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1.
报道了缢蛏碱性磷酸酶(简称ALP)经不同浓度盐酸胍处理时酶的分子构象所发生的变化以及酶变化和失活的动力学过程。在胍中酶荧光发射峰强度下降,紫外差光谱在246nm和285nm处出现2个负峰,CD谱中酶的α螺旋度下降,且随浓度增大,变化程度也加大。动力学研究表明,酶在0.5mol/L、1.0mol/L、2.0mol/L3.0mol/L、4.0mol/L盐酸胍中的变性速度常数分别为3.21×10~(-4)s~(-1)、6.38×10~(-4)s~(-1)、2.17×10~(-3)s~(-1)、2.33×10~(-3)s~9-1)、5.17×10~(-3)s~(-1);而酶在相应盐酸胍中的失活速度常数分别为2.33×10~(-4)s~(-1)、3.57×10~(-4)s~(-1)、5.86×10~(-4)s~(-1)、1.14×10~(-3)s~(-1)、3.45×10~(-3)s~(-1);表现为失活与构象伸展变化基本平行。 相似文献
2.
1植物名称巴拉斯白鹤芋(Spathiphyllumpalas)。2材料类别小苗茎尖或茎段。3培养条件以MS为基本培养基:(1)诱导分化与生长培养基为MS+BA2mp·L-1(单位下同)+NAA0.2+3%蔗糖;(2)生根培养基为1/2MS+IBA0.2+1.5%蔗糖。以上培养基均加0.75%琼脂,pH5.8,培养温度26~28℃,每日光照10~12h,光照度1500~2500lx。4生长与分化情况剪取顶芽或茎段约0.5~1.0cm长,用70%~75%乙醇消毒30~60s,以0.1%HgCl2溶液… 相似文献
3.
侵染双翅目昆虫的新种,新记录,新组合及新修订 总被引:1,自引:0,他引:1
记录了最近在中国记载的侵染双翅目昆虫的虫霉目两个新种,毛蚊虫疠霉(Pandorabibionis)发现于浙江元的毛蚊(Bibiosp.)其初生分生孢子拟卵形,多对称14.4~20.5×7.2~11.5μm(平均16.5~17.4×8.4~10.4μm)L/D1.4~2.3(平均1.7~2.0);假根2倍粗于分生包子梗,末端膨大为吸盘状固着器,休眠孢子外壁刺毛状。19.1~21.4μm,食蚜蝇干尸霉 相似文献
4.
丹皮酚对心肌细胞自律性和延迟后除极的影响 总被引:8,自引:0,他引:8
目的与方法:采用常规玻璃微电极技术研究丹皮酚对离体心肌细胞自律性(AM)、延迟后除极(DAD) 及触发活动(TA)的影响。结果:1.8×10-4mol/L丹皮酚灌流组,肾上腺素(Adr)的阈浓度空白对照组为(1.28±0.57)μmol/L,药后为(1.56±0.53)μmol/L(n=9,P>0.05);用(1.8×10- 3) mol/L丹皮酚(Pae)灌流组,Adr 浓度由空白对照组的(1.22 ±0.62)μmol/L升高到(6.22±2.11)μmol/L(n=9,P<0.01)。1.8×10-3mol/L的Pae 能明显抑制哇巴因(Oua)诱发的DAD的幅值,当基本刺激周长为500,400,300 和200 ms 时,其DAD幅值从(5.5±2.0)mV,(7.3±2.1)mV,(8.0 ±2.4)mV和(9.2±1.9)mV减小到(3.0±1.1)mV、(3.6±1.7)mV,(4.3±2.0) mV和(5.9 ±1.6) mV,P<0.01。当基本刺激周长为200 ms时,TA 数目由5.5±1.0 降至0.7±0.3(P<0.01)。结论:丹皮酚能抑制心肌细胞AM、DAD及TA,具有抗心律失常作用 相似文献
5.
6.
黄花蒿和菊花的组培嫁接成苗 总被引:1,自引:0,他引:1
1植物名称黄花蒿(Artemisiaannua)、菊花(Chrysanthemum morifolium)。2材料类别带腋芽的茎段。3培养条件3.1黄花蒿剪取2~3cm长带芽的半木质化壮枝,用试管刷蘸少许洗衣粉在流水下刷洗干净,再在70%酒精液中洗涤30s,用0.1%升汞消毒15min,无菌水冲洗4次,在无菌条件下切成0.5~1.0cm大小,在1/2MS+NAA0.1mg·L-1(单位下同)+6-BA2下培养。室温20~22℃,每天光照12h,光照度2000lx。3.2菊花选用“黄秀凤”品种为接… 相似文献
7.
