients with unmethylated GLDC promoters than those with methylated GLDC promoters( P = 0.003). The diagnostic accuracy of alpha-fetoprotein(AFP) combined with GLDC promoter methylation for HBV-HCC was improved compared with that of AFP alone(AUC: 0.782 vs. 0.630, P < 0.001). In addition, GLDC promoter methylation was an independent predictor for overall survival of HBV-HCC patients( P = 0.038). Conclusions: The methylation frequency of GLDC promoter was lower in PBMCs from HBV-HCC patients than that from patients with CHB and HCs. The combination of AFP and GLDC promoter hypomethylation significantly improved the diagnostic accuracy of HBV-HCC.
基金the National Natural Science Foundation of China(No.42072284,No.42027801,No.41877186)the National Key R&D Program of China(2021YFC2902004)+1 种基金the Major Science and Technology Projects of Inner Mongolia Autonomous Region(2020ZD0020-4)the Fundamental Research Funds for the Central Universities(2022YQSH01,2020YJSSH01,2021YJSSH01)。
文摘Chifeng is a concentrated mining area for non-ferrous metal minerals,as well as a key prevention and control area for heavyduty enterprises.This situation necessitates an efective ecological and human health risk assessment of heavy metal(loid)s driven by the wide distribution of metal ore processing,mining,and smelting factories in Hexigten Banner and Bairin Left Banner.We conducted surveys to assess the levels of heavy metal(loid)s(Cr,As,Pb,Cd,and Hg)in the topsoil and groundwater of the areas.The results indicated that the concentrations of As,Cd,and Pb in partial soil samples exceeded the environmental quality standards of Grade II.Based on contamination assessments,such as geoaccumulation indices and pollution indices,we inferred that Cd,Pb,and As were primary pollutants in topsoil.Potential ecological risks when considered as part of the average risk indices(RI)are up to 1626.40 and 2818.76,respectively,in the two areas.Comparative analysis revealed that Cd posed a very high potential ecological risk,followed by As.Moreover,the evaluation showed that the three exposure pathways of carcinogenic and non-carcinogenic risk followed a descending order:inhalation>ingestion>dermal contact,except for Pb.Arsenic in topsoil posed a potential non-carcinogenic risk to human health,while there were no adverse efects of As in groundwater.In addition,the average total carcinogenic risk for As in the two areas,as well as the risk of Pb in the topsoil of Bairin Left Banner and all the fve heavy metal(loid)s in groundwater,exceeded human tolerance.Pb–Zn mines caused higher human health risks.In addition,the tandem contamination of heavy metal(loid)s in soil and groundwater was not obvious.This research study provides a basis for pollution remediation to control heavy industry-induced ecological and health risks of heavy metal(loid)s.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12035019,12105339,and62174180)the Opening Special Foundation of State Key Laboratory of Intense Pulsed Radiation Simulation and Effect,China(Grant No.SKLIPR2113)。
文摘The variations of single event transient(SET)pulse width of high-LET heavy ion irradiation in 16-nm-thick bulk silicon fin field-effect transistor(Fin FET)inverter chains with different driven strengths are measured at different temperatures.Three-dimensional(3D)technology computer-aided design simulations are carried out to study the SET pulse width and saturation current varying with temperature.Experimental and simulation results indicate that the increase in temperature will enhance the parasitic bipolar effect of bulk Fin FET technology,resulting in the increase of SET pulse width.On the other hand,the increase of inverter driven strength will change the layout topology,which has a complex influence on the SET temperature effects of Fin FET inverter chains.The experimental and simulation results show that the device with the strongest driven strength has the least dependence on temperature.
基金the financial support from the National Natural Science Foundation of China (No.51574024)Fundamental Research Funds for the Central Universities (FRF-TP-18-005B1)Technological Research and Development Programs of China Railways Corporation (No.2017G006-J)
文摘Red mud is a type of highly alkaline waste residue produced in the process of alumina smelting by the Bayer process.Based on the idea of medium calcium content,solid wastes such as red mud and fly ash were used to prepare non-burnt bricks;and the mass ratio of CaO/SiO2 was selected in the range of 0.88–1.42.Mechanical properties and durability were investigated with a compressive strength test.X-ray diffractometry(XRD),scanning electron microscope(SEM),and Fourier transform infrared spectroscopy(FTIR)techniques were used to characterize the hydration characteristic.The environmental performance was analyzed by Inductively Coupled Plasma Mass Spectrometry(ICP).The results indicated that the mechanical properties and the durability were optimal when the mass ratio of CaO/SiO2 was 1.23.The hydration products were mostly C–S–H gel,ettringite,Na4Ca(Si10All6)O32·12H2O and Ca3Al2(SiO4)(OH)8.They were responsible for the strength development,and the CaO/SiO2 mass ratio of 1.23 had the best polymerized structure.The results of an environmental performance test showed that the heavy metals in the raw materials were well-solidified in the brick.Therefore,this paper provides an effective solution for use of solid wastes in building material.
