单壁碳纳米管对C–C键水解酶BphD的固定化性能

采用修饰与未修饰单壁碳纳米管固定C–C键水解酶BphD,并对固定化酶的相对活性、稳定性、重复使用性进行了考察.结果表明,未修饰单壁碳纳米管固定的BphD相对活性为游离态的52.5%,其热稳定性和在变性剂中的稳定性均有所提高,且重复使用10次仍可保持初始活力的90%.修饰单壁碳纳米管固定的BphD相对活性可达99.7%,但其稳定性没有明显提高.同源模建及分子对接分析结果显示,未修饰的单壁碳纳米管对BphD亚基之间的联系可能存在干扰作用,从而对其活性产生影响.

Electric-field promoted C–C coupling over Cu nanoneedles for CO_(2) electroreduction to C_(2) products

Cu-based catalysts are the most promising candidates for electrochemical CO_(2)reduction(CO_(2)RR)to multi-carbon(C_(2))products.Optimizing the C-C coupling process,the rate-determining step for C_(2)product generation,is an important strategy to improve the production and selectivity of the C_(2)products.In this study,we determined that the local electric field can promote the C-C coupling reaction and enhance CO_(2)electroreduction to C_(2)products.First,finite-element simulations indicated that the high curvature of the Cu nanoneedles results in a large local electric field on their tips.Density functional theory(DFT)calculations proved that a large electric field can promote C-C coupling.Motivated by this prediction,we prepared a series of Cu catalysts with different curvatures.The Cu nanoneedles(NNs)exhibited the largest number of curvatures,followed by the Cu nanorods(NRs),and Cu nanoparticles(NPs).The Cu NNs contained the highest concentration of adsorbed K+,which resulted in the highest local electric field on the needles.CO adsorption sensor tests indicated that the Cu NNs exhibited the strongest CO adsorption ability,and in-situ Fourier-transform infrared spectroscopy(FTIR)showed the strongest*COCO and*CO signals for the Cu NNs.These experimental results demonstrate that high-curvature nanoneedles can induce a large local electric field,thus promoting C-C coupling.As a result,the Cu NNs show a maximum FEC_(2)of 44%for CO_(2)RR at a low potential(-0.6 V vs.RHE),which is approximately 2.2 times that of the Cu NPs.This work provides an effective strategy for enhancing the production of multi-carbon products during CO_(2)RR.

Solar‐energy‐driven photothermal catalytic C–C coupling from CO_(2) reduction over WO_(3–x)

Solar‐energy‐driven catalytic CO_(2) reduction for the production of value‐added carbon‐based materials and chemical raw materials has attracted great interest to alleviate the global climate change and energy crisis.The production of multicarbon(C2)products through CO_(2) reduction is extremely attractive,however,the yield and selectivity of C2 products remain low because of the low reaction temperature required and the low photoelectron density of the substrate.Here,we introduce WO3–x,which contains oxygen vacancies and exhibits an excellent photothermal conversion efficiency,to improve the generation of C2 products(C2H4 and C2H6)under simulated sunlight(UV‐Vis‐IR)irradiation.WO3–x produced 5.30 and 0.93μmol·g^(–1)C2H4 and C2H6,respectively,after 4 h,with a selectivity exceeding 34%.In situ Fourier transform infrared spectra and theoretical calculations showed that the oxygen vacancies enhanced the water activation and hydrogenation of adsorbed CO for the formation of C2 products via C–C coupling from CH2/CH3 intermediates.The findings of this study could assist in the design of highly active solar‐energy‐driven catalysts to produce C–C coupling products through CO2 reduction.

