西藏砂生槐种子营养成份的初步研究

砂生槐(Sophora moorcroftiana)是藏南河谷地带分布极广的一种多年生豆科灌木,具有极强的抗旱、耐瘠、抗风沙等生态适应性。目前当地群众挖其植株作为生活燃料,收其干叶作为牲畜越冬饲料,破坏相当严重。为充分开发其利用价值,首次取其种子进行营养成份分析,发现其富含蛋白质和脂肪17种氨基酸含量达 23％以上除色氨酸未能测定外,其余7种必须氨基酸含量均高于豌豆(Pisum sativrm)热值 4 800千卡/公斤左右。具有较高的饲用或食用开发价值。     

Dioxin-/Furan-“Verbrennungsprofile” in Abgasen aus Hochtemperaturprozessen

Zusammenfassung  Verschiedene Mechanismen in der Abkühlungsphase von Hochtemperaturprozessen führen zur Neubildung von polychlorierten Dibenzo(p) dioxinen (PCDD) und polychlorierten Dibenzofuranen (PCDF) und, unabh?ngig von den jeweiligen Absolutkonzentrationen, zu vergleichbaren PCDD/F-Profilen, also prozentualen Anteilen einzelner Kongenere bzw. Homologengruppen an der Summe der betrachtten 17 Kongenere nach 17. BImSchV bzw. Homologengruppen Tetra-bis Octa CDD/F. Die Charakteristik dieser “Verbrennungs-profile” kann zur Plausibilit?tsprüfung von Messergebnissen sowie zur weitergehenden Deutung und zum Verst?ndnis der ablaufenden Reaktionsmechanismen beitragen. Online-First: 9. M?rz 2000     

(<Emphasis Type="Italic">Z</Emphasis>)-9-Pentacosene − contact sex pheromone of the locust borer, <Emphasis Type="Italic">Megacyllene robiniae</Emphasis>

Summary. Male locust borers, Megacyllene robiniae (Förster), responded to females only after contacting them with their antennae, indicating that mate recognition was mediated by a contact sex pheromone. GC-MS analyses of whole-body extracts of males and females determined that the profiles of compounds in the extracts were qualitatively similar, but differed considerably in the ratios of compounds between sexes. Biological activities of reconstructed blends of the most abundant straight-chain (nC₂₃, nC₂₄, nC₂₅, nC₂₆), methyl-branched (3me-C₂₃, 3me-C₂₅), and unsaturated (Z9:C₂₃, Z9:C₂₅, Z9:C₂₇ compounds in extracts from females were assessed in arena bioassays, assessing four distinct steps in the mating behavior sequence of males (orientation, arrestment, body alignment, mounting and attempting to couple the genitalia). Males were unresponsive to freeze-killed, solventwashed females treated with blends of straight-chain and methyl-branched alkanes, but responded strongly to females treated with the blend of alkenes. Further trials determined that the complete sequence of mating behaviors, up to and including coupling the genitalia, was elicited by Z9:C₂₅ alone. Z9:C₂₅ comprised 16.4 ± 1.3% of the total hydrocarbons in whole-body hexane extracts of females and was co-dominant with two other hydrocarbons that were not active. In contrast, in solid phase microextraction (SPME) wipe samples from several areas of the cuticle, Z9:C₂₅ appeared as the single dominant peak, comprising 34.6 – 37.8% of the sampled hydrocarbons. Our data indicate that Z9:C₂₅ is a contact sex pheromone of M. robiniae, being the most abundant hydrocarbon on the surface of the cuticular wax layer of females where it is readily accessible to the antennae of males.     

石墨烯在装备技术相关领域的应用研究(二)

基于石墨烯的材料和器件正在传统和新兴领域广泛应用,简要综述了石墨烯基材料在电化学储能、装备抗腐蚀和吸波领域的研究进展,介绍了基于不同物理机制和观点的研究热点。指出高质量单层或少层、分散良好的石墨烯材料的制备尚未有工业化的方法,且大量的应用是基于石墨烯为模板的衍生物是石墨烯大规模工业化应用仍然为数不多的原因。提出高效地对石墨烯的表面、化学键进行功能化,同时保留石墨烯本体完美碳骨架的技术难题。最后提出研究石墨烯与其他功能材料的复合机理和微观机制,解决复合界面问题,开发绿色、高效、低成本的复合工艺,将促进石墨烯的应用。     

有机肥与化肥配施对土壤养分的影响研究

不同有机肥与化肥配施比例都有促进土壤养分含量的作用,土壤中有机质、碱解氮、速效磷和速效钾含量均随有机肥在肥料中比例的增加而增加,增幅分别为1.04％～63.49％、5.57％～24.50％、28.65％～48.42％、16.7％ ～ 28.65％.有机肥与化肥配施能够明显改善土壤理化性质,降低土壤pH值和土壤容重,提高土壤总孔隙度,提高土壤有机质、碱解氮、速效磷、速效钾的含量,表明有机肥与化肥配施对土壤养分的提高效果明显,并明显高于单施化肥和不施肥.综合分析,有机肥与化肥配施比例为7∶3是值得推广应用的优化方案.     

