白细胞介素对大鼠海马培养神经元膜电特性的影响

用细胞内微电极记录方法研究了重组人白细胞介素－１β（ｒｈＩＬ－１β）和重组人白细胞介素－２（ｒｈｉＬ－２）对分散培养的新生大鼠海马神经元膜电性质的影响。采用压力脉冲微量给药技术将白介素施加于所记录的细胞表面。结果发现：１００Ｕ／ｍｌ浓度的ｒｈＩＬ－１β使受作用的海马神经元超极化４．２０±１．８６ｍＶ;１００Ｕ／ｍｌ浓度的ｒｈＩＬ－２使５０％受作用的海马神经元去极化１１．１２±３．７１ｍＶ,并伴有强烈的自发放电反应,而１０００Ｕ／ｍｌ浓度的ｒｈＩＬ－２使１００％受作用的神经元超极化３．２５±０．６３ｍＶ,这些神经元的膜阻抗均无明显变化。本实验结果提示ｒｈＩＬ－１β和ｒｈＩＬ－２可显著影响体外培养海马神经元的膜兴奋性。     

高原（2260m）女子公路自行车运动员的通气无氧阈,乳酸阈和最大氧…

采用实验室递增负荷运动试验和运动现场血乳酸的测定,研究了高原（２２６０ｍ）女子公路自行车运动员的通气无氧阈,乳酸阈及最大氧耗量,结果发现,通气无氧阈时的氧耗量为２．０３１／ｍｉｎ,功率为１３１．４Ｗ乳酸阈（以运动速度表示）为３３．０ｋｍ／ｈ。通气无氧时对应的心率（１３７次／ｍｉｎ）低于乳酸阈的心率（１５３次／ｍｉｎ）。最大氧耗量的绝对值（２．８１／ｍｉｎ）和相对值（４７．４ｍｌ／ｋｇ．ｍｉｎ）分别     

长白山北坡不同土壤N2O和CH4排放的初步研究

用箱法技术原位测定了长白山北坡不同土壤（苔原土、生草森林土、棕色针叶林土和暗棕色森林土）６—８月间的Ｎ２Ｏ和ＣＨ４排放．结果表明,这些土壤既是Ｎ２Ｏ的源,又同时是ＣＨ４的汇．Ｎ２Ｏ通量变化于６．１７—１２．３３μｇ·ｍ－２·ｈ－３之间（平均９．３７μｇ·ｍ－２·ｈ－１）,ＣＨ４通量为－８５．６３—－７．５８μｇ·ｍ－２·ｈ－１（平均－４１．４５μｇ·ｍ－３·ｈ－１）,并观察到在Ｎ２Ｏ排放和ＣＨ４吸收之间有着相互消长关系．实验室培养实验表明,最大反硝化作用活性存在于土壤上层（０—６ｃｍ）;不同土壤的反硝化作用活性明显不同．山地暗棕色森林土的ＣＨ４吸收作用也主要发生在土壤的上层（０—１２ｃｍ）．     

重离子束对酵母细胞的失活与突变

双倍体酵母细胞Ｄ７经单核能为１１．４ＭｅＶ／ｕ的Ａｎ和Ｕ离子辐照后,测定了细胞随剂量的存活率和突变率。获得细胞对Ａｕ和Ｕ离子的失活截面分别为２．５４μｍ２和１．９２μｍ２。在存活率为３７％的条件下,Ａｕ、Ｕ离子的ＲＢＥ分别为０．２８和０．１９。在突变实验中,研究了ＤＮＡ断链后的重组与倒位,它们对Ａｕ和Ｕ离子的截面为：８．３×１０－２μｍ２［σｍ－ｒｅｃ（Ａｕ）］,９．５×１０－５μｍ２［σｍ－ｒｅｃ（Ｕ）］和６．１×１０－４μｍ２［σｍ－ｒｅｖ（Ａｕ）］和３．８×１０－５μｍ２［σｍ－ｒｅｖ（Ｕ）］．最后,对所获结果进行了讨论。     

