Accelerating net-zero carbon emissions by electrochemical reduction of carbon dioxide

Electroreduction of CO_(2)shows great potential for global CO_(2)utilization and uptake when collaborated with renewable electricity.Recent advances have been achieved in fundamental understanding and electrocatalyst development for CO_(2)electroreduction.We think this research area has progressed to the stage where significant efforts can focus on translating the obtained knowledge to the development of largescale electrolyzers,which have the potential to accelerate the transition of the current energy system into a sustainable and zero-carbon emission energy structure.In this perspective paper,we first critically evaluate the advancement of vapor-feed devices that use CO_(2)as reactants,from the point of view of industry applications.Then,by carefully comparing their performance to the state-of-the-art water electrolyzers which are well-established technology providing realistic performance targets,we looped back and discussed the remaining challenges including electrode catalysts,reaction conditions,mass transporting,membrane,device durability,operation mode,and so on.Finally,we provide perspectives on the challenges and suggest opportunities for generating fundamental knowledge and achieving technological progress toward the development of practical CO_(2)electrolyzers for the goal of building lowcarbon or/and net carbon-free economies.

Oncological features and prognosis of colorectal cancer in human immunodeficiency virus-positive patients: A retrospective study

BACKGROUND Due to the prolonged life expectancy and increased risk of colorectal cancer(CRC)among patients with human immunodeficiency virus(HIV)infection,the prognosis and pathological features of CRC in HIV-positive patients require examination.AIM To compare the differences in oncological features,surgical safety,and prognosis between patients with and without HIV infection who have CRC at the same tumor stage and site.METHODS In this retrospective study,we collected data from HIV-positive and-negative patients who underwent radical resection for CRC.Using random stratified sampling,24 HIV-positive and 363 HIV-negative patients with colorectal adenocarcinoma after radical resection were selected.Using propensity score matching,we selected 72 patients,matched 1:2(HIV-positive:negative=24:48).Differences in basic characteristics,HIV acquisition,perioperative serological indicators,surgical safety,oncological features,and long-term prognosis were compared between the two groups.RESULTS Fewer patients with HIV infection underwent chemotherapy compared to patients without.HIV-positive patients had fewer preoperative and postoperative leukocytes,fewer preoperative lymphocytes,lower carcinoembryonic antigen levels,more intraoperative blood loss,more metastatic lymph nodes,higher node stage,higher tumor node metastasis stage,shorter overall survival,and shorter progression-free survival compared to patients who were HIV-negative.CONCLUSION Compared with CRC patients who are HIV-negative,patients with HIV infection have more metastatic lymph nodes and worse long-term survival after surgery.Standard treatment options for HIV-positive patients with CRC should be explored.

Nanocarbon-Enhanced 2D Photoelectrodes:A New Paradigm in Photoelectrochemical Water Splitting

Solar-driven photoelectrochemical(PEC)water splitting systems are highly promising for converting solar energy into clean and sustainable chemical energy.In such PEC systems,an integrated photoelectrode incorporates a light harvester for absorbing solar energy,an interlayer for transporting photogenerated charge carriers,and a co-catalyst for triggering redox reactions.Thus,understanding the correlations between the intrinsic structural properties and functions of the photoelectrodes is crucial.Here we critically examine various 2D layered photoanodes/photocathodes,including graphitic carbon nitrides,transition metal dichalcogenides,layered double hydroxides,layered bismuth oxyhalide nanosheets,and MXenes,combined with advanced nanocarbons(carbon dots,carbon nanotubes,graphene,and graphdiyne)as co-catalysts to assemble integrated photoelectrodes for oxygen evolution/hydrogen evolution reactions.The fundamental principles of PEC water splitting and physicochemical properties of photoelectrodes and the associated catalytic reactions are analyzed.Elaborate strategies for the assembly of 2D photoelectrodes with nanocarbons to enhance the PEC performances are introduced.The mechanisms of interplay of 2D photoelectrodes and nanocarbon co-catalysts are further discussed.The challenges and opportunities in the field are identified to guide future research for maximizing the conversion efficiency of PEC water splitting.

