ROLE AND IMPORTANCE OF RADIUS OF GYRATION OF CHAINS IN THE MELT IN THE CRYSTALIZATION OF POLY(1-BUTENE)

Crystallization in polymer systems actually is a process that transfers the entangled melts into a semi-crystalline layered structure. Whether or not a chain disentangles may result in different crystallization mechanism. When compared to the crystal thickness (d(c)), the volume occupied by the chain in the melts i.e., the radius of gyration (R-g), plays a very important role in polymer crystallization. When d(c) less than or equal to R-g, crystallization does not necessitate a chain disentangling. The entanglements are just shifted into the amorphous regions. However, as d(c)>R-g, i.e., as the crystal thickness gets larger than the radius of gyration of the chain in the melt, it becomes necessary for a chain to disentangle. Then a change of crystallization mechanism occurs. Such change has been experimentally observed in the crystallization of poly(I-butene). A change in the crystal morphologies from spherulite to quadrangle, is seen via PLM, as crystallization temperatures increase. Even more, such a change is molecular weight dependent, and shifts to lower temperature as molecular weight decreases. There exists a jump of crystal thickness and crystallinity associated with morphological change, as seen via SAXS. A change of crystallization kinetics and crystallinity is further evidenced via dilatometry. The unique feature of P1b crystallization has been discussed based on the radius of gyration of chain in the melt (R-g), and very good agreement is obtained.

Crystallization and Crystalline Structure of Syndiotactic Polypropylene and Syndiotactic-Poly(1-Butene) Blend

The crystallization and crystalline structure of syndiotactic-polypropylene (sPP) and syndiotactic-poly(1-butene) (sPB) blend containing 10 (Bl-10), 25 (Bl-25), 50 (Bl-50), 75 (Bl-75), and 90 (Bl-90) wt% of sPB, have been investigated by means of differential scanning calorimetry (DSC), FT-IR, and wide-angle X-ray diffraction (WAXD) analyses. The melt-crystallization behavior of the blend samples was studied by DSC on the cooling process at constant rates. Bl-50, Bl-75, and Bl-90 showed lower crystallization temperatures than the neat sPP. sPP in Bl-75 showed the lowest crystallization rate among the blend samples. Bl-90 showed a two-phase molten state, and sPP in Bl-90 crystallized via two-stepprocess. Time evolution of FT-IR spectroscopy at room temperature detected conformational transformation of the sPP polymer chain in the blend samples of Bl-50 and Bl-75. The absorption peaks intensity in the FT-IR spectra derived from the helical conformations in the crystalline phase decreased, and the planar zigzag conformations in the amorphous and mesophase phases decreased over the crystallization time. The time evolution of the WAXD profile of Bl-90 indicated that sPP in the blend accelerated the crystallization of sPB. The crystallized Bl-10, Bl-25, and Bl-50 samples showed diffraction peaks in WAXD profiles and melting endothermic peak in DSC profiles derived from only the sPP crystal. The crystallinity and melting temperature of sPP in the crystallized Bl-10, Bl-25, and Bl-50 samples were almost independent of the sPB content. Both the crystalline structure of sPP and sPB were detected in Bl-75 and Bl-90. Bl-75 showed the lowest crystallinity and melting temperature of sPP among the blend samples.