链霉菌Z94-2碱性脂肪酶产生条件及酶学性质 总被引:2,自引:0,他引:2
在152 株脂肪酶产生菌中,链霉菌Z942 产脂肪酶活力为596u/ mL,其最适培养基(g/L) 为:糊精10 、黄豆饼粉30 、尿素10 、K2HPO4 0-5 、MgSO4 0-5 、NaCl 1 和AEO9 0 .5 ,产酶的最适条件为:初始pH9 .5 ~10-0 ,在26 ℃培养48h 。用PVA 橄榄油乳化系统测定该酶的最适pH9 .8 ,最适温度37 ℃,在pH8-6 ~10-2 于5 ℃存放24 h ,酶活力不变。0-14mol/L 的氯化钙有较大的激活作用。 相似文献
8.
α受体激动对绵羊心肌瞬时性内向离子流的影响 总被引:1,自引:0,他引:1
用乙酰毒毛旋花子甙元(AS)0.05μmol/L诱发绵羊心浦肯野纤维产生稳定的瞬时性内向离子流(Iti),用普萘洛尔0.5μmol/L阻断β受体,观察α受体激动剂苯肾上腺素(PE)0.3,1.0μmol/L对Iti幅值与时程的影响。PE1.0μmol/L灌流20,50min时Iti幅值分别由对照值12.8±1.9nA减小至10.7±1.2nA(n=5,P<0.05)与9.6±1.9nA(n=5,P<0.01);ItiD50时程分别由对照值145±24.4ms延长至183.3±28.1ms(n=5,P<0.05)与207.5±34.2ms(n=5,P<0.01),PE对Iti的抑制作用呈剂量依赖性与时间依赖性。Iti到达峰值的时间和回复到基线的时间都延长,提示PE作用下Iti通道动力学发生了变化。如果在β受体激动剂异丙肾上腺素(ISO)1.0μmol/L增强Iti的基础上,PE1.0μmol/L灌流10min,对Iti幅值的抑制及时程的延长作用更显著,Iti幅值由对照值15.6±3.2nA减小到10.3±2.2nA;ItiD50由92.5±14.3ms延长到132.5±36.0ms(n=5,P<0.01)。 相似文献
9.
链霉菌Z94-2碱性脂肪酶产生条件及酶学性质 总被引:2,自引:0,他引:2
在152株脂肪酶产生菌中,链霉菌Z94-2产脂肪酶活力为596u/mL,其最适培养基(g/L)为:糊精10、黄豆饼粉30、尿素10、K2HPO40.5、MgSO40.5、NaCl1和AEO90.5,产酶的最适条件为:初始pH9.5~10.0,在26℃培养48h。用PVA橄榄油乳化系统测定该酶的最适pH9.8,最适温度37℃,在pH8.6~10.2于5℃存放24h,酶活力不变。0.14mol/L的氯 相似文献
10.
菜心下胚轴原生质体培养和植株再生 总被引:6,自引:0,他引:6
以萌发3—4 天(长约4 cm )的菜心(Brassica campestris var.parachinesis)无菌苗苍白下胚轴为材料,酶解分离原生质体。经纯化的原生质体,在含0.5 m g/LZT、0.5 m g/L2,4-D、1.0 m g/LNAA 和0.4 m ol/L葡萄糖的K8p 培养基中,进行微滴培养。在起始培养14—18小时,原生质体再生新的细胞壁。36 小时再生细胞开始第一次分裂。第三天分裂细胞频率可达35% 。培养第8—9 天,可见含8—16个细胞的小细胞团,植板率为15% —18% 。3 周后将发育成直径为2 m m 的白色小愈伤组织,转到含0.3 m g/L 2,4-D并用gelrite半固化的培养基上,增殖成4—5 m m 直径的愈伤组织。在MS+ 3.2(或1.6) m g/L BA+ 1.6(或0.8) m g/LZT+ 0.01 m g/L NAA+ 0.1 m g/LGA3 和0.2% 蔗糖的分化培养基上,获得芽的分化。切下约2 cm 长的芽苗,转移到含0.2 m g/LIAA 和2% 蔗糖的培养基上,生根形成完整植株 相似文献
11.
