Electron characteristics and dynamics in sub-millimeter pulsed atmospheric dielectric barrier discharge

The discharge characteristics and mechanism of sub-millimeter pulsed dielectric barrier discharge in atmosphericpressure helium are investigated experimentally and theoretically, demonstrating that when the discharge gap distance is reduced from 1.00 mm to 0.20 mm, the discharge ignition time is reduced to approximately 40 ns and discharge intensity is enhanced in terms of the discharge optical emission intensity and density of the plasma species,(energetic electrons with energy above 8.40 e V). The simulated results show that as the discharge gap distance is further reduced to 0.10 mm,the number of energetic electrons decreases, which is attributable to the contraction of plasma bulk regime and reduction of electron density in the discharge bulk. Conversely, the proportion of energetic electrons to the total electrons in the discharge monotonically increases as the discharge gap distance is reduced from 1.00 mm to 0.10 mm. It is proposed that a gap distance of 0.12 mm is optimal to achieve a high concentration and proportion of energetic electrons in sub-millimeter pulsed atmosphere dielectric barrier discharge.

Wilhelmy吊片法测定磷脂溶液的表面张力等温线

表面活性物质的表面张力等温线测定是大学物理化学实验的重要内容。随着磷脂类表面活性剂的广泛应用,有必要在大学化学中更新经典表面张力等温线测定的实验内容,并使学生掌握先进的测量方法。以二硬脂酰基磷脂酰胆碱(DSPC)和二棕榈酰基磷脂酰胆碱(DPPC)为研究对象,应用界面张力仪测定了两种溶液表面张力等温线,计算了其表面超量和分子横截面积,并设计了拓展性实验内容,对于培养学生分析问题和解决问题的能力具有积极的意义。

Strengthening absorption ability of Co-N-C as efficient bifunctional oxygen catalyst by modulating the d band center using MoC

Co-N-C is a promising oxygen electrochemical catalyst due to its high stability and good durability.However,due to the limited adsorption ability improvement for oxygen-containing intermediates,it usually exhibits inadequate catalytic activity with 2-electron pathway and high selectivity of hydrogen peroxide.Herein,the adsorption of Co-N-C to these intermediates is modulated by constructing heterostructures using transition metals and their derivatives based on d-band theory.The heterostructured nanobelts with MoC core and pomegranate-like carbon shell consisting of Co nanoparticles and N dopant(MoC/Co-N-C)are engineered to successfully modulate the d band center of active Co-N-C sites,resulting in a remarkably enhanced electrocatalysis performance.The optimally performing MoC/Co-N-C exhibits outstanding bi-catalytic activity and stability for the oxygen electrochemistry,featuring a high wave-half potential of 0.865 V for the oxygen reduction reaction(ORR)and low overpotential of 370 mV for the oxygen evolution reaction(OER)at 10 mA cm^(-2).The zinc air batteries with the MoC/Co-N-C catalyst demonstrate a large power density of 180 mW cm^(-2)and a long cycling lifespan(2000 cycles).The density functional theory calculations with Hubbard correction(DFT+U)reveal the electron transferring from Co to Mo atoms that effectively modulate the d band center of the active Co sites and achieve optimum adsorption ability with"single site double adsorption"mode.

The effects of radio frequency atmospheric pressure plasma and thermal treatment on the hydrogenation of TiO_(2) thin film