关于重组乙肝表面抗原纯化收率的研究

本文采用回归分析法研究了超速离心纯化时,固定一次溴化钾密度梯度比例,选择不同的二次溴化钾梯度比例对下一步ＳｅｐｈａｒｏｓｅＣＬ－４Ｂ柱层析纯化收率的影响。结果表明：回归分析不仅能揭示纯化的最佳条件,即,二次溴化钾超速离心时溶液由２４０ｍｌ（１．０４ｇ／ｍｌ）：８００ｍ１（１．２８ｇ／ｍｌ）：６００ｍｌ（１．３２ｇ／ｍｌ）：５０ｍｌ（１．３４ｇ／ｍｌ）构成时柱层析收率最高。而且还能解释层析纯化中出现的异常结果。     

高原（2260m）女子公路自行车运动员的通气无氧阈、乳酸阈和最大氧耗量的研究

采用实验室递增负荷运动试验和运动现场血乳酸的测定,研究了高原（２２６０ｍ）女子公路自行车运动员的通气无氧阈、乳酸阈及最大氧耗量。结果发现,通气无氧阈时的氧耗量为２．０３ｌ／ｍｉｎ,功率为１３１．４Ｗ;乳酸阈（以运动速度表示）为３３．０ｋｍ／ｈ。通气无氧阈时对应的心率（１３７次／ｍｉｎ）低于乳酸阈的心率（１５３次／ｍｉｎ）。最大氧耗量的绝对值（２．８ｌ／ｍｉｎ）和相对值（４７．４ｍｌ／ｋｇ．ｍｉｎ）分别比平原运动员低２２．２％和２２．９％,但与平原运动员高原训练期间的测试值（２．８ｌ／ｍｉｎ）比较,高原与平原运动员最大氧耗量的差异消失。在相同氧耗量（２．８ｌ／ｍｉｎ）条件下运动时,高原运动员完成的功率（２５１Ｗ）低于平原运动员（２７４Ｗ）。     

利用恒溶氧．补料分批技术高密度培养大肠杆菌生产重组人骨形成蛋白-2A

对表达人骨形成蛋白２Ａ（ＢＭＰ２Ａ）的重组大肠杆菌ＹＫ５３７／ｐＤＨＢ２ｍ在５００ｍｌ摇瓶中进行了培养条件的摸索实验,继后用５Ｌ自控发酵罐进行分批培养和分批补料培养,以获取ｒｈＢＭＰ２Ａ。两种培养方式结果比较表明,在培养过程中保持３０％～４０％左右的溶解氧和限制性流加葡萄糖可以使ＢＭＰ２Ａ的含量达到２７８ｇ／Ｌ,最终菌体密度为ＯＤ６００５３（相当于干菌２１２ｇ／Ｌ）,重组蛋白的表达量占菌体总蛋白的２５％。该培养技术的关键是：（１）在培养过程中保持适当的溶解氧;（２）限制性流加葡萄糖;（３）４２℃起始诱导的时间控制在对数生长中期,持续表达时间为４ｈ;（４）细菌持续生长的比生长速率控制在０３ｈ１左右。     

解剖和生理死腔变化在高频双向喷射通气中的意义

本实验对９只蒸汽吸入伤犬在高频喷射通气（ＨＦＪＶ）或高频双向喷射通气（ＨＦＴＪＶ）条件下解剖死腔（Ｖ＿（ａｎａｔ））和生理死腔（Ｖ＿（ｐｈｙｓ）的变化进行了观察。结果：①ＨＦＪＶ和ＨＦＴＪＶ的ＣＯ＿２排出量（Ｖｃｏ＿２）（４．９０±０．６５,６．３２±１．３０ｍｌ·ｍｉｎ￣１·ｋｇ￣１）的差异非常显著（Ｐ＜０．０１）,②ＨＦＴＪＶ的ＶＶ＿（ａｎａｔ）（７６．６６±１９ｍｌ）和Ｖ＿（ｐｈｙｓ）（８０．８７±２０ｍｌ）比ＨＦＪＶ（分别为８８．１７±２２ｍｌ和９０．６９±２２ｍｌ）的均显著减少（Ｐ＜０．０５）。③ＨＦＪＶ和ＨＦＴＪＶ的功能残气量（ＦＲＣ）（４３３±５６,４４４±５６ｍｌ无显著差异。因此,ＨＦＴＪＶ确有加速ＣＯ＿２排除的效能,其作用应归因于Ｖ＿（ａｎａｔ）,和Ｖ＿（ｐｈｙｓ）的减少,它可能成为解决Ⅱ型呼吸衰竭ＣＯ＿２排除障碍的一种有效途径。     