Efficient splitting of alcohols into hydrogen and C–C coupled products over ultrathin Ni‐doped ZnIn_(2)S_(4) nanosheet photocatalyst

Integrating selective organic synthesis with hydrogen(H_(2))evolution in one photocatalytic redox reaction system sheds light on the underlying approach for concurrent employment of photogenerated electrons and holes towards efficient production of solar fuels and chemicals.In this work,a facile one‐pot oil bath method has been proposed to fabricate a noble metal‐free ultrathin Ni‐doped ZnIn_(2)S_(4)(ZIS/Ni)composite nanosheet for effective solar‐driven selective dehydrocoupling of benzyl alcohol into value‐added C–C coupled hydrobenzoin and H_(2) fuel,which exhibits higher performance than pure ZIS nanosheet.The remarkably improved photoredox activity of ZIS/Ni is mainly attributed to the optimized electron structure featuring narrower band gap and suitable energy band position,which facilitates the ability of light harvesting and photoexcited charge carrier separation and transfer.Furthermore,it has been demonstrated that it is feasible to employ ZIS/Ni for various aromatic alcohols dehydrocoupling to the corresponding C–C coupled products.It is expected that this work can stimulate further interest on the establishment of innovative photocatalytic redox platform coupling clean solar fuels synthesis and selective organic conversion in a sustainable manner.

Boosting C–C coupling to multicarbon products via high-pressure CO electroreduction

Electrochemical CO reduction reaction(CORR) provides a promising approach for producing valuable multicarbon products(C_(2+)), while the low solubility of CO in aqueous solution and high energy barrier of C–C coupling as well as the competing hydrogen evolution reaction(HER) largely limit the efficiency for C_(2+)production in CORR. Here we report an overturn on the Faradaic efficiency of CORR from being HER-dominant to C_(2+)formation-dominant over a wide potential window, accompanied by a significant activity enhancement over a Moss-like Cu catalyst via pressuring CO. With the CO pressure rising from 1 to 40 atm, the C_(2+)Faradaic efficiency and partial current density remarkably increase from 22.8%and 18.9 mA cm^(-2)to 89.7% and 116.7 mA cm^(-2), respectively. Experimental and theoretical investigations reveal that high pressure-induced high CO coverage on metallic Cu surface weakens the Cu–C bond via reducing electron transfer from Cu to adsorbed CO and restrains hydrogen adsorption, which significantly facilitates the C–C coupling while suppressing HER on the predominant Cu(111) surface, thereby boosting the CO electroreduction to C_(2+)activity.

C–C formation mediated by photoinduced electrons from crystallized carbon nitride nanobelts under visible light irradiation

Crystal structure and crystallinity of carbon nitride support, size and dispersity of active-metal nanoparticles(NPs), and surface engineering of composites have great roles in generation and separation of photogenerated charge carries and photocatalyzed organic reactions for the conversion of solar energy into chemical energy. Herein, we deposited well-dispersed Pd NPs with small size on crystallized carbon nitride(CN–C) to construct a Schottky-type Pd/CN–C hybrid for photocatalyzed Ullmann C–C homocoupling of aryl halides under visible light irradiation at room temperature. Compared to Pd NPs supported g-C_3N_4(Pd/g-C_3N_4), Pd/CN–C exhibits excellent visible light photocatalytic activity for Ullmann C–C coupling of aryl halides due to high crystallinity of CN–C support, high dispersion and smaller size of Pd NPs, and the interfacial heterojunction of Pd/CN–C. Upon visible light irradiation, more photogenerated electrons from CN–C flow across the Schottky junction to metallic Pd and trigger the Ullmann C–C coupling of aryl halides. The photogenerated holes on CN–C surface are captured by a protic solvent(such as EtOH). In the presence of base K_2CO_3, the solvent undergoes dissociation, dehydrogenation, and finally can be oxidized by captured photogenerated holes. Moreover, Pd/CN–C has general applicability for various substrates and shows excellent stability and reusability for more than nine cycles.

Scission of C–O and C–C linkages in lignin over RuRe alloy catalyst

The performance of lignin depolymerization is basically determined by the interunit C–O and C–C bonds.Numerous C–O bond cleavage strategies have been developed, while the cleavage of C–C bond between the primary aromatic units remains a challenging task due to the high dissociation energy of C–C bond.Herein, a multifunctional Ru Re alloy catalyst was designed, which exhibited exceptional catalytic activity for the cleavage of both C–O and C–C linkages in a broad range of lignin model compounds(β-1, a-5, 5–5,β-O-4, 4-O-5) and two stubborn lignins(kraft lignin and alkaline lignin), affording 97.5% overall yield of monocyclic compounds from model compounds and up to 129% of the maximum theoretical yield of monocyclic products based on C–O bonds cleavage from realistic lignin. Scanning transmission electron microscopy(STEM) characterization showed that Ru Re(1:1) alloy particles with hexagonal close-packed structure were homogeneously dispersed on the support. Quasi-in situ X-ray photoelectron spectroscopy(XPS), and X-ray absorption spectroscopy(XAS) indicate that Ru species were predominantly metallic state, whereas Re species were partially oxidized;meanwhile, there was a strong interaction between Ru and Re, where the electron transfer from Re to Ru was occurred, resulting in great improvement on the capability of C–O and C–C bonds cleavage in lignin conversion.

