夏季高温对水牛瘤胃代谢的影响

利用南京地区夏季炎热的自然条件,连续两年在高温季节(7—8月)进行实验。第一年(系列Ⅰ)的实验动物为四头装置瘤胃瘘管的空怀母水牛,研究高温初期(27.5～33.4℃)和持续高温期(28.0～35℃)对水牛瘤胃消化代谢的影响。第二年实验(系列Ⅱ)利用三头装置瘤胃瘘管的海仔母水牛重复高温(26～35.3℃)实验。 夏季高温期间,实验水牛的呼吸率、瘤胃温度和直肠温度升高,采食量减少,饮水量增加,瘤胃液流速减缓。高温初期出现瘤胃代谢升高[总挥发性脂肪酸(TVFA)和氨氮(NH_3-N)浓度及乙酸/丙酸(A/P)比率升高]。但在持续高温情况下,水牛的采食和瘤胃代谢均明显抑制。采取瘤胃内降温措施(投入冰袋)或冷水淋浴,均能迅速降低呼吸率、直肠和瘤胃温度,恢复采食和反刍,并缓解瘤胃代谢的抑制。提示动物机体参与调节瘤胃代谢的变化,并为改善水牛夏季的饲养管理提供生理学依据。     

神农香菊干花净油成分的研究

神农香菊全草提取的香浸膏香气浓郁独特,可用于调配多种高档化妆用香精,也可直接用于饮料中,在香精香料工业中具有较大的实用价值。本文首次报告了我们用毛细管气相色谱仪和色谱/质谱/计算机联用分析仪,对神农香菊干花净油成分进行分析的初步结果。鉴定出的已知成分包括脂肪族类,含氧或非含氧的单萜及倍半萜类化合物32个。     

营养膜无土栽培技术

前言营养膜技术(Nutrient Film Technique简称NFT)是国外广泛采用的一种特殊的无土栽培方法。它是将植物栽植在一个狭长的不透水的营养槽中,槽中有缓慢流动的营养液。植物根系的一部分浸没在营养液中,一部分露在空气中,植物从这种小环境中吸收水、营养物和氧气。由于这种方法采用很薄一层营养液在根际周围流动,裸露的根     

一种新病毒——兔出血症病毒的鉴定初报

从我国新发生的一种家兔急性败血性传染病死兔内脏抽提物中,观察到典型的病毒粒子,回归兔可引起典型发病,再从病死兔内脏回收到同样病毒,证明该病系病毒性传染病,暂定名为“兔病毒性出血症”,病原暂定为“兔出血症病毒”。经初步鉴定,认为本病毒可能是一种首次发现的新病毒,属双股RNA病毒。但从病毒大小和核酸节段看,又不同于呼肠病毒科。最终归属正在进一步研究。     

Air pollution as a possible cause for the decline of some phanerogamic species in The Netherlands

In The Netherlands the decline of some phanerogamic species cannot be readily explained from obvious factors such as lowering of the groundwater table, eutrophication or land reclamation. For a number of species the hypothesis was tested that the decline is partly due to air pollution. A two-factor model was made in which decline is accounted for by (a) habitat destruction assessed from topographic maps and (b) air pollution measured as the SO₂ 95-percentile over the winter period 1978/1979. Effects of both factors were assumed to follow a sigmoid dose-effect curve. For a number of species decline proved to be significantly correlated with air pollution. These are notably species from the syntaxon Violion caninae. A comparison was made with results obtained for epiphytic lichens. It appears that for some phanerogamic species sensitivity is about the same as for moderately sensitive lichens.Nomenclature follows Heukels & van der Meijden (1983).Thanks are due to the Rijksherbarium, for providing some of their unpublished data; and to Ada Groeneveld, for technical assistance.     