电容器用双向拉伸聚4-甲基-1-戊烯(BOPMP)薄膜开发与应用

聚4-甲基-1-戊烯(PMP)是一种具有等规结构的新型热塑性塑料,PMP为结晶性树脂,熔点在235℃~240℃之间,耐热性好,可在高温下使用,并具有卓越的电气绝缘和介电性能。与聚丙烯树脂相比,熔点高60℃,介电常数、介电损耗相近。随着我国电子工业的发展,PMP的用量在近年来有大幅的增长。目前世界上只有日本三井化学株式会社生产,由于产量有限、售价较高,限制了PMP在国内的应用。为此本文尝试采用双向拉伸的方法,试制聚4-甲基-1-戊烯(BOPMP)薄膜,并加工成金属化膜,试制电容器,最后对电容器的性能进行相应测试评价。采用不同牌号原料生产BOPMP薄膜,其电压击穿强度差别较大,不同频率下的BOPMP薄膜电容器损耗角正切值、介电常数均与BOPP薄膜电容器接近,但其高温下的性能有待进一步验证。如何提升BOPMP薄膜电压击穿强度及其耐热性,开发出适宜于双向拉伸的PMP粒子原料,生产出高质量的BOPMP电容薄膜,将是未来重点研究的方向。

Preparation of phosphorus-modified PITQ-13 catalysts and their performance in 1-butene catalytic cracking

A series of phosphorus-modified PITQ-13 catalysts was prepared by wet impregnation of NH4H2PO4 solution into an HITQ-13 parent. The catalysts were characterized using XRD, N2 adsorption, MAS NMR and NH3-TPD. Their catalytic performance in 1-butene catalytic cracking was evaluated in a fixed fluidized bed reactor. The results showed that the crystallinity, surface area and pore volume of P-modified PITQ-13 catalysts decreased with the increasing amounts of P. The number of weak acid sites increased, whereas that of strong acidity decreased. The selectivity to propylene in 1-butene cracking reactions increased because of the decrease in strong acidity. The yield of propylene achieved 41.6% over PITQ-13-2 catalyst with a P content of 1.0 wt%, which was 5.1% greater than that achieved over HITQ-13 catalyst.

1-Butene isomerization and metathesis over Mo/mordenite-alumina: Factors influencing product distribution and induction period

Effects of space velocity, reaction temperature and support acidity on product distribution and induction period in 1-butene isomerization and metathesis over Mo/mordenite-alumina were investigated. As revealed by the catalytic performance results, induction period and objective product were closely related to the reaction conditions. Lower space velocity led to longer induction period and higher propene yield. The optimal reaction temperature for propene production is around 150 ~C and it shifted to 100 ~C for ethene production. 1-Butene auto-metathesis predominated in the reaction network if the support with lower degree of sodium exchanged. And propene gradually became the dominant product upon increasing the support sodium exchange degree. 6Mo/H100Na0M-30A1 catalyst with a support of full sodium exchange degree exhibited the highest propene yield.

Production of propene from 1-butene metathesis reaction on tungsten based heterogeneous catalysts

A new propene production route from 1-butene metathesis has been developed on heterogeneous 10WO3/Al2O3-HY catalysts with different HY contents. It is found that the catalysts play bi-functionally first for the isomerization of 1-butene to 2-butene and then for the cross-metathesis between 1-butene and 2-butene to propene and 2-pentene. The combination of HY zeolite and Al2O3 is prerequisite for the production of propene. The propene yield keeps increasing with the HY content in the range of 10-70 wt%, where 10WO3/Al2O3-70HY exhibits the highest propene yield. The MS-H2-TPR and MS-O2-TPO characterizations indicate that the increase of HY content in the catalysts weakens the interaction between W species and supports, whereas enhance the probability of coking on the metal species and acid sites.

MCM-36 zeolites tailored with acidic ionic liquid to regulate adsorption properties of isobutane and 1-butene