受5龄末期和羽化初期较高保幼激素滴度的影响,褐飞虱Nilaparvata lugens(Stal)短翅型成虫性成熟比长翅型成虫早40~50h。5日龄前短翅型雌成虫的交配成功率较高,雄成虫的交配竞争能力较强;1、2日龄的长翅型雌成虫不交配,5日龄后长翅型成虫的交配能力渐渐超过短翅型成虫。实验种群的交配持续时间为(70.38±41.77)s;交配成功率为51.63%;雌、雄虫均可重复交配。一日中0~4h和10~14h交配成功率较高。 相似文献
12.
The influence of light wavelength on reproductive photorefractoriness in migratory blackheaded bunting (Emberiza melanocephala). 总被引:2,自引:0,他引:2
There are two effects of long day length on reproductive responses in birds, one is the photoinduction of gonadal growth and maturation and the other is the induction of gonadal regression and photorefractoriness. Although it is likely that the same photoreceptors are involved in the photoinduction of gonadal growth and the onset and maintenance of photorefractoriness. and so the influence of wavelength should be similar, this has not been investigated. Therefore, we investigated the influence of light wavelength on reproductive photorefractoriness in the migratory male blackheaded bunting held under long photoperiods. In mid May, when photoperiod was approximately 14L:10D (14 hours light:10 hours darkness), eight groups of sexually mature birds were moved indoors on an artificial photoperiod of 14L:10D (L - 450 lux. D - 0 lux). Then after 3 weeks, for six groups, a 4-h light period in the morning (zt 0-4; zt 0 [zeitgeber time 0] refers to the beginning of lights-on period) or in the evening (zt 10-14) was substituted with green (428 nm), red (654 nm) or white light at 16 +/- 2 lux intensity. Of the remaining two groups, one was maintained on 14L: 10D and the other transferred to 10L:14D: these served as controls. At the end of 4 weeks, all birds were found to have undergone testicular regression, irrespective of LD cycle they were exposed to. When these gonadally regressed birds were subjected to 16L:8D for another 4 weeks, to test their responsiveness to the stimulatory effects of long day lengths, only those exposed to 10L:14D and 14L:10D with a 4-h green light period showed testicular regrowth. On the other hand, birds exposed to 14L:10D with a 4-h white or red light period remained fully regressed, similar to 14L:10D controls. Except for some individual difference, there was no difference in response between the groups that received a 4-h light period in the morning and that received it in the evening. These results suggest that the wavelengths of light influence induction of buntings from the photosensitive state into the photorefractory state. Whereas the short light wavelengths facilitated recovery from the photorefractoriness, the long light wavelengths were more effective in maintaining the photorefractoriness. 相似文献
13.
美洲斑潜蝇实验种群的饲养技术 总被引:5,自引:1,他引:4
本文阐述了寄主植物的室内培养及美洲斑潜蝇的饲养技术。实验以花斑芸豆作为寄主植物。经试验,去除复叶对增加真叶有效利用面积有一定作用。经10天左右的培养,叶片长、宽度增长速率明显减慢,此时是接种斑潜蝇的最佳时机,15天后即斑潜蝇幼虫生长到3龄时,叶面积达最大。在25℃室温下,14小时光照,60%的相对湿度,2只接种箱,每天加入成虫100头(雌:雄=1:1),并更换新苗10~12盆,共60~72片叶子,生长期10~15天,每片叶子的面积可达25~40cm。照此每天可得600~1000头蛹即可基本满足室内工作的需要。 相似文献
14.
C. Oliveira M. T. Dinis F. Soares E. Cabrita P. Pousão-Ferreira F. J. Sánchez-Vázquez 《Journal of fish biology》2009,75(1):61-74
A periodicity of 29 days was observed in spawning rhythms in Senegal sole Solea senegalensis , with an acrophase around the last quarter and the new moon. In both spring and autumn, a very marked nocturnal spawning rhythm was registered, with spawning beginning after dusk and the acrophase occurring around 2300 hours. When the photoperiod was artificially extended (from 10L:14D to 14L:10D), S. senegalensis synchronized to the new photoperiod: spawning took place after the new 'dusk', the beginning gradually shifting from 2100 to 2300 hours and the acrophase from 2325 to 0032 hours. Under continuous light conditions, fish sustained rhythmicity for 2 days, with an acrophase at 2249 hours, which suggested the existence of an endogenous pacemaker controlling the daily spawning rhythm. These findings provided new insights for better understanding the reproductive physiology of this species and for optimizing the timing protocols of egg collection and larvae production in S. senegalensis aquaculture. 相似文献
15.