The effects of radio frequency(RF)atmospheric pressure(AP)He/H_(2)plasma and thermal treatment on the hydrogenation of TiO_(2)thin films were investigated and compared in this work.The color of the original TiO_(2)film changes from white to black after being hydrogenated in He/H_(2)plasma at160 W(gas temperature~381℃)within 5 min,while the color of the thermally treated TiO_(2)film did not change significantly even in pure H_(2)or He/H_(2)atmosphere with higher temperature(470℃)and longer time(30 min).This indicated that a more effective hydrogenation reaction happened through RF AP He/H_(2)plasma treatment than through pure H_(2)or He/H_(2)thermal treatment.The color change of TiO_(2)film was measured based on the Commission Internationale d’Eclairage L*a*b*color space system.Hydrogenated TiO_(2)film displayed improved visible light absorption with increased plasma power.The morphology of the cauliflower-like nanoparticles of the TiO_(2)film surface remained unchanged after plasma processing.X-ray photoelectron spectroscopy results showed that the contents of Ti3+species and Ti-OH bonds in the plasma-hydrogenated black TiO_(2)increased compared with those in the thermally treated TiO_(2).X-ray diffraction(XRD)patterns and Raman spectra indicated that plasma would destroy the crystal structure of the TiO_(2)surface layer,while thermal annealing would increase the overall crystallinity.The different trends of XRD and Raman spectra results suggested that plasma modification on the TiO_(2)surface layer is more drastic than on its inner layer,which was also consistent with transmission electron microscopy results.Optical emission spectra results suggest that numerous active species were generated during RF AP He/H_(2)plasma processing,while there were no peaks detected from thermal processing.A possible mechanism for the TiO_(2)hydrogenation process by plasma has been proposed.Numerous active species were generated in the bulk plasma region,accelerated in the sheath region,and bumped toward the TiO_(2)film,which will react with the TiO_(2)surface to form OVs and disordered layers.This leads to the tailoring of the band gap of black TiO_(2)and causes its light absorption to extend into the visible region.

Ignition dynamics of radio frequency discharge in atmospheric pressure cascade glow discharge

A cascade glow discharge in atmospheric helium was excited by a microsecond voltage pulse and a pulse-modulated radio frequency(RF) voltage, in which the discharge ignition dynamics of the RF discharge burst was investigated experimentally. The spatio-temporal evolution of the discharge, the ignition time and optical emission intensities of plasma species of the RF discharge burst were investigated under different time intervals between the pulsed voltage and RF voltage in the experiment. The results show that by increasing the time interval between the pulsed discharge and RF discharge burst from 5 μs to 20 μs, the ignition time of the RF discharge burst is increased from 1.6 μs to 2.0 μs, and the discharge spatial profile of RF discharge in the ignition phase changes from a double-hump shape to a bell-shape. The light emission intensity at 706 nm and 777 nm at different time intervals indicates that the RF discharge burst ignition of the depends on the number of residual plasma species generated in the pulsed discharges.

Generation of Ultrafast Attosecond Magnetic Field from Ne Dimer in Circularly Polarized Laser Pulses

By numerically solving time-dependent Schr?dinger equations,we investigate the generation of electron currents,ultrafast magnetic fields and photoelectron momentum distributions(PMD) when circularly polarized laser pulses interact with a Ne dimer in the charge migration(CM) process.By adjusting the laser wavelength,we consider two cases:(i) coherent resonance excitation(λ=76 nm) and(ii) direct ionization(λ=38 nm).The results show that the current and magnetic field generated by the Ne dimer under resonance excitation are stronger than under direct ionization.This phenomenon is due to the quantum interference between the initial state 2pσ_(g) and the excited state 3sσ_(g) under resonance excitation,so the CM efficiency of the dimer can be improved and the strength of the PMD under different ionization conditions is opposite to the strength of the electron current and induced magnetic field.In addition,we also find that both 2pπ_(g) and 2pπ_(u) have coherent resonance excitation with 3sσ_(g) state and generate periodic oscillating currents for the Ne dimer.The study of the dynamics of the Ne dimer under different ionization conditions lays a foundation for research of ultrafast magnetism in complex molecular systems.

A Novel Method for the Quantitative Detection of Sericin Content in Silk Fiber Based on the Ratio of Aspartate to Alanine

The development of a method for the quantitative determination of the sericin content ratio(SCR)is urgently needed for silk refining and the purification of silk fibroin for biomedical applications.In this work,a series of sericin/fibroin mixed samples with known SCRs were prepared by mixing initial samples of extracted sericin and fibroin from Bombyx mori silk.Significant differences were found in the contents of characteristic hydrophilic amino acids abundant in sericin and hydrophobic amino acids abundant in fibroin,and several linear relation-ships of SCR associated with the content ratios of Ser/Ala,Asp/Ala,Lys/Ala,Asp/Gly and Ser/Gly were estab-lished by amino acid analysis.Subsequently,the linear equation expressing SCR(%)as a function of the Asp to Ala content ratio X(%)was established as SCR=2.5634X−12.5587(R 2=0.9972).The results indicated that the SCR of degummed silks calculated by the equation is more objective and effective than the results obtained by the traditional weight loss method.Our study provides a novel approach for the sensitive and quantitative detection of the sericin content within the detection limit in unknown silks,which can contribute to quality control in the silk production process.