Effects of indium on Ni/SiO_2 catalytic performance in hydrodeoxygenation of anisole as model bio-oil compound: Suppression of benzene ring hydrogenation and C–C bond hydrogenolysis

SiO2‐supported monometallic Ni and bimetallic Ni‐In catalysts were prepared and used for hydrodeoxygenation of anisole,which was used as a model bio‐oil compound,for BTX(benzene,toluene,and xylene)production.The effects of the Ni/In ratio and Ni content on the structures and performances of the catalysts were investigated.The results show that In atoms were incorporated into the Ni metal lattice.Although the Ni‐In bimetallic crystallites were similar in size to those of monometallic Ni at the same Ni content,H2uptake by the bimetallic Ni‐In catalyst was much lower than that by monometallic Ni because of dilution of Ni atoms by In atoms.Charge transfer from In to Ni was observed for the bimetallic Ni‐In catalysts.All the results indicate intimate contact between Ni and In atoms,and the In atoms geometrically and electronically modified the Ni atoms.In the hydrodeoxygenation of anisole,although the activities of the Ni‐In bimetallic catalysts in the conversion of anisole were lower than that of the monometallic Ni catalyst,they gave higher selectivities for BTX and cyclohexane as a result of suppression of benzene ring hydrogenation and C–C bond hydrogenolysis.They also showed lower methanation activity.These results will be useful for enhancing carbon yields and reducing H2consumption.In addition,the lower the Ni/In ratio was,the greater was the effect of In on the catalytic performance.The selectivity for BTX was primarily determined by the Ni/In ratio and was little affected by the Ni content.We suggest that the performance of the Ni‐In bimetallic catalyst can be ascribed to the geometric and electronic effects of In.

一种嵌有双亚胺基吡啶配体的全共轭有机聚合物材料及其在C–C偶联反应中的应用(英文)

报道了一种嵌有双亚胺基吡啶配体的全共轭有机聚合物材料.该材料所具有的双亚胺基吡啶配体起到链接聚合物单元和络合金属中心的双重作用.采用紫外可见光谱、红外光谱以及基质辅助激光解吸电离飞行时间质谱等对其结构进行了详细表征和确认.由于具有全共轭结构,该材料的热稳定性达到440 oC,并且在常规溶剂中较难溶解.作为多相催化剂载体,可以络合Pd离子形成新的多相配位催化剂,在经典的Suzuki-Miyaura C–C偶联反应中转化率和选择性均达到99%.

Catalytic transformation of cellulose and its derived carbohydrates into chemicals involving C–C bond cleavage

The catalytic transformation of cellulose, the major component of abundant and renewable lignocellulosic biomass, into building-block chemicals is a key to establishing sustainable chemical processes. Cellulose is a polymer of glucose and a lot research effort has been devoted to the conversion of cellulose to six-carbon platform compounds such as glucose and glucose derivatives through C-O bond activation. There also ex- ist considerable studies on the catalytic cleavage of C-C bonds in biomass for the production of high-value chemicals, in particular polyols and organic acids such as ethylene glycol and lactic acid. This review article highlights recent advances in the development of new catalytic systems and new strategies for the selective cleavage of C-C bonds in cellulose and its derived carbohydrates under inert, reductive and oxidative atmospheres to produce Q -Cs polyols and organic acids. The key factors that influence the catalytic performance will be clarified to provide insights for the design of more efficient catalysts for the transformation of cellulose with precise cleavage of C-C bonds to high-value chemicals. The reaction mechanisms will also be discussed to understand deeply how the selective cleavage of C-C bonds can be achieved in biomass.