Adsorption properties of an adsorbent or a catalyst towards adsorbates are crucial in the process of adsorption separation or catalytic reaction. Surface morphology and structure of adsorbents have a significant impact on the adsorption properties. In this study, a novel acidic ionic liquid, 1-butyl-3-(triethoxysilylpropyl)imidazolium hydrogen sulfate(i.e., [BTPIm][HSO_4]), was synthesized and subsequently grafted onto the MCM-36 zeolite for the regulation of its adsorption properties towards isobutane and 1-butene. The resultant [BTPIm][HSO_4]-immobilized MCM-36(i.e., MCM-36-IL) was characterized by FT-IR, XPS, XRD, SEM, TG/DTG and N_2 adsorption–desorption measurement. It was found that the specific surface area, micropore volume and mesopore volume of the MCM-36 support underwent a reduction upon the immobilization of ionic liquid,while the surface density of acid increased from 0.0014 to 0.0035 mmol·m^(-2). The adsorption capacity of isobutane and 1-butene on the MCM-36-IL was determined by a static volumetric method. Results demonstrated that the interaction between isobutane and MCM-36-IL was enhanced and the interaction between 1-butene and MCM-36-IL was reduced. As a result, a tunable adsorption ratio of isobutane/1-butene on MCM-36 was achieved.With the increase in surface density of acid and the tunable adsorption ratio of isobutane and 1-butene on the functionalized MCM-36, the acidic ionic liquid-immobilized zeolites are beneficial to obtain an improved reaction yield and a prolonged catalyst life in the reactions catalyzed by solid acid.

The influence of different monodentate P-ligand mixtures on Rh-catalyzed 1-butene hydroformylation

Four monodentate P-ligands and their mixtures（six groups of double-ligand systems,four groups of triple-ligand systems and one group of tetra-ligand system）were used with Rh（acac）（CO）2（acac=acetylacetonate）or Rh（acac）CO（PPh3）as the catalyst in the hydroformylation reaction of 1-butene.It was found that different Rh catalysts showed little difference in the catalysis performance.The general order of catalysis performance is doubleligand system 〉 single-ligand system〉triple-ligand system 〉 tetra-ligand system.Some synergistic effect in the double-ligand system was detected which needs a further investigation.

Regulation of isobutane/1-butene adsorption behaviors on the acidic ionic liquids-functionalized MCM-22 zeolite

The adsorption ratio of isobutane/1-butene on the catalyst surface is one of the most important factors for the C4 alkylation process. Regulation of isobutane/1-butene adsorption ratio on the zeolite-supported acid catalyst is a big challenge for catalyst preparation. To regulate the isobutane/1-butene adsorption ratio, four types of ionic liquid （i.e., IL） with different alkyl chain lengths and different acid group numbers were synthesized and were subsequently immobilized onto the MCM-22 zeolite. The as-synthesized IL-immobilized MCM-22 （i.e., MCM-22-IL） was characterized by FT1R, TGA, BET, XPS and XRD, and their adsorption capacities and adsorption molar ratios of isobutane to l-butene （I/O） were investigated to correlate with surface features of MCM-22-IL Results showed that the immobilization of ILs led to a decrease of specific surface area and pore volume. But the surface density of acid groups was increased and the adsorption molar ratio of isobutane/1-butene （I/O） was significantly im- proved by the immobilization of ionic liquids. The adsorption molar ratio of I/O is substantially improved from 0.75 to above 0.9 at 300 kPa upon immobilizing ILs. Although the alkyl chain length oflLs was found to have little effect on the adsorption molar ratio of I/O, the increase of acid group numbers led to a dramatic decrease in the adsorption I/O ratio. The results illustrated that immobilizing ionic liquids is an effective way to modify the textural, chemical and morphological properties of MCM-22. Accordingly, the immobilization of ionic liquids provides a novel and a feasible way to regulate the adsorption I/O ratio on an adsorbent or a solid catalyst.

多聚ADP-核糖聚合酶-1在放射性认知功能障碍中的研究进展

放射治疗后多聚ADP核糖聚合酶-1(PARP-1)的过度激活与神经炎症反应密切相关,而神经炎症是放射性认知功能障碍(RICD)的主要发病机制。该文分析了RICD中神经炎症反应的病理生理机制,包括小胶质细胞激活、星形胶质细胞的增生、少突胶质细胞的破坏、海马微环境改变和血脑屏障损伤,并对PARP-1通过这些共同机制介导神经炎症反应进而加重RICD的研究进展进行综述。最后,探讨了PARP-1抑制剂对RICD的潜在保护作用,旨在为RICD防治药物的开发提供新方向。

