丝切蛋白-1、磷酸化丝切蛋白-1、CD11c在鼻咽癌组织中的表达及临床意义

目的探讨丝切蛋白1(Cofilin-1)、磷酸化丝切蛋白1(p-Cofilin-1)及树突状细胞(DCs)亚群在鼻咽癌组织中的表达及与预后的关系。方法回顾性分析2011年1月至2015年12月97例鼻咽癌患者的临床资料,采用免疫组化法检测鼻咽癌组织中Cofilin-1、p-Cofilin-1及CD11c+DCs的表达情况。分析三者表达与鼻咽癌临床病理特征和预后的关系。结果97例鼻咽癌患者中,Cofilin-1低表达率为26.8%(26/97),高表达率为73.2%(71/97);p-Cofilin-1低表达率为27.8%(27/97),高表达率为72.2%(70/97)。CD11c低表达率为80.4%(78/97),高表达率为19.6%(19/97)。M分期、临床分期、治疗后转移、治疗前骨转移和治疗后出现骨转移与Cofilin-1的表达有关(P<0.05);治疗后转移和治疗后出现骨转移与p-Cofilin-1的表达有关(P<0.05);CD11c表达与鼻咽癌临床病理参数均无关(P>0.05)。Cofilin-1低表达组和高表达组1、3、5年生存率分别为84.6%、73.1%、73.1%和93.0%、61.7%、46.7%(P=0.094);低表达组和高表达组1、3、5年无远处转移生存率分别为100.0%、100.0%、100.0%和87.2%、73.3%、68.6%(P=0.002)。p-Cofilin-1低表达组和高表达组1、3、5年生存率分别为85.2%、51.9%、40.4%和92.9%、72.7%、59.3%(P=0.075);低表达组和高表达组1、3、5年无远处转移生存率分别为83.5%、53.7%、53.7%和95.1%、89.9%、85.5%(P=0.001)。CD11c低表达组和高表达组1、3、5年生存率分别为89.7%、61.3%、46.5%和94.7%、89.5%、89.5%(P=0.007);低表达组和高表达组1、3、5年无远处转移生存率分别为88.8%、80.2%、76.1%和100.0%、93.8%、87.1%(P=0.175)。结论Cofilin-1表达水平越高,肿瘤转移风险越高,无远处转移生存时间越短;p-Cofilin-1表达水平越高,肿瘤发生转移的风险越低,无远处转移生存时间越长;CD11c表达水平越高,总生存时间越长。Cofilin-1、p-Cofilin-1、CD11有望成为鼻咽癌靶向治疗和预后预测的标志物。

Total three-dimensional laparoscopic radical resection for Bismuth type Ⅳ hilar cholangiocarcinoma

Hilar cholangiocarcinoma(HCCA)(also known as Klatskin tumor)has a poor prognosis worldwide,and accounts for more than half of cholangiocarcinoma cases.HCCA originates from epithelium and often arises from the confluence of the bile ducts or the right or left hepatic ducts[1,2].Because of its aggressiveness and refractory biological characteristics,the median survival time of patients with unresectable HCCA is less than 1 year.Radical resection is the most effective treatment for HCCA.

