安徽省达到芒属植物资源及其开发利用

安徽省芒属植物有3种量变种:五节芒(Miscanthus floridulus)、芒(M.sinensis var. sinensis)、紫芒(M. sinensis var. purpurascens)和荻(M. saccharifl-orus);其中紫芒为本省地理分布新记录。它们的资源量大;如全省仅连片五节芒草地即达260多万亩,一般亩产鲜草1000—2500公斤。芒属植物是利用价值很高的资源禾草:饲用价值“良等”;保持水土能力强;纤维品质优良,为制浆造纸及编织的上等原料;并可药用。最后,提出了开发利用芒属植物资源的几点建议。     

天祝高寒珠芽蓼草甸群落的热值和营养成分的初步研究

 本文报告了甘肃天祝高寒珠芽蓼(Polygonum viviparum)草甸群落地上及地下四部分生物量的热值和营养成分动态,并对其放牧利用的价值进行了总的评价。 6—9月现存量的热值平均为18330焦／克干物质,或20279焦／克去灰分物质,较立枯物+凋落物、活根、死根的平均值为大;死根略大于活根。在珠芽蓼及其他大多数植物种子成熟期的8月下旬,现存量的热值最大,其他三部分的热值变化也有其各自的特点。现存量6—9月的平均营养成分以绝对干重计为：粗蛋白13.52%,粗脂肪2.25,粗纤维22.99,无氮浸出物51.88,粗灰分9.61(其中钙1.627,磷0.164);在时间变化上四部分各有其特点。根据地形、植物组成、产量、易食性、适口性、热值和营养成分等综合条件,认为珠芽蓼草甸是良好的放牧地。     

福建武夷山甜槠群落能量的研究

在生物量、生产力研究基础上,对武夷山甜槠（Ｃａｓｔａｎｏｐｓｉｓ ｅｙｒｅｉ（Ｃｈａｍ ｐ．ｅｘ Ｂｅｎｔｈ．） Ｔｕｔｃｈ．）群落各组分的热值、群落能量现存量、能量年净固定量以及太阳能转化效率进行了研究。结果表明：（１）甜槠群落各组分样品的干重热值具有一定的差异,树皮热值最高,细根热值最低。（２）甜槠群落的能量现存量达７８０５８４．１ ｋＪ·ｍ － ２,其中地上部分为６７８９１３．８ ｋＪ·ｍ － ２,占总量的８６．９８％ ;地下部分为１０１６７０．３ ｋＪ·ｍ － ２,占１３．０２％ 。（３）甜槠群落的能量年净固定量（１９９２年）为２６８５６．２ ｋＪ·ｍ － ２·ａ－ １,林地太阳光合有效辐射能的转化效率为１．２９６％ 。     

Biological and physicochemical characterization of recombinant human erythropoietins fractionated by Mono Q column chromatography and their modification with sialytransferase

Ten erythropoietin (EPO) fractions differing in sialic acid content, ranging from 9.5 to 13.8 mol mol^–1 of EPO, were obtained from baby hamster kidney cell-derived recombinant human EPO by Mono Q column chromatography. The mean pI values of the EPO fractions determined by IEF-gel electrophoresis systematically shifted from 4.11 to 3.31, coinciding with the sialic acid content, without a change in the constitution of asialo N-linked oligosaccharides of each fraction. Although a linear relationship between thein vivo bioactivity and the sialic acid content of the fractionated, samples was observed until 12.1 mol mol^–1 of EPO, there was no further increase in their activity over 12.4 mol mol^–1 of EPO. On the other hand, an inverse relationship between thein vitro bioactivity and sialic acid content of EPO was observed. Also, we showed that thein vivo bioactivity of some fractions with low sialic acid contents was increased after treatment with 2,6-sialyltransferase, but thein vivo bioactivity of the other fractions with high sialic acid contents was either decreased or not affected.Abbreviations EPO erythropoietin - rHuEPO recombinant human erythropoietin - hCG human chorionic gonadotropin - BHK baby hamster kidney - CHO Chinese hamster ovary - NeuAc N-acetyl neuraminic acid - Gal galactose - HRCs hemolyser-resistant cells - WST-1 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium Na - IEF isoelectric focusing - pI isoelectric point     

Estimation of the position and effect of a lethal factor locus on a molecular marker linkage map