基金financially supported by National Natural Science Foundation of China (No. 51774031)Open Project of State Key Laboratory of Advanced Special Steel, Shanghai University (SKLASS 2017-12)
文摘In order to improve the strength and toughness of Q690 E steel sheets,the effect of rare earth element Ce on the strength and toughness of Q690 E steel was studied by means of transmission electron microscopy,scanning electron microscopy,and metallographic microscope.The results showed that the addition of Ce in steel limited the combination of S with Mn and Ca,transformed Al2O3 inclusion into spherical CeAlO3 inclusion,and modified the precipitate form of some composite inclusions of TiN and sulfide oxides into TiN precipitation alone.The inclusions were spheroidizing.The size of inclusions was decreased from 3–5μm to 1–2μm,and the distribution was dispersed.Ce played a role in purifying molten steel through desulphurization and deoxidization.Meanwhile,the addition of Ce in steel effectively increased the nucleation particles in the liquid phase,improved the nucleation rate,enlarged the equiaxed grain refinement area,and limited the development of columnar crystals.The average grain size of slab decreased from 45.76 to 35.25μm,and the proportion of large grain size(>50μm)decreased from 40.41%to 23.74%.The macrostructural examination of slab was improved from B0.5 to C2.0,which realized the refinement of the solidified structure and reduced the banded structure of hot rolled plate.In addition,due to the inheritance of refined structure in the upstream,the recrystallization of deformed austenite and the growth of grain after recrystallization were restrained,and a refined tempered sorbite structure was obtained.When rare earth element Ce was added,the width of the martensite lath bundle was narrowed from about 500 nm to about 200 nm,which realized a remarkable grain refinement strengthening and toughening effect.Mechanical properties such as tensile,yield,and low-temperature impact toughness were significantly improved.
基金Supported by National Natural Science Foundation of China,No.81171579,No.81201287 and No.81371832
文摘AIM:To investigate the potential of promoter methylation of two tumor suppressor genes(TSGs)as biomarkers for hepatocellular carcinoma(HCC).METHODS:A total of 189 subjects were included in this retrospective cohort,which contained 121 HCC patients without any history of curative treatment,37 patients with chronic hepatitis B(CHB),and 31 normal controls(NCs).DNA samples were extracted from 400μL of serum of each subject and then modified using bisulfite treatment.Methylation of the promoters of the TSGs(metallothionein1M,MT1M;and metallothionein 1G,MT1G)was determined using methylation-specific polymerase chain reaction.The diagnostic value of combined MT1M and MT1G promoter methylation was evaluated using the area under the receiver operating characteristic curves.RESULTS:Our results indicated that the methylation status of serum MT1M(48.8%,59/121)and MT1G(70.2%,85/121)promoters in the HCC group was significantly higher than that in the CHB group(MT1M 5.4%,2/37,P<0.001;MT1G 16.2%,6/37,P<0.001)and NC group(MT1M 6.5%,2/31,P<0.001;MT1G 12.9%,4/27,P<0.001).Aberrant serum MT1M promoter methylation gave higher specificity to discriminate HCC from CHB(94.6%)and NCs(93.5%),whereas combined methylation of serum MT1M and MT1G promoters showed higher diagnostic sensitivity(90.9%),suggesting that they are potential markers for noninvasive detection of HCC.Furthermore,MT1M promoter methylation was positively correlated with tumor size(rs=0.321,P<0.001),and HCC patients with both MT1M and MT1G promoter methylation tended to show a higher incidence of vascular invasion or metastasis(P=0.018).CONCLUSION:MT1M and MT1G promoter methylation may be used as serum biomarkers for noninvasive detection of HCC.