油料树种千年桐的SSR标记开发、遗传多样性与群体结构分析

【目的】千年桐是大戟科油桐属的一种重要的工业油料树种,较同属的油桐具有更强的抗枯萎病能力,近年来受到了广泛关注。然而,因千年桐栽培历史短及种质管理的不足,目前对其分子遗传方面的研究还非常有限。本研究旨在开发千年桐的基因组SSR标记,进而开展其种质的鉴定、遗传多样性与群体结构分析。【方法】采用RAD测序技术获得千年桐简化基因组以开发SSR标记,基于SSR标记利用分子变异分析(AMOVA)、非加权组平均法(UPGMA)聚类、主坐标(PCoA)与群体结构分析等方法对来自3个不同地理分布的共105份千年桐种质资源进行研究。【结果】17个多态性的三核苷酸基因组SSR标记被开发,并能够很好地鉴别所有收集的105份千年桐种质。在其中62份种质中检测到85个私有等位基因,涉及15个SSR位点。AMOVA分析发现,千年桐群体间呈现出中等程度的遗传分化,但群体内的遗传变异远高于群体间的遗传变异。群体结构分析显示,3个来自不同地理分布的千年桐群体中存在4个不同的基因库,群体间既有进化独立性,又有较高程度的遗传混合,这一结果与UPGMA和PCoA分析的结果基本一致。【结论】新开发的17个SSR标记有效鉴定了105份千年桐种质,揭示了其遗传多样性和群体遗传结构,对千年桐种质保存和育种计划具有非常重要的参考价值。

Laparoscopic hepaticoplasty using gallbladder as a subcutaneous tunnel for hepatolithiasis

AIM: To investigate the feasibility, efficacy and safety of laparoscopic hepaticoplasty using gallbladder as subcutaneous tunnel and sphincter-of-Oddi preservation for hepatolithiasis.

Oddi sphincter preserved cholangioplasty with hepaticosubcutaneous stoma for hepatolithiasis

AIM: To evaluate the long-term outcomes of Oddi sphincter preserved cholangioplasty with hepaticosubcutaneous stoma(OSPCHS) and risk factors for recurrence in hepatolithiasis.METHODS: From March 1993 to December 2012, 202 consecutive patients with hepatolithiasis underwent OSPCHS at our department. The Oddi sphincter preserved procedure consisted of common hepatic duct exploration, stone extraction, hilar bile duct plasty, establishment of subcutaneous stoma to the bile duct. Patients with recurrent stones can undergo stone extraction and/or biliary drainage via the subcutaneous stoma which can be incised under local anesthesia. The long-term results were reviewed. Cox regression model was employed to analyze the risk factors for stone recurrence.RESULTS: Ninety-seven(48.0%) OSPCHS patients underwent hepatic resection concomitantly. The rate of surgical complications was 10.4%. There was no perioperative death. The immediate stone clearance rate was 72.8%. Postoperative cholangioscopic lithotomy raised the clearance rate to 97.0%. With a median follow-up period of 78.5 mo(range: 2-233 mo), 24.8% of patients had recurrent stones, 2.5% had late development of cholangiocarcinoma, and the mortality rate was 5.4%. Removal of recurrent stones and/or drainage of inflammatory bile via subcutaneous stoma were conducted in 44(21.8%) patients. The clearance rate of recurrent stones was 84.0% after subsequent choledochoscopic lithotripsy via subcutaneous stoma.Cox regression analysis showed that residual stone was an independent prognostic factor for stone recurrence.CONCLUSION: In selected patients with hepatolithiasis, OSPCHS achieves excellent long-term outcomes, and residual stone is an independent prognostic factor for stone recurrence.

Killing effects of cytosine deaminase gene mediated by adenovirus vector on human pancreatic cancer cell lines in vitro

OBJECTIVE: To evaluate the killing effects of the cytosine deaminase (CD) gene mediated by adenovirus vector on human pancreatic cancer cell lines in vitro. METHODS: The CD gene was cloned into pAdTrack-CMV-CD, and pAdTrack-CMV-CD and pAdEasy-l were recombinated in bacteria. The newly recombinated Ad-CD containing green fluoreseent protein (GFP) was propagated in 293 cells and purified by cesium chloride gradient centrifugation. Human pancreatic cancer cell lines Patu8988 and SW1990 were infected with this virus, then 5-FC was added. XTT assay was used to estimate relative numbers of viable cells. RESULTS: The positive clones were selected by using endonuclease to digest the combinatants and the concentration of viral liquids containing the CD gene was 2×1O^(11) pfu/ml. It was found that significant cytotoxic activities were possesscd by 5-FC for the CD gene transduced pancreatic cell lines, but little effects exerted on the nontransduced pancreatic carcinoma cells. CONCLUSIONS: The CD gene mediated by adenovirus with a high infectivity is efficient for gene therapy of pancreatic carcinoma cell lines. These data demonstrate the therapeutic efficacy of an enzyme prodrug strategy in experimental pancreatic cancer.