在大鼠哮喘发生中SO2致凋亡相关基因及蛋白质表达的改变

为了研究SO2对哮喘大鼠肺细胞凋亡相关基因mRNA和蛋白表达的影响.对健康雄性Wistar大鼠随机分为正常组、SO2暴露组、卵蛋白(OVA)致敏哮喘组、SO2和OVA联合作用组,采用荧光实时定量RT-PCR和Westem Blot方法研究吸入SO2对哮喘大鼠肺细胞p53、box、bcl-2三种细胞凋亡相关基因mRNA和蛋白表达的影响.结果表明,SO2暴露组肺中p53和box mRNA和蛋白水平降低,bcl-2表达和bcl-2/bax比值均有升高,但与对照组相比无显著性差异.与对照组相比,哮喘组肺中p53和bax mRNA和蛋白的表达水平呈现不同程度的降低;bcl-2的表达和bcl-2/bax比值显著升高.SO2和OVA联合作用后,与哮喘组相比,肺中p53和bax蛋白表达显著下降,而bcl-2蛋白表达显著升高.结论:SO2可加剧哮喘大鼠的哮喘症状,其机制可能是通过影响哮喘大鼠肺组织凋亡相关基因(p53、bax、bcl-2)的表达水平,抑制气道炎性细胞的凋亡来实现的.这些机制的阐明有助于对SO2毒作用机制的理解和所致疾病的治疗.     

Revealing life‐history traits by contrasting genetic estimations with predictions of effective population size

Effective population size, a central concept in conservation biology, is now routinely estimated from genetic surveys and can also be theoretically predicted from demographic, life‐history, and mating‐system data. By evaluating the consistency of theoretical predictions with empirically estimated effective size, insights can be gained regarding life‐history characteristics and the relative impact of different life‐history traits on genetic drift. These insights can be used to design and inform management strategies aimed at increasing effective population size. We demonstrated this approach by addressing the conservation of a reintroduced population of Asiatic wild ass (Equus hemionus). We estimated the variance effective size (N_ev) from genetic data () and formulated predictions for the impacts on N_ev of demography, polygyny, female variance in lifetime reproductive success (RS), and heritability of female RS. By contrasting the genetic estimation with theoretical predictions, we found that polygyny was the strongest factor affecting genetic drift because only when accounting for polygyny were predictions consistent with the genetically measured N_ev. The comparison of effective‐size estimation and predictions indicated that 10.6% of the males mated per generation when heritability of female RS was unaccounted for (polygyny responsible for 81% decrease in N_ev) and 19.5% mated when female RS was accounted for (polygyny responsible for 67% decrease in N_ev). Heritability of female RS also affected N_ev; (heritability responsible for 41% decrease in N_ev). The low effective size is of concern, and we suggest that management actions focus on factors identified as strongly affecting , namely, increasing the availability of artificial water sources to increase number of dominant males contributing to the gene pool. This approach, evaluating life‐history hypotheses in light of their impact on effective population size, and contrasting predictions with genetic measurements, is a general, applicable strategy that can be used to inform conservation practice.     

Research progress on CRISPR/Cas9-mediated genome editing technique in plants北大核心CSCD

Many physical, chemical, and biotic stresses always threaten plants during their growth and development. Using the genome editing technique is a good strategy to improve plant characteristics. CRISPR/Cas (clustered regulatory interspaced short palindromic repeats / CRISPR-associated protein), the adaptive and heritable immune system of prokaryotes, is a genome editing technique newly developed during recent years. At present, the type II CRISPR / Cas9 system is most widely used. Many plants, such as Arabidopsis thaliana, tobacco, soybean, tomato, potato, rice, wheat, maize, sorghum, petunia, banana, sweet orange, apple, poplar, and Marchantia polymorpha, have been edited successfully for stress tolerance, delay of fruit ripening, herbicide resistance, and disease resistance, etc. This system is achieved by the formation of nuclease Cas9 and crRNA: tracrRNA (CRISPR-derived RNA:trans-activating RNA) complex. Further studies about the effect of the promoters of Cas9 and gRNA and the number of gRNA targets on gene editing efficiency have been discussed. © 2018 Science Press. All rights reserved.     

用醌式染料的合成反应光度法测定水中NO_2~-

报道了以N、N－二甲基苯氨、对氨基苯乙酮为偶联、重氮试剂,利用醌式染料的合成反应测定NO2-的新方法。本法灵敏度高（ε=5．33×104）,选择性好,无试剂空白。NO2-在0～800μg／L内服从比耳定律。醌式染料及试剂均稳定,已用于环境水中NO2-的测定。     

全氟辛烷磺化物(PFOS)诱导斑马鱼胚胎p53基因的点突变

将斑马鱼胚胎于0μg·1-1(空白对照),5μg·l-1,16μg·l-1和50μg·l-1全氟辛烷磺化物(PFOS)溶液中暴露染毒5h,采用变性高效液相色谱方法对PCR扩增的含斑马鱼胚胎p53基因外显子7的173 bp的目标片段进行突变分析.结果显示,16μg·l-1和50μg·l-1两个处理组与对照组相比均有显著性差异,表明PFOS可以诱导斑马鱼胚胎p53基因外显子7的点突变.