基金financially supported by the National Natural Science Foundation of China(No.51874021)Fundamental Research Funds for the Central Universities of China(No.FRF-IC-18-002)State Key Laboratory of Advanced Metallurgy Foundation of China(No.41618019)
文摘For ultra-low-carbon(ULC)steel production,the higher oxygen content before Ruhrstahl-Heraeus(RH)decarburization(de-C)treatment could shorten the de-C time in the RH degasser.However,this would lead to oxidation rates being exceeded by molten steel production,affecting ULC steel surface quality.In this work,a carbon powder addition(CPA)process was proposed to reduce the dissolved oxygen content at the end of RH de-C through addition of carbon powder to molten steel in the vacuum vessel.Carbon and oxygen behavior during the CPA and conventional process was then studied.The results demonstrated that the de-C rate with CPA was lower compared to the conventional process,but the carbon content at the end of de-C presented no difference.The de-C reaction for CPA process took place in the four reaction sites:(1)within the bulk steel where the spontaneous CO bubbles form;(2)splashing area on the liquid steel surface;(3)Ar bubble surface;(4)molten steel surface.The CPA process could significantly reduce the dissolved oxygen content at the end of de-C,the sum content of FeO and MnO in the slag,the aluminum consumption,and the defect rate of rolled products.This was beneficial in improving ULC steel cleanliness.
基金the National Natural Science Foundation of China(Nos.12035019,11690041,and 11805244).
文摘A dual double interlocked storage cell(DICE)interleaving layout static random-access memory(SRAM)is designed and manufactured based on 65 nm bulk complementary metal oxide semiconductor technology.The single event upset(SEU)cross sections of this memory are obtained via heavy ion irradiation with a linear energy transfer(LET)value ranging from 1.7 to 83.4 MeV/(mg/cm^(2)).Experimental results show that the upset threshold(LETth)of a 4 KB block is approximately 6 MeV/(mg/cm^(2)),which is much better than that of a standard unhardened SRAM with an identical technology node.A 1 KB block has a higher LETth of 25 MeV/(mg/cm^(2))owing to the use of the error detection and correction(EDAC)code.For a Ta ion irradiation test with the highest LET value(83.4 MeV/(mg/cm^(2))),the benefit of the EDAC code is reduced significantly because the multi-bit upset proportion in the SEU is increased remarkably.Compared with normal incident ions,the memory exhibits a higher SEU sensitivity in the tilt angle irradiation test.Moreover,the SEU cross section indicates a significant dependence on the data pattern.When comprehensively considering HSPICE simulation results and the sensitive area distributions of the DICE cell,it is shown that the data pattern dependence is primarily associated with the arrangement of sensitive transistor pairs in the layout.Finally,some suggestions are provided to further improve the radiation resistance of the memory.By implementing a particular design at the layout level,the SEU tolerance of the memory is improved significantly at a low area cost.Therefore,the designed 65 nm SRAM is suitable for electronic systems operating in serious radiation environments.
基金supported by the National Natural Science Foundation of China(Nos.12035019 and 11690041).
文摘For modern scaling devices,multiple cell upsets(MCUs)have become a major threat to high-reliability field-programmable gate array(FPGA)-based systems.Thus,both performing the worst-case irradiation tests to provide the actual MCU response of devices and proposing an effective MCU distinction method are urgently needed.In this study,high-and medium-energy heavy-ion irradiations for the configuration random-access memory of 28 nm FPGAs are performed.An MCU extraction method supported by theoretical predictions is proposed to study the MCU sizes,shapes,and frequencies in detail.Based on the extraction method,the different percentages,and orientations of the large MCUs in both the azimuth and zenith directions determine the worse irradiation response of the FPGAs.The extracted largest 9-bit MCUs indicate that high-energy heavy ions can induce more severe failures than medium-energy ones.The results show that both the use of high-energy heavy ions during MCU evaluations and effective protection for the application of high-density 28 nm FPGAs in space are extremely necessary.