Methylation of PTCH1a gene in a subset of gastric cancers

AIM： To establish if PTCHla transcriptional regulation region （TRR） is methylated in gastric cancer and its influence in gastric tumorigenesis.METHODS： The CpG islands in PTCHla TRR were analyzed by Methyl Primer Express v1.0 software. The region from -643 to -355 bp （the transcription initiation site of PTCHla was designated as 0） that contained 19 CpG sites was chosen for bisulfitesequencing PCR （BSP） and methylation-specific PCR （MSP） detection. The gastric cancer cell line AGS was treated with 5-aza-2′-deoxycytidine （5-Aza-dC; 1 μmol/L） for 3 d. Alterations in PTCHla TRR methylation in treated AGS cells was measured through BSP clone sequences, and their PTCH1 expression was measured by quantitative RT-PCR. The cell cycle and apoptosis were observed with flow cytometry through propidium iodide （PI） staining or annexin V/PI double staining. The prevalence of PTCHla TRR methylation was investigated in 170 gastric cancer tissue samples and the adjacent normal tissues by MSP. The correlation of PTCH1a TRR methylation with PTCH1 expression or with patients＇ clinical features was analyzed.RESULTS： Methylation of PTCHla TRR was observed in AGS ceils and a subset of gastric cancer tissues （32%, 55/170）, while no methylation amplification products were observed in any normal tissues by MSP. The methylation of PTCH1α TRR was correlated negatively with PTCH1 expression （Spearman＇s r = -0.380, P = 0.000）. However, methylation of PTCHla TRR was not related to the gastric cancer patients＇ clinical features, such as sex, age of onset, clinical stage, lymph node metastasis or histological grade. The methylation of PTCHla TRR in AGS cells was almost converted to non-methylation after 5-Aza-dC treatment, which increased PTCH1 expression （5.3 ± 2.5 times; n = 3） and apoptosis rate （3.0 ± 0.26 times; P 〈 0.05; n = 3）.CONCLUSION： Methylation of PTCH1α TRR is present in a subset of gastric cancers and correlated negatively with PTCH1 expression. This may be an early event in gastric tumorigenesis and a new treatment target.

Profiles and Source Apportionment of Nonmethane Volatile Organic Compounds in Winter and Summer in Xi’an, China, based on the Hybrid Environmental Receptor Model

Summer and winter campaigns for the chemical compositions and sources of nonmethane hydrocarbons(NMHCs)and oxygenated volatile organic compounds(OVOCs)were conducted in Xi’an.Data from 57 photochemical assessment monitoring stations for NMHCs and 20 OVOC species were analyzed.Significant seasonal differences were noted for total VOC(TVOC,NMHCs and OVOCs)concentrations and compositions.The campaign-average TVOC concentrations in winter(85.3±60.6 ppbv)were almost twice those in summer(47.2±31.6 ppbv).Alkanes and OVOCs were the most abundant category in winter and summer,respectively.NMHCs,but not OVOCs,had significantly higher levels on weekends than on weekdays.Total ozone formation potential was higher in summer than in winter(by 50%)because of the high concentrations of alkenes(particularly isoprene),high temperature,and high solar radiation levels in summer.The Hybrid Environmental Receptor Model(HERM)was used to conduct source apportionment for atmospheric TVOCs in winter and summer,with excellent accuracy.HERM demonstrated its suitability in a situation where only partial source profile data were available.The HERM results indicated significantly different seasonal source contributions to TVOCs in Xi’an.In particular,coal and biomass burning had contributions greater than half in winter(53.4%),whereas traffic sources were prevalent in summer(53.1%).This study’s results highlight the need for targeted and adjustable VOC control measures that account for seasonal differences in Xi’an;such measures should target not only the severe problem with VOC pollution but also the problem of consequent secondary pollution(e.g.,from ozone and secondary organic aerosols).