Effect of mass transfer and solution composition on the quantification of reaction kinetics by differential electrochemical mass spectrometry

Differential electrochemical mass spectrometry(DEMS)is one of the most powerful techniques for both the mechanistic and kinetic study of complicated electrocatalytic reactions.It can provide information on the nature and yields of the products generated,their production rate,and the structure-activity relationship between the electrocatalysts and the target reactions.The precise calibration of the mass signal is a prerequisite for the accurate evaluation of reaction kinetics.In this work,we use the oxidation reactions of CO and HCOOH to demonstrate how certain conditions,such as the flow rate and solution composition,affect the collection efficiency and ionization probability of the species to be detected.These parameters can affect the determination of the mass calibration constant and the accuracy of the subsequent quantitative DEMS analysis.We show the relationship between the mass calibration constant and the flow rate,and provide strategies for eliminating this and the related problems.

Emotional and Behavioral Problems of Left-Behind Children in Impoverished Rural China:A Comparative Cross-Sectional Study of First Grade Junior High School

Objective:To investigate the prevalence of emotional and behavioral problems and related factors of left-behind children in impoverished rural China(mainly in thefirst grade of junior high school).Methods:A cross-sectional survey of rural households in 27 poverty-stricken counties in 12 provinces across China was conducted using the Strengths and Difficulties Questionnaire(SDQ).Results:The prevalence of emotional and behavioral problems in left-behind children was 11.7%,and that of non-left-behind children was 8.9%.There was statistical difference between the two groups(P<0.01).There are no differences between the two groups in terms of the various factors of SDQ.The incidence of insomnia in the left-behind group was 58.3%,which was higher than that in the non-left-behind group 50.9%(P<0.01);loneliness(62.1%vs.51.8%,P<0.01);running away from home(23.1%vs.18.8%,P<0.01),and self-injury behavior(16.8%vs.12.2%,P<0.01).Left-behind children are more likely to have negative psychological feelings including insomnia,loneliness,self-injury,and run away from home.They also experienced more bullying including maliciously teased by peers,intentionally excluded or isolated,physically threatened or intimidated.All of these factors are associated with their abnormal emotional and behavioural development.Conclusion:The incidence of emotional and behavioral problems of left-behind children in rural areas in poverty-stricken areas is significantly higher than that of non-left-behind children;Logistic regression analysis showed that bullying behavior and abnormal psychological characteristics are significantly associated with left-behind adolescents abnormal emotional and behavioral development.

Research on Heating Clay by Low Carbon Catalytic Combustion Furnace of Natural Gas

This article did a research about exhaust gas constituent inside the catalytic combustion furnace with Pd-based honeycomb monoliths of lean natural gas-air mixtures and discussed the feature of the exhaust gas. In addition, the near-zero pollutant emissions of catalytic combustion burner was proved by a test report provided by NIM. From a low-carbon prospective, the application prospect of catalytic combustion furnace was

Characteristics of home oxygen therapy for preterm infants with bronchopulmonary dysplasia in China:results of a multicenter cohort

Background Home oxygen therapy(HOT)is indicated upon discharge in some preterm infants with severe bronchopulmonary dysplasia(BPD).There is a lack of evidence-based consensus on the indication for HOT among these infants.Because wide variation in the institutional use of HOT exists,little is known about the role of regional social-economic level in the wide variation of HOT.Methods This was a secondary analysis of Chinese Neonatal Network(CHNN)data from January 1,2019 to December 31,2019.Infants at gestational ages<32 weeks,with a birth weight<1500 g,and with moderate or severe BPD who survived to discharge from tertiary hospitals located in 25 provinces were included in this study.Infants with major congenital anomalies and those who were discharged against medical advice were excluded.Results Of 1768 preterm infants with BPD,474 infants(26.8%)were discharged to home with oxygen.The proportion of HOT use in participating member hospitals varied from 0 to 89%,with five of 52 hospitals’observing proportions of HOT use that were significantly greater than expected,with 14 hospitals with observing proportions significantly less than expected,and with 33 hospitals with appropriate proportions.We noted a negative correlation between different performance groups of HOT and median GDP per capita(P=0.04).Conclusions The use of HOT varied across China and was negatively correlated with the levels of provincial economic levels.A local HOT guideline is needed to address the wide variation in HOT use with respect to different regional economic levels in countries like China.

