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221.
采用组织灌流和组织块贴壁法体外培养奶牛乳腺组织,通过LDH活力测定、台盼蓝染色、琼脂糖凝胶电泳、透射电镜技术比较两种培养方法对奶牛乳腺组织活性及组织超微结构的影响,建立奶牛乳腺组织的培养体系。结果表明,以1mL/h的速度灌流培养的奶牛乳腺组织在DMEM 10%小牛血清培养基中12~60h内保持良好的组织活性和超微结构,贴壁培养的奶牛乳腺组织在DMEM 10%小牛血清的培养基中60~108h内保持良好的组织活性和超微结构,两种培养方法各有优缺点。 相似文献
222.
为获得ɑ-乙酰乳酸脱羧酶的高产突变株,以产ɑ-ALDC的枯草芽孢杆菌3226-5为出发菌株进行了诱变处理。经过微波(小火)物理诱变得到3株高产正突变株W181、W184、W195,经过多次传代实验,表明W181、W195是稳定的突变株。突变株W195的ɑ-ALDC相对酶活(OD522)由出发菌株的0.35提高到0.617,提高了76%,突变株W181提高了66.9%。 相似文献
223.
1. This study investigates the basis and ecological significance of the extremely high propensity for mixis (sexual reproduction) observed in laboratory populations of Brachionus calyciflorus from a temporary pond in Patagonia. 2. Experiments with stem females hatched from resting eggs showed that these females were exclusively amictic but produced mictic daughters even at very low population densities. In six experiments, newly hatched stem females were cultured individually in different volumes (1.5, 12, 40 and 150 mL). The percentage of mictic daughters (mixis ratio) was high in the smaller volumes (e.g. 44–83% in 1.5 mL) and lower in the largest volume (6–21% in 150 mL). A regression analysis combining the data from these experiments showed a highly significant decrease in mixis ratio with volume and indicated that the lowest population density at which mixis still occurs (mixis threshold) would be 3.4 females L?1 (95% CL 2.9–4.0 females L?1). This value is considerably lower than mixis thresholds for other rotifers (25–250 females L?1 for many species and 9000–477 000 females L?1 for some Spanish Brachionus plicatilis). 3. In three additional experiments, stem females and their amictic daughters were cultured individually in 150 mL. The percentage of mictic daughters produced by these two generations of females was not significantly different, showing that the mixis response to crowding is not inhibited in the stem‐female generation. 4. Laboratory experiments showed that two common predators of the Patagonian B. calyciflorus (the calanoid copepod Parabroteas sarsi and the backswimmer Notonecta vereertbruggheni) each ate 60–70 B. calyciflorus predator?1 per day and cleared all rotifers from c. 250 mL per day. Thus, a very low mixis threshold and high maximal mixis ratio may ensure production of some resting eggs soon after colonisation of the pond and before complete removal from the plankton. 5. Two laboratory experiments showed that resting eggs of the Patagonian B. calyciflorus hatched at variable rates (28 and 81%) after a brief diapause when kept in the conditions under which they were produced and oviposited (20–21 °C; L: D 16: 8). Early hatching of resting eggs from pond sediment may allow multiple periods of colonisation and resting egg production in a season. This may offset the fitness cost of limited population growth through female parthenogenesis in the face of unpredictable and abrupt risk of extinction because of predators. 相似文献
224.
Renato Milani Carmen V. Ferreira José M. Granjeiro Edgar J. Paredes‐Gamero Rodrigo A. Silva Giselle Z. Justo Helena B. Nader Eduardo Galembeck Maikel P. Peppelenbosch Hiroshi Aoyama Willian F. Zambuzzi 《Journal of cellular biochemistry》2010,109(5):957-966
Cell adhesion on surfaces is a fundamental process in the emerging biomaterials field and developmental events as well. However, the mechanisms regulating this biological process in osteoblasts are not fully understood. Reversible phosphorylation catalyzed by kinases is probably the most important regulatory mechanism in eukaryotes. Therefore, the goal of this study is to assess osteoblast adhesion through a molecular prism under a peptide array technology, revealing essential signaling proteins governing adhesion‐related events. First, we showed that there are main morphological changes on osteoblast shape during adhesion up to 3 h. Second, besides classical proteins activated upon integrin activation, our results showed a novel network involving signaling proteins such as Rap1A, PKA, PKC, and GSK3β during osteoblast adhesion on polystyrene. Third, these proteins were grouped in different signaling cascades including focal adhesion establishment, cytoskeleton rearrangement, and cell‐cycle arrest. We have thus provided evidence that a global phosphorylation screening is able to yield a systems‐oriented look at osteoblast adhesion, providing new insights for understanding of bone formation and improvement of cell–substratum interactions. Altogether, these statements are necessary means for further intervention and development of new approaches for the progress of tissue engineering. J. Cell. Biochem. 109: 957–966, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
225.
