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31.
Sedat Altug Orhan Uludag Bahar Tunctan Iclal Cakici Hakan Zengil 《Chronobiology international》2013,30(3):583-591
We previously demonstrated the rhythmic pattern of L‐arginine/nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) cascade in nociceptive processes. The coupled production of excess NO and superoxide leads to the formation of an unstable intermediate peroxynitrite, which is primarily responsible for NO‐mediated toxicity. In the present study, we evaluated the biological time‐dependent effects of exogenously administered peroxynitrite on nociceptive processes and peroxynitrite‐induced changes in the analgesic effect of morphine using the mouse hot‐plate pain model. Experiments were performed at four different times of day (1, 7, 13, and 19 hours after lights on, i.e., HALO) in mice of both sexes synchronized to a 12 h:12 h light‐dark cycle. Animals were injected intraperitoneally (i.p.) with saline or 10 mg/kg morphine 30 min before and 0.001 mg/kg peroxynitrite 30 sec before hot‐plate testing, respectively. The analgesic effect of morphine exhibited significant biological time‐dependent differences in the thermally‐induced algesia; whereas, administration of peroxynitrite alone exhibited either significant algesic or analgesic effect, depending on the circadian time of its injection. Concomitant administration of peroxynitrite and morphine reduced morphine‐induced analgesia at three of the four different study time points. In conclusion, peroxynitrite displayed nociceptive and antinociceptive when administered alone according to the circadian time of treatment, while it diminished analgesic activity when administered in combination with morphine at certain biological times. 相似文献
32.
E. W. Evans N. R. Carlile M. B. Innes N. Pitigala 《Journal of Applied Entomology》2013,137(5):383-391
Variation in weather among years may affect biological control of insect pests by influencing how well matched in phenology specialist parasitoids are with their pest hosts. A 10‐year study in western North America (Utah) revealed greater change with warm versus cool springs in the life cycle timing of the cereal leaf beetle (CLB), Oulema melanopus (L.), than of its principal enemy, the parasitoid wasp Tetrastichus julis (Walker). The beetle laid eggs, and larval populations developed in crop fields earlier on a calendar‐day basis, but nonetheless after more degree‐days had accumulated, in warmer than in cooler springs. The phenology of parasitism by wasps, in contrast, varied little among springs in relation to accumulated degree‐days. Consequently, in warmer springs, larval phenology of the CLB was delayed relative to adult parasitoid activity, and parasitism was reduced. Presently, a significant degree of biological control of the CLB results from parasitism by T. julis. By promoting phenological mismatch between host and parasitoid, however, a warming climate could weaken this biological control of the insect pest. 相似文献
33.
34.
Batrachochytrium dendrobatidis (Bd) is a fungus that can potentially lead to chytridiomycosis, an amphibian disease implicated in die-offs and population
declines in many regions of the world. Winter field surveys in the last decade have documented die-offs in populations of
the lowland leopard frog Rana yavapaiensis with chytridiomycosis. To test whether the fungus persists in host populations between episodes of observed host mortality,
we quantified field-based Bd infection rates during nonwinter months. We used PCR to sample for the presence of Bd in live
individuals from nine seemingly healthy populations of the lowland leopard frog as well as four of the American bullfrog R. catesbeiana (a putative vector for Bd) from Arizona. We found Bd in 10 of 13 sampled populations. The overall prevalence of Bd was 43%
in lowland leopard frogs and 18% in American bullfrogs. Our results suggest that Bd is widespread in Arizona during nonwinter
months and may become virulent only in winter in conjunction with other cofactors, or is now benign in these species. The
absence of Bd from two populations associated with thermal springs (water >30°C), despite its presence in nearby ambient waters,
suggests that these microhabitats represent refugia from Bd and chytridiomycosis. 相似文献
35.
《Saudi Journal of Biological Sciences》2022,29(4):2291-2298
The study aims to investigate the effect of foliar spray with three plant growth regulators (PGRs) p-Chlorophenoxyacetic acid (CPA) at 20 and 40 ppm; Gibberellic acid (GA3) at 20 and 30 ppm, 1-Naphthaleneacetic acid (NAA) at 10 and 20 ppm on the response of fruit set, yield, and fruit quality of some hot pepper cultivars (Chillina, Parbirian, Shampion, and Hyffa) grown in sandy soil under plastic tunnels as compared to the control. Spraying Chillina cultivar GA3 at 30 ppm significantly increased the number of fruits/ plant and fruit set (%), yield/plant, and total yield/fad. In addition, the contents of TSS and Vit C, furthermore, maximum capsaicin content were observed in chili fruits in both seasons. However, the interaction between Chillina cultivar and spraying with GA3 at 20 ppm ranked second in yield and quality. The interaction between Parbirian cultivars and spraying with GA3 at 20 or 30 ppm increased the number of flowers/plants in both seasons. On the other hand, the interaction between Shampion cultivar and spraying with tap water (control) gave the lowest values of the number of flowers/ plants, the number of fruits/ plant and fruit set (%), yield, and its components, and fruit quality in both seasons. 相似文献
36.