CD74 and macrophage migration inhibitory factor as therapeutic targets in gastric cancer

AIM:To investigate the relationship and molecular features of CD74/macrophage migration inhibitory factor(MIF)/Toll-like receptor 4(TLR4) in gastric cancer.METHODS:CD74,MIF and TLR4 expression in the paraffin-embedded sections of gastric cancer from 120 patients were detected by immunohistochemical staining.Knock down of CD74 expression in gastric cancer cell line MKN-45 was performed by lentivirus transduction and detected by Western blotting.MKN-45 cell proliferation assay under the stimulants was measured by the cell counting kit 8(CCK8) assay and MIF concentration in the culture medium was detected by enzymelinked immunosorbent assay.Surface staining of CD74 in the MKN-45 cell line under the stimulation of lipopolysaccharide(LPS) was measured by flow cytometry.MIF,CD74 and TLR4 co-localization in the MKN-45 cell line was performed by the immunoprecipitation.RESULTS:CD74,MIF and TLR4 were found to be expressed in gastric cancer and increased significantly in the advanced stage,and were also associated with lymph node metastasis.Correlation analysis revealed that CD74 was positively correlated with MIF(r = 0.2367,P < 0.01) and both proteins were also associated with TLR4(r = 0.4414,r = 0.5001,respectively,P < 0.01).LPS can significantly promote MKN-45 cell proliferation(3.027 ± 0.388 vs 4.201 ± 0.092,P < 0.05),induce MIF production(54.333 ± 2.906 pg/mL vs 29.667 ± 3.180 pg/mL,P < 0.01) and cell surface expression of CD74(75.6% ± 4.046%vs 9.4% ± 0.964%,P < 0.01) at LPS concentration of 1 μg/mL compared to medium control.Knockdown of CD74 or using antiCD74 and MIF antagonist ISO-1 significantly reduced LPS-induced MKN-45 cell proliferation(4.201 ± 0.092 vs 3.337 ± 0.087,4.534 ± 0.222 vs 3.368 ± 0.290,4.058 ± 0.292vs 2.934 ± 0.197,respectively,P < 0.01).MIF,CD74 and TLR4 could co-localize in the MKN-45 cell line.CONCLUSION:Upregulation of MIF,CD74 and TLR4 are associated with increasing clinical stage and provide an opportunity as novel gastric cancer chemoprevention and/or treatment strategy.

Cut-off value of ulcerative colitis endoscopic index of severity(UCEIS)score for predicting the need for pouch construction in ulcerative colitis:results of a multicenter study with long-term follow-up

Background Total proctocolectomy with ileal pouch–anal anastomosis(IPAA)was the first choice for the surgical treatment of the ulcerative colitis(UC)patients.The data on the predictive value of the ulcerative colitis endoscopic index of severity(UCEIS)for the need for IPAA in UC patients is scarce.We aimed to establish the UCEIS cut-off value to further analyse whether the UCEIS cut-off was suitable for predicting the need for IPAA in UC patients.Methods The clinical data of UC patients from June 1986 to March 2020 at our institute were retrospectively assessed.The UCEIS scores recorded at the time of the first colonoscopy after hospitalization were used in the study.Receiver operating characteristic curve analysis was performed to determine the UCEIS cut-off value for predicting the need for IPAA.Results A total of 283 UC patients were included in the study,with a median UCEIS of 4.During a median follow-up of 13 years,80 patients(28.3%)received surgery invention,among whom 75(93.8%)underwent IPAA surgery and 5(6.2%)received subtotal colectomy with permanent ostomy.A UCEIS cut-off of 6 had the most significant area under the curve of 0.769 for predicting the need for IPAA(P<0.001),with a sensitivity of 72.0%and specificity of 81.8%.UCEIS≥6 was an independent predictive factor for the need for IPAA(P<0.001)and malignant transformation(P=0.010).Patients with UCEIS≥6 had a significantly shorter IPAA-free survival time than those with UCEIS<6(P<0.001).Conclusions UCEIS≥6 may be a threshold value for decision-making for IPAA and should be recommended for UC patients for reducing the incidence of malignant transformation.

