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941.
The phospholipids of Hyphomicrobium vulgare NQ-521 have been separated by preparative thin-layer chromatography and analyzed by paper chromotography of the water-soluble products of acid and mild alkaline hydrolysis. The principal phospholipids are phosphatidyl ethanolamine (23%), phosphatidyl N,N'-dimethylethanolamine (36%), lecithin (29%), and phosphatidyl glycerol (10%). Three other strains of Hyphomicrobium were found to have similar phospholipid compositions. Growing cells incorporated the methyl group of methionine into lipid-bound N,N'-dimethylethanolamine and choline. Experiments with sonic extracts of H. vulgare NQ-521 and (14)C (methyl) S-adenosylmethionine demonstrated the formation of phosphatidyl N-monomethylethanolamine in addition to the dimethylethanolamine and choline phosphatides. 相似文献
942.
The Differentiation of Pigmentation in Flower Parts, IV. Flavonoid Elaborating Enzymes From Petals of Impatiens balsamina s
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Extracts of the flower petals of Impatiens balsamina L. contain enzymes which catalyze the glycosylation of phenolic compounds. Enzymes have been extracted which glycosylate hydroquinone to arbutin and at least 3 different flavonols to the 3-monoglucoside. The hydroquinone glucosylating enzyme is similar to enzymes previously described except that it requires an unidentified low molecular weight cofactor. The glucosylation of flavonols follows normal enzyme kinetics; it requires a nucleotide diphosphate glucose donor for activity, and is made more evident by the presence of glucono-1:5-lactone, an inhibitor of endogenous glucosidases. It is suggested that the flavonol glucosylating enzyme acts naturally to glucosylate a precursor of both flavonols and anthocyanins to the 3-monoglucoside. The only elaboration of an anthocyanin observed with petal extracts was an acylation of pelargonidin-3-monoglucoside. 相似文献
943.
Short‐ and long‐term acclimation patterns of the giant kelp Macrocystis pyrifera (Laminariales,Phaeophyceae) along a depth gradient
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Kristina Koch Martin Thiel Wilhelm Hagen Martin Graeve Iván Gómez David Jofre Laurie C. Hofmann Fadia Tala Kai Bischof 《Journal of phycology》2016,52(2):260-273
The giant kelp, Macrocystis pyrifera, is exposed to highly variable irradiance and temperature regimes across its geographic and vertical depth gradients. The objective of this study was to extend our understanding of algal acclimation strategies on different temporal scales to those varying abiotic conditions at various water depths. Different acclimation strategies to various water depths (0.2 and 4 m) between different sampling times (Jan/Feb and Aug/Sept 2012; long‐term acclimation) and more rapid adjustments to different depths (0.2, 2 and 4 m; short‐term acclimation) during 14 d of transplantation were found. Adjustments of variable Chl a fluorescence, pigment composition (Chl c, fucoxanthin), and the de‐epoxidation state of the xanthophyll cycle pigments were responsible for the development of different physiological states with respect to various solar radiation and temperature climates. Interestingly, the results indicated that phlorotannins are important during long‐term acclimation while antioxidants have a crucial role during short‐term acclimation. Furthermore, the results suggested that modifications in total lipids and fatty acid compositions apparently also might play a role in depth acclimation. In Aug/Sept (austral winter), M. pyrifera responded to the transplantation from 4 m to 0.2 m depth with a rise in the degree of saturation and a switch from shorter‐ to longer‐chain fatty acids. These changes seem to be essential for the readjustment of thylakoid membranes and might, thus, facilitate efficient photosynthesis under changing irradiances and temperatures. Further experiments are needed to disentangle the relative contribution of solar radiation, temperature and also other abiotic parameters in the observed physiological changes. 相似文献
944.
