超稳低汞催化剂的稳定机理:炭表面含氧基团及缺陷协同作用实验及理论研究（英文）

聚氯乙烯(PVC)作为五大工程塑料之首在材料领域应用广泛.2017年,中国PVC产能逾2600万吨,占世界总产量的70%以上, PVC产业是我国重要支柱产业之一.基于中国富煤少气缺油的能源格局, PVC产量的90%以上都是基于煤化工的乙炔法生产的,而氯化汞催化剂是目前乙炔法氯乙烯工业上唯一实现产业化应用的催化剂.但是由于氯化汞属于金属氯化物中唯一的共价化合物,其热稳定极差,涉汞催化剂的汞污染问题一直是氯乙烯行业的世界级难题.中国电石法聚氯乙烯产业每年催化剂消耗量高达2.0万吨,年耗汞近1000吨,可回收不足40%,占世界汞消耗量的70%.而无汞催化剂由于成本高、使用寿命短等原因,短期内实现工业化应用及推广仍有困难.中国政府早在2014年开始限汞行动,提出了氯乙烯产业汞催化剂减量化直至无汞化的战略目标.根据2015年拟定的氯乙烯用低汞触媒的国标要求,氯化汞负载量最高不得超过6.5%,而高汞催化剂的氯化汞负载量在10%–12%之间,在氯化汞负载量降低一半的情况下保持催化剂的高性能及高热稳定性对催化剂的制备技术提出了很大的挑战.催化剂是参与化学反应而自身不会消耗的物质,其在工业使用过程中理论上并不会消耗,解决了催化剂的热稳定性问题,不但可以延长催化剂使用寿命,而且还可以缓解涉汞催化剂的资源消耗及环境污染问题.活性炭具有较高的比表面积、可调控的表面化学性质和耐酸碱腐蚀性,在工业中应用广泛.氯乙烯单体合成的原料为氯化氢和乙炔,由于氯化氢的腐蚀性,活性炭基催化剂在工业化应用方面具有明显的优势.而活性炭载体的表面性质调控及对负载型金属催化剂的相互作用研究一直是近年来多相催化领域的一个热点.本文通过热处理的方法调控了活性炭的表面含氧基团,研究了活性炭的表面结构的区别,通过浸渍法制备了三种活性炭负载的低汞催化剂,对比了三种不同的活性炭载体的乙炔氢氯化性能及稳定性,发现表面基团的调控对低汞催化剂的稳定性具有较大的影响.热重实验表明,Hg Cl2/AC-C催化剂中氯化汞的最大失重温度提高到了380°C以上.该催化剂在反应温度140°C,乙炔空速30 h–1条件下稳定运行10000 h,乙炔转化率只下降了8%.DFT理论计算发现,碳氧双键旁边的缺陷位和氯化汞可以形成强的化学吸附,其吸附能可达120–130 kJ/mol,而氯化汞在含氧基团的表面吸附能只有3–35 kJ/mol.本文通过对活性炭表面结构的调控,使氯化汞和炭表面活性位形成化学吸附,可大大提高催化剂的耐热稳定性,从理论上给出了低汞催化剂的热稳定性解决方案,目前该催化剂已经成功实现了产业化应用,在工业转化器上使用寿命超过12000 h,性能表现卓越.超稳低汞催化剂的工业化应用不仅能够降低氯乙烯单体生产过程中的单耗,节约PVC生产成本,还能够有效减少汞触媒使用过程中造成的重金属污染,为我国电石法氯碱行业的节能减排及限汞公约履约提供了很好的技术支撑和保障.