In the mapping of DNA markers the distortion of segregation of marker genotypes is often observed, which may be caused by a lethal factor acting in filial generations derived from distant crosses. A method is presented for estimating the recombination values between a lethal factor locus and neighboring molecular markers, and the relative viability or fertilization ability of gametes or zygotes affected by the lethal factor in an F₂ population using the maximum likelihood method and the expectation conditional maximization (ECM) algorithm. Three selection models of gamete or zygote were considered, and the most likely one was determined by goodness of fit of the observed frequency of the phenotypes to the expected ones under the models. The method was applied to segregation data of molecular markers of an F₂ population consisting of 144 individuals derived from a cross between an Indica and a Japonica rice variety. The presence of a lethal factor locus (L) located on chromosome III that caused partial gametic selection in both the male and female sides was suggested. The locus L was tightly linked to RFLP marker number 23 of the RFLP linkage map of Saito et al. (1991a), and the fertilization chance of a male or female gamete possessing the lethal factor was, on average, 41.5% of that of the normal gamete.     

The evolution of phage lysis timing

Summary The effect of host quantity and host quality on the evolution of phage lysis timing is analysed using marginal value theorem of optimal foraging theory. Both factors have been shown to strongly influence the latent period. A high host density selects for short latent period, which is the same result as previous investigators have found. A good host quality also promotes a short latent period. However, elasticity analysis shows that these two factors exert their influences under different sets of conditions. When host density is low, the host density is more important in determining the length of latent period, whereas when host density is high, the host quality is more important.     

精制蚕蛹油中碱液和过氧化值的控制

作者采用碱皂化的方法来达到精炼蚕蛹油的目的。实验表明,碱的浓度以１０％￣１３％比较合适,超碱量必须视酸值大小,通过小样试验来确定。精制油的过氧化值与皂化后中性油的洗涤温度、洗涤次数及搅拌速度有密切关系,必须严格控制。     

Y-intercept of the maximal work-duration relationship and anaerobic capacity in cyclists

The degree to which the y-intercept (Y-int) of the linear regression of maximal work output on exercise duration represented anaerobic capacity was determined in ten well-trained male cyclists [peak oxygen uptake ( = 69.8 (SD 4.2) ml · kg ^–1 · min ^–1). Each cyclist performed three exhausting cycle sessions on separate occasions; the mean exercise durations were 312, 243 and 141 s for the low (approximately 104% , medium (approximately 108% and high (approximately 113% intensities respectively, and Y-int (kilojoules; joules per kilogram was derived from the regression of work output on exercise duration. The muscle anaerobic adenosine 5-triphosphate (ATP) yield (ATP) and anaerobic capacity (AC) were estimated from changes in metabolites in the vastus lateralis muscle and blood lactate concentration during the high intensity cycling session. The activities of glycogen phosphorylase, phosphofructokinase and citrate synthase, as well as muscle buffer value (in vitro ) were also determined. The Y-int (kilojoules) was positively correlated (P0.05) with AC (r=0.73), ATP (r=0.70) and in vitro (r=0.71); similar correlations (P0.05) were observed for Y-int (joules per kilogram). The Y-int was not correlated (P>0.05) with any enzyme activity. When the Y-int was transformed into oxygen equivalents [litres of oxygen equivalent (1 O₂ Eq)] it was, on average, 0.92 1 O₂ Eq lower than AC (P0.05); however, an alternative method of establishing the work-duration regression yielded a mean Y-int which was only 0.19 1 O₂ Eq less than AC (P0.05). These findings support the validity of Y-int as a work estimate of anaerobic capacity in well-trained cyclists.     

Pleural Fluid Adenosine Deaminase and Lymphocyte Proportion: Clinical Usefulness In the Diagnosis of Tuberculosis

Adenosine deaminase (ADA) and lymphocyte proportion are known to be independently elevated in tuberculous effusions, but are non-specific, and false positive results are frequent. to overcome this problem the combined use of both parameters was prospectively studied in 276 patients with pleural effusion seen at Porto Alegre, Brazil. Using a cut-off level of 40 U/l at 37°C (method of Giusti¹⁹) for ADA activity and lymphocyte proportion of more than 50%, the correct diagnosis of tuberculosis (sensitivity) was made in 90.7% (CI 87.3–94.1%) of 54 patients. A specificity of 97.7% (CI 95.9–99.5%) was recorded. Five false positive diagnoses of tuberculous effusion were made. Five false negative diagnoses were made: three cases with haematogenous tuberculous dissemination with low ADA levels, and two other patients with low lymphocyte proportion. the combined use of ADA activity determination and lymphocyte proportion is a highly efficient diagnostic strategy of low cost, that merits wider use.