硫酸西梭霉素微生物检定法研究

以短小芽孢杆菌为检定菌,比较了培养基原料对抑菌圈的影响,进行了检定菌的分离和敏感活性测定,标准曲线的可倍限率检测;一剂量和二剂量法的可靠性试验;样品效价测定和统计分析,确认我们建立的硫酸西梭霉素的生测方法是准确、可行的。＊ｐ＜０．００１）,试品间和偏离平行不显著（＊ｐ＞０．０５）,可倍限率小于５％,本实验成立。按ｎ次实验结果合并计算,处理２＃、３＃两批样品的实验结果,见表４。经统计分析,２＃样品标定效价为６２９ｕｇ／ｍｇ,可倍限率４．１９％。３＃样品标定效价５７９ｕｇ／ｍｇ,可倍限率３．７１％。３结论３．１硫酸西梭霉素生物效价测定,美国药典［１］以表皮葡萄球菌作检定菌。我们用短小芽孢杆菌作检定菌,抑菌圈清晰,菌液易于保藏,测定结果准确,复现性强。因此,短小芽孢杆菌可作为硫酸西梭霉素的检定菌,培养时间１４～１６小时,培养温度３５～３７℃。３．２采用标准曲线法和二剂量法进行生物效价测定。前者标准品溶液校正点为５ｕｇ／ｍｌ,后者标准品溶液浓度分别为１０ｕｇ／ｍｌ,５ｕｇ／ｍｌ,剂距比２：１。３．３试验结果表明,培养基的原料直接影响检定菌的生长和样品扩散,从而影响抑菌圈的大小和清晰程度。蛋白陈和琼脂的质量尤为重量。?     

青海南部太白韭4居群的核型研究

研究了葱属太白韭青海４个居群的染色体数目和核型。结果如下,居群１：２ｎ＝２ｘ＝１６＝１２ｍ＋２ｓｍ＋２ｓｔ（２ＳＡＴ）,居群２：２ｎ＝２ｘ＝１６＝１４ｍ＋２ｓｔ（２ＳＡＴ）;居群３：２ｎ＝４ｘ＝３２＝２４ｍ＋４ｓｍ＋４ｓｔ（４ＳＡＴ）,居群４：２ｎ＝２ｘ＝１６＝１４ｍ＋２ｓｔ（２ＳＡＴ）＋Ｂｓ（０－２）。并讨论了多倍体和Ｂ染色体形成与分析。     

羊毛生物整理复合酶L86发酵工艺优化研究

采用L9（34）正交试验对L86复合酶生产菌的发酵培养基进行优化、并通过溶氧浓度调节和中期补加蛋白水解液对发酵过程进行调控。结果表明较优的培养基组成为（g/100ml）：黄豆粉4.0、玉米粉1.0、鱼粉0.6、蚕蛹粉0.6、CaCl20.5、NH4Cl1.0、Na2HPO4·2H2O 0.4;通气量控制30h前1:0.5、30-50h1:1.0、50h后1:1.2 v/v/m。在上述条件下摇瓶,酸性蛋白酶酶活10000u/ml、纤维素CMC酶3600u/ml;在0.5m3搅拌罐中扩大中试平均发酵单位酸性蛋白酶5500u/ml、纤维素CMC酶2200u/ml。     

A method for estimating dry forage intake by sheep using polyethylene glycol as a faecal marker measured with NIRS