烟草内生菌根真菌的分离鉴定

本文报道了从烟草(Nicotiana tabacum L.)的根际土壤中分离出内生菌根真菌的孢子,用单孢接种烟苗并在温室内水培条件下培养。选出能在烟草上形成菌根的菌株,经过再次单孢接种确认后,进行种的鉴定。从分离的8个菌株中已鉴定出球囊霉属(Glomus)的3个新记录种:漏斗孢球囊霉[G.mosseae(Nic.& Gerd.)GeM.& Trappe]、根内孢球囊霉(G.intraradics Schenck & Smith)和联结球囊霉(G.constrictum Trappe)。     

Chromosome-mediated transfer of murine alleles for hypoxanthine-guanine phosphoribosyl transferase (HGPRT) and ouabain resistance into human cell lines

Genetic drug-resistance markers were transferred via purified metaphase chromosomes from mouse L cells into the human fibrosarcoma line HT1080 and HeLa S3 cells. Interspecific chromosome-mediated transfer of hypoxanthine-guanine phosphoribosyl transferase (HGPRT; EC 2.4.2.8) from mouse L cells into HGPRT^– HT1080 cells occurred at a frequency of approximately 1×10^–7. The presence of the mouse allele for HGPRT in transferent isolates was confirmed by isoelectric focusing. Transfer of ouabain resistance from mouse L cells to HT1080 and HeLa S3 cells occurred at an average frequency of approximately 4×10^–7. Expression of the mouse trait in transferent isolates was confirmed by their ability to withstand doses of ouabain which would be lethal to spontaneous ouabain-resistant mutants of the human cells but not to mouse L cells. Ouabain-resistant transferents of human cells showed 10⁴- to >10⁵-fold enhanced drug resistance, characteristic of either wild-type or mutant alleles, respectively, from ouabain-resistant donor L cells. Unstable expression of the transferred phenotypes in the absence of selection was seen in some isolates, but expression was lost at slow rates.This work was supported by National Institutes of Health Grant GM30383/21665 to RMB, Core Grants CA14051 to S. E. Luria and CA24538 to E. Mihich, and institutional predoctoral Training Grant GM07287.     

Characterization of some East African Theileria species isolates by isoenzyme analysis, with particular reference to T. parva

Eight different isolates of Theileria parva and one isolate of T. taurotragi, in the form of intra-lymphocytic schizonts and/or purified piroplasms, were subjected to isoenzyme analysis for 24 enzymes by both isoelectric focusing in agarose and electrophoresis in starch gel. Twelve enzymes distinguished between T. parva and T. taurotragi; five enzymes (HK, GPI, PEP1, LDH and SOD) showed variations within T. parva. The metabolism of the host cell was affected by schizont infection, which masked intraspecific variations. Piroplasms were of more potential value for characterization of T. parva.     

食蟹猴疟原虫晚期卵囊、成孢子细胞与子孢子扫描电镜观察

本研究对实验感染食蟹猴疟原虫后9、10和14天的斯氏按蚊阳性蚊胃,进行扫描电镜观察。晚期(分化的)卵囊表面呈现凹凸不平皱褶。成孢子细胞体常呈圆球形或椭圆形,表面光滑,子孢子芽从其表面长出。子孢子体细长,稍弯曲,体表光滑;虫体前部较细,顶端稍平,后部稍粗,末端钝圆。本文对成孢子细胞不同发育阶段的形态予以较详细描述,对子孢子出囊方式做了初步讨论。     

Adenine nucleotide translocase-dependent anion transport in pea chloroplasts

Pea chloroplasts were found to take up actively ATP and ADP and exchange the external nucleotides for internal ones. Using carrier-free [¹⁴C]ATP, the rate of nucleotide transport in chloroplasts prepared from 12–14-day-old plants was calculated to be 330 μmol ATP/g chlorophyll/min, and the transport was not affected by light or temperature between 4 and 22°C. Adenine nucleotide uptake was inhibited only slightly by carboxyatractylate, whereas bongkrekic acid was nearly as effective an inhibitor of the translocator in pea chloroplasts as it was in mammalian mitochondria. There was no counter-transport of adenine nucleotides with substrates carried on the phosphate translocator including inorganic phosphate, 3-phosphoglycerate and dihydroxyacetone phosphate. However, internal or external phosphoenolpyruvate, normally considered to be transported on the phosphate carrier in chloroplasts, was able to exchange readily with adenine nucleotides. Furthermore, inorganic pyrophosphate which is not transported by the phosphate carrier initiated efflux of phosphoenolpyruvate as well as ATP from the chloroplast. These findings illustrate some interesting similarities as well as differences between the various plant phosphate and nucleotide transport systems which may relate to their role in photosynthesis.