基金Supported by Key Project of Chinese Ministry of Science and Technology,No.2012ZX10002007 and No.2013ZX10002001National Natural Science Foundation of China,No.81171579,No.81201287 and No.81371832Science and Technology Development Plan of Shandong Province,China,No.2014GSF118068
文摘AIM: To evaluate tumor necrosis factor-α converting enzyme(TACE) methylation status in patients with chronic hepatitis B(CHB).METHODS: Eighty patients with hepatitis B e antigen(HBe Ag)-positive CHB, 80 with HBe Ag-negative CHB, and 40 healthy controls(HCs) were randomly enrolled in this study. Genomic DNA was extracted from peripheral blood mononuclear cells and methylation status of TACE promoter was determined by methylation-specific polymerase chain reaction. The clinical and laboratory parameters were collected.RESULTS: One hundred and thirty of 160 patients with CHB(81.25%) and 38 of 40 HCs(95%) displayed TACE promoter methylation. The difference was significant(χ2 = 4.501, P < 0.05). TACE promoter methylation frequency in HBe Ag-positive CHB(58/80, 72.5%) was significantly lower than that in HBe Ag-negative CHB(72/80, 90%; χ2 = 8.041, P < 0.01) and HCs(χ2 = 8.438, P < 0.01). However, no significant difference was observed in the methylation frequency between HBe Agnegative CHB and HCs(χ2 = 0.873, P > 0.05). In the HBe Ag-positive group, TACE methylation frequency was significantly negatively correlated with HBe Ag(r =-0.602, P < 0.01), alanine aminotransferase(r =-0.461, P < 0.01) and aspartate aminotransferase(r =-0.329, P < 0.01). CONCLUSION: Patients with HBe Ag-positive CHB have aberrant demethylation of the TACE promoter, which may potentially serve as a biomarker for HBe Ag seroconversion.
基金This paper was supported by Natural Science Basic Research Program of Shaanxi Province,China(2019JLZ-03).
文摘Groundwater of Luohe Formation is the main water source for industrial and agricultural and residential use in Binchang mining area,which is one of the key elements to water conservation coal mining.However,few studies are available to document the enrichment characteristics and influence of underground coal mining on groundwater for the Luohe Formation.This study evaluates the changes of groundwater levels and spring flow caused by mining activities to explore the influence mechanism of coal mining on groundwater by comparatively analysing existing mining data and survey data combined with a series of mapping methods.The results show that the aquifer of Luohe Formation are gradually thinning south-eastwards,disappeared at the mining boundary.In the vertical direction,the lithological structure is distinct,due to alternative sedimentation of meandering river facies and braided river facies.According to the yielding property,the aquifer is divided into three sections,namely,strong water-rich section,medium water-rich section,and weak water-rich section,which are located in northwest and central part,southwest,and the rest part of the mining area,respectively.Mining of Tingnan Coal Mine since 2004 has caused a 3.16 to 194.87 meters drop in groundwater level of Luohe Formation.Until 2015,70.10%of the mining area undergoes a groundwater level drop larger than 10.00 meters.Another influence of underground mining is that the total flow from 34 springs in 8 southern coal mines of the area has decreased by 286.48 L/s with a rate of decrease at 46.95%from 2007 to 2017.The areas that groundwater level falls or spring flow declines are manly located in the mine gob areas.Results also indicate that the ratio of the height of water conducted fracture zone to the mining height in Binchang mining area is between 16.85 and 27.92.This may increase ground water flow in vertical direction,causing a water level in the aquifer system to drop and ultimately decreasing the flow from the springs.The research results will provide data and theoretical support for the protection of groundwater resources and water conservation coal mining of Luohe Formation in Binchang mining area.
基金the National Natural Science Foundation of China(Nos.12035019 and 12105339).
文摘Multiple-bit upsets(MBUs)have become a threat to modern advanced field-programmable gate arrays(FPGAs)applications in radiation environments.Hence,many investigations have been conducted using mediumenergy heavy ions to study the effects of MBU radiation.However,high-energy heavy ions(HEHIs)greatly affect the size and percentage of MBUs because their ionizationtrack structures differ from those of medium-energy heavy ions.In this study,the different impacts of high-energy and medium-energy heavy ions on MBUs in 28 nm FPGAs as well as their mechanisms are thoroughly investigated.With the Geant4 calculation,more serious energy effects of HEHIs on MBU scales were successfully demonstrated.In addition,we identified worse MBU responses resulting from lowered voltages.The MBU orientation effect was observed in the radiation of different dimensions.The broadened ionization tracks for tilted tests in different dimensions could result in different MBU sizes.The results also revealed that the ionization tracks of tilted HEHIs have more severe impacts on the MBU scales than mediumenergy heavy ions with much higher linear energy transfer.Therefore,comprehensive radiation with HEHIs is indispensable for effective hardened designs to apply highdensity 28 nm FPGAs in deep space exploration.