In experiments based on ruminants’ individual dry matter intake (DMI) assessment, several external markers can be used to estimate faecal output when total faeces collection is not possible. However, preparation of the markers to be administered and analytical procedures used for marker content determination are time-consuming thus strongly limiting the number of animals involved in the experiments. In this paper, polyethylene glycol (PEG, molecular weight 6000 da) was tested as a faecal marker. Four trials were conducted on dry, non-lactating ewes kept in digestibility crates that allowed individual measurements. The overall experiment was designed to assess the major factors that could lessen the effectiveness of this method, assuming that the use of grab samples of faeces is sufficient. Trial 1 was designed to test two levels of PEG (20 and 40 g/day) administered in two equal amounts. Trial 2 was designed to test the effect of either a single morning (0800 h) dose (20 g/day) or a twice daily administration (0800 and 1600 h) of the same fractionated dose. Trial 3 was designed to test a 20 g/day dose of PEG administered once daily to ewes fed with hays of different qualities: medium (MH) and low (LH). In trial 4, a lower dose of PEG (10 g/day) was administered once a day to ewes fed with fresh oat–vetch forage. It was demonstrated that PEG could be precisely estimated (average prediction error = 3.47 g/kg) with near-infrared reflectance spectroscopy (NIRS). On the basis of the four trials, it has been proved that PEG administration (20 and 40 g/day) did not significantly affect the DMI of ewes fed dry diets (trials 1, 2 and 3), whereas there was an unexpected increase of DMI for ewes fed exclusively with green feed (trial 4) without DM digestibility modification. Providing PEG as a single dose (0800 h) or split into two equal parts (0800 and 1600 h) did not alter the estimated DMI. Considering the interest of grab sampling, there were clear variations of PEG in faeces with higher concentrations observed at 0800 and 1600 h and lower concentrations at 1400 h. Consequently, with PEG (measured with NIRS) administered once and using the grab sampling procedure (morning collection), it is possible to estimate the DMI of dry feeds with good accuracy. For green feeds, more research is needed as the estimated results are still highly variable.     

Inhibition of coagulase activity and growth ofStaphylococcus aureus by garlic extracts

Garlic extract (1 mg dry weight/ml) produced an inhibition of the coagulase reaction and increased the time of coagulation by a factor of 1.5, whereas 4 mg dry weight/ml increased the coagulation time factor by 2.75. At this latter concentration of garlic, coagulation was only partially complete at 4 h. Garlic extract (1.4 mg dry weight/ml) reduced growth in nutrient broth whereas 5.6 mg dry weight/ml was completely inhibitory. These effects were not observed until 8 h after exposure of the organisms to the garlic extracts. There were 5.9% more survivors among garlic treated mice compared to non-treated animals, but this difference is not significant.     

Photosynthate partitioning in diploid and autotetraploid barley (Hordeum vulgare)

Net rates of carbon assimilation per unit leaf area by fully expanded, vegetative leaves of diploid (2x) and autotetraploid (4x) barley (Hordeum vulgare L. cultivars OAC-21 and Brant) were not significantly different (90% level) when measured under controlled environment conditions with air levels of CO₂ and either 2 or 20% O₂. Leaf thickness increased with ploidy so that net photosynthetic rates measured on single leaves were lower for 4x than 2x barley varieties when compared on a dry or fresh weight basis. Rates of ¹⁴CO₂ fixation by isolated mesophyll protoplasts prepared from seedlings were also lower for 4x than 2x varieties [about 108 and 125 μmol (mg ChI)^?1 h^?1, respectively]. Carbohydrate accumulation in leaves of 5-weekold plants averaged 28% (2x) and 47% (4x) of the total photosynthetic weight gain during the first 9 h of the light period. Estimated photoassimilate export from leaves was 15% (OAC-21) and 38% (Brant) lower for 4x compared to 2x isolines. The sucrose and oligofructan content of 4x compared to 2x leaves increased as a result of decreased photosynthate transport. Total tiller dry weight of plants raised in a glasshouse was greater for 4x than 2x barley varieties at ear emergence, but tiller height decreased with increasing ploidy. The nonstructural carbohydrate content of the inflorescence, leaves and lower stem organs was significantly (P≤ 0.01) higher in 4x than in 2x lines at this sampling. During the first 15 days of grain development total tiller dry weight increased by 46% (2x) compared to 8% (4x) when the results of both varieties were averaged together. The dry weight gain of the ear during this period was about 60 to 80% lower for 4x compared to 2x isolines. The nonstructural carbohydrate content of the inflorescence was also about 24% (Brant) and 51% (OAC-21) lower for 4x as compared to 2x plants 15 days post ear emergence. The above results suggested that photosynthate partitioning in autotetraploid barley was sink-limited.     