近些年来,治疗性重组蛋白类药物是生物制药领域研究的热点。工业化生产中常用于重组蛋白表达的细胞系是中国仓鼠卵巢(Chinese hamster ovary,CHO)细胞。传统CHO细胞系的表达大多数基于随机整合的方式,这可能会使目标基因整合到异染色质区域或者不稳定的染色质区域,导致CHO细胞表达不稳定,需要多轮筛选才能获得理想的表达细胞系。最新研究表明,外源基因在CHO细胞预测/特定的基因组位点中进行特异性整合,可以使重组CHO细胞的表达保持长期一致性和稳定性。CHO细胞基因组中高效稳定的转录整合位点被称为热点(hot spot)。阐述CHO细胞基因组稳定的hot spot位点近几年的研究进展,其中包括热门的hot spot位点,以及如何研究新的hot spot位点的方法。总结如何将外源基因高效定位于预测的CHO细胞hot spot位点,实现高水平稳定的表达重组蛋白,为发现新的有效的hot spot位点,构建稳定表达CHO细胞系提供参考。 相似文献
37.
38.
The Availability of Phosphorus and the Species Composition of the Spring Phytoplankton in Lake Erken
Kurt Pettersson 《International Review of Hydrobiology》1985,70(4):527-546
The spring development of phytoplankton and the phosphorus content were monitored intensively in Laken Erken during the springs of 1979 and 1980. The dominant species were dinoflagellates, mainly Woloszynskia ordinata and Peridinium aciculiferum, during the entire spring of 1979. The long period of ice-cover (21 weeks) favoured the motile species, which were able to utilize the available light immediately below the ice. A considerable vertical migration was noticed in March 1979. These large and slow-growing algae were able to store luxury phosphorus, and surplus phosphorus concentrations up to 12 μg P/l were measured, which corresponded to an algal content of 10 μg P/mg C. These values were more than twice as high as those recorded earlier in Lake Erken. Although a spring outburst of diatoms did not occur in 1979 and 1980, the algae were phosphorus-limited in May, as indicated by high alkaline phosphatase activity, low algal surplus phosphorus content and high inorganic N : P ratios. 相似文献
39.
Ferreira AC Nobre MF Moore E Rainey FA Battista JR da Costa MS 《Extremophiles : life under extreme conditions》1999,3(4):235-238
In this study we characterized new strains of the slightly thermophilic species Rubrobacter radiotolerans and the thermophilic species Rubrobacter xylanophilus, both of which were previously represented only by the type strains isolated, respectively, from Japan and the United Kingdom.
The new isolates were recovered from two hot springs in central Portugal after gamma irradiation of water and biofilm samples.
We assessed biochemical characteristics, performed DNA–DNA hybridization, and carried out 16S rDNA sequence analysis to demonstrate
that the new Rubrobacter isolates belong to the species R. radiotolerans and R. xylanophilus. We also show for the first time that the strains of R. xylanophilus and other strains of R. radiotolerans are extremely gamma radiation resistant.
Received: October 16, 1998 / Accepted: April 25, 1999 相似文献
40.
A new bacterial strain capable of producing cellulose was isolated from a hot spring. The isolate was Gram-negative, aerobic, and rod-shaped. The optimum temperature for growth was 40-45 degrees C. Methanol, glucose and other common carbohydrates were not utilized as sole growth substrates. Thiosulfate was not oxidized. The G+C content of the DNA was determined to be 64.0 mol%. Comparative 16S rDNA analysis indicated that Bosea thiooxidans and some strains of the genus Methylobacterium were the nearest relatives. The isolate can be distinguished from these relatives by its defectiveness in methanol utilization and thiosulfate oxidation. On the basis of its phenotypic properties and phylogeny, it is proposed that the isolate be designated Balneomonas flocculans gen. nov., sp. nov. The type strain is TFBT (= JCM 11936T, = KCTC 12101T, = IAM 15034T, = ATCC BAA-817T). 相似文献