Stable Cycling of All-Solid-State Lithium Batteries Enabled by Cyano-Molecular Diamond Improved Polymer Electrolytes

The interfacial instability of the poly(ethylene oxide)(PEO)-based electrolytes impedes the long-term cycling and further application of all-solid-state lithium metal batter-ies.In this work,we have shown an effective additive 1-adaman-tanecarbonitrile,which con-tributes to the excellent per-formance of the poly(ethylene oxide)-based electrolytes.Owing to the strong interaction of the 1-Adamantanecarboni-trile to the polymer matrix and anions,the coordination of the Li^(+)-EO is weakened,and the binding effect of anions is strengthened,thereby improving the Li^(+)conductivity and the electrochemical stability.The diamond building block on the surface of the lithium anode can sup-press the growth of lithium dendrites.Importantly,the 1-Adamantanecarbonitrile also regulates the formation of LiF in the solid electrolyte interface and cathode electrolyte interface,which contributes to the interfacial stability(especially at high voltages)and protects the electrodes,enabling all-solid-state batteries to cycle at high voltages for long periods of time.Therefore,the Li/Li symmetric cell undergoes long-term lithium plating/stripping for more than 2000 h.1-Adamantanecarbonitrile-poly(ethylene oxide)-based LFP/Li and 4.3 V Ni_(0.8)Mn_(0.1)Co_(0.1)O_(2)/Li all-solid-state batteries achieved stable cycles for 1000 times,with capacity retention rates reaching 85%and 80%,respectively.

Low testing rates and high BRCA prevalence: Poly (ADP-ribose) polymerase inhibitor use in Middle East BRCA/homologous recombination deficiency-positive cancer patients

BACKGROUND Poly(ADP-ribose)polymerase inhibitors(PARPis)are approved as first-line therapies for breast cancer gene(BRCA)-positive,human epidermal growth factor receptor 2-negative locally advanced or metastatic breast cancer.They are also effective for new and recurrent ovarian cancers that are BRCA-or homologous recombination deficiency(HRD)-positive.However,data on these mutations and PARPi use in the Middle East are limited.AIM To assess BRCA/HRD prevalence and PARPi use in patients in the Middle East with breast/ovarian cancer.METHODS This was a single-center retrospective study of 57 of 472 breast cancer patients tested for BRCA mutations,and 25 of 65 ovarian cancer patients tested for HRD.These adult patients participated in at least four visits to the oncology service at our center between August 2021 and May 2023.Data were summarized using descriptive statistics and compared using counts and percentages.Response to treatment was assessed using Response Evaluation Criteria in Solid Tumors criteria.RESULTS Among the 472 breast cancer patients,12.1%underwent BRCA testing,and 38.5%of 65 ovarian cancer patients received HRD testing.Pathogenic mutations were found in 25.6%of the tested patients:26.3%breast cancers had germline BRCA(gBRCA)mutations and 24.0%ovarian cancers showed HRD.Notably,40.0%of gBRCA-positive breast cancers and 66.0%of HRD-positive ovarian cancers were Middle Eastern and Asian patients,respectively.PARPi treatment was used in 5(33.3%)gBRCA-positive breast cancer patients as first-line therapy(n=1;7-months progression-free),for maintenance(n=2;>15-months progression-free),or at later stages due to compliance issues(n=2).Four patients(66.6%)with HRD-positive ovarian cancer received PARPi and all remained progression-free.CONCLUSION Lower testing rates but higher BRCA mutations in breast cancer were found.Ethnicity reflected United Arab Emirates demographics,with breast cancer in Middle Eastern and ovarian cancer in Asian patients.