基金financially supported by the Special Project of Guangdong Academy of Sciences,China(2020GDASYL-20200103073)the Special Project for Research and Development in Key areas of Guangdong Province(2019B020238001)the National Natural Science Foundation of China(32072027)。
文摘The root system is fundamental for maize growth and yield.Characterizing its heterogeneity and cell type-specific response to nitrate at the single-cell level will shed light on root development and nutrient uptake.We profiled the transcriptomes of>7000 cells derived from root tips of maize seedlings grown on media with or without nitrate,and identified 11 major cell types or tissues and 85 cell type-specific nitrate-response genes,including several known nitrate metabolic genes.A pseudotime analysis showed a continuous pseudotime series with the beginning at meristematic zone cells and showed that the root hair cell was derived by differentiation of a subset of epidermal cells.Interspecies comparison of root cells between maize and rice revealed the conservation and divergence of the root cell types and identified 57,216,and 80 conserved orthologous genes in root hair,endodermis,and phloem cells respectively.This study provides a global view of maize root tip developmental processes and responses to nitrate at the single-cell level.The genes described in the present work could serve as targets for further genetic analyses and accurate regulation of gene expression and phenotypic variation in specific cell types or tissues.
文摘Magnesium alloys,the lightest structural metal,are used in the field of aeronautics and astronautics more and more,however they are still limited for the poor corrosion resistant and high temperature property.In order to satisfy the need of long time store and short time operation at elevated temperature,coating with excellent corrosion resistance and thermal resistance was prepared on the surface of Mg alloy AZ31B.The cathodic electrophoretic deposition was applied for the preparation of coating.The bonding of organic electrophoretic deposition coating with substrate was improved using silane pretreatment.Nano-ZrO_(2) powder treated by silane was added into electrophoretic deposition solution.The corrosion resistance property of electrophoretic coating was evaluated using Machu test,and thermal characteristic using the thermal shock experiment and DTA respectively.The morphology of the coating was examined by SEM.It is found that both the corrosion resistant and thermal shock resistant properties can be improved by modifying the Mg specimen with APS silane,while adding nano-ZrO_(2)powder treated by GPS silane to the coating has the optimal effect.And the results also show that the main reason of the coating damage after thermal shock at 400°C or 500°C is mainly for the thermal stress.
文摘Objective:This study aimed to analyze and evaluate the results of mid-term follow-up after fetal pulmonary valvuloplasty(FPV)in fetuses with pulmonary atresia with intact ventricular septum(PA/IVS).Methods:From August 31,2018,to May 31,2019,seven fetuses with PA/IVS and hypoplastic right heart were included in this study.All underwent echocardiography by the same specialist and were operated on by the same team.Intervention and echocardiography data were collected,and changes in the associated indices noted during follow-up were analyzed.Results:All seven fetuses successfully underwent FPV.The median gestational age at FPV was 27.54 weeks.The average FPV procedural time was 6 min.Persistent bradycardia requiring treatment occurred in 4/7 procedures.Finally,five pregnancies were successfully delivered,and the other two were aborted.Compared to data before fetal cardiac interventions(FCI),tricuspid valve annulus diameter/mitral valve annulus diameter(TV/MV)and right ventricle diameter/left ventricle diameter(RV/LV)of all fetuses had progressively improved.The maximum tricuspid regurgitation velocity decreased from 4.60 m/s to 3.64 m/s.The average follow-up time was 30.40±2.05 months.During the follow-up period,the diameter of the tricuspid valve ring in five children continued to improve,and the development rate of the tricuspid valve was relatively obvious from 6 months to 1 year after birth.However,the development of the right ventricle after birth was relatively slow.It was discovered that there were individual variations in the development of the right ventricle during follow-up.Conclusion:The findings support the potential for the development of the right ventricle and tricuspid valve in fetuses with PA/IVS who underwent FCI.Development of the right ventricle and tricuspid valve does not occur synchronously during pregnancy.The right ventricle develops rapidly in utero,but the development of tricuspid valve is more apparent after birth than in utero.
基金Supported by Grants from Key Project of Chinese Ministry of Science and Technology,No.2012ZX10002007,2013ZX10002001National Natural Science Foundation of China,No.81171579,81201287Science and Technology Development Plan of Shandong Province,No.2012GSF11846
文摘Recently, growing evidences show that the combination of epigenetic and genetic abnormalities contribute together to the development of liver diseases. DNA methylation is a very important epigenetic mechanism in human beings. It refers to addition of the methyl groups to DNA and mainly occurs at cytosine adjacent to guanine. DNA methylation is prevalent across human genome and is essential for the normal human development, while its dysfunction is associated with many human diseases. A deep understanding of DNA methylation may provide us deep insight into the origination of liver diseases. Also, it may provide us new tools for diseases diagnosis and prognosis prediction. This review summarized recent progress of DNA methylation study and provided an overview of DNA methylation and liver diseases. Meanwhile, the association between DNA methylation and liver diseases including hepatocellular carcinoma, liver fibrosis, nonalcoholic steatohepatitis and liver failure were extensively discussed. Finally, we discussed the potential of DNA methylationtherapeutics for liver diseases and the value of DNA methylation as biomarkers for liver diseases diagnosis and prognosis prediction. This review aimed to provide the emerging DNA methylation information about liver diseases. It might provide essential information for managing and care of these patients.