微型仿生爬虫机器人类脑环境感知方法

微型仿生机器人是一种仿照生物外形和运动形态制作设计的机器人,凭借其体型小、机动性高、环境适应性强等优点,在复杂环境探索、敌情侦察等特殊场景中具有较高的应用前景,近年来备受研究人员的关注.但是微型机器人运动稳定性弱、单目相机环境感知精度低等问题的存在一直制约着其实际应用.本文仿照昆虫“独角仙”设计了一种新的微型仿生爬虫机器人,开发了基于生物运动调控机制的六足机器人控制系统,改进了基于啮齿类动物空间导航原理的同时定位与建图系统.使用自研的微型仿生爬虫机器人在人造沙盘和真实室内走廊两个场景中进行了实验验证.在人造沙盘场景,由于微型仿生爬虫机器人提供的环境图像质量模糊,ORB-SLAM3算法无法完成回环检测,不能正确识别曾经见过的场景.类脑同步定位与地图构建(simultaneous localization and mapping,SLAM)系统回环准确率高达100%,比原RatSLAM算法提高了4.36%.在真实室内走廊场景,ORB-SLAM3算法和RatSLAM算法建图效果都比较差,而类脑SLAM不仅有着较好的建图结果,而且在准确率100%的同时召回率也高达97.87%.与ORB-SLAM3和RatSLAM算法相比,类脑SLAM系统取得了较好的建图结果.因此,自研的微型仿生爬虫机器人具有灵活的运动能力、鲁棒的导航定位能力,促使微型仿生机器人离实际应用更近了一步.

Flexible servo riveting system control strategy based on the RBF network and self-pierce riveting process

As more and more composite materials are used in lightweight vehicle white bodies,self-pierce riveting(SPR)technology has attracted great attention.However,the existing riveting tools still have the disadvantages of low efficiency and flexibility.To improve these disadvantages and the riveting qualification rate,this paper improves the control scheme of the existing riveting tools,and proposes a novel controller design approach of the flexible servo riveting system based on the RBF network and SPR process.Firstly,this paper briefly introduces the working principle and SPR procedure of the servo riveting tool.Then a moving component force analysis is performed,which lays the foundation for the motion control.Secondly,the riveting quality inspection rules of traditional riveting tools are used for reference to plan the force-displacement curve autonomously.To control this process,the riveting force is fed back into the closed-loop control of the riveting tool and the riveting speed is computed based on the admittance control algorithm.Then,this paper adopts the permanent magnet synchronous motor(PMSM)as the power of riveting tool,and proposes an integral sliding mode control approach based on the improved reaching law and the radial basis function(RBF)network friction compensation for the PMSM speed control.Finally,the proposed control approach is simulated by Matlab,and is applied to the servo riveting system designed by our laboratory.The simulation and riveting results show the feasibility of the designed controller.