Cathryn Glazener Lynda Constable Christine Hemming Suzanne Breeman Andrew Elders Kevin Cooper Robert Freeman Anthony R. B. Smith Suzanne Hagen Alison McDonald Gladys McPherson Isobel Montgomery Mary Kilonzo Dwayne Boyers Beatriz Goulao John Norrie 《Trials》2016,17(1)
BackgroundOne in three women who have a prolapse operation will go on to have another operation, though not necessarily in the same compartment. Surgery can result in greater impairment of quality of life than the original prolapse itself (such as the development of new-onset urinary incontinence, or prolapse at a different site). Anterior and posterior prolapse surgery is most common (90 % of operations), but around 43 % of women also have a uterine (34 %) or vault (9 %) procedure at the same time. There is not enough evidence from randomised controlled trials (RCTs) to guide management of vault or uterine prolapse. The Vault or Uterine prolapse surgery Evaluation (VUE) study aims to assess the surgical management of upper compartment pelvic organ prolapse (POP) in terms of clinical effectiveness, cost-effectiveness and adverse events.Methods/designVUE is two parallel, pragmatic, UK multicentre, RCTs (Uterine Trial and Vault Trial). Eligible for inclusion are women with vault or uterine prolapse: requiring a surgical procedure, suitable for randomisation and willing to be randomised. Randomisation will be computer-allocated separately for each trial, minimised on: requiring concomitant anterior and/or posterior POP surgery or not, concomitant incontinence surgery or not, age (under 60 years or 60 years and older) and surgeon. Participants will be randomly assigned, with equal probability to intervention or control arms in either the Uterine Trial or the Vault Trial. Uterine Trial participants will receive either a vaginal hysterectomy or a uterine preservation procedure. Vault Trial participants will receive either a vaginal sacrospinous fixation or an abdominal sacrocolpopexy. Participants will be followed up by postal questionnaires (6 months post surgery and 12 months post randomisation) and also reviewed in clinic 12 months post surgery. The primary outcome is the participant-reported Pelvic Organ Prolapse Symptom Score (POP-SS) at 12 months post randomisation.DiscussionDemonstrating the efficacy of vault and uterine prolapse surgeries is relevant not only to patients and clinicians but also to health care providers, both in the UK and globally.
Trial registration
Current controlled trials ISRCTN86784244 (assigned 19 October 2012), and the first subject was randomly assigned on 1 May 2013Electronic supplementary material
The online version of this article (doi:10.1186/s13063-016-1576-x) contains supplementary material, which is available to authorized users. 相似文献945.
Uncoupling proteins 1 and 3 are regulated differently 总被引:3,自引:0,他引:3
Using a heterologous yeast expression system, we have previously found a marked discordance between the effects of uncoupling protein (UCP) 1 and UCP3L on basal O(2) consumption in whole yeast versus isolated mitochondria. In whole yeast, UCP3L produces a greater stimulation of basal O(2) consumption, while in isolated mitochondria, UCP1 produces a much greater effect. As shown previously and in this report, UCP3L, in contrast to UCP1, is not inhibited by purine nucleotides. In the present study, we addressed two hypothetical mechanisms that could account for the observed discordance: (i) in whole yeast, purine nucleotides inhibit UCP1 but not UCP3L and (ii) preparations of isolated mitochondria lack an activator of UCP3L that is normally present in vivo. By use of a mutant of UCP1 that lacks purine nucleotide inhibition, it is demonstrated that cytosolic concentrations of purine nucleotides present in yeast effectively inhibit UCP1 activity. This suggests that the lower activity of UCP1 compared to UCP3L in whole yeast is due to purine nucleotide inhibition of UCP1 but not UCP3L. As potential activators of UCP3L we tested free fatty acids in whole yeast and isolated mitochondria. While UCP1 was strongly activated by free fatty acids, no stimulatory effect on UCP3L was observed. In summary, this study indicates that UCP1 and UCP3L differ in their regulation by purine nucleotides and free fatty acids. This different regulation may be related to different physiological functions of the two proteins. 相似文献
946.
Cornils A.; Schnack-Schiel S. B.; Hagen W.; Dowidar M.; Stambler N.; Plahn O.; Richter C. 《Journal of plankton research》2005,27(6):505-518
The distribution pattern, taxonomic composition and communitystructure of mesozooplankton was studied along a transect with10 positions between the Gulf of Aqaba and the northern RedSea. Five positions were resampled two or three times duringa cruise of RV Meteor in February/March 1999.In spite of clear differences in the density stratificationbetween the Gulf of Aqaba and the northern Red Sea, the mesozooplanktoncomposition was very similar: Copepods were by far the mostabundant taxon, contributing 7695% to the total community.The remainder was composed largely of ostracods, chaetognaths,appendicularians and molluscs. The mesozooplankton of the deeplymixed stations was homogeneously distributed, at all other stationsthe bulk of the mesozooplankton (>70%) was concentrated inthe mixed surface layer with peaks of calanoids, cyclopoidsand appendicularians in the vicinity of the chlorophyll a (Chla) maximum layer. Ostracods and poecilostomatoids dominatedthe layers below. Standing stocks within the total water column(5501200 m) varied between 93 and 431 x 103 individualsm2 for copepods and 576 x 103 individuals m2for other mesozooplankton with highest numbers in the northernGulf of Aqaba, where vertical mixing was deep (400500m) and Chl a and mesozooplankton distributions homogeneous throughoutthe water column. Towards the south, the mixed depth decreasedfrom 300 m in the central Gulf of Aqaba to 50 m in the Red Sea.Cluster analysis separated three distinct groups of stations,compounding the observed differences between the northern Gulfof Aqaba (Position I) and the other positions. The analysisalso revealed temporal differences between the February andMarch sections of the cruise, indicating the winterspringtransition. The stations sampled in March are characterisedby a higher total abundance and by a higher percentage of appendiculariansand ostracods than the stations sampled in February 相似文献
947.