YKL-40基因沉默对裸鼠子宫内膜癌移植瘤生长及CD68表达的影响（英文）

目的:探讨YKL-40基因沉默对裸鼠子宫内膜癌移植瘤生长及CD68表达的影响。方法:采用小干扰RNA技术沉默人子宫内膜癌(HEC)-1A细胞中的YKL-40基因,将HEC-1A细胞分为对照组(未经慢病毒转染)、空载体组(只转染空病毒)和YKL-40-siRNA组(转染带有YKL-40siRNA干扰片段慢病毒)。将HEC-1A细胞皮下注射于4周龄BALB/c裸鼠腋窝,建立裸鼠子宫内膜癌模型,观察裸鼠移植瘤的生长情况。采用免疫组化法检测裸鼠移植瘤组织中YKL-40和CD68的表达水平。结果:YKL-40-siRNA组移植瘤体积明显小于阴性对照组和空白对照组(均P<0.05)。重组慢病毒载体YKL-40-siRNA注射组裸鼠肿瘤组织中YKL-40表达水平显著降低(P<0.05)。YKL-40表达的抑制降低了CD68在肿瘤组织中的表达(P<0.05)。相关分析表明,YKL-40在裸鼠肿瘤组织中的表达与CD68的表达呈正相关关系。结论:沉默YKL-40基因可抑制子宫内膜癌肿瘤的生长,降低CD68的表达。

Comparison of the short-term and long-term outcomes of laparoscopic hysterectomies and of abdominal hysterectomies： a case study of 4,895 patients in the Guangxi Zhuang Autonomous Region, China

Background： To evaluate the short-term and long-term outcomes after laparoscopic hysterectomy （LH） compared with abdominal hysterectomy （AH） in case of benign gynecological disease. Methods： A multi-center cohort retrospective comparative study of population among 4,895 hysterectomies （3,539 LH vs.1,356 AH） between 2007 and 2013 was involved. Operative time （OT）, estimated blood loss （EBL）, intra-operative and post-operative complications, passing flatus; days with indwelling catheter, questionnaires covering pelvic floor functions and sexual functions were assessed. Results： The EBL （174.1±157.4 vs. 263.1±183.2 cc, LH and AH groups, respectively）, passing flatus （38.7±14.1 vs. 48.1±13.2 hours）, days with indwelling catheter （1.5±0.6 vs. 2.2±0.8 days）, use of analgesics （6.5% vs. 73.1%）, intra-operative complication rate （2.4% vs. 4.1%）, post-operative complication rate （2.3 % vs. 5.7%）, post-operative constipation （12.1% vs. 24.6%）, mild and serious stress urinary incontinence （SUI） post-operative （P〈0.001; P=0.014）, and proportion of Female Sexual Functioning Index （FSFI） total score 〈26.55 post-operative （P〈0.001） of the LH group were significantly less than those of AH group. There were no significant differences in OT （106.5±34.5 vs. 106.2±40.3 min） between the two groups. Conclusions： LH is a safe and efficient operation for improving patients＇ long-term quality of life （QoL）, and LH is a cost-effectiveness procedure for treating benign gynecological disease. LH is superior to AH due to reduced EBL, reduced post-operative pain and earlier passing flatus.

Mechanisms of inhibition by aspirin of endometrial carcinoma cell proliferation, migration and invasion

Objective:To investigate the effects and mechanisms of aspirin on the proliferation,migration and invasion of endometrial carcinoma HEC-1 A cell lines.Methods:HEC-1 Acells were cultured to the exponential phase and treated with different concentrations of aspirin(0.625 mmol/L,1.25 mmol/L,2.5 mmol/L,5 mmol/L and 10 mmol/L)for 24 to 120 hours.Cell proliferation was assessed by methyl thiazolyl tetrazolium(MTT)assay.The migration and invasion of HEC-1 Acells were detected by transwell assay.The protein expressions of vascular endothelial growth factor(VEGF)and ascular endothelial growth factor receptor 2(VEGFR-2)in HEC-1 Acells were determined by western blotting.Results:MTT results showed that aspirin inhibited the growth and proliferation of endometrial cancer cells in concentration and time-dependent manner.Aspirin had a significant inhibitory effect on the migration and invasion of HEC-1 Acells(P<0.05).In addition,aspirin obviously suppressed concentration-dependently the expression levels of VEGF and VEGFR-2(P<0.05).Conclusion:Aspirin could inhibit the proliferation,migration and invasion of endometrial cancer cells.The anti-tumor mechanism of aspirin might be related to the inhibition of tumor angiogenesis via blocking the VEGF/VEGFR-2 signaling pathway.