PARP1通过调控POU2F2的表达促进肝细胞癌的进展研究

背景与目的:肝细胞癌(hepatocellular carcinoma,HCC)是严重威胁人类健康的重大疾病。多腺苷二磷酸核糖聚合酶1[poly(ADP-ribose)polymerase 1,PARP1]作为一种腺苷二磷酸核糖转移酶,能够促进DNA损伤修复进程,因此,PARP1通常被看作是一种促癌基因,但其在HCC中的表达和机制尚不明确。本研究旨在探讨PARP1在HCC患者中的表达趋势及其在HCC发生、发展中的作用。方法:首先,通过对癌症基因组图谱(The Cancer Genome Atlas,TCGA)和临床蛋白质组学癌症分析联盟(Clinical Proteomic Tumor Analysis Consortium,CPTAC)HCC数据库的分析鉴定PARP1的临床表达情况,采用实时荧光定量聚合酶链反应(real-time fluorescence quantitative polymerase chain reaction,RTFQ-PCR)和蛋白质印迹法(Western blot)检测PARP1在HCC患者癌组织及癌旁组织样本中的表达情况。然后,借助PARP1的抑制剂PJ34抑制PARP1酶活性,同时借助小RNA干扰技术下调HCC细胞系中PARP1的表达,并以此为模型,采用细胞计数试剂盒-8(cell counting kit-8,CCK-8)和流式细胞术检测PARP1对细胞活力的影响,采用RTFQ-PCR检测HCC细胞干性基因的表达变化,采用细胞迁移和侵袭实验检测HCC细胞迁移和侵袭能力。采用生物信息学方法分析HCC进展中受PARP1调控的靶基因及其参与通路,并通过回补实验确定PARP1靶基因是否参与HCC细胞恶性表型。结果:在TCGA和CPTAC数据库中,PAPR1的表达均在HCC组中显著上调。RTFQ-PCR和Western blot检测结果表明,相比癌旁组织,HCC组织中的PARP1在转录和翻译水平均显著上调。生存分析结果表明,PARP1的表达与HCC患者的预后呈显著负相关。CCK-8、流式细胞术、RTFQ-PCR、细胞迁移及侵袭实验结果显示,在HCC细胞中下调PARP1表达可以抑制HCC细胞增殖,降低HCC细胞活性及干性,并减弱HCC细胞迁移和侵袭能力。生物信息学分析提示,PARP1调控基因富集在核因子κB(nuclear factor-κB,NF-κB)和Necroptosis通路中,POU2类同源框2(POU class homeobox 2,POU2F2)可能是PARP1的潜在靶基因。相关性分析、RTFQ-PCR和Western blot检测一致证实POU2F2的表达受到PARP1的调控,但PJ34不能抑制POU2F2的表达。CCK-8、流式细胞术和RTFQ-PCR结果显示,采用共转染的方式在敲低PARP1的HCC细胞系中回补POU2F2可以增强HCC细胞增殖能力,提高HCC细胞活性,促进HCC细胞干性。结论:PARP1可以通过非酶活性正向调控POU2F2表达促进HCC细胞恶性表型,本研究结果有望为HCC的临床治疗和新药开发提供新的思路。

