Cyclic octatomic sulfur: a possible infrared and visible chromophore in the clouds of jupiter

A brown polymeric material, produced under simulated Jovian conditions, is composed primarily of cyclic octatomic sulfur, although a range of complex organic compounds is also present. The polymeric sulfur, produced from the ultraviolet photolysis of hydrogen sulfide, exhibits its strongest band at 465 reciprocal centimeters, in fair agreement with the frequency of the unidentified Jovian absorber recently announced by Houck et al. Polymeric octatomic sulfur may be an important constituent of the Jovian clouds.     

非洛地平分子印迹聚合物微球的制备及选择吸附性研究

[目的]以非洛地平（Felodipine,FP）为模板分子,合成非洛地平分子印迹聚合物微球（MIPMs）。[方法]研究悬浮聚合法合成的分子印迹聚合物微球,并通过Scatchard方程研究非洛地平分子印迹聚合物微球的选择吸附特性是否大于传统的封管聚合法制备的分子印迹聚合物的选择吸附性。[结果]利用悬浮聚合法合成的分子聚合物微球具有较高的选择性。[结论]在医学上,悬浮聚合法有望替代传统的分子印迹聚合法应用到,临床的检验。     

聚合硫酸铁制备研究

聚合硫酸铁是一种新型高效絮凝水处理剂．可用于生活用水、工业用水和城市污水的净化处理．研究了聚合硫酸铁的制备方法．从聚合硫酸铁制备反应温度、反应时间，反应比例以及氧化剂的用量等各方面因素的影响进行了探讨。     

合成的土壤结构改良剂对土壤性状的影响

合成的土壤结构改良剂对土壤性质的影响较大,能使土壤结构改善,团粒结构和水稳性团粒提高,土壤容重减小,孔隙度增大,土壤水的渗透率增大,同时可以防止土壤侵蚀,改良土壤,但是其施用量要比老的土壤结构改良剂要小得多。     

Large odd-numbered carbon clusters from fullerene-ozone reactions

The odd-numbered carbon clusters C(119), C(129), and C(139) have been observed in the mass spectra of toluene extracts of fullerene soots and of the products of ozone-fullerene reactions. Specifically, ozone-C(60) reactions yield C(119), ozone-C(70) reactions yield C(139), and ozone-(C(60)/C(70)) reactions produce C(119), C(129), and C(139). These unexpected species correspond to dimers of C(60), C(60)/C(70), and C(70), respectively, less one carbon atom, and are stable gas-phase ions with behavior similar to that of fullerenes. The results suggest a new route to functionalization and derivatization of fullerenes through controlled ozone-catalyzed cage-opening reactions.     

Open Framework Structures Based on Sex2- Fragments: Synthesis of (Ph4P)[M(Se6)2] (M = Ga, In, TI) in Molten (Ph4P)2Sex

Polychalcogenide compounds with open polymeric frameworks are rare, and they represent a class of compounds in which microporosity might be achieved. Microporous frameworks that are not oxide-based are now attracting interest because of the combination of catalytic and electronic properties they may simultaneously possess. Three new compounds that may be forerunners to such materials have been discovered and are reported here. The reaction of gallium (Ga), indium (In), and thallium (TI) metal with (Ph(4)P)(2)Se(5) (Ph, phenyl) and an excess of elemental selenium (Se) in a sealed, evacuated Pyrex tube at 200 degrees C yielded small red crystals of (Ph(4)P)[Ga(Se(6))(2)] (I), (Ph(4)P)[In(Se(6))(2)] (II), and (Ph(4)P)[TI(Se(6))(2)] (III), respectively. The [M(Se(6))(2)](-) (M = Ga, In, TI) ions form a two-dimensional, open framework filled with Ph(4)P(+) ions. The [M(Se(6))(2)](n)(n-) structure consists of tetrahedral M(3+) centers and bridging Se(6)(2-) ligands, leading to an extended structure in two dimensions. These layers stack perfectly one on top of the other giving rise to one-dimensional channels running down the c axis that are filled with Ph(4)P(+) cations. These cations are situated in the layers, as opposed to between the layers, and the whole structure can be viewed as a template. Compound II shows remarkable thermal stability and melts congruently at 242 degrees C. Upon cooling to room temperature it gives a glassy phase that recrystallizes upon subsequent heating to 160 degrees C.     