Irisin-loaded electrospun core-shell nanofibers as calvarial periosteum accelerate vascularized bone regeneration by activating the mitochondrial SIRT3 pathway

The scarcity of native periosteum poses a significant clinical barrier in the repair of critical-sized bone defects.The challenge of enhancing regenerative potential in bone healing is further compounded by oxidative stress at the fracture site.However,the introduction of artificial periosteum has demonstrated its ability to promote bone regeneration through the provision of appropriate mechanical support and controlled release of proosteogenic factors.In this study,a poly(L-lactic acid)(PLLA)/hyaluronic acid(HA)-based nanofibrous membrane was fabricated using the coaxial electrospinning technique.The incorporation of irisin into the core-shell structure of PLLA/HA nanofibers(PLLA/HA@Irisin)achieved its sustained release.In vitro experiments demonstrated that the PLLA/HA@Irisin membranes exhibited favorable biocompatibility.The osteogenic differentiation of bone marrow mesenchymal stem cells(BMMSCs)was improved by PLLA/HA@Irisin,as evidenced by a significant increase in alkaline phosphatase activity and matrix mineralization.Mechanistically,PLLA/HA@Irisin significantly enhanced the mitochondrial function of BMMSCs via the activation of the sirtuin 3 antioxidant pathway.To assess the therapeutic effectiveness,PLLA/HA@Irisin membranes were implanted in situ into critical-sized calvarial defects in rats.The results at 4 and 8 weeks post-surgery indicated that the implantation of PLLA/HA@Irisin exhibited superior efficacy in promoting vascularized bone formation,as demonstrated by the enhancement of bone matrix synthesis and the development of new blood vessels.The results of our study indicate that the electrospun PLLA/HA@Irisin nanofibers possess characteristics of a biomimetic periosteum,showing potential for effectively treating critical-sized bone defects by improving the mitochondrial function and maintaining redox homeostasis of BMMSCs.

考虑推进器失效的深海工程船舶动力定位数值模拟

基于PID控制器的动力定位数值模拟方法,开发控制参数自动整定程序,采用非线性最优化方法分配推力,考虑推进器转角限制以及推进器失效情况,实现对动力定位船舶的控制。针对某动力定位深海工程船舶,在风、浪、流组合海况下,开展平面运动响应及其定位能力的预报和对比研究工作,在时域和频域上分析典型海况下的运动结果。结果表明该方法在动力定位能力和运动响应预报方面有较好的工程应用价值。

大理岩剪切裂隙渗流特性

针对高水头抽水蓄能电站、高坝枢纽工程和深埋隧洞工程的建设和运行中,由于高水压造成的突涌水及岩体失稳问题,以大理岩为例,研究了大理岩剪切裂隙渗流规律.试验结果表明:径向渗流试验中,渗流过程符合达西定律,水头压力与流量呈线性关系;裂隙面中局部张拉破坏的特征对渗流起到了阻碍作用;法向力对裂隙渗流的影响显著,在法向应力从14 MPa升至19 MPa过程中,渗流通道随法向力的增加出现了闭合现象,裂隙中形成了大面积死水区,渗流特性表现出突变.