The 1998 El Ni?o significantly reduced garden productivity in the Upper Orinoco region in Venezuela. Consequently, parents were forced to allocate food carefully to their children. Nutrition data collected from village children combined with genealogical data allowed the determination of which children suffered most, and whether the patterns of food distribution accorded with predictions from parental investment theory. For boys, three social variables accounted for over 70% of the variance in subcutaneous fat after controlling for age: number of siblings, age of the mother's youngest child, and whether the mother was the senior or junior co-wife, or was married monogamously. These results accord well with parental investment theory. Parents experiencing food stress faced a trade-off between quantity and quality, and between investing in younger versus older offspring. In addition, boys with access to more paternal investment (i.e. no stepmother) were better nourished. These variables did not account for any of the variance in female nutrition. Girls' nutrition was associated with the size of their patrilineage and the number of non-relatives in the village, suggesting that lineage politics may have played a role. An apparent lack of relationship between orphan status and nutrition is also interesting, given that orphans suffered high rates of skin flea infections. The large number of orphans being cared for by only two grandparents suggests that grooming time may have been the resource in short supply. 相似文献
948.
Detection and Identification of Lactobacillus Species in Crops of Broilers of Different Ages by Using PCR-Denaturing Gradient Gel Electrophoresis and Amplified Ribosomal DNA Restriction Analysis
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Le Luo Guan Karen E. Hagen Gerald W. Tannock Doug R. Korver Gaylene M. Fasenko Gwen E. Allison 《Applied microbiology》2003,69(11):6750-6757
The microflora of the crop was investigated throughout the broiler production period (0 to 42 days) using PCR combined with denaturing gradient gel electrophoresis (PCR-DGGE) and selective bacteriological culture of lactobacilli followed by amplified ribosomal DNA restriction analysis (ARDRA). The birds were raised under conditions similar to those used in commercial broiler production. Lactobacilli predominated and attained populations of 108 to 109 CFU per gram of crop contents. Many of the lactobacilli present in the crop (61.9% of isolates) belonged to species of the Lactobacillus acidophilus group and could not be differentiated by PCR-DGGE. A rapid and simple ARDRA method was developed to distinguish between the members of the L. acidophilus group. HaeIII-ARDRA was used for preliminary identification of isolates in the L. acidophilus group and to identify Lactobacillus reuteri and Lactobacillus salivarius. MseI-ARDRA generated unique patterns for all species of the L. acidophilus group, identifying Lactobacillus crispatus, Lactobacillus johnsonii, and Lactobacillus gallinarum among crop isolates. The results of our study provide comprehensive knowledge of the Lactobacillus microflora in the crops of birds of different ages using nucleic acid-based methods of detection and identification based on current taxonomic criteria. 相似文献
949.
The Tetrahymena pre-rRNA self-splicing intron is shown to function in the unnatural context of an mRNA transcribed by RNA polymerase II in mammalian cells. Mutational analysis supports the conclusion that splicing in cells occurs by the same RNA-catalyzed mechanism established for splicing in vitro. Insertion of the intron at five positions spanning the luciferase open reading frame revealed 10-fold differences in accumulation of ligated exons and in luciferase activity; thus, the intron self-splices in many exon contexts, but the context can have a significant effect on activity. In addition, even the best self-splicing constructs, which produced half as much mRNA as did an uninterrupted luciferase gene, gave approximately 100-fold less luciferase enzyme activity, revealing an unexpected discontinuity between mRNA production and translation in cells. The finding that production of accurately spliced mRNA in cells does not guarantee a corresponding level of protein production is surprising, and may have implications for the development of trans-splicing ribozymes as therapeutics. 相似文献
950.
Arabidopsis thaliana contains at least four genes that are predicted to encode polypeptides related to the RPB5 subunit found in yeast and human RNA polymerase II. This subunit has been shown to be the largest subunit common to yeast RNA polymerases I, II, and III (RPABC27). More than one of these genes is expressed in Arabidopsis suspension culture cells, but only one of the encoded polypeptides is found in purified RNA polymerases II and III. This polypeptide has a predicted pI of 9.6, matches 14 of 16 amino acids in the amino terminus of cauliflower RPB5 that was microsequenced, and shows 42 and 53% amino acid sequence identity with the yeast and human RPB5 subunits, respectively. 相似文献