VALERIA DI BONA MARIA CRISTINA LORENZI GABRIELLA SELLA 《Biological journal of the Linnean Society. Linnean Society of London》2010,100(2):451-456
In the mating system of simultaneously hermaphroditic animals, sexual allocation is predicted to vary as a function of the number of potential mates. According to the Hermaphrodite's Dilemma, sexual conflict over the preferred sexual role in hermaphroditic animals is resolved by reciprocity (i.e. by alternating sexual roles), accompanied by the animals' occasional cheating in the preferred role at a relatively low frequency. In a 350‐generation‐old laboratory strain of the pair‐mating outcrossing hermaphroditic polychaete worm Ophryotrocha diadema, we show that 9% of the individuals mated only in the male role over long periods, indicating a male‐role preference (temporary functional males). Furthermore, 2% of the individuals mated for their whole lifetime exclusively as males (permanent functional males). These findings indicate that the sex allocation of some individuals may vary from the predicted optimal sex allocation for the population. Morphologically, functional males exhibited a hermaphroditic phenotype (i.e. they matured a single batch of oocytes that they never laid and acted as functional males). We show that temporary functional males appeared in hermaphroditic populations under promiscuous mating regimes significantly more often than under monogamous ones. Indeed, under promiscuity, there are many mating opportunities and O. diadema hermaphrodites compete for mates, whereas, under monogamy, the two partners regularly take turns in laying cocoons and fertilizing their partner's cocoon. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100 , 451–456. 相似文献
226.
Paul Eastwood Jacob Gonzalez Sergio Paredes Arsenio Nueda Teresa Domenech Joan Alberti Bernat Vidal 《Bioorganic & medicinal chemistry letters》2010,20(5):1697-1700
The synthesis and SAR of a series of N-(5,6-diarylpyridin-2-yl)amide derivatives as potent A2B adenosine receptor antagonists is described. Several compounds showed good selectivity versus other adenosine receptors. The potent and selective analogue 9 was shown to have good oral bioavailability in the rat. 相似文献
227.
Seven years of recent European net terrestrial carbon dioxide exchange constrained by atmospheric observations 总被引:1,自引:0,他引:1
W. PETERS M. C. KROL G. R. Van Der WERF S. HOUWELING C. D. JONES J. HUGHES K. SCHAEFER K. A. MASARIE A. R. JACOBSON J. B. MILLER C. H. CHO M. RAMONET M. SCHMIDT L. CIATTAGLIA F. APADULA D. HELTAI F. MEINHARDT A. G. DI SARRA S. PIACENTINO D. SFERLAZZO T. AALTO J. HATAKKA J. STRÖM L. HASZPRA H. A. J. MEIJER S. VAN DER LAAN R. E. M. NEUBERT A. JORDAN X. RODÓ J.‐A. MORGUÍ A. T. VERMEULEN E. POPA K. ROZANSKI M. ZIMNOCH A. C. MANNING M. LEUENBERGER C. UGLIETTI A. J. DOLMAN P. CIAIS M. HEIMANN P. P. TANS 《Global Change Biology》2010,16(4):1317-1337
228.
目的:探索了超声波对石榴皮鞣花酸提取率的影响.方法:利用超声萃取和酸水解一步提取鞣花酸,分别探讨了萃取温度、水解酸度和超声时间对鞣花酸提取率的影响,并对工艺参数进行优化.结果:在最佳工艺条件:萃取温度60℃,水解酸度1.5mol/L,超声萃取30min时,鞣花酸提取率最高达4.3%.结论:超声波萃取石榴皮鞣花酸工艺具有低成本、节能和高效的特点,值得在医药和食品加工企业推广应用. 相似文献
229.
Oscar Chacon‐Camacho Rafael B. R. Leon‐Cachon Sergio G. Munoz‐Jimenez Stefanie Nowak Jessica Becker Ruth Herberz Kerstin U. Ludwig Mario Paredes‐Zenteno Abelardo Arizpe‐Cantú Susanne Raeder Stefan Herms Rocio Ortiz‐Lopez Michael Knapp Per Hoffmann Markus M. Nöthen Elisabeth Mangold 《Birth defects research. Part A, Clinical and molecular teratology》2010,88(7):535-537
INTRODUCTION: Nonsyndromic cleft lip with or without cleft palate (NSCL/P) is one of the most common of all birth defects. NSCL/P has a multifactorial etiology that includes both genetic and environmental factors. The IRF6 gene and three further susceptibility loci at 8q24, 10q25, and 17q22, which were identified by a recent genome‐wide association scan (GWAS), are confirmed genetic risk factors for NSCL/P in patients of European descent. METHODS: A case‐control association study was performed to investigate whether these four risk loci contribute to NSCL/P in a Mesoamerican population using four single nucleotide polymorphisms to represent IRF6 and the three novel susceptibility loci. A total of 149 NSCL/P patients and 303 controls of Mayan origin were included. RESULTS: Single marker analysis revealed a significant association between NSCL/P and risk variants in IRF6 and the 8q24 and 10q25 loci. In contrast to previous findings, the association at the 8q24 locus was driven solely by homozygote carriers of the risk allele. This suggests that this locus might act in a recessive manner in the Mayan population. No evidence for association was found at the 17q22 locus. This may have been attributable to the limited power of the sample. CONCLUSION: These results suggest that IRF6 and the 10q25 and 8q24 loci confer a risk for the development of NSCL/P in persons of Mayan origin. Birth Defects Research (Part A), 2010. © 2010 Wiley‐Liss, Inc. 相似文献