钼基化合物超级电容器电极材料研究进展

对高能量密度超级电容器需求的不断增长极大促进了赝电容电极材料的发展。纳米级钼基材料存在多种化合物形式,具有优异的电化学性能,是一类极具发展潜力的赝电容材料。综述了钼基氧化物、钼酸无机盐及钼基氮化物等在超级电容器中的研究现状,介绍了用于提升该类材料电导率、循环性能等方面的改性手段及其局限性。并展望了超级电容器用钼基电极材料商业化应用所面临的机遇与挑战,为该材料进一步开发和应用拓展思路。

较深水近距离导管架海管起始技术研究

研究的主要目的在于克服现有技术的缺点,提供一种深水海底管道起始的铺设方法。由于该方法能够在较深水域海底管道起始端与导管架进行近距离起始铺设,解决了现有的起始铺设方式无法满足海底管道起始端与导管架近距离起始铺设的技术难题,为在较深水域海底管道起始端与导管架进行近距离起始铺设打下了基础。

基于LQG算法和复合形法的深水铺管船动力定位数值模拟

基于线性二次高斯算法和复合形法开发一套动力定位数值模拟程序。针对某深水铺管船,用该程序与Simo软件进行模拟对比,结果吻合较好,验证了程序的准确性。利用该程序对深水铺管船进行铺管作业动力定位时域模拟,分析运动轨迹、推进器推力和转角、海管受力等响应特性,结果表明该程序可以合理预报动力定位铺管作业响应。

Pd修饰Cu电极的电化学CO2还原

利用微分电化学质谱和电化学原位衰减全反射红外光谱技术探究了Cu和CuPd催化剂上CO2和CO的电化学还原行为.红外光谱观察到了生成甲醇、甲烷与乙烯的CHx中间物种.在CuPd电极CO2还原过程中,红外光谱的CO吸附峰起始电位比Cu正移大约300 mV,说明CuPd能够有效促进CO2还原;CO饱和溶液中,Cu和CuPd电极CO起始吸附电位基本相同;两电极上CO谱带出现的电位与CO3^2-的谱带降低的电位基本相同,说明C O的吸附需要CO3^2-的脱附.利用电化学在线质谱发现在CuPd电极上CO还原产生CH4和CH3OH的起始电位比Cu电极正移约200 mV.推测催化活性的提升可能是由于Pd的引入改变了Cu的d能带,且Pd吸附更多的H,从而促进CO2还原,使CO能够与H结合并被深度还原.

上埋式高填土涵洞模型地基应力分布数值模拟分析

针对涵侧填土高度对高填土涵洞地基土中应力影响的问题,提出了采用数值模拟来探讨地基土中典型部位的土压力分布.分析不同涵洞结构形式、基础类型和涵洞侧面填土高度对地基土中应力的影响,研究地基土中典型部位的土压力分布.结果表明:涵洞结构形式对地基土中应力分布影响甚微;在距涵洞基础底部第一层土的中心点处,整体式基础较分离式基础相比地基应力增大约17%;随着涵侧填土的增加,地基土中应力的提高率先增加后减少,在涵侧填土为0.3 m时,地基土中应力提高率达到最大值.