Development of Metal Tolerance in Soil Bacterial Communities Exposed to Experimentally Increased Metal Levels

The development of metal tolerance in soil bacterial communities exposed to different heavy metals was examined under laboratory conditions. An agricultural soil amended with different Zn concentrations was studied most intensively, and measurements were made over a 28-month incubation period by means of the thymidine incorporation technique. Tolerance levels were not affected by metal concentrations lower than 2 mmol of Zn kg (dry weight) of soil(sup-1), but above this value, the level of Zn tolerance increased exponentially with the logarithm of the soil Zn concentration. An increased metal tolerance was detected after only 2 days of Zn exposure. Thereafter, stable tolerance values were observed at different sampling times for bacterial communities exposed to up to 8 mmol of Zn kg (dry weight)(sup-1), indicating no changes in tolerance with time. The tolerance of bacterial communities exposed to 32 mmol of Zn kg (dry weight)(sup-1) increased rapidly within the second week of incubation, but then the values remained unchanged until the end of the experiment. Bacterial communities from soil contaminated with 16 mmol of Zn kg (dry weight)(sup-1) showed an increase of the same magnitude, but the increase started later, after 4 months of incubation, and took place for a much longer period (more than 1 year). Cd, Cu, and Ni addition also resulted in metal-tolerant communities, and the level of tolerance increased with prolonged incubations of the soils. The bacterial community at the end of the incubation period also exhibited a lower pH optimum and an increased tolerance to low osmotic potential. The results suggest that the increase in metal tolerance of the community after adding metals can be attributed to an immediate effect due to the death of sensitive species and a later effect due to different competitive abilities and adaptation of surviving bacteria.     

水稻苗期磷高效基因型筛选研究

采用难溶性磷酸盐Ca3 (PO4) 2 为唯一磷源 ,在pH值为 5 .5条件下产生相对高浓度低磷胁迫及以NaH2 PO4为磷源配制P浓度为 0 .5mg·L-1的相对低浓度低磷胁迫的两个水培环境 ,分别对不同基因型水稻的磷效率进行评价 .以相对分蘖干重 (RTW )、相对总生物量 (RPW )、相对分蘖数 (RTN)、相对根系干重(RRW )、相对地上部干重 (RSW )、相对叶龄 (RLA)和相对株高 (RPH)作为耐性指标进行相关分析 .结果表明 ,供试材料的磷效率存在极显著差异 ,若以能产生分蘖的相对高浓度低磷胁迫进行筛选时 ,相对分蘖干重、相对地上部干重、相对总生物量可作为较好的筛选指标 ,其中相对分蘖干重不仅与其它指标间的相关性强 ,且品种间差异和变异系数均较大 ,能准确、灵敏地反映不同基因型间的耐低磷胁迫能力 ;若采用相对低浓度的低磷胁迫对不同基因型水稻进行耐低磷种质筛选时 ,筛选指标则不同 ,最好的单一筛选指标应是相对地上部干重或相对总生物量 .     

北美车前(Plantago virginica)种群密度制约的统计分析

本文调查了北美车前(Plantago virginica)种群密度对植株形态参数的影响。统计表明:北美车前营养生长期间,种群密度对形态参数的影响不大,在生殖生长期间,各形态参数受到种群密度较大的制约,单株叶数(Y₁)、叶长(Y₂)、叶宽(Y₃)、鲜重(Y₄)、根重(Y₅)、花穗数(Y₆)、花穗长(Y₇)、花数(Y₈)、花序重(Y₉)和花穗重/营养体(Y₁₀)与种群密度(X)存在如下关系:Y₁=22.0428-2.3022lnX、Y₂=21.4185+2.183lnX、Y₃=4.9934-0.5048lnX、Y₄=0.1567+699.574/X、Y₅=7.7310X^-0.7606、Y₆=0.9019+318.886/X、Y₇=2.4236+179.425/X、Y₈=46.3069+6914.07/X、Y₉=0.1382+15.9598/X和Y₁₀=0.047+0.0002X。文章还比较了北美车前与车前(Plantago virginica)在繁殖期的密度制约作用特点。     