综合规范治疗联合功能性内镜鼻窦手术对中、重度无息肉型慢性鼻-鼻窦炎疗效及复发率的影响

目的分析综合规范治疗联合功能性内镜鼻窦手术对中、重度无息肉型慢性鼻-鼻窦炎疗效及复发率的影响。方法选取2017年1月-2018年9月大连大学附属中山医院收治的中、重度无息肉型慢性鼻-鼻窦炎患者92例,采用随机数字表法将所有患者均分为对照组(n=46)和观察组(n=46),对照组行功能性内镜鼻窦手术治疗,观察组行综合规范治疗联合功能性内镜鼻窦手术治疗。两组药物治疗方案一致。对两组临床治疗效果和复发率进行比较。结果两组患者治疗前鼻腔鼻窦结局评分和鼻内镜评分比较,差异均无统计学意义(P>0.05),两组治疗后6和12个月均较治疗前明显改善,差异有统计学意义(P<0.05),且观察组均优于对照组,两组比较,差异有统计学意义(P<0.05);两组治疗前嗅觉功能比较,差异无统计学意义(P>0.05),观察组治疗后12个月优于对照组,两组比较,差异有统计学意义(P<0.05);两组治疗满意度和复发率分别为95.65%、4.35%和86.96%、13.04%,观察组均优于对照组,两组比较,差异有统计学意义(P<0.05)。结论综合规范治疗联合功能性内镜鼻窦手术治疗中、重度无息肉型慢性鼻-鼻窦炎,能够取得理想的治疗效果且复发率低,值得临床推广使用。

碳量子点的制备及其在生物巯基化合物检测中的应用——推荐一个大学化学研究型综合实验

介绍了一个综合性化学实验,实验涵盖了碳量子点的制备、表征以及利用碳量子点荧光性质检测生物巯基化合物等内容。该实验既能让学生了解碳量子点及化学生物学检测等当前科学研究的前沿热点,还能通过本实验使学生熟悉膜过滤、透析、水热合成、紫外-可见光谱仪及荧光光谱仪等相关原理及操作,对于培养学生综合素养和创新意识具有积极意义。

血栓弹力图评价急性心肌梗死患者主动脉内球囊反搏术后凝血状态的临床应用

目的通过凝血功能、血栓弹力图(TEG)、活化凝血时间(ACT)、抗Xa因子活性检测急性心肌梗死(AMI)患者使用主动脉内球囊反搏(IABP)后的凝血状态,评估肝素残余情况、出血及血栓风险,寻找能更好地评估凝血状态的方法。方法选取2017年2月—11月湖南省人民医院因AMI需行急诊经皮冠状动脉介入术(PCI)并IABP的患者。比较手术前后血常规及凝血功能的差异性;收集并分析术后血小板(PLT)与血栓弹力图枸橼酸化高岭土激活样品肝素酶杯(CKH-TEG)的相关性;CKH-TEG的R差值(△R)与活化凝血时间(ACT)、抗Xa因子活性的相关性;以抗Xa因子活性为低分子肝素浓度标准绘制△R和ACT的诊断价值综合评估的受试者工作特征(ROC)曲线。结果CKH-TEG参数中PLT与MA、凝固角呈正相关(r=0.571和0.681,均P<0.05),与K呈负相关(r=-0.783,P<0.05);△R与抗Xa因子活性呈正相关(r=0.421,P<0.05);ACT与抗Xa因子活性无关(r=0.214,P>0.05);ROC曲线分析结果显示,△R的曲线下面积(AUC)为0.814(95%CI:0.732,0.903),当△R截断值为-0.211时具有最优的诊断价值,敏感性为0.885(95%CI:0.801,0.952),特异性为0.892(95%CI:0.815,0.957);ACT的AUC为0.556(95%CI:0.474,0.638),当ACT截断值为172.99 s时具有最优的诊断价值,敏感性为0.612(95%CI:0.538,0.719),特异性为0.584(95%CI:0.507,0.673)。△R在评估肝素残留的AUC值大于ACT。结论IABP术后使用TEG较常规凝血功能凝血状态评估更优,较ACT能更好地评估低分子肝素残余量,对指导肝素类抗凝药物的使用具有临床意义。