表达HPV16L1、L2和E7蛋白的非复制重组痘苗病毒的构建(英文)

Objective:To construct a non-replicating vaccinia virus expressing human papillomavirus 16(HPV16) L1, L2E7 proteins as a candidate vaccine for cervical cancer.Methods:Using vaccinia virus vector, we generated a strain of non-replicating recombinant vaccinia virus vaccine expressing HPV16 L1, L2E7 proteins by homologous recombination and identified by PCR and Western-bloting.Results:We demonstrated that the L1, L2E7 gene of HPV16 were integrated into vaccinia genosome and could express L1, L2E7 protein stably when infected the CEF using PCR and Western-blot assay.Conclusion:NTVJL1/L2E7 can express L1, L2E7 protein of HPV16 and can be taken as a candidate vaccine for HPV16-associated diseases.

Thermal stable and ultralow dielectric loss in(Gd_(0.5)Ta_(0.5))_(x)Ti_(1-x)O_(2)giant permittivity ceramics by defect engineering

High dielectric loss and poor temperature stability are the current barriers to the application of dielectric materials.In present work,we synthesized a system of acceptor Gd^(3+)and donor Ta^(5+)co-doped(Gd_(0.5)Ta_(0.5))_(x)Ti_(1-x)O_(2)(GTTOx,x=0,0.01,0.02,0.04,0.06)ceramics to enhance dielectric response.It was found that a colossal permittivity(CP,2.65×10^(4)@1 kHz,2.37×10^(4)@1 MHz),a very low dielectric loss(tanδ,0.007@1 kHz,0.03@1 MHz),good stability of frequency(20–10^(6)Hz)and temperature(RT–250°C,Δε′(T)/ε′30<±15%,at 1 kHz)were achieved simultaneously in GTTO0.01 ceramic.Complex impedance spectroscopy,XPS,SEM,and Raman spectroscopy were used to investigate the reasons for the improved dielectric properties.The result indicated that the main reasons for CP and low dielectric loss are the synergistic effect of the electron pinning defect-dipole(EPDD)model,the internal blocking layer capacitance(IBLC)mechanism,and electrode response.This work provides a promising approach for the design of defect-related high-performance giant dielectric ceramics.

Climate-related changes in seasonal habitat pattern of Sthenoteuthis oualaniensis in the South China Sea

A habitat suitability index model(HSI)was established to examine seasonal habitat pattern of Sthenoteuthis oualaniensis in the South China Sea and assessed the impacts of the El Niño event on habitat variations based on sea surface temperature(SST),chlorophyll-a(Chla)and sea surface height(SSH).Environmental conditions and habitat patterns showed significant seasonal and spatial variations.Spatial pattern of favorable environmental conditions played important roles in regulating the ranges and longitudinal and latitudinal distributions of suitable habitats(areas with HSI≥0.6)of S.oualaniensis across seasons.Significant positive correlation was found between SST and HSI,whereas negative relationship was revealed between HSI and Chla as well as SSH by correlation analysis.Comparing to normal climate condition in spring 2014,the El Niño events in spring 2015 and 2016 yielded lower SST and higher Chla and SSH,which were unfavorable for the formation of high-quality habitats.Favorable ranges of environmental conditions showed decreasing trend from spring 2014 to 2016.Consequently,the suitable habitats in spring 2015 and 2016 largely contracted and became discontinuity.Our findings indicated that seasonal habitat patterns of S.oualaniensis in the South China Sea were strongly affected by the El Niño events and local environmental conditions.

Genomes of Two Flying Squid Species Provide Novel Insights into Adaptations of Cephalopods to Pelagic Life

Pelagic cephalopods have evolved a series of fascinating traits,such as excellent visual acuity,high-speed agility,and photophores for adaptation to open pelagic oceans.However,the genetic mechanisms underpinning these traits are not well understood.Thus,in this study,we obtained high-quality genomes of two purpleback flying squid species(Sthenoteuthis oualaniensis and Sthenoteuthis sp.),with sizes of 5450 Mb and 5651 Mb,respectively.Comparative genomic analyses revealed that the S-crystallin subfamily SL20-1 associated with visual acuity in the purpleback flying squid lineage was significantly expanded,and the evolution of high-speed agility for the species was accompanied by significant positive selection pressure on genes related to energy metabolism.These molecular signals might have contributed to the evolution of their adaptative predatory and anti-predatory traits.In addition,the transcriptomic analysis provided clear indications of the evolution of the photophores of purpleback flying squids,especially the recruitment of new genes and energy metabolism-related genes which may have played key functional roles in the process.