文摘The high porosity and interconnectivity of scaffolds are critical for nutrient transmission in bone tis-sue engineering but usually lead to poor mechanical properties.Herein,a novel method that combines acid etching(AE)with selective laser sintering(SLS)and reaction bonding(RB)of Al particles is pro-posed to realize highly improved porosity,interconnectivity,mechanical strength,and in vitro bioactivity in 3D Al_(2)O_(3) scaffolds.By controlling the oxidation and etching behaviors of Al particles,a tunable hol-low spherical feature can be obtained,which brings about the distinction in compressive response and fracture path.The prevention of microcrack propagation on the in situ formed hollow spheres results in unique near elastic buckling rather than traditional brittle fracture,allowing an unparalleled compressive strength of 3.72±0.17 MPa at a high porosity of 87.7%±0.4%and pore interconnectivity of 94.7%±0.4%.Furthermore,scaffolds with an optimized pore structure and superhydrophilic surface show excellent cell proliferation and adhesion properties.Our findings offer a promising strategy for the coexistence of out-standing mechanical and biological properties,with great potential for tissue engineering applications.
基金supported in part by a scholarship from the China Scholarship Council(CSC)(No.201806880007)the National Natural Science Foundation of China(No.11872222)the State Key Laboratory of Tribology(No.SKLT2021D11)。
文摘The term“over-skidding”indicates that the cage rotational speed ratio exceeds the theoretical value as ball purely rolls on the raceway.Different from the skidding phenomenon that occurs in low-load and high-speed bearing,over-skidding usually occurs in large-size angular contact bearings,and it is still difficult to suppress under high load conditions.The main forms of damage to the raceway by over-skidding are spinning and gyro slip.To further explore the vibration characteristics and thermal effects of this phenomenon,a set of over-skidding tests of an angular contact bearing with a bore diameter of 220 mm were conducted on an industrial-size test bench.Through the experiment,the influence of axial load,rotational speed,and lubrication conditions on the occurrence of over-skidding were determined.Based on a previous dynamics model,the heat generation and thermal network models were integrated in the present study to predict the over-skidding and its thermal behavior.The model was validated in terms of the measured degree of over-skidding and temperature rise.The results showed that the degree of over-skidding reaches up to 12%of the theoretical value,and the friction power loss of the ball-pocket accounts for 30%of the total power loss.The analysis of the vibration signal showed a strong correlation between the bearing vibration characteristics and over-skidding behavior,thereby providing a way to indirectly measure the degree of over-skidding.
基金funded by the National Science and Technology Major Project for Water Pollution Control and Treatment (No. 2018ZX07110-008)National Natural Science Foundation of China (No. 21777065)+1 种基金Basic Scientific Re-search Business Expense Project of Beijing University of Civil Engineering and Architecture (No. X18005)the 2021 BUCEA Post Graduate Innovation Project。
文摘Photocatalytic fuel cell (PFC) holds great potential for the sustainable production of electricity and degradation of organic pollutants for solving global energy and environmental problems.However,the efficient photodegradation of organic dyes and antibiotic drugs,such as ciprofloxacin (CIP) and methylene blue(MB),remains challenging.Aiming at improving the separation efficiency of hole and electron for electricity generation in the PFC system,TiO_(2)-NPs@NF-x photoanode was fabricated by a cost-effective and laborsaving hydrothermal approach.The as-fabricated photoanode demonstrated abundant active sites,enhanced light harvesting capacity and photogenerated charge carrier separation.At a CIP-HCl concentration of 10 mg/L and p H value of about 7,85%of CIP-HCl can be efficiently removed after 3 h irradiation by 300 W Xe lamp.TiO_(2)-NPs@NF-20 photoelectrode based PFC system exhibited an impressed ability to simultaneously degrade ciprofloxacin and generate electricity under light irradiation with an open circuit voltage of 1.021 V,short circuit current density and maximum power density of 2.4 mA/cm^(2),0.357 mW/cm^(2),respectively.This work provided a cost-effective method for the treatment of organic waste and generation of electrical power.