贝伐珠单抗治疗复发胶质母细胞瘤疗效和预后分析

目的:探讨贝伐珠单抗治疗复发胶质母细胞瘤的疗效及预后因素。方法:回顾性分析2011年12月至2020年7月中山大学肿瘤防治中心接受贝伐珠单抗治疗的81例成人复发胶质母细胞瘤患者的临床资料,评价其疗效和不良反应,以总生存期为预后指标进行单因素和Cox比例风险模型多因素分析。结果:81例患者的客观有效率为62.9%,疾病控制率为80.2%,90.1%的患者生存质量状况(KPS)评分和神经症状有改善。中位无进展生存期(median progression-free survival,mPFS)和中位总生存期(median overall survival,mOS)分别为4.4个月(95%CI:4.0~4.8)和7.8个月(95%CI:6.8~8.8)。单因素分析显示用药时机(首次或≥2次复发时用药)、剂量(5 mg/kg,6~9 mg/kg,10 mg/kg)和是否联合化疗对mOS无影响,多因素分析显示KPS评分和MGMT启动子甲基化状态是影响mOS的独立预后因素。不良事件主要为1~2级。结论:贝伐珠单抗可以改善成人复发胶质母细胞瘤患者的生存质量,治疗耐受性好。KPS评分和MGMT启动子甲基化状态是影响mOS的独立预后因素,贝伐珠单抗在复发后的用药时机、剂量、是否联合化疗对mOS无影响。

羧甲司坦对人气道上皮细胞炎症的影响及调控机制研究

目的通过比较羧甲司坦单用或联合布地奈德对人气道上皮细胞炎症的影响探讨其调控机制。方法MTT法检测不同浓度烟雾提取物(CSE)对细胞生存率的影响。给予不同药物抑制剂和激动剂干预后,检测炎症因子水平、ERK和IκBα蛋白,以及ERK和NF-κB mRNA的表达。结果模型组炎症因子水平、p-ERK和p-IκBα蛋白,以及ERK和NF-κB mRNA表达均增高;用药组上述指标较模型组均有所改善,但用药组之间比较差异无统计学意义(P>0.05)。羧甲司坦、PD98059干预后p-ERK蛋白及ERK、NF-κB mRNA水平均降低,而给予EGF干预后上述指标较羧甲司坦组有所回升。结论羧甲司坦的抗炎机制可能与糖皮质激素存在重叠,基础应用糖皮质激素者由于抑制了相同的信号转导通路,故再联合应用羧甲司坦时效果不佳。

Significant value of 18F-FDG-PET/CT in diagnosing small cervical lymph node metastases in patients with nasopharyngeal carcinoma treated with intensity-modulated radiotherapy