Cartilage growth inhibition and necrosis in vitro caused by prostaglandin A

This paper details experiments using the Fell technique of organ culture of 8-day chick embryo femoral and tibial rudiments to test the effects of prostaglandin A1 (PGA1) on cartilage growth. Growth was studied during 8 days in vitro by measurement of rudiment length and wet and dry weight, and by histology. PGA1 inhibited explant growth in a dose-related manner. Linear growth was significantly decreased by 20 and 25 microgram/ml PGA1 at 2, 4, 6 and 8 days, and by 15 microgram/ml at 6 and 8 days. Linear growth was unaffected by 1 and 10 microgram/ml doses. Weight measurements were significantly reduced by 25 microgram/ml PGA1 (2, 4 and 8 days) and by 20 microgram/ml (8 days). Chondroblast degeneration was caused by doses of 15, 20 and 25 microgram/ml PGA1. Progressive degeneration was seen at the 25 microgram/ml concentration after 2 days in vitro. Cellular changes as early as 27 h in vitro were seen using electron microscopy. Tritiated thymidine autoradiography confirmed reduced chondroblast proliferation in the presence of PGA1 (25 microgram/ml). The mechanisms of prostaglandin-induced changes in embryonic cartilage remain uncertain. The possible role of intracellular cyclic nucleotides in the reaction is discussed.     

胡麻资源萌发期耐盐综合性评价

筛选胡麻耐盐品种,对胡麻产业可持续发展应对盐渍胁迫具有重要现实意义。试验选用100 mmol·L^-1的NaCl溶液对28份胡麻资源种子进行胁迫,并测定发芽率、总鲜重、下胚轴鲜重、下胚轴干重、下胚轴长、胚根鲜重、胚根干重和胚根长等相关指标,通过相关性分析、因子和主成分分析、聚类分析和逐步回归分析对11个指标进行综合分析,对28份胡麻资源萌发期耐盐性做出评价,并筛选出胡麻萌发期耐盐性鉴定的关键指标。结果表明：经相关分析,11个指标中多项指标间都是极显著或显著的正相关;因子和主成分分析将11个单项指标转化成3个综合指标,第Ⅰ主成分为下胚轴长势情况,第Ⅱ主成分为胚根长势情况,第Ⅲ主成分为种子萌发情况;聚类分析将28份胡麻资源划分为4大类：耐盐型、中等耐盐型、盐敏感型和强盐敏感型。雁杂10号、轮选1号为强耐盐材料;陇亚4号、R40号、DYMS为较强耐盐材料;逐步回归分析建立了胡麻萌发期耐盐能力预测的数学评价模型,筛选出总鲜重、胚根干重、发芽指数和下胚轴长这4个鉴定指标是胡麻萌发期耐盐能力鉴定的关键指标。以这4个筛选指标计算出的预测值与综合评价计算出的综合Z值之间极显著相关（R²=0.991 8^**）,表明鉴定结果具有较高的准确性,可以代替原来11个指标对胡麻萌发期耐盐性进行评价。     

The effect of essential oil of Ammoides pusilla (brot.) breistr on the growth and the production of solanapyrone a by Ascochyta rabiei

Biological control such as the use of plant extracts has emerged as promising option to the phenomena of fungi resistance to chemical. Several constituent of essential oil have been studied for their biological activity including antibacterial and antifungal activity. In this study the effect of Ammoides pusilla essential oil with different concentrations was test against the growth of Ascochyta rabiei and the production of solanapyrone A by the fungus. After 14 days the mycelium was collected and the dry weight measured. A. rabiei did not grow at a final concentration of 6 and 3 mg/ml, at 1.5 mg/ml and 0.625ml there was little growth of the fungus with a dry weight of 55 mg and 99 mg respectively compared to the control with 519 mg dry weight, but there was no solanapyrone A produced. However a new compound appeared at the HPLC at 10 min. 30 sec. compared with the solanapyrone A which elutes at nearly 14 minutes.