可食性玉米淀粉膜的制备及改性剂对膜性能的影响

【目的】研究可食性玉米淀粉膜的成膜工艺条件和改性剂的作用,为开发多功能可食包装提供理论和技术支持。【方法】选择不同的淀粉液质量浓度、糊化温度、干燥温度和干燥时间制备玉米淀粉膜,根据成膜效果及膜的物理性能,确定玉米淀粉膜适宜的制备工艺条件。在此基础上,分别研究添加10 g/L的6种糖醇型改性剂（乙二醇、丙三醇、木糖醇、甘露糖醇、山梨醇和麦芽糖醇）以及5种聚合型改性剂（羧甲基纤维素钠、海藻酸钠、明胶、葡甘聚糖和聚氧化乙烯）对膜物理性能的影响。【结果】玉米淀粉膜适宜的制备工艺条件为：浆液淀粉质量浓度50～60 g/L,糊化温度90 ℃,膜干燥温度40～60 ℃,膜干燥时间4～6 h。木糖醇可使淀粉膜表面结构平滑,且其对膜断裂伸长率的提高效果最优;葡甘聚糖可使膜表面结构平整,颗粒细腻,热稳定性增强,抗拉强度和断裂伸长率均衡提高;海藻酸钠和羧甲基纤维素钠的作用效果与葡甘聚糖相近。【结论】利用玉米淀粉可以制备可食性淀粉膜;添加改性剂木糖醇和葡甘聚糖能够选择性地提高玉米淀粉膜的物理性能。     

液化气罐再生过程中烟气的循环废水处理的研究

为了更好的处理液化气罐再生过程中烟气的循环废水利用,以桂林市某液化气灌装公司烟气厂处理废水为实验对象,通过絮凝法、砂滤法处理试验。结果显示,絮凝剂聚合硫酸铝和聚合硫酸铁均对废水中悬浮物絮凝有良好效果,但聚合硫酸铁处理后的清液色度超过要求,聚合硫酸铝絮凝后的废水清液在后继处理中加入氧化剂后溶液变黄,色度超标;砂滤法在以32cm砂滤厚度,14mL·min-1流量下,出水浊度为2.0,后继处理以NaClO为氧化剂,当加入2mLNaClO,溶液COD降低15.4%,重金属Zn、Mg、Mn、Cu、Fe时指标值分别降低66.5%、38.1%、72.8%、76.0%、95.7%,处理后出水浊度为1.3,色度为浅黄色。结果表明:采用絮凝法处理效果欠佳;采用以砂滤法-氧化法系统处理废水,具有高的悬浮物去除效果和色度去除效果。     

The Higher Fullerenes: Isolation and Characterization of C76, C84, C90, C94, and C70O, an Oxide of D5h-C70

The toluene extract of the fluffy carbon material produced by resistive heating of graphite contains a variety of molecules larger than C(60) and C(70) in a total amount of 3 to 4% by weight. Repeated chromatography of this material on neutral alumina has led to the isolation of stable solid samples of C(76), C(84), C(90), and C(94). The characterization, which includes mass spectrometry, (13)C nuclear magnetic resonance, electronic absorption (ultraviolet/visible) and vibrational (infrared) spectroscopy identifies these all-carbon molecules as higher fullerenes. In addition, C(70)O, a stable oxide, has been isolated that is structurally and electronically closely related to D5h-C(70). This compound forms during the resistive heating process and probably has an oxygen atom inserted between two carbon atoms on the convex external surface of the C(70) skeleton.     

植物中分离的儿茶素类及其聚合物的抑菌作用

以儿茶素类和4种儿茶素类聚合物为材料,采用平板打孔药敏法,对蜡状芽孢杆菌、大肠杆菌和枯草杆菌等3种细菌进行抑菌试验。结果表明,上述5种试样对3种细菌均具有显著的抑制作用,各试样的抑菌能力依次为TP>GOPC>LOPC>LPPC>LPR。其中,儿茶素类的抑菌能力强于它的聚合物,在本实验条件下,儿茶素类的MIC为0·12mg/mL,IC50为0·87~1·33mg/mL;儿茶素类聚合物的抑菌能力强弱顺序为低聚物(GOPC、LOPC)>多聚物(LPPC)>高聚物(LPR),其抑菌能力强弱与聚合度大小相关;其中的儿茶素类低聚物(GOPC、LOPC)的抑菌能力与儿茶素接近,具有一定应用价值。     

High titers of autoantibodies to topoisomerase I (Scl-70) in sera from scleroderma patients

Patients with rheumatic diseases often have circulating autoantibodies to nuclear components. The clinical significance of the antibodies is controversial, although in some cases they are valuable in the diagnosis of the disease. This report presents results of a study of Scl-70, an autoantigen recognized by sera of many patients with the most severe form of progressive systemic sclerosis. It was possible to show, by three independent criteria, that Scl-70 is the abundant nuclear enzyme DNA topoisomerase I. Therefore, antibody probes of high titer and high affinity are now available for the study of this important nuclear enzyme.     