Background: Little is known about the nature of metaistasis to small cervical lymph nodes(SCLNS) in the patients with nasopharyngeal carcinoma(NPC)examined by using 18-fluoro-2-deoxy-glucose(^(18)F-FDG) positron emission tomography/computed tomography(PET/CT).The present study aimed to evaluate the diagnostic values of PET/CT in identifying metastasis in SCLNs in NPC patients.Methods: Magnetic resonance images(MRI) and PET/CT scans for 470 patients with newly diagnosed, non-distant metastatic NPC were analyzed. Metastatic rates of SCLNs were defined by the positive number of SCLNs on PET/CT scans and total number of SCLNs on MRI scans. Receiver operating characteristic curve was applied to compare PET/CT-determined stage with MRI-determined stage.Results: In total, 2082 SCLNs were identified, with 808(38.8%) ≥ 5 and < 6 mm in diameter(group A), 526(25.3%)≥ 6 and < 7 mm in diameter(group B),374(18.0%)≥ 7 and < 8 mm in diameter(group C), 237(11.4%) ≥8 and<9 mm in diameter(group D),and 137(6.5%) ≥ 9 and <10 mm in diameter(group E).The overall metastatic rates examined by using PET/CT for groups A, B,C,D, and E were 3.5%, 8.0%, 31.3%, 60.0%, and 83.9%, respectively(P< 0.001). In level IV/Vb, the metastatic rate for nodes ≥ 8 mm was 84.6%. PET/CT examination resulted in modification of N category and overall stage for 135(28.7%) and 46(9.8%) patients, respectively. The areas under curve of MRIdetermined and PET/CT-determined overall stage were 0.659 and 0.704 for predicting overall survival, 0.661 and 0.711 for predicting distant metastasis-free survival, and 0.636 and 0.663 for predicting disease-free survival.Conclusions: PET/CT was more effective than MRI in identifying metastatic SCLNs, and the radiologic diagnostic criteria for metastatic lymph nodes in level IV/Vb should be re-defined.

Long-term outcomes of a phase Ⅱ randomized controlled trial comparing intensity-modulated radiotherapy with or without weekly cisplatin for the treatment of locally recurrent nasopharyngeal carcinoma

Background:Salvage treatment for locally recurrent nasopharyngeal carcinoma(NPC) is complicated and relatively limited.Radiotherapy,combined with effective concomitant chemotherapy,may improve clinical treatment outcomes.We conducted a phase Ⅱ randomized controlled trial to evaluate the efficacy of intensity-modulated radiotherapy with concomitant weekly cisplatin on locally recurrent NPC.Methods:Between April 2002 and January 2008,69 patients diagnosed with non-metastatic locally recurrent NPC were randomly assigned to either concomitant chemoradiotherapy group(n = 34) or radiotherapy alone group(n = 35).All patients received intensity-modulated radiotherapy.The radiotherapy dose for both groups was 60 Gy in 27 fractions for 37 days(range 23-53 days).The concomitant chemotherapy schedule was cisplatin 30 mg/m^2 by intravenous infusion weekly during radiotherapy.Results:The median follow-up period of all patients was 35 months(range 2-112 months).Between concomitant chemoradiotherapy and radiotherapy groups,there was only significant difference in the 3-year and 5-year overall survival(OS) rates(68.7%vs.42.2%,P = 0.016 and 41.8%vs.27.5%,P = 0.049,respectively).Subgroup analysis showed that concomitant chemoradiotherapy significantly improved the 5-year OS rate especially for patients in stage rT3-4(33.0%vs.13.2%,P = 0.009),stages Ⅲ-Ⅳ(34.3%vs.13.2%,P = 0.006),recurrence interval >30 months(49.0%vs.20.6%,P = 0.017),and tumor volume >26 cm^3(37.6%vs.0%,P = 0.006).Conclusion:Compared with radiotherapy alone,concomitant chemoradiotherapy can improve OS of the patients with locally recurrent NPC,especially those with advanced T category(rT3-4) and stage(lll-IV) diseases,recurrence intervals >30 months,and tumor volume >26 cm^3.

Hepatitis B virus reactivation and hepatitis in diffuse large B-cell lymphoma patients with resolved hepatitis B receiving rituximab-containing chemotherapy:risk factors and survival