Im LH Isoldi MC Scarparo AC Visconti MA Castrucci AM 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2007,147(3):691-696
To investigate whether teleost fish GEM-81 erythrophoroma cells were photosensitive, the cells were submitted to constant darkness (DD), 14 h of light and 10 h of darkness (14L:10D), and 10 h of light and 14 h of darkness (10L:14L). The doubling times (hours) were: DD 35.33+/-0.05; 14L:10D 67.85+/-0.04; and 10L:14D 49.60+/-0.08. In order to verify whether proliferation was dependent on light phase length, GEM-81 cells were submitted to 7L: 5D. The proliferation curves and doubling times were similar in 14L:10D and 7L:5D (respectively 69.44+/-0.03 and 67.85+/-0.04), suggesting that the cell cycle was regulated by the length of the light phase within 24 h, or by the light/dark ratio. We have also demonstrated the expression of Carassius retinal rhodopsin mRNA in GEM-81 cells, which cycles in a circadian rhythm, entrained by light. In addition, we showed that alpha-melanocyte stimulating hormone (alpha-MSH, 10(-10) to 10(-8) M), a conspicuous hormone that exerts mitogenic and melanogenic activity in most vertebrates, decreased rhodopsin mRNA in the first 3 days; after 4 days the inhibition was reversed, and after 5 days an increase in rhodopsin mRNA level was elicited. This is the first report of rhythmic expression of extra-ocular rhodopsin and its modulation by light and hormones. 相似文献
16.
双斑截尾寄蝇成虫生物学特性 总被引:3,自引:0,他引:3
双斑截尾寄蝇Nemorilla maculosa Meigen (双翅目:寄蝇科)是草地螟Loxostege sticticalis和其他鳞翅类昆虫的重要寄生天敌,但国内外对其生物学特性知之甚少。为了揭示双斑截尾寄蝇的生物学特性,在22℃,光周期16L∶8D的室内条件下对成虫羽化时期,交配持续时间,产卵量和寿命及其与补充营养的关系等进行了实验观察。结果表明: 双斑截尾寄蝇主要在08: 00-10: 00和14: 00-16: 00羽化。雄蝇比雌蝇早羽化1 d,雌蝇羽化后可立即进行交配,但雄蝇羽化1 d后才可交配; 交配持续时间为10~54 min,但多数为20~30 min; 平均产卵量为154.1粒,雌蝇平均寿命26.6 d,雄蝇为10.2 d,雌雄寿命差异显著。取食10%蜂蜜水的平均产卵前期为3.8 d,平均产卵历期为15.4 d; 而且取食10%蔗糖水、葡萄糖水或蜂蜜水之间的成虫产卵量没有显著差异,但均显著高于取食清水或纯饥饿空白对照的;同时,取食补充营养的雌蝇寿命均显著高于取食清水或空白对照的,但雄蝇的寿命则不受补充营养的影响。取食补充营养的雌蝇寿命与产卵量为正相关,即雌蝇的寿命越长,产卵量越大。最后,就这些结果的应用价值进行了讨论。 相似文献
17.
Entrainment of Melatonin Rhythms in Rams By Symmetrical Light-Dark Cycles of Different Period Length 总被引:3,自引:0,他引:3
Jean-Paul Ravault Josephine Arendt Irene Tobler Didier Chesneau Odile Maulin 《Chronobiology international》1989,6(4):329-339
The objective of this study was to investigate the entrainment of melatonin rhythms in rams using symmetrical light-dark cycles of different period length. Five groups of six He de France rams were kept in 12L: 12D for 7 weeks and then (i) 12L: 12D, (ii) 11L: 11D, (iii) 10L: 10D, (iv) 13L: 13D and (v) 14L: 14D for a further 3 weeks. Environmental factors other than the light dark cycle were not controlled. The onset and offset of the plasma melatonin rhythm in DD after 3 weeks of the respective light treatments was assessed for 48 hr, immediately after transferring to DD. The duration of secretion in DD was positively related to the length of the previous dark phase. The phase of the melatonin rhythm with respect to the anticipated dark phase suggested entrainment with no change in phase-relationship to the zeitgeber by 12L: 12D and 13L : 13D. Entrainment with a phase-delay or a phase-advance was apparent after 11L: 11D and 14L: 14D, but the individual rhythms were not all synchronized with respect to each other after 10L: 10D. Activity recordings for 2-3-week periods during 12L: 12D, 10L: 10D and 14L: 14D all showed a major 24-hr component at all times, with activity during the light phase in 12L: 12D. It appears that melatonin may be readily desynchronized from overt activity-rest cycles in sheep. The upper and lower entrainment limits are probably greater than 28 hr and close to 20 hr cycles, respectively. 相似文献
18.