淋巴细胞和树突状细胞亚群对局部晚期鼻咽癌治疗后免疫功能及预后的影响

目的 探索局部晚期鼻咽癌患者诱导化疗及同步放化疗前后,外周血中淋巴细胞和树突状细胞(DC)亚群的变化及其与临床预后的关系。方法 回顾性分析2016-12-05-2018-05-31于贵州医科大学附属肿瘤医院就诊的134例局部晚期鼻咽癌患者临床资料,所有患者均接受2~3个周期多西他赛+顺铂+氟尿嘧啶(TPF方案)诱导化疗联合铂类方案同步放化疗。诱导化疗前后及同步放化疗结束后1周内,流式细胞术检测外周血中淋巴细胞及DC亚群。治疗结束后2年内随访1次/3个月;3~5年随访1次/6个月,观察生存情况。采用Friedman M检验比较外周血中淋巴细胞亚群和DC亚群在治疗前、诱导化疗后及同步放化疗后的变化,采用ROC曲线确定相应指标的临界值,Kaplan-Meier法和Cox回归模型进行生存分析。结果 TPF方案诱导化疗后外周血中CD3+[60.29(51.76,67.49)vs 63.85(58.63,70.10)]、CD4+[32.31(25.97,38.26)vs 34.10(28.28,40.90)]、CD8+[20.64(16.26,27.48)vs 23.32(18.37,29.10)]、活化CD4+[1.36(0.90,2.61)vs 2.02(1.14,2.82)]、活化CD8+[0.77(0.38,2.11)vs 1.90(0.78,4.00)]、CD8^(+)CD28^(+)[12.08(9.16,15.01)vs 13.86(10.34,16.63)]和髓样树突状细胞[MDC;5.04(2.73,7.07)vs 6.06(4.26,9.28)]均较治疗前升高,均P<0.05。同步放化疗后外周血中CD3^(+)[60.29(51.76,67.49)vs 57.60(47.39,66.50)]、CD4+[32.31(25.97,38.26)vs 26.06(20.06,32.29)]、CD8^(+)CD28^(+)[12.08(9.16,15.01)vs 10.09(6.74,13.15)]、CD4^(+)/CD8^(+)[1.58(1.07,1.97)vs 1.22(0.82,1.71)]和CD4+CD25+[4.10(2.79,5.60)vs 3.15(1.49,5.37)]较治疗前降低,均P<0.05。Kaplan-Meier单因素分析显示,治疗前外周血中CD3^(+)、CD4^(+)、活化CD4^(+)、CD8^(+)CD28^(+)、CD4^(+)/CD8^(+)、CD3-CD16^(+)、浆细胞样树突状细胞(pDC)和MDC的水平与患者生存预后相关,P<0.05。Cox模型预后分析发现高水平CD4+(HR=0.39,95%CI:0.18~0.89,P=0.021)和pDC(HR=0.37,95%CI:0.15~0.90,P=0.030)是局部晚期鼻咽癌总生存期(OS)的良好独立影响因素。结论 TPF方案诱导化疗可能杀死肿瘤细胞,释放肿瘤相关抗原,解除局部晚期鼻咽癌患者的免疫抑制状态,改善肿瘤微环境,使机体免疫功能得到恢复,同步放化疗后,机体免疫功能下降。治疗前外周血中CD4^(+)和pDC可能是局部晚期鼻咽癌的OS独立影响因素。

鼻咽癌患者放疗前后免疫原性细胞死亡相关蛋白的研究

目的:探索临床常规分割剂量射线对鼻咽癌患者免疫原性细胞死亡(ICD)相关蛋白表达水平的影响。方法:收集2020年11月—2021年12月就诊于贵州医科大学附属肿瘤医院的局部晚期鼻咽癌初治患者38例,均接受诱导化疗+同步放化疗,另选20例健康志愿者作为对照,行前瞻性研究。检测患者治疗前、诱导化疗后、同步放化疗后外周血中ICD相关蛋白钙网蛋白、高迁移率族蛋白1(HMGB-1)和热休克蛋白70(HSP70)的含量,以及树突状细胞亚群的占比。使用t检验及方差分析等统计学方法分析上述指标与一般临床资料、近期疗效的相关性。结果:鼻咽癌患者治疗前外周血中HMGB-1、HSP70含量较健康人群高(P<0.05)。同步放化疗后,鼻咽癌患者治疗前外周血中钙网蛋白的含量显著高于治疗前(P<0.05),然而其诱导化疗后与治疗前的差值、同步放化疗后与治疗前的差值均与患者的近期疗效无显著相关性。鼻咽癌患者外周血中HSP70含量同步放化疗后较治疗前显著降低(P<0.001),而HMGB-1含量诱导化疗后及同步放化疗后较治疗前均无显著差异(P>0.05)。结论:鼻咽癌患者接受TPF方案(多西他赛+顺铂+氟尿嘧啶)诱导化疗序贯顺铂同步放化疗,可能诱导鼻咽癌细胞发生了ICD,钙网蛋白具有反映鼻咽癌临床疗效的潜在价值。