miR-139-5p靶向PAK5基因通过Wnt/β-catenin信号通路对胃癌细胞侵袭和迁移的影响

背景胃癌(Gastric cancer,GC)是人类消化系统最常见的癌症类型,发生局部或全身转移是导致患者预后差的主要原因.微小RNA(microRNA,miRNA)是胃癌发生发展的重要调控因子.然而,miR-139-5p对胃癌细胞侵袭和转移的影响及机制尚不清楚.目的探究miR-139-5p靶向p21活化的激酶5(PAK5)基因调控Wnt/β-catenin信号通路对胃癌细胞侵袭和迁移的影响.方法采用实时荧光定量PCR(qRT-PCR)和Western blot分别检测永生化胃黏膜细胞GES1和不同胃癌细胞SGC-7901、AGS和BGC-823中miR-139-5p和PAK5的表达情况;在胃癌SGC-7901细胞中转染miR-139-5p mimics,qRT-PCR检测转染效果;Transwell侵袭和划痕实验检测过表达miR-139-5p对SGC-7901细胞侵袭和迁移能力的影响;双荧光素酶报告基因实验和Western blot检测miR-139-5p对PAK5的靶向调控关系;Western blot检测过表达miR-139-5p对Wnt/β-catenin信号通路激活的影响.结果胃癌细胞中miR-139-5p的表达水平明显低于正常胃黏膜细胞(P<0.05),而PAK5 mRNA和蛋白表达水平均明显高于正常胃黏膜细胞(P<0.05);转染miR-139-5p mimics能够上调SGC-7901细胞中miR-139-5p的表达;过表达miR-139-5p可明显抑制SGC-7901细胞侵袭和迁移能力;双荧光素酶报告基因实验和Western blot检测结果显示,miR-139-5p可靶向负调控PAK5的表达;过表达miR-139-5p后,SGC-7901细胞中Wnt3a、β-连环蛋白(β-catenin)、细胞周期蛋白D1(CyclinD1)蛋白表达均明显下调.结论miR-139-5p靶向PAK5并通过阻断Wnt/β-catenin信号通路抑制胃癌细胞侵袭和迁移能力.

Assisted Hatching in Couples with Advanced Maternal Age： A Systematic Review and Meta-analysis

This systematic review aimed to evaluate the efficacy and safety of assisted hatching （AH） performed in couples with advanced maternal age. We searched for randomized controlled trials （RCTs） in electronic databases, including MEDLINE, EMBASE and CENTRAL （from inception to January 2018）; in addition, we hand-searched the reference lists of included studies and similar reviews. We included RCTs comparing AH versus no treatment （control）. The meta-analysis was performed by RevMan 5.3 software. The search retrieved 943 records and 8 RCTs were included, comprising 870 cycles （n=440 for AH, and n=430 for control）. There was no significant difference in the rates of live birth （RR 0.88, 95% CI 0.65 to 1.18, 3 RCTs, n-427,I^2=0%）, clinical pregnancy （RR 1.00, 95% CI 0.83 to 1.19, 8 RCTs, n=870, I^2=22%）, implantation （RR 1.07, 95% CI 0.83 to 1.39, 4 RCTs, n=1359, I^2=0%）, miscarriage （RR 1.13, 95% CI 0.66 to 1.94, 2 RCTs, n=116, I^2=0%） and multiple pregnancy （RR 0.89, 95% CI 0.31 to 2.52, 1 RCT, n=97,I^2=not applicable） between the treatment group and control group. No reasonable conclusions could be drawn regarding reproductive outcomes after AH in patients with advanced maternal age due to the small sample pooled in meta-analyses. Studies of high methodological quality and with adequate power are necessary to further investigate the value of AH in assisted conception of those patients.

超超临界直流炉机组负荷非线性预测控制及其仿真研究

超超临界直流炉机组协调控制系统存在非线性、强耦合等特性,常规PID控制器较难获取满意的控制效果。提出了一种非线性预测控制方法,将直流炉机理模型作为预测模型,利用二进制编码的免疫优化算法在线滚动优化得到最优控制序列,给出当前时刻最优的控制量并作用于对象。通过对超超临界机组负荷控制模型的试验仿真,表明该非线性优化预测控制方法的有效性,为超超临界协调控制系统的设计提供参考。