麦谷蛋白亚基与小麦品质的关系研究进展

麦谷蛋白对小麦加工品质具有重要决定作用。高分子量麦谷蛋白亚基（HMW-GS）与低分子量麦谷蛋白亚基（LMW-GS）通过分子间二硫键形成麦谷蛋白聚合体,影响面团流变学特性。HMW-GS组成可作为品质育种中亲本选配和杂交后代选择的重要蛋白标记。由于LMW-GS基因拷贝数较多、分子量小,且在电泳图谱上与醇溶蛋白相互重叠,其与品质的关系研究远不及HMW-GS深入。从麦谷蛋白亚基的质和量两个层次包括HMW-GS组成与品质的关系、LMW-GS组成对品质的贡献大小、HMW-GS和LMW-GS的比例对品质的影响等全面综述了麦谷蛋白亚基与品质的关系,并对麦谷蛋白亚基在品质育种中的应用前景进行探讨,为HMW-GS和LMW-GS用于小麦品质改良提供理论基础。     

Structural basis for misaminoacylation by mutant E. coli glutaminyl-tRNA synthetase enzymes

A single-site mutant of Escherichia coli glutaminyl-synthetase (D235N, GlnRS7) that incorrectly acylates in vivo the amber suppressor supF tyrosine transfer RNA (tRNA(Tyr] with glutamine has been described. Two additional mutant forms of the enzyme showing this misacylation property have now been isolated in vivo (D235G, GlnRS10; I129T, GlnRS15). All three mischarging mutant enzymes still retain a certain degree of tRNA specificity; in vivo they acylate supE glutaminyl tRNA (tRNA(Gln] and supF tRNA(Tyr) but not a number of other suppressor tRNA's. These genetic experiments define two positions in GlnRS where amino acid substitution results in a relaxed specificity of tRNA discrimination. The crystal structure of the GlnRS:tRNA(Gln) complex provides a structural basis for interpreting these data. In the wild-type enzyme Asp235 makes sequence-specific hydrogen bonds through its side chain carboxylate group with base pair G3.C70 in the minor groove of the acceptor stem of the tRNA. This observation implicates base pair 3.70 as one of the identity determinants of tRNA(Gln). Isoleucine 129 is positioned adjacent to the phosphate of nucleotide C74, which forms part of a hairpin structure adopted by the acceptor end of the complexed tRNA molecule. These results identify specific areas in the structure of the complex that are critical to accurate tRNA discrimination by GlnRS.     

玉米ZmEXO70s基因家族鉴定及苗期耐热性关联分析

【目的】鉴定玉米EXO70s（ZmEXO70s）基因家族成员,分析其遗传变异与玉米耐热性的关联性,为揭示其在玉米耐热方面的功能和分子机制打下基础。【方法】以拟南芥EXO70s（AtEXO70s）基因家族成员序列为参考,利用MaizeGDB和NCBI数据库从玉米全基因组中鉴定出ZmEXO70s基因家族成员,对其进行基因结构及系统进化分析,根据其在系统发育进化树上的位置对其进行系统命名,并基于转录组测序（RNA-Seq）数据分析ZmEXO70s基因家族成员在不同组织及非生物胁迫下的表达模式。最后,鉴定玉米自交群体AM368中ZmEXO70s基因SNP位点,结合玉米AM368群体苗期耐热存活率进行基因家族关联分析。【结果】从玉米全基因组序列中共鉴定出36个ZmEXO70s基因,分布在10条染色体上,长度为228～3726 bp,编码75～1241个氨基酸残基,蛋白分子量为8.6～136.6 kD,理论等电点（pI）介于4.5～9.9,大部分蛋白pI小于7.0。拟南芥、水稻和玉米的EXO70s蛋白被分为9组（A组～I组）,其中ZmEXO70s蛋白在各组中均有分布。大多数ZmEXO70s基因不含内含子,只有少数基因含有内含子,且内含子数量不同。36个ZmEXO70s蛋白共含8种基序（Motif 1～Motif 8）,主要集中在C端,说明这些蛋白端序列较保守,且Motif 1～Motif 8组成Exo70保守结构域。ZmEXO70s基因在不同组织中的表达水平均存在明显差异,其中ZmEXO70B3基因在雄穗、花药、叶片和花丝中高表达,ZmEXO70C1a基因只在雄穗和花药中高表达,ZmEXO70D2b基因在胚乳和萌发种子中低表达,ZmEXO70G1c基因在花丝和萌发种子中低表达。有23个ZmEXO70s基因至少可响应一种非生物胁迫,说明这些ZmEXO70s基因参与非生物胁迫响应过程。ZmEXO70D2a和ZmEXO70E1基因的遗传变异与玉米苗期耐热性具有显著相关性（P≤0.01）。【结论】ZmEXO70s基因家族成员在系统发育进化上较保守,其基因组复制事件可能发生在禾本科植物分化后,且大多数ZmEXO70s基因被保留,仅部分基因被丢失。ZmEXO70s基因可能在非生物胁迫响应过程中发挥重要作用,ZmEXO70D2a和ZmEXO70E1基因可作为调控玉米苗期耐热性重要候选基因。     