基于探测器响应机理的碳/碳构件CT图像环状伪影的校正方法

在碳/碳复合材料的计算机断层扫描(CT)中,由于探测器单元的响应非线性及不一致性导致重建图像出现严重的环状伪影,干扰图像中缺陷的检出,影响检测系统对被检构件的质量评价。结合碳/碳复合材料组分单一且密度均匀的特点,提出了一种基于探测器响应机理的CT图像环状伪影的校正方法,利用采集的劣化投影数据做预重建,对重建结果做阈值分割以获得被检测物体的三维模型。结合已知的材料和密度信息,对被检物体进行重投影,得到投影数据的理论值与实测值之间的映射关系,用于探测器响应校正以优化检测图像。与传统低通滤波的环状伪影校正方法相比,该方法考虑了环状伪影的物理成因并充分利用了检测对象的先验信息。研究结果表明,该校正方法在保留图像细节和纹理的同时,能够有效减少环状伪影,提升图像质量,消除伪影对于图形中缺陷识别的干扰,为提升检测系统对碳/碳复合材料构件缺陷的检出能力提供理论依据。

液体冲压发动机燃烧室C/C-SiC复合材料的烧蚀行为及力学性能

采用固体粒子和不含固体粒子在不同含氧量下的液体冲压发动机对C/C-SiC复合材料燃烧室内层进行测试,研究两种实验条件下烧蚀严重区域和一般区域的烧蚀量、烧蚀行为及材料烧蚀后的力学性能。结果表明:在含固体粒子条件下,烧蚀严重区域烧蚀量较大,而一般区域也有一定的烧蚀量,均比不含固体粒子条件下相应区域烧蚀量大;C/C-SiC复合材料表面涂层先发生氧化反应,生成的SiO2玻璃态膜覆盖在涂层表面,阻挡了氧气的进入,有效地保护了基体材料。随着温度不断上升,材料发生主动氧化,气流的剥蚀和冲刷会加速该过程,使得SiO2难以附着在产品内表面上,SiC基体和碳纤维失去保护而被损耗。纤维变细,强度逐渐降低,纤维的增韧效果大幅减小,两种实验条件下C/C-SiC复合材料的弯曲强度和剪切强度均发生了下降,在颗粒冲刷下,材料的力学性能损失更加严重。

血清CX3CL1、CCL17与类风湿关节炎相关间质性肺疾病患者肺功能及预后的关系研究

目的分析血清C-X3-C基序趋化因子配体1(CX3CL1)、C-C基序趋化因子配体17(CCL17)与类风湿关节炎相关间质性肺疾病(RA-ILD)患者肺功能及预后的关系。方法选取2017年1月—2018年1月上海中医药大学附属龙华医院风湿科收治RA患者295例,根据是否合并ILD分为ILD组115例和非ILD组180例,根据预后情况将RA-ILD患者分为预后不良亚组和预后良好亚组。检测血清CX3CL1、CCL17水平及肺功能指标[第1秒用力呼气容积(FEV_(1))、用力肺活量(FVC)、FEV_(1)/FVC和肺一氧化碳弥散量(DLCO)]。采用Pearson相关性分析RA-ILD患者血清CX3CL1、CCL17水平与肺功能指标的相关性,多因素Logistic回归分析RA-ILD患者预后不良的影响因素,受试者工作特征(ROC)曲线分析血清CX3CL1、CCL17水平预测RA-ILD患者预后不良的价值。结果与非ILD组比较,ILD组血清CX3CL1、CCL17水平升高,FEV_(1)、FVC、FEV_(1)/FVC、DLCO降低(t/P=14.359/<0.001、13.855/<0.001、12.015/<0.001、2.732/0.007、14.749/<0.001、14.010/<0.001)。Pearson相关性分析显示,RA-ILD患者血清CX3CL1、CCL17水平与FEV_(1)、FVC、FEV_(1)/FVC、DLCO呈负相关(r=-0.762、-0.711、-0.577、-0.534、-0.707、-0.692、-0.735、-0.672,P均<0.001)。随访5年,115例RA-ILD患者预后不良发生率为46.96%。多因素Logistic回归分析显示,普通型间质性肺炎和高分辨率电子计算机断层扫描(HRCT)评分、CX3CL1、CCL17升高为RA-ILD患者预后不良的独立危险因素[OR(95%CI)=3.745(1.245~11.264)、1.051(1.008~1.095)、1.008(1.003~1.012)、1.037(1.012~1.062)],FEV_(1)、FEV_(1)/FVC、DLCO升高为独立保护因素[OR(95%CI)=0.952(0.896~0.988)、0.892(0.867~0.981)、0.857(0.789~0.949)]。ROC曲线分析显示,血清CX3CL1、CCL17水平联合预测RA-ILD患者预后不良的曲线下面积为0.875,大于CX3CL1、CCL17单独预测的0.783、0.788(Z=2.807、2.698,P=0.005、0.007)。结论RA-ILD患者血清CX3CL1、CCL17水平升高,与肺功能降低和预后不良有关,血清CX3CL1、CCL17水平联合检测对RA-ILD患者预后具有较高的预测价值。