Introduction:Hepatitis B virus(HBV) reactivation has been reported in B-cell lymphoma patients with resolved hepatitis B(hepatitis B surface antigen[HBsAg]-negative and hepatitis B core antibody[HBcAb]-positive).This study aimed to assess HBV reaaivation and hepatitis occurrence in diffuse large B-cell lymphoma(DLBCL) patients with resolved hepatitis B receiving rituximab-containing chemotherapy compared with HBsAg-negative/HBcAb-negative patients to identify risk factors for HBV reaaivation and hepatitis occurrence and to analyze whether HBV reaaivation and hepatitis affect the survival of DLBCL patients with resolved hepatitis B.Methods:We reviewed the clinical data of 278 patients with DLBCL treated with rituximab-containing therapy between January 2004 and May 2008 at Sun Yat-sen University Cancer Center,China.Prediaive faaors for HBV reaaivation,hepatitis development,and survival were examined by univariate analysis using the chi-square or Fisher's exact test and by multivariate analysis using the Cox regression model.Results:Among the 278 patients,165 were HBsAg-negative.Among these 165 patients,6(10.9%) of 55 HBcAb-positive(resolved HBV infeaion) patients experienced HBV reactivation compared with none(0%) of 110 HBcAb-negative patients(P=0.001).Patients with resolved hepatitis B had a higher hepatitis occurrence rate than HBsAg-negative/HBcAb-negative patients(21.8%vs.8.2%,P = 0.013).HBcAb positivity and elevated baseline alanine aminotransferase(ALT) levels were independent risk factors for hepatitis.Among the 55 patients with resolved hepatitis B,patients with elevated baseline serum ALT or aspartate aminotransferase(AST) levels were more likely to develop hepatitis than those with normal serum ALT or AST levels(P = 0.037,P = 0.005,respeaively).An elevated baseline AST level was an independent risk factor for hepatitis in these patients.Six patients with HBV reactivation recovered after immediate antiviral therapy,and chemotherapy was continued.HBcAb positivity,HBV reactivation,or hepatitis did not negatively affect the survival of DLBCL patients.Conclusions:DLBCL patients with resolved hepatitis B may have a higher risk of developing HBV reaaivation and hepatitis than HBsAg-negative/HBcAb-negative patients.Close monitoring and prompt antiviral therapy are required in these patients.

The impact of both platinum-based chemotherapy and EGFR-TKIs on overall survival of patients with advanced non-small cell lung cancer

Both platinum-based doublet chemotherapy(PBC) and epidermal growth factor receptor tyrosine kinase inhibitors(EGFR-TKIs) prolong the survival of patients with advanced non-small cell lung cancer(NSCLC). In early studies, most patients underwent PBC as first-line treatment, but not all patients could afford EGFR-TKIs as second-line treatment. To understand the impact of PBC and EGFR-TKIs on NSCLC prognosis, we evaluated the association between the receipt of both regimens and overall survival(OS). Using MEDLINE and EMBASE, we identified prospective, randomized, controlled phase III clinical trials in advanced NSCLC that met the inclusion criteria: in general population with advanced NSCLC, the percentage of patients treated with both PBC and EGFR-TKIs was available in the trial and OS was reported. After collecting data from the selected trials, we correlated the percentage of patients treated with both PBC and EGFR-TKIs with the reported OS, using a weighted analysis. Fifteen phase III clinical trials—involving 11,456 adult patients in 32 arms—were included in the analysis, including 6 trials in Asian populations and 9 in non-Asian(predominantly Caucasian) populations. The OS was positively correlated with the percentage of patients treated with both PBC and EGFR-TKIs(r = 0.797, P < 0.001). The correlation was obvious in the trials in Asian populations(r = 0.936, P < 0.001) but was not statistically significant in the trials in predominantly Caucasian populations(r = 0.116, P = 0.588). These results suggest that treatment with PBC and EGFR-TKIs may provide a survival benefit to patients with advanced NSCLC, highlighting the importance of having both modalities available for therapy.

Characterization and mapping of QTLs on chromosome 2D for grain size and yield traits using a mutant line induced by EMS in wheat