肿瘤浸润淋巴细胞功能及对头颈鳞癌预后价值

目的>90%头颈部肿瘤病理类型以鳞癌为主,需要稳定且有效的生物学指标来预测患者预后、指导治疗。本研究探讨肿瘤浸润淋巴细胞(tumor infiltrating lymphocytes,TILs)对头颈部鳞癌(head and neck squamous cell,HNSCC)的预后价值。方法以“头颈鳞癌、肿瘤微环境、TILs、免疫细胞和预后价值”为关键词,应用PubMed及CNKI期刊全文数据库主要检索2015-01-2018-12的相关文献及注册临床研究。纳入标准:(1)HNSCC;(2)TILs;(3)TILs与预后的相关临床研究。共纳入30篇文献进行分析。结果肿瘤微环境是独特、复杂的环境,存在大量的淋巴细胞浸润,主要是T淋巴细胞,其亚型包括了CD3^+、CD4^+和CD8^+T淋巴细胞等。肿瘤浸润淋巴细胞TILs在HNSCC中具有显著的预后价值,与较好的总生存率(overall survival,OS)、无进展生存期(progression-free survival,PFS)和无远处转移生存率(distant metastasis-free survival,DMFS)等是显著相关的。同时TILs每个亚群的作用机制不尽相同,导致了TILs在肿瘤微环境中的作用尚不十分明确。除了与淋巴细胞亚群有关外,人类乳头瘤病毒(Human papillomavirus,HPV)、人类疱疹病毒(Epstein-Earr virus,EBV).生物学因素和评估方法都可作为影响TILs评估HNSCC预后价值的相关因素。结论TILs在HNSCC中具有较高的预后价值,但肿瘤微环境仍有很多机制不明。

Toxic activity of a protein complex purified from Xenorhabdus nematophila HB310 to Plutella xylostella larvae

Xenorhabdus nematophila, a Gram-negative proteobacterium belonging to the family Enterobacteriaceae and associated symbiotically with soil entomopathogenic nematodes, Steinernema carpocapsae, is pathogenic to a wide range of insects. A protein complex with insecticidal activity was isolated from the cells ofX. nematophila HB310 strain using methods of salting out and native polyacrylamide gel electrophoresis （PAGE）. Seven polypeptides ranging 50~250 kDa were well separated from the protein complex （named Xnpt） by sodium dodecyl sulfate （SDS）-PAGE, five of which are identified as XptA2, xptC 1, XptB 1, GroEL and hypothetical protein by matrix-assisted laser desorption- time-of-flight mass spectrometry （MALDI-TOFMS）. Xnpt showed high oral virulence to larvae of diamondback moth （DBM）, Plutella xylostella L. （Lepidoptera, Plutellidae） as its median lethal concentration （LC50） against second and third instar larvae were 331.45 ng/mL and 553.59 ng/mL at 72 h, respectively. The histological analysis of Xnptfed DBM larvae showed extensive histopathological effects on the midgut. Biochemical analysis indicated that Xnpt markedly inhibited the activities of three important enzymes in the midgut. Overall, our data showed that the protein complex isolated from X. nematophila HB310 induced the antifeedant and death of insects by destroying midgut tissues and inhibiting midgut proteases activities.