Fullerenes from the geological environment

By means of high-resoluton transmission electron microscopy, both C(60) and C(70) fullerenes have been found in a, carbon-rich Precambrian rock from Russia The fullerenes were confirmed by Fourier transform mass spectrometry with both laser desorption and thermal desorption/electron-capture methods to verify that the fullerenes were indeed present in the geological sample and were not generated by the laser ionization event. The mass spectra were measured under conditions sufficient to resolve the (13)C/(12)C isotopic ratios for C(60) and C(70) and indicate that these ratios correspond to the normal range of isotopic values.     

Molecular Identification and Characterization of Cryptosporidium spp. from Mainland China

Three isolates of the genus Cryptosporidium, namely, Guangdong isolate, Anhui isolate and Jiangsu isolate from Mainland China, were identified and characterized genetically utilizing nuclear DNA regions of the small subunit of ribosomal RNA (SSU rRNA) and heat shock protein 70 gene (HSP70) as genetic markers. These two regions were amplified by PCR from DNA extracted from oocysts and amplicons of approximately 290 bp and 450 bp were produced, respectively. The amplicons were purified, cloned and sequenced. Sequences of 446 bp and 290-292 bp were obtained for the SSU rRNA and HSP70 regions, respectively. The obtained SSU rRNA and HSP70 sequences representing the three Cryptosporidium isolates were compared with those retrieved from the DNA database. Genetic analyses using either DNA region revealed that members of Cryptosporidium formed two clusters, with C. parvum, C. wariri, C. felis and C. meleagridis clustered together, while C. andersoni, C. muris and C. serpentis belong to the other cluster. Based on SSU rRNA and HSP70 sequences, both Guangdong and Anhui isolates of Cryptosporidium were identified as C. muris of the calf genotype (i.e., C. andersoni), whereas the Jiangsu isolate was identified as C. parvum of the calf genotype. The findings of the present study should have important implications for the diagnosis and control of Cryptosporidium infections in both humans and animals in China.     

Synthesis, Isolation, and Equilibration of 1,9- and 7,8-C70H2

Equilibration of 1,9- and 7,8-C(70)H(2) has allowed the relative free energy of these isomers to be measured. These "simplest hydrocarbon derivatives of C(70)" are formed by hydroboration of C(70) at room temperature. Analysis of the platinum-catalyzed equilibration of these isomers yielded a relative free energy at 295 kelvin of 1.4 +/- 0.2 kilocalories per mole, with the 1,9 isomer being more stable. This value is in excellent agreement with the ab initio HF/6-31 G(*) calculated energy difference of 1.3 kilocalories per mole, whereas semiempirical calculations gave poor agreement.     

Peptide binding and release by proteins implicated as catalysts of protein assembly

Two members of the hsp70 family, termed hsc70 and BiP, have been implicated in promoting protein folding and assembly processes in the cytoplasm and the lumen of the endoplasmic reticulum, respectively. Short hydrophilic (8 to 25 residues) synthetic peptides have now been tested as possible mimics of polypeptide chain substrates to help define an enzymatic basis for these activities. Both BiP and hsc70 have specific peptide binding sites. Peptide binding elicits hydrolysis of adenosine triphosphate, with the subsequent release of bound peptide.     

聚合物减阻机理研究

介绍了聚合物减阻的发展历史以及聚合物的主要应用领域。根据不同的研究切入点，将有关聚合物减阻机理研究大致分为三类，并分别进行了综述。评述了聚合物减阻机理的研究现状，认为虽然该项研究已达到了相当的深度，但最终要想解决与此相关的问题还需要做相当多的工作。     

Isolable compounds containing a silicon-silicon double bond

After 70 years of unsuccessful attempts, several stable disilene-compounds with double bonds between silicon atoms-have now been made. The silicon-silicon double bond resembles in many ways the well-known carbon-carbon double bond of organic chemistry. However, striking dissimilarities are also found between disilenes and alkenes in both their structures and chemical reactions.