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1.
We present phylogenetic analyses (parsimony, maximum likelihood and Bayesian inference) for 69 lineages of anthoathecate hydroids based on 18 morphological characters (12 proposed for the first time) plus mitochondrial (16S and COI) and nuclear (18S and 28S) molecular markers. This study aims to test the monophyly of the present concept of the family Bougainvilliidae, assessing its phylogenetic position within Hydroidolina. Our working hypothesis is used as a context for inferring the evolution of certain morphological characters, focusing on the exoskeleton. Our results shed light on some phylogenetic uncertainties within Hydroidolina, delimiting eight well‐supported linages, viz. Hydