A Preliminary Study of Crassulacean Acid Metabolism (CAM) in the Endangered Aquatic Quillwort Isoetes sinensis Palmer in China

Isoetes sinensis Palmer (Isoetaceae) is an aquatic or amphibious plant that is critically endangered in China. Previous studies have revealed the crassulacean acid metabolism (CAM)-like photosynthetic pathway occurs commonly in submerged leaves in genus Isoetes. Water chemistry parameters and the titratable acidity content of the plant extract were measured from samples obtained in the early morning (7:00) and late afternoon (15:00) from two I. sinensis populations in China. One population occurs in the eulittoral zone of a freshwater tidal river at low elevation (134 m) and another occurs in a densely vegetated, high elevation (1 100 m) alpine shallow pool. Significant differences in pH and titratable acidity of the plant extract were detected between the morning and afternoon samples. These changes are associated with diurnal changes in water chemistry. Our results provide the first evidence for the existence of the CAM pathway in the East Asian endemic Isoetes sinensis Palmer. The magnitude of fluctu     

RAPD Analysis for Genetic Variation within the Endangered Quillwort Isoetes hypsophila （Isoetaceae）

The genetie variation in the critically endangered species Isoetes hypsophila was investigated using Random Amplified Polymorphism DNA (RAPD) markers. Thirteen primers were screened from sixty primers, and a total of 104 DNA fragments were scored, of which, 52 were polymorphic loci. Low-level genetic diversity within populations with PPB values ranging from 7.69% to 25.96% was found. An Analysis of Molecular Variance (AMOVA) indicated that the most of variance (78.30%) occurred between Yunnan and Sichuan. The variances among populations within regions and within populations were only 3.89% and 17.82%, respectively.     

Morphological evolution from aquatic to terrestrial in the genus Oreolalax （Amphibia, Anura, Megophryidae）

A phylogeny of 17 species in the genus Oreolalax is reconstructed based on 21 morphological characters from adult specimens, skeleton specimens, tadpoles and eggs. Four species groups are recognized, of which the O. rugosus species group is the most primitive, the O. weigoldi species group is the second, the O. omeimontis species group is the third and the O. pingii species group is the most recently diversified. Based on the evolutional tendency of the morphological characters on the phylogenetic tree, it is proposed that the evolution of tympanum, tympanic annulus, columella, spoon-like cartilage and the web between toes reflect the habit changes from aquatic to terrestrial. Thus, Oreolalax is regarded as one important representative genus to study further the evolution of morphological characters from aquatic to terrestrial.     

聚乳酸-聚乙二醇嵌段共聚物及其交联聚氨酯弹性体的性能研究

通过改变聚乙二醇的用量,将丙交酯与聚乙二醇共聚制成嵌预聚体,用二苯基甲烷二异氰酸酯扩链后再用三羟甲基丙烷交联,制得系列聚氨酯型新颖性体。通过对其性能研究表明,随着ＰＥＧ含量的增加,共聚物的特性粘度降低,玻璃化转变温度降低,拉伸强度先升后降;聚氨酯弹性体的玻璃化转变温度降低,拉伸强度降低,而降解速度去加快。     

Sequence analysis of the gene correlated with cytoplasmic male sterility (CMS) in rape-seed (Brassica napus) Polima and Shaan 2A

orf224 is a CMS-related mitochondrial gene discovered in Polima cytoplasm. Shaan 2A CMS line is the parent of the first rapeseed hybrid cultivar Qinyou No. 2 that has been grown in many regions of China. In this work, genomic DNA of Polima CMS line and Shaan 2A CMS line were used as templates, two primers of specific oligonucleotides at 5′ and 3′ ends were used, PCR was performed, the amplification fragments were cloned into pGEM-T Easy vectors and DNA sequences were determined. The CMS-associated gene, orf224-1 present in Shaan 2A CMS line, has a sequence highly homologous to the orf224 of the Polima CMS line, except for one nucleotide at position +398. There were only one base (AAC→AGC) and one amino acid (Asn →Ser) differences between the two. The homologies of the two sequences in nucleotide and amino acid were 99.9% and 99.6%, respectively. It is concluded that orf224 in Polima CMS line and orf224-1 of Shaan 2A CMS line are the allele at the same locus in mitochondria.     

Synthesis and characterization of amphiphilc block copolymer poly(methyl acrylic acid)-block-polytetrahydrofuran

Under the specially designated condition the polymerization of both tetrahydrofuran (THF) andtert-butyl methacrylate (tBMA) is a living one. The diblock copolymer, poly(tert-butyl methacrylate)-block-polytetrahydrofuran (PtBMA-b-PTHF), was successfully synthesized by means of the coupling reaction of living cationic PTHF⁺, SbF₆ with living anionic PtBMA^-, Li⁺. LiCI, which has a beneficial effect on the molecular weight distribution (MWD) in the anionic polymerization of (meth)acrylates, hinders the coupling reaction of living chains and cannot be used in the preparation of tBMA precursor. The hydrolysis of the aforementioned diblock copolymer under acid condition results in the amphiphilic diblock copolymer, i.e. poly(methy1 acrylic acid)-block-polytetrahydrofuran (PMAA-b-PTHF). The diblock copolymers were characterized with GPC and IR.     

A Novel Degradation Pathway of Zn（dmid） （ phen）2 in Pyridine

The light-oxidation degradation processes of Zn(dmid)(phen)2(dmid = 4, 5-dimercapto-1,3-dithiole-2 one, phen = 1,10-phenanthroaline) in pyridine solvent has been monitored, h has been found under the light, dmid^2- of Zn(dmid)(phen)2 in pyridine solution could generate NCS^- and NCS^-replaces dmid^2- to form Zn(NCS)2 (phen)2 simultaneously. The crystal structure of Zn(NCS)2 (phen)2 has been determined. In the crystal of Zn(NCS)2 (phen)2. two NCS^- ligands are arranged in syn-configuration, and there is strong π-π interaction between the two adjacent parallel phen.     

葡聚糖-聚丙烯酸纳米粒子的制备及载药性能

选用不同的投料比合成了葡聚糖-聚丙烯酸纳米粒子,通过红外光谱(FT-IR)、热重分析(TGA)、动态光散射(DLS)和表面电位分析等多种手段研究了投料比对产物粒子的流体力学直径和表面电位的影响,并选择一种阳离子药物D im inazene aceturate(DA)来考察产物粒子的载药能力,结果显示葡聚糖-聚丙烯酸纳米粒子在载药领域有潜在的应用前景。     

谷氨酸、褪黑素导致海马脑薄片诱发群体峰电位的变化过程研究

在大鼠海马脑薄片上电刺激海马Schaffer侧支纤维 ,胞外记录CA1区锥体细胞层诱发群体峰电位 (PopulationSpike ,PS) ,观察灌流谷氨酸 (Glu)和褪黑素 (MEL) 40min ,人工脑脊液冲洗30min对PS的影响 ,结果显示 :不同浓度 ( 1 .0、1 .2 5、2 .5和 5.0mmol/L)的Glu作用下 ,70min末PS值百分比分别为 1 560 .5%、1 50 .7%、1 3.1 %、4.1 % ;并且Glu浓度高时 ( 2 .5或 5.0mmol/L) ,恢复期末增加刺激强度均不能使PS值升高 .不同浓度MEL( 0 .4μmol/L、0 .5μmol/L、0 .6μmol/L、0 .7μmol/L)作用下PS值在 70min内波动幅度随浓度升高而变小 ,70min末PS值百分比分别为1 93.8%、1 2 9%、75.2 % (恢复期末增大刺激强度 ,则可恢复到 1 0 0 % )、97.1 % .上述结果提示 :低浓度Glu( 1mmol/L ,1 .2 5mmol/L)对神经元具有兴奋作用 ;高浓度Glu( 2 .5mmol/L ,5mmol/L)具有神经毒性作用 ;MEL对神经元具有兴奋和抑制双重作用 ,因MEL浓度不同 ,其作用形式会有不同     

Reproductive biology and prospects for conservation ofCaldesia parnassifolia (Alismataceae)—A threatened monocot in China

Caldesia parnassi folia (Bassi ex Linn.) Parl. in China has declined in number in recent years and is increasingly faced with the risk of extirpation arising from anthropogenic changes associated with rapid urbanization and expansion of both agriculture and infrastructure. To aid in provision of the data needed for effective conservation of the species, studies on the habitat, pollination ecology, and breeding system ofC. parnassi folia were carried out on natural populations occurring in Southeastern China. Flowering in the study populations extended for more than eighty days beginning in early summer. Floral anthesis occurred in the morning hours and proceeded rapidly, lasting about 45 min. Flowers lasted ca. 8 h.Caldesia parnassi folia is self-compatible; however autogamy resulted in lower seed set than geitonogamy and xenogamy as well as free pollination. The data on pollen/ ovule (P∶O) ratio is consistent with a partially selfing and outcrossing mating system. Interpopulational crosses yielded similar seed set to within-population crosses. Agamospermy did not occur in the study populations. Propagation is achieved through seeds as well as through turions which commonly occur in the inflorescences. Flies (Insecta; Diptera) were the most frequent visitors to the flowers ofC. parnassi folia; however bees (Insecta; Hymenoptera) composed a larger proportion of effective pollinators. The Syrphidae speciesSphaerophoria indiana (Bigot) presents evidence of oligolectic foraging behavior. Recommendations are made on the immediate steps necessary for conservation ofCaldesia species in China. Foundation item: Supported by the State Key Basic Research and Development Plan of China (973) (G2000046805) and the National Natural Science Foundation of China (30070055) Biography: Robert Wahiti, Gituru (1967-), male, Kenya, Ph. D., research direction: plant biosystematics.     

超氧物歧化酶对糖尿病自由基代谢的影响

观察结果表明用超氧物歧化酶（ＳＯＤ）治疗糖尿病，患者机体中自由基发生改变．糖尿病患者血液中超氧阴离子（Ｏ－２）、丙二醛（ＭＤＡ）水平均高于正常人（ｐ＜０．０５），而红细胞ＳＯＤ（ｒｂｃ一ＳＯＤ）、总ＳＯＤ（Ｔ一ＳＯＤ），以及铜锌ＳＯＤ（Ｃｕ·Ｚｎ一ＳＯＤ）水平均明显低于正常人（Ｐ＜０．０１）．用ＳＯＤ肌注治疗后，不仅改善了患者的自觉症状，而且使血液ＭＤＡ较用药前下降（ｐ＜０．０５），并使ｒｂｅ一ＳＯＤ、Ｔ—ＳＯＤ、Ｃｕ·Ｚｎ—ＳＯＤ均较用药前升高（Ｐ＜０．０１，ｐ＜０．０５，ｐ＜０．０５），提示ＳＯＤ可作为治疗糖尿病患者的一种药物．     

CTAB对不同中和度聚丙烯酸溶液粘度行为影响

利用聚丙烯酸（PAA）和聚丙烯酸钠（NaPAA）的水溶液作为溶剂,测定了不同浓度的十六烷基三甲基溴化铵（CTAB）在高分子溶剂中的相对粘度ηr,结果表明：对PAA溶液来说,随着CTAB浓度的增加,其ηr经历了迅速下降、保持恒定和迅速上升直到溶液中出现沉淀的过程;对NaPAA溶液来说,随着CTAB浓度的增加,其ηr虽然同样经历了迅速下降、保持恒定和迅速上升的过程,但是NaPAA溶液ηr上升幅度显著减小.当NaPAA中和度达到0.042时,NaPAA溶液ηr上升的幅度完全可以忽略,溶液也不出现沉淀.溶液中高分子链电荷密度的不同是导致PAA和NaPAA与CTAB在溶液中聚集行为不同的根本原因,具体表现为PAA溶液和NaPAA溶液ηr对CTAB浓度依赖性出现显著差异.     

高原鼢鼠油脂中油酸含量定量分析

用气象色谱和气象色谱-质谱联用方法对高原鼢鼠油脂中油酸含量进行了定量分析,并对方法的准确度进行了检验。结果发现,高原鼢鼠油脂中油酸含量为18.57%±0.43%,皂化和酯化最佳时间分别为15min和7min,油酸甲酯标准曲线回归系数r=0.9999,油酸甲酯色谱峰面积的相对偏差为0.0171,样品中油酸甲酯回收率为94.08%。     

高原鼢鼠油脂中亚油酸含量定量分析

用气象色谱方法对高原鼢鼠油脂中亚油酸含量进行了定量分析,并对方法的准确度进行了检验。结果发现:高原鼢鼠油脂中亚油酸含量为10.84%±0.38%,皂化和酯化最佳时间分别为15min和7min,亚油酸甲酯标准曲线回归系数r=0.9999,亚油酸甲酯色谱峰面积的相对偏差为0.0124,样品亚油酸甲酯回收率为95.08%。     

New fossil elaterids （Insect： Coleoptera： Polyphaga： Elateridae） from the Middle Jurassic of Inner Mongolia, China

A new genus with a new species of fossil elaterid, Paraprotagrypnus superbus gen. et sp. nov., from the Middle Jurassic Jiulongshan Formation in Daohugou Village (N41°18.979′, E119°14.318′), Shantou Township, Ningcheng County, Inner Mongolia, China is described and illustrated. The genus Paraprotagrypnus belongs to the family of Elateridae, subfamily of Protagrypninae and tribe of Protagrypnini. Some primitive characters of the new genus and new species shed light on the ages between the Jiulongshan Formation in Inner Mongolia and the Yixian Formation in the western Liaoning Province of China. The habitat of the new species is briefly discussed.     

A taxonomic investigation of variation withinCissus quadrangularis L. (Vitaceae) in Kenya

Using information from literature as well as records of localities on herbarium specimen labels at the East African Herbarium Nairobi (EA), materials ofCissus quadrangularis L.,C. cactiformis Gilg. andC. quinquangularis Chiov. were collected and new localities were sought. On the basis of the nature of their stem angles, the specimens ofC. quadrangularis were sorted into two variants, A and B. Variant A has smooth stem angles while variant B has rough stem angles. The authors have proposed that variant B should be recognized as a new variety withinC. quadrangularis. Variant A is the type variety ofC. quadrangularis. A map showing the distribution of the two variants in Kenya has been prepared. The rough-edged variant was found to be absent from the low-lying semi-arid regions of northern Kenya. The variants were found occurring in distinct, separate populations but without separate geographical patterns. The results of t-test show no significant difference (p=0.05) between the means of measurements of dimensions of various organs in the two variants. The stem angles of specimens of the two variants were studied under scanning electron microscope (SEM). This showed a clear morphological difference between the two variants. The results of the investigation support the hypothesis that the variation withinC. quadrangularis represents distinct kinds that can be recognized as taxa at infra-specific level. Foundation item: Supported by the China Ministry of Education Fund for University Staff Development in Key Subject Areas and Kenyatta University. Biography: Robert Wahiti. Gituru (1967-), male, Kenya, Ph. D. candidate, research direction: plant biosystematics.     

食品中山梨酸的比色测定

以Fe(Ⅲ)为氧化剂，用分光光度法测定了食品、饮料中的山梨酸含量．方法简便、选择性好．共存物对测定无影响，对实际样品进行测定，并做加标回收试验．山梨酸回收率为96．9%—102％。     

Influence of Mica Particles on the Rheological Properties and Thermal Stability of Poly（ lactic acid）

The influence of mica particles on the rheological and thermal properties of poly（ lactic acid）（ PLA） / mica composites were investigated by capillary rheometer and thermogravimetric（ TG）analysis. The results show that the PLA / mica blends are nonNewtonian pseudoplastic and display shear-thinning. The value of non-Newtonian index of the blends melt decreased obviously with the addition of mica particles but somehow even increased when shear rate exceeded 4 500 s- 1. In this work,it could be indicated that appropriate amount of mica particles could somehow enhance the resistance of PLA melt under high shear rate to deviate from Newtonian fluid. TG analysis shows that the thermal stability of PLA decreases a little after the incorporation of the mica particles.As mica particles decompose in a completely different way in contrast to PLA,this abnormal decrease of thermal stability of PLA / mica composite may be attributed to moisture stored between mica layers released at high temperature.     

Effect of global warming on the distribution of Lucifer intermedius and L. hanseni （Decapoda） in the Changjiang estuary

We conducted an oceanographic census in 1959, 2002, and 2005 to evaluate changes in the temporo-spatial distribution and abundance of Lucifer intermedius and L. hanseni in the Changjiang estuary. In general, the abundance and frequency of occurrence (OF) for these two species were highest during the summer. We measured a significant change in the abundance and OF between years. The abundance and OF of L. intermedius increased from 3.7 individuals m⁻³ and 66.67%, respectively, in 1959, to 8.93 individuals m⁻³ and 85.19%, in 2002. In 1959, L. hanseni was only found during the summer (abundance: 0.01 individuals m⁻³, OF: 3.70%). However, in 2002, this species was collected during all seasons except the winter. Furthermore, abundance (0.47 individuals m⁻³) and OF (25.93%) were higher in 2002 than in 1959. Further increases in abundance and OF were measured during cruises during the spring of 2005. We hypothesize that global warming is responsible for the increase in abundance of L. intermedius and L. hanseni and the northward expansion of L. hanseni in the Changjiang estuary. Given our results, monitoring of both species may be useful to evaluate the effects of climate change.