基质细胞衍生因子1修饰左旋聚乳酸多孔微球促进软骨细胞增殖和组织形成

背景:二维培养条件下的软骨细胞增殖及表型维持受限,多孔微球作为支架材料可提供三维培养环境,以更好地模拟体内生长条件。基质细胞衍生因子1是有强趋化效力的稳态细胞因子,能够促进细胞的黏附与增殖。目的:明确接枝基质细胞衍生因子1左旋聚乳酸多孔微球对软骨细胞生物学特性及软骨组织形成的影响。方法:(1)体外验证不同质量浓度基质细胞衍生因子1对兔软骨细胞增殖、迁移、表型维持的影响。(2)采用复乳法制备左旋聚乳酸多孔微球,利用碳二亚胺法将基质细胞衍生因子1接枝于左旋聚乳酸多孔微球上,通过酶联免疫吸附实验及孵育基质细胞衍生因子1特异荧光抗体验证接枝情况。(3)将兔软骨细胞分别接种于左旋聚乳酸多孔微球、接枝基质细胞衍生因子1左旋聚乳酸多孔微球上,检测细胞增殖与黏附。(4)在裸鼠背部皮下分别植入甲基丙烯酰胺基明胶-软骨细胞复合体(对照组)、左旋聚乳酸多孔微球-甲基丙烯酰胺基明胶-软骨细胞复合体(多孔微球组)、接枝基质细胞衍生因子1左旋聚乳酸多孔微球-甲基丙烯酰胺基明胶-软骨细胞复合体(多孔微球修饰组),8周后取材,分别进行组织学染色与成软骨相关基因qRT-PCR检测。结果与结论:(1)相较于0,1 000 ng/mL基质细胞衍生因子1,500 ng/mL基质细胞衍生因子1可促进软骨细胞的增殖与迁移,提升软骨细胞内Ⅱ型胶原、弹性蛋白、增殖细胞核抗原、Bcl-2 mRNA表达;(2)基质细胞衍生因子1成功接枝于左旋聚乳酸多孔微球上,接枝率为93.75%;(3)相较于左旋聚乳酸多孔微球,接枝基质细胞衍生因子1左旋聚乳酸多孔微球可促进软骨细胞的增殖、黏附;(4)裸鼠皮下植入8周后,相较于对照组、多孔微球组,多孔微球修饰组具有更明显的软骨陷窝结构、更丰富的软骨特异性基质和Ⅱ型胶原沉积,弹性蛋白、Ⅱ型胶原、增殖细胞核抗原、Bcl-2 mRNA表达升高。结果表明:接枝基质细胞衍生因子1左旋聚乳酸多孔微球有利于软骨细胞的黏附、增殖、表型维持以及体内软骨组织形成。

聚ADP-核糖聚合酶-1在喉鳞状细胞癌细胞DNA氧化损伤及凋亡中的作用

目的探究聚ADP-核糖聚合酶-1(PARP1)在喉鳞状细胞癌(LSCC)中的表达及其对LSCC细胞DNA氧化损伤与凋亡的影响。方法收集40例患者的LSCC组织及癌旁组织样本,采用免疫组化染色和qRT-PCR检测LSCC组织与癌旁组织中PARP1的表达。采用不同浓度Menadione诱导LSCC细胞系Hep-2,MTT法检测不同浓度诱导下细胞增殖抑制率。将Hep-2细胞随机分为对照组(正常培养)、Men组(20μmol/L Menadione处理)、Men+PARP1抑制剂组(20μmol/L Menadione+10μmol/L PARP1抑制剂Olaparib共处理)。MTT法计算各组细胞增殖抑制率;流式细胞术检测各组细胞内活性氧(ROS)水平;细胞免疫荧光染色观察各组细胞DNA损伤标记分子γ-H2AX焦点生成情况;Western blot测定各组细胞γ-H2AX、DNA-PKcs、BRCA1、LIG4、Caspase-3及Caspase-9蛋白表达;Hoechst33258染色观察各组细胞凋亡情况。结果LSCC组织中PARP1阳性表达率及PARP1 mRNA表达均明显高于癌旁组织(P<0.01)。Hep-2细胞经不同浓度Menadione诱导后,细胞增殖抑制率均升高(P<0.05)。与对照组比较,Men组和Men+PARP1抑制剂组的细胞增殖抑制率升高,细胞ROS水平升高,γ-H2AX焦点形成明显增加,γ-H2AX蛋白表达上调,DNA-PKcs、BRCA1、LIG4蛋白表达均下调,细胞出现浓缩、碎裂的蓝色凋亡体,Caspase-3和Caspase-9蛋白表达上调,差异均有统计学意义(P<0.05),且Men+PARP1抑制剂组以上变化较Men组更明显(P<0.05)。结论PARP1在LSCC组织中高表达,抑制其表达能够进一步加重Menadione诱导的Hep-2细胞DNA氧化损伤,并促进细胞凋亡。