HbA1c、LDL-C、HDL-C联合检测在2型糖尿病肾病中的诊断价值

目的:探究糖化血红蛋白(HbA1c)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)联合检测在2型糖尿病肾病中的诊断价值。方法:选取2019年1月—2021年12月南京中医药大学附属苏州市中医医院收治的120例2型糖尿病患者作为研究对象。根据患者是否发生糖尿病肾病将其分为合并肾病组(n=35)和未合并肾病组(n=85)。收集两组患者一般资料。检测两组Hb A1c、LDL-C、HDL-C。比较两组一般资料及Hb A1c、LDL-C、HDL-C水平。分析2型糖尿病肾病的危险因素。分析HbA1c、LDL-C、HDL-C对2型糖尿病肾病的诊断价值。结果:合并肾病组糖尿病病程长于未合并肾病组,吸烟史占比高于未合并肾病组,差异有统计学意义(P<0.05)。合并肾病组HbA1c、LDL-C水平均高于未合并肾病组,HDL-C水平低于未合并肾病组,差异有统计学意义(P<0.05)。logistic分析结果显示,HbA1c、LDL-C、吸烟史、糖尿病病程均是2型糖尿病患者合并糖尿病肾病的危险因素,HDL-C是保护因素(P<0.05)。HbA1c、LDL-C、HDL-C联合检测的AUC最高。结论:HbA1c、LDL-C、HDL-C联合检测应用于2型糖尿病肾病诊断中,具有较高的诊断价值,为临床对2型糖尿病肾病的早期诊断提供新思路。

Photothermal catalytic C-C coupling to ethylene from CO_(2) with high efficiency by synergistic cooperation of oxygen vacancy and half-metallic WTe_(2)

Photothermal catalytic CO_(2) conversion provides an effective solution targeting carbon neutrality by synergistic utilization of photon and heat.However,the C-C coupling initiated by photothermal catalysis is still a big challenge.Herein,a three-dimensional(3D)hierarchical W_(18)O_(49)/WTe_(2) hollow nanosphere is constructed through in-situ embodying of oxygen vacancy and tellurium on the scaffold of WO_(3).The light absorption towards near-infrared spectral region and CO_(2) adsorption are enhanced by the formation of half-metal WTe_(2) and the unique hierarchical hollow architecture.Combining with the generation of oxygen vacancy with strengthened CO_(2) capture,the photothermal effect on the samples can be sufficiently exploited for activating the CO_(2) molecules.In particular,the close contact between W_(18)O_(49)and WTe_(2) largely promotes the photoinduced charge separation and mass transfer,and thus the~*CHO intermediate formation and fixedness are facilitated.As a result,the C-C coupling can be evoked between tungsten and tellurium atoms on WTe_(2).The ethylene production by optimized W_(18)O_(49)/WTe_(2) reaches 147.6μmol g^(-1)with the selectivity of 80%.The in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and density functional theory(DFT)calculations are performed to unveil the presence and significance of aldehyde intermediate groups in C-C coupling.The half-metallic WTe_(2) cocatalyst proposes a new approach for efficient CO_(2) conversion with solar energy,and may especially create a new platform for the generation of multi-carbon products.