在温度为(24±2)℃、光周期为L∶D=14∶10、相对湿度为50%~70%环境条件下观察了马铃薯块茎蛾Phthorimaea operculella(Zeller)交配行为。结果表明,1~2日龄、3~4日龄成虫交配高峰期分别发生在进入暗期后的8.0~10.0h、6.5~8.0h内。两性交配率随日龄的增加显著下降。马铃薯块茎蛾雄成虫具有多次交配能力,在连续发生2次以上行为交配时会导致雄蛾有效交配率下降。雄蛾平均有效交配次数可达3.8次/头,最高达6次。增加雄性比例不会显著提高单雌产卵量,但将性比(♀:♂)由1∶1升至2∶1时即可显著降低单雌产卵量。 相似文献
19.
Abstract: Diapause was induced in a Central European population of Ips typographus grown at 20°C when the day length decreased below 16 h [50% diapause incidence occurred in the 14.7:9.3 h L:D (light:dark) regime]. The non-diapausing adults fed on days 2–6 and 10–14 after the ecdysis and swarmed after the second feeding bout with chorionated eggs in the ovaries and sperm in the spermiducts. Neither gonads nor the flight muscles matured and no swarming occurred in the diapausing adults. The development from egg to adult took about 34 days in both 18:6 h (no diapause) and 12:12 h L:D (diapause) regimes, but it was extended by up to 30% without diapause induction when only larvae or pupae were exposed to L:D 12:12 h. Diapause was induced in insects reared at L:D 12:12 h through the last larval and the pupal instars and/or in the adult stage. Temperature ≥ 23°C prevented diapause induction at L:D 12:12 h but diapause occurred at L:D 14:10 h associated with 26:6°C thermoperiod. The effect of thermoperiods on the developmental rate requires further research. Exposure of the non-diapausing adults to 5°C for several days blocked feeding and evoked a diapause-like state, whereas diapausing adults fed and their gonads slowly developed at this temperature. Diapausing adults exposed in forest to low night temperatures and transferred in October to 20°C readily reproduced at 18:6, but not 12:12 h L:D photoperiods. After 2-months at 5°C and darkness, they became insensitive to the photoperiod, matured and most of them also swarmed at 20°C in the 12:12 h L:D regime. In a Scandinavian population, diapause occurred at 18:6 h L:D and was terminated either by exposure to 5°C or by very long photoperiod (L:D 20:4 h) combined with high temperature (23°C). 相似文献
20.
The tachinid Celatoria compressa Wulp has been evaluated as a candidate biological control agent for the western corn rootworm, Diabrotica virgifera virgiferaLeConte, in Europe, where it is an invasive alien pest of maize. Special emphasis has been placed on understanding aspects of the parasitoid basic biology and on developing a rearing technique for a small-scale production of C. compressapuparia. The age of C. compressa adults was found to be the most crucial factor in achieving mating. Only newly emerged, 1-h-old females, mated successfully with 2- to 5-day-old males, achieving a success rate of 74%. After mating, a prelarviposition period of 4 days occurred. The 5-day-old C. compressa females inserted their eggs containing fully-developed first instars directly into adults of D. v. virgifera. Total larval and pupal developmental time, including a pre-larviposition period of 4 days, was 29 days under quarantine laboratory conditions (25 degrees C daytime, 15 degrees C at night, L:D 14:10, 50% +/- 10% r.h). Females of C. compressa were capable of producing on average 30 puparia throughout a female's mean larviposition period of 15 days. A large number of host attacks by C. compressa were unsuccessful, resulting in a mean larviposition success rate of 24% per female. Parasitoid females appear to have difficulties inserting the egg through the intersegmental sutures or membranes around leg openings of the host adults. Although the small-scale rearing technique of C. compressa presented is both time and labour intensive, C. compressa has been reared successfully for at least 20 successive generations without shifting the 1 male : 1 female sex ratio using a non-diapause strain of D. v. virgifera. 相似文献