中国吻额蛛属一新种（蜘蛛目：皿蛛科：微蛛亚科）

本文描述了作者1986年采自湖北省神农架林区的吻额蛛属Aprifrontalia一新种:膨大吻额蛛,新种Aprifrontalia afflata sp.nov.。目前,除本新种外,世界仅报道过1种:Aprifrontalia mascula,本新种雄蛛最显著的特征是:其额向前突呈吻状,触肢胫节前端甚膨大。外雌器形成一斜向下方的突起。模式标本保存于白求恩医科大学生物教研室。     

Seasonal changes in the activation of crossbridge motions of isolated thick filament from Limulus striated muscle

Summary In dynamic light scattering, measurements of the intensity-intensity time correlation function from a suspension of rod-like particles of length L could reveal dynamical information related to translational and internal motions of those particles. For a suspension of thick filaments isolated from the myosin-regulated, striated muscles of Limulus at KL>1 (where K is the scattering vector), the average characteristic linewidth ( ) increased with the addition of Ca²⁺ or with the depletion of ATP. The increase in the with the addition of Ca²⁺ could be due to the presence of energy-requiring, high-frequency motions of the crossbridges activated by Ca²⁺. The increase in which occurred with the depletion of ATP was assumed to be mainly due to the thermal motions of the crossbridges after they had moved radially away from the filament backbone. The percentage increase in following the addition of Ca²⁺ was found to be seasonal, i.e., values of obtained from thick filaments isolated between the middle of June and the middle of September were smaller than those obtained during the rest of the year. The effect of temperature on the percentage increase in was also different. The increase showed a maximum at about 35°C during the summer and at about 25°C at other times. However, the percentage increase in developed under ATP-depleted conditions showed no temperature-related maximum. The number of bound Ca²⁺ per myosin molecule was 1 during the summer and 2 at other times.Abbreviations DLS dynamic light scattering - L length - K scattering vector - SDS-PAGE sodium dodecyl sulfate polyacrylamide gel electrophoresis - average characteristic line width Deceased     

幼年大鼠诱发排卵条件下卵巢前列腺素(PGs)的含量变化及其生理作用

本实验用幼年大鼠经PMSG/hCG诱发排卵,研究了印巢PGE_2、PGF_(2α) 、6-酮-PGF_(1α) 及TXB_2在排卵过程中的变化。实验表明卵巢PGE_2、PGF_(2α) 及6-酮-PGF_(1α) 在排卵前达到峰值,在排卵后,均趋下降。TXB_2未出现明显变化。受试动物经消炎痛处理后,不仅使排卵受到严重抑制,而对上述三种PGs在排卵前的上升也表现了显著的抑制。提示在卵泡破裂过程中PGs的重要调节作用,PGE_2、PGF_(2α)均可能参与排卵,其中尤以PGE_2的作用最为显著。     

A laboratory study on the thermal tolerance of four southeastern stream insect species (Trichoptera,Ephemeroptera)

The acute thermal tolerances of four southeastern stream insect species, Ephemerella invaria (Walker), Stenonema ithaca (Clemens and Leonard), Symphitopsyche morosa (Hagun), and Brachycentrus lateralis (Say) were determined using an artificial stream enclosure. All species were acclimated at 10°C for 72 hours prior to instantaneous immersion into heated water for 96 hours. Percent mortality was recorded and the temperature at which 50% mortality occurred determined (LT5o). Data were subjected to standard statistical analysis.Thermal tolerance values were compared between species tested and to results from previous investigations using similar methodologies. The evolution and life histories of these species were also discussed in relation to their thermal tolerance values.     

Studies on quantitative physiology of Trichoderma reesei with two-stage continuous culture for cellulose production

By employing a two-stage continuous-culture system, some of the more important physiological parameters involved in cellulose biosynthesis have been evaluated with an ultimate objective of designing an optimally controlled cellulose process. The two-stage continuous-culture system was run for a period of 1350 hr with Trichoderma reesei strain MCG-77. The temperature and pH were controlled at 32°C and pH 4.5 for the first stage (growth) and 28°C and pH 3.5 for the second stage (enzyme production). Lactose was the only carbon source for the both stages. The ratio of specific uptake rate of carbon to that of nitrogen, Q(C)/Q(N), that supported good cell growth ranged from 11 to 15, and the ratio for maximum specific enzyme productivity ranged from 5 to 13. The maintenance coefficients determined for oxygen, M_O, and for carbon source, M_C, are 0.85 mmol O₂/g biomass/hr and 0.14 mmol hexose/g biomass/hr, respectively. The yield constants determined are: Y_X/O = 32.3 g biomass/mol O₂, Y_X/C = 1.1 g biomass/g C or Y_X/C = 0.44 g biomass/g hexose, Y_X/N = 12.5 g biomass/g nitrogen for the cell growth stage, and Y_X/N = 16.6 g biomass/g nitrogen for the enzyme production stage. Enzyme was produced only in the second stage. Volumetric and specific enzyme productivities obtained were 90 IU/liter/hr and 8 IU/g biomass/hr, respectively. The maximum specific enzyme productivity observed was 14.8 IU/g biomass/hr. The optimal dilution rate in the second stage that corresponded to the maximum enzyme productivity was 0.026 ～ 0.028 hr^?1, and the specific growth rate in the second stage that supported maximum specific enzyme productivity was equal to or slightly less than zero.