血清MIP-3α、CCR3对结肠癌患者根治术后复发转移的预测价值

目的探究血清巨噬细胞炎性蛋白-3α(MIP-3α)、CC趋化因子受体3(CCR3)对结肠癌患者根治术后复发转移的预测价值。方法选取2018年6月—2021年5月西安市中心医院普外科收治的结肠癌患者198例为结肠癌组,患者均接受结肠癌根治术。术后随访3年根据患者复发转移情况分为复发转移亚组(n=65)与未复发转移亚组(n=133)。另选取医院同期健康体检者192例为健康对照组。采用酶联免疫吸附法测定血清MIP-3α、CCR3水平;多因素Logistic回归分析结肠癌患者根治术后复发转移的影响因素;受试者工作特征(ROC)曲线评价血清MIP-3α、CCR3水平对结肠癌患者根治术后复发转移的预测价值。结果结肠癌组血清MIP-3α、CCR3水平均高于健康对照组(t/P=22.813/<0.001,15.164/<0.001);复发转移亚组血清MIP-3α、CCR3水平均高于未复发转移亚组(t/P=11.813/<0.001,12.545/<0.001);随访3年,198例结肠癌患者复发转移发生率为32.83%(65/198)。复发转移亚组患者TNM分期T3~T4期、低分化程度、术前癌胚抗原(CEA)>10μg/L的比例均大于未复发转移亚组(χ^(2)/P=4.694/0.030,14.253/<0.001,5.602/0.018);TNM分期T3~T4期、低分化程度、术前CEA>10μg/L、MIP-3α高、CCR3高均为结肠癌患者根治术后复发转移的独立危险因素[OR(95%CI)=1.869(1.008~3.465),1.998(1.097~3.640),1.887(1.090~3.267),2.335(1.194~4.565),2.318(1.200~4.478)];血清MIP-3α、CCR3水平及二者联合预测结肠癌患者根治术后复发转移的曲线下面积(AUC)分别为0.808、0.795、0.899,二者联合的AUC大于血清MIP-3α、CCR3水平单独预测的AUC(Z/P=2.989/0.003、2.575/0.010)。结论结肠癌患者血清MIP-3α、CCR3水平升高,对结肠癌患者术后复发转移具有一定辅助预测价值,可能作为潜在的肿瘤标志物。

Enhancement of CH_(3)CO^(*) adsorption by editing d-orbital states of Pd to boost C–C bond cleavage of ethanol eletrooxidation

Improving the complete ethanol electrooxidation on Pd-based catalysts in alkaline media has drawn widely attention due to the high mass energy density.However,the weak adsorption energy of CH_(3)CO^(*) on Pd restricts the C–C bond cleavage.Inspired by the molecular orbital theory,we proposed the d-state-editing strategy to construct more unoccupied d-states of Pd for the enhanced interaction with CH_(3)CO^(*) to break C–C bonds.As expected,the reduced number of e_g electrons and more unoccupied d-states of Pd successfully formed on as-prepared porous Rh Au–Pd Cu nanosheets(PNSs).Theoretical calculations show that the optimized d-states of Rh Au–Pd Cu PNS can effectively improve the adsorption of CH_(3)CO^(*) and drastically reduce the energy barrier of C–C bond cleavage,thus boosting the complete oxidation of ethanol.The charge ratio of C_1 pathway on Rh Au–Pd Cu PNSs is 51.5%,more than 2 times higher than that of Pd NSs.Our finding provides an innovative perspective for the design of highly-efficient noble-based electrocatalysts.