聚4-甲基-1-戊烯的合成、结构与应用研究进展

从聚4-甲基-1-戊烯(PMP)的单体、催化剂、合成、分子链结构、晶体结构以及结晶行为进行阐述,综述了其在电子电器、节能降耗、包装材料以及医疗器械等领域的最新应用。PMP的合成包括丙烯二聚合成单体4-甲基-1-戊烯及其聚合。PMP合成技术有两种:一种是采用Ziegler-Natta催化剂的配位聚合,使用的主催化剂为TiX(X表示卤素原子),助催化剂为烷基铝;第二种是阳离子聚合。最后对PMP性能优化以及国产化提出展望。

SYNTHESIS,CHARACTERIZATION AND OPTICAL PROPERTIES OF THE COPOLYMERS OF C_(60) AND 1-PHENYL-1-PROPYNE

While WCl_6-Ph_4Sn fails to polymerize 1-phenyl-1-propyne (PP) at room temperature, highmolecular weight (M_w up to 410× 10~3) polymers are obtained in high yields (up to 80%) when thepolymerizations of PP are carried out in the presence of C_(60) using the W catalyst under the same conditions.The polymers are soluble in common organic solvents such as THF, chloroform, and toluene. Molecularstructures of the polymers are characterized by FT-IR, UV, NMR, GPC and XRD, and it is found that C_(60) iscopolymerized with PP. Thus C_(60) plays the dual roles of comonomer and cocatalyst in the polymerizationreaction. C_(60) contents of the copolymers can be easily changed by varying the C_(60) amounts in the feedmixtures. The copolymers effectively limit strong 532 nm laser pulses, whose limiting performance issuperior to that of parent C_(60).

MORPHOLOGIES AND GAS SEPARATION PROPERTIES OF MELT-SPUN ASYMMETRIC POLY(4-METHYL-1-PENTENE)HOLLOW FIBER MEMBRANES

Poly(4-methyl-1-pentene) (PMP) hollow fiber membranes were prepared by the melt-spun and cold-stretch(MSCS) method. Scanning electronic microscopy (SEM) was used to characterize the section and surface structures of themembranes with special asymmetric structure. The preliminary results of gas permeation measurements indicated that the resultant hollow fiber membranes have the potential ability for oxygen/nitrogen separation.

Characterization and Apparent Kinetics of Polymerization of 1-Decene Catalyzed by Boron Trifluoride/Alcohol System

Poly-α-olefin(PAO) synthetic oil is the base oil of high-quality lubricants, and has a huge market potential.We illustrate PAO synthesis by catalytic polymerization of 1-decene with a boron trifluoride(BF_3)/alcohol system. Gas chromatography–mass spectrometry, proton nuclear magnetic resonance and ^(13) C nuclear magnetic resonance analysis confirmed dimer, trimer and tetramer structures of PAO. Each component contained branched chains with a 1,2 insertion of a head-to-tail link; a 2,1 insertion of a tail-to-tail link and a methyl-containing linked structure. At a low conversion rate, the reaction rate was related directly with the reaction temperature and the catalyst/1-decene concentration. An apparent kinetic equation for PAO formation was determined during 1-decene polymerization.

Multiple facets of poly(ADP-ribose) polymerase-1 in neurological diseases

The highly conserved abundant nuclear protein poly （ADP-ribose） polymerase-1 （PARP-1） is activated by DNA damage. PARP-1 activation is associated in DNA repair, cell death and inflammation. Since oxidative stress induced robust DNA damage and wide spread inflamma- tory responses are common pathologies of various CNS diseases, the attention towards PARP-1 as a therapeutic target has been amplifying. This review highlights the multiple roles of PARP- 1 in neurological diseases and po- tential of PARP- 1 inhibitors to enter clinical translation.