Neodymium Organic Sulfonate Complexes: Tunable Electronegativity/Steric Hindrance and Application in Controlled Cis-1,4-polymerization of Butadiene

Rare earth catalysts possessing characteristics of cation-anion ion pair show advantages of adjusting electronegativity and steric hindrance of metal active sites, which can control the catalytic performance and stereoselectivity better than those of traditional metallocene and Ziegler-Natta catalysts in diene polymerization. In this work, a series of neodymium organic sulfonate complexes,Nd(CF_3SO_3)_3·x H_2O·y L(x, y: the coordination number; L refers to an organic electron donating ligand, such as acetylacetone(acac), isooctyl alcohol(IAOH), tributyl phosphate(TBP), etc.), have been synthesized to form the cationic active species in the presence of alkylaluminum such as Al(i-Bu)_3, AlEt_3, and Al(i-Bu)_2H, which display high activities and distinguishing cis-1,4 selectivities(up to99.9%) for the polymerization of butadiene. The microstructures, yield, molecular weight, and molecular weight distribution of the resulting polymer are well controlled by adjusting electronegativity/steric hindrance of the complexes. In addition, the kinetics, active species, and the possible process of polymerization are also discussed in this article.

Diacylglycerol Compounds from Barks of Betula platyphylla with Inhibitory Activity against Acyltransferase

Objective To identify the active compounds from the barks of Betula platyphylla for inhibitory on diacylglycerol acyltransferase（DGAT1）.Methods Bioassay-guided fractionation resulted in the isolation of DGAT1 inhibitory activity of lupane triterpenes.Results Ten compounds were identified as lupenone（1）,lupeol（2）,betulinic acid（3）,betulinaldehyde（4）,betulin（5）,3-deoxybetulonic acid（6）,glochidonol（7）,lup-20/29-ene-1β/3β-diol（8）,3α-hydroxy-lup-20（29）-en-23,28-dioic acid（9）,and 3α,11α-dihydroxy-23-oxo-lup-20（29）-en-28-oic acid（10）.Compounds 3-6,9,and 10 inhibited DGAT1 with IC50 values ranging from（11.2±0.3）to（38.6±1.2）μmol/L.Conclusion Compounds 6,9,and 10 are first isolated from the barks of B.platyphylla.,and compounds 3-6,9,and 10 from the barks of B.platyphylla are responsible for the inhibition on DGAT1.

High impact of vehicle and solvent emission on the ambient volatile organic compounds in a major city of northwest China

Monitoring of ambient volatile organic compounds(VOCs)was conducted within typical residentialcommercial area in the city of Xi’an in northwest China during typical ozone(O_(3))episodes,to investigate the major contributors to the characteristic of ambient VOCs and their impact on O_(3) production.In the residential-commercial area,diurnal variation of VOCs was highly impacted by vehicle exhaust,fuel evaporation,and local solvent use.Relative higher contributions(up to 60%)of VOCs from solvent use to the ozone formation potential were found.The present findings highlight the urgent need for restrictions on the emission of VOCs from solvent use and non-vehicle-traffic-related sources,such as oil storage.

Real-time measurements of PM_(2.5),PM_(10-2.5),and BC in an urban street canyon

A continuous dichotomous beta gauge monitor was used to characterize the hourly content of PM2.5, PM10-2.5, and Black Carbon （BC） over a 12-month period in an urban street canyon of Hong Kong. Hourly vehicle counts for nine vehicle classes and meteorological data were also recorded. The average weekly cycles of PM2.5, PM10-2.5, and BC suggested that all species are related to traffic, with high concentrations on workdays and low concentrations over the weekends. PM2.s exhibited two comparable concentrations at 10：00-11：00 （63.4 μg/m3） and 17：00-18：00 （65.0 p.g/m3 ） local time （LT） during workdays, correspond- ing to the hours when the numbers of diesel-fueled and gasoline-fueled vehicles were at their maximum levels： 3179 and 2907 h-1, respectively. BC is emitted mainly by diesel-fueled vehicles and this showed the highest concentration （31.2μg/m3） during the midday period （10：00-11：00 LT） on workdays. A poor correlation was found between PM2.s concentration and wind speed （R= 0.51, P-value 〉 0.001 ）. In contrast, the concentration of PM10-2.s was found to depend upon wind speed and it increased with obvious statistical significance as wind speed increased （R = 0,98, P-value 〈 0.0001 ）.