CC类趋化因子受体2、Th1/Th2细胞在IgA肾病大鼠肾间质纤维化中的表达及意义

目的检测IgA肾病大鼠肾间质纤维化中CC类趋化因子受体2(C-C motif chemokine receptor 2,CCR2)的表达和辅助性T细胞1/2(helper T cell 1/2,Th1/Th2)的含量,并观察其在肾脏纤维化中的作用。方法40只SD雄性大鼠,随机分为模型组和对照组,每组20只。采用脂多糖+改良牛血清白蛋白+四氯化碳法构建免疫球蛋白A(IgA)肾病模型。观察大鼠肾组织病理改变和IgA沉淀,计算胶原纤维占肾组织百分比,采用Katafuchi评分标准评估肾小管间质损伤程度。蛋白质印迹测定肾组织CCR2水平。双抗体夹心酶联免疫吸附法测定血清白细胞介素-4(IL-4)和干扰素-γ(IFN-γ)水平。流式细胞术检测Th1/Th2细胞比例。结果模型组大鼠肾组织胶原纤维面积百分比和Katafuchi评分显著高于对照组(P<0.05);模型组大鼠肾组织CCR2、血清IL-4水平、Th2细胞含量及IL-4/IFN-γ比值显著高于对照组,血清IFN-γ水平、Th1细胞含量显著低于对照组(P<0.05);CCR2和IL-4水平及IL-4/IFN-γ比值与胶原纤维面积百分比、Katafuchi评分呈正相关(P<0.05);IFN-γ水平与胶原纤维面积百分比、Katafuchi评分呈负相关(P<0.05)。结论CCR2和Th1/Th2失衡参与IgA肾病大鼠肾间质纤维化发生和发展,拮抗CCR2和调节Th1/Th2平衡有可能减轻IgA肾病大鼠肾脏纤维化改变。

过渡金属参与切断苄位C—H键构建C—C键

过渡金属参与切断苄位C—H键构建C—C键是有机合成化学的研究热点之一。该领域具有广阔的应用前景和发展潜力,可应用于中间体的合成、医药和农药等领域。综述了过渡金属参与切断苄位C—H键构建C—C键的研究进展。

TET2重塑CXCR4 DNA甲基化对急性心肌梗死小鼠心肌组织自噬、炎症反应及凋亡的影响

目的:探究急性心肌梗死(AMI)过程中内皮细胞tet甲基胞嘧啶双加氧酶2(TET2)对趋化因子受体4(CXCR4)DNA甲基化的影响以及对AMI小鼠心肌组织自噬、炎症反应及组织细胞凋亡的影响机制,为临床探究AMI发展的分子机制提供理论依据。方法:8周龄雄性C57/BL6小鼠50只,制备AMI模型,尾部注射TET2、CXCR4过表达质粒;蛋白免疫印迹(Western Blot)法检测心肌组织TET2、CXCR4、微管相关蛋白3(LC3)、P62、B细胞淋巴瘤/白血病-2基因(Bcl-2)关联X蛋白(Bax)、半胱氨酸蛋白酶3(Caspase-3)、Bcl-2表达;甲基化检测CXCR4 DNA甲基化水平;酶联免疫吸附法(ELISA)检测心肌组织内炎性因子白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)水平;原位末端转移酶标记技术(TUNEL)检测各组心肌组织细胞凋亡指数。结果:与假手术组比较,模型组心肌组织内TET2、CXCR4均表达上调,TET2、CXCR4均在心肌组织内过表达,TET2过表达促进CXCR4表达,差异有统计学意义(P<0.05);与模型组比较,TET2 mimic组CXCR4启动子区域DNA甲基化程度降低,CXCR4蛋白表达升高,差异有统计学意义(P<0.05);与假手术组比较,模型组小鼠心肌组织自噬蛋白LC3、抑制细胞凋亡蛋白Bcl-2表达下调,炎性因子IL-6、TNF-α、IL-1β水平、自噬蛋白P62、促细胞凋亡蛋白Bax、cleaved Caspase-3表达上调,差异有统计学意义(P<0.05);TET2、CXCR4过表达进一步下调LC3、Bcl-2蛋白表达,上调炎性因子IL-6、TNF-α、IL-1β水平,P62、Bax、cleaved Caspase-3蛋白表达;TET2、CXCR4二者联合体现出最低LC3、Bcl-2蛋白表达,最高炎性因子IL-6、TNF-α、IL-1β水平以及P62、Bax、cleaved Caspase-3蛋白表达,差异有统计学意义(P<0.05)。结论:AMI发展中,TET2通过降低CXCR4 DNA甲基化,促进CXCR4基因表达,进而抑制AMI小鼠心肌组织自噬,上调炎症反应及细胞凋亡程度,促进疾病发展。