HPSE2通过抑制NF-κB、Wnt/β-catenin信号通路调控胃癌细胞恶性生物学行为的机制

背景随着医医疗水平的提高,胃癌的早期诊断及治疗取得了明显成效,但患者的死亡率仍居高不下,且预后较差,侵袭与转移是影响患者预后的重要因素.因此,探究胃癌的发病机制,抑制胃癌细胞的侵袭转移,改善患者预后意义重大.乙酰肝素酶(heparanase,HPSE)是一种内源性糖苷内切酶,有研究发现,期在胃癌组织中的表达水平明显升高.但关于乙酰肝素酶2(heparanase,HPSE2)在胃癌中的相关作用及其作用机制尚不明确.本研究旨在HPSE2在胃癌中的相关作用及其作用机制.目的分析HPSE2通过抑制核转录因子κB(NF-κB)、wnt基因/β-连环蛋白(Wnt/β-catenin)信号通路调控胃癌细胞恶性生物学行为的机制.方法收集2019-09/2021-04期间在本院进行手术切除治疗的74例胃癌患者的胃癌组织及癌旁正常组织,测定HPSE2的表达水平.将人胃癌细胞系MKN-28细胞进行传代培养并转染,获得HPSE2过表达组及对照组.测定各组细胞增殖能力、细胞凋亡率、细胞侵袭及迁移能力,并测定细胞中HPSE2、上皮型钙黏蛋白(epithelial cadherin,E-cadherin)、神经型钙黏蛋白(neuralcadherin,N-cadherin)、波形蛋白(Vimentin)、转化生长因子-β1(transforming growth factor-β1,T G F-β1)、磷酸化核转录因子-κBp65(n u c l e a r transcriptionfactorκBp65,p-NF-κBp65)、β-catenin表达水平变化.结果与癌旁正常组织对比,胃癌组织中HPSE2表达水平明显降低(P<0.01).与对照组比较,HPSE2过表达组HPSE2表达水平明显升高(P<0.01).两组1d时细胞增殖能力无明显差异(P>0.05);与2 d与对照组比较,H P S E2过表达组细胞增殖能力明显降低(P<0.05或P<0.01).与对照组比较,HPSE2过表达组细胞凋亡率及Bax、E-cadherin表达水平均明显升高,细胞侵袭、迁移能力及Bax、Suivivin、N-cadherin、Vimentin、TGF-β1、p-NF-κBp65、β-catenin表达水平均明显降低(P<0.01).结论上调HPSE2表达能够明显抑制细胞增殖、侵袭及迁移,抑制细胞发生EMT,促进细胞凋亡,其可能是通过抑制NF-κB及Wnt/β-catenin信号通路的激活实现.

OXIDIZED HIGH-DENSITY LIPOPROTEIN PROMOTES MATURATION AND MIGRATION OF BONE MARROW DERIVED DENDRITIC CELLS FROM C57BL/6J MICE

Objective To explore the influence of oxidized high-density lipoprotein (oxHDL) on the maturation and migration of bone marrow-derived dendritic cells (BMDCs) from C57BL/6J mice. Methods The C57BL/6J mice bone marrow cell suspension was prepared and purified. Recombinant granulocyte-macrophage colony-stimulating factor (rmGM-CSF) and recombinant interleukin-4 (rmIL-4) were used to promote monocytes to differentiate and suppress lymphocytes. Then 50 μg/mL oxHDL was added to stimulate BMDCs, using 50 μg/mL high-density lipoprotein (HDL) as homologous protein control, PBS as negative control, and 1 μg/mL lipopolysaccharide (LPS) as positive control. The CD86 and MHCII expression rates were detected with fluorescence-activated cell sorting (FACS). Liquid scintillation counting (LSC) was used in mixed lymphocyte reactions (MLRs) to reflect the ability of BMDCs in stimulating the proliferation of homologous T cells. Levels of cytokines IL-12 and IL-10 were detected by ELISA. The cell migration was evaluated with the transwell system. Results Compared with PBS group, the expressions of CD86 and MHCII, counts per minute of MLRs, secretion of IL-12 and IL-10, and number of migrated cells in oxHDL group and LPS group significantly increased (all P < 0.05), while the increment was less in oxHDL group than LPS group. The number of migrated cells in oxHDL group was about twice of that in HDL group. Conclusion OxHDL may promote the maturation and migration of BMDCs in vitro.