Production of mutants with altered phenotypes is a powerful approach for determining the biological functions of genes in an organism. In this study, a high-grain-weight mutant line M8008 was identified from a library of mutants of the common wheat cultivar YN15 treated with ethylmethane sulfonate(EMS). F2 and F2:3generations produced from crosses of M8008 × YN15(MY) and M8008 × SJZ54(MS) were used for genetic analysis. There were significant differences between M8008 and YN15 in plant height(PH), spike length(SL),fertile spikelet number per spike(FSS), grain width(GW), grain length(GL), GL/GW ratio(GLW), and thousand-grain weight(TGW). Most simple correlation coefficients were significant for the investigated traits, suggesting that the correlative mutations occurred in M8008. Approximately 21% of simple sequence repeat(SSR) markers showed polymorphisms between M8008 and YN15, indicating that EMS can induce a large number of mutated loci. Twelve quantitative trait loci(QTLs) forming QTL clusters(one in MY and two in MS) were detected. The QTL clusters coinciding with(MY population) or near(MS population) the marker wmc41 were associated mainly with grain-size traits, among which the M8008 locus led to decreases in GW, factor form density(FFD), and TGW and to increases in GLW. The cluster in the wmc25–barc168 interval in the MS population was associated with yield traits, for which the M8008 locus led to decreased PH, spike number per plant(SN), and SL.

Low-Temperature Selective Catalytic Reduction of NO with NH_3 over Fe–Ce–O_x Catalysts

In this study,we used a simple impregnation method to prepare Fe-Ce-O_x catalysts and tested them regarding their low-temperature(200-300 ℃) selective catalytic reduction(SCR) of NO using NH_3.We investigated the effects of Fe/Ce molar ratio,the gas hourly space velocity(GHSV),the stability and SO_2/H_2O resistance of the catalysts.The results showed that the FeCe(1:6)O_x(Ce/Fe molar ratio is 1:6) catalyst,which has some ordered parallel channels,exhibited good SCR performance.The FeCe(1:6)O_x catalyst had the highest NO conversion with an activity of 94-99%at temperatures between 200 and300 ℃ at a space velocity of 28,800 h^(-1).The NO conversion for the FeCe(1:6)O_x catalyst also reached 80-98%between 200 and 300 ℃ at a space velocity of204,000h^(-1).In addition,the FeCe(1:6)O_x catalyst demonstrated good stability in a 10-h SCR reaction at200-300 ℃.Even in the presence of SO_2 and H_2O,the FeCe(1:6)O_x catalyst exhibited good SCR performance.

Emodin and baicalein inhibit sodium taurocholate-induced vacuole formation in pancreatic acinar cells

AIM To investigate the effects of combined use of emodin and baicalein(CEB) at the cellular and organism levelsin severe acute pancreatitis(SAP) and explore the underlying mechanism.METHODS SAP was induced by retrograde infusion of 5% sodium taurocholate into the pancreatic duct in 48 male SD rats. Pancreatic histopathology score, serum amylase activity, and levels of tumour necrosis factor alpha(TNf-α), interleukin 6(IL-6), and IL-10 were determined to assess the effects of CEB at 12 h after the surgery. The rat pancreatic acinar cells were isolated from healthy male SD rats using collagenase. The cell viability, cell ultrastructure, intracellular free Ca2+ concentration, and inositol(1,4,5)-trisphosphate receptor(IP3 R) expression were investigated to assess the mechanism of CEB.RESULTS Pancreatic histopathology score(2.07 ± 1.20 vs 6.84 ± 1.13, P < 0.05) and serum amylase activity(2866.2 ± 617.7 vs 5241.3 ± 1410.0, P < 0.05) were significantly decreased in the CEB(three doses) treatment group compared with the SAP group(2.07 ± 1.20 vs 6.84 ± 1.13, P < 0.05). CEB dose-dependently reduced the levels of the pro-inflammatory cytokines IL-6(466.82 ± 48.55 vs 603.50 ± 75.53, P < 0.05) and TNF-α(108.04 ± 16.10 vs 215.56 ± 74.67, P < 0.05) and increased the level of the anti-inflammatory cytokine IL-10(200.96 ± 50.76 vs 54.18 ± 6.07, P < 0.05) compared with those in the SAP group. CEB increased cell viability, inhibited cytosolic Ca2+ concentration, and significantly ameliorated intracellular vacuoles and IP3 m RNA expression compared with those in the SAP group(P < 0.05). There was a trend towards decreased IP3 R protein in the CEB treatment group; however, it did not reach statistical significance(P > 0.05).CONCLUSION These results at the cellular and organism levels reflect a preliminary mechanism of CEB in SAP and indicate that CEB is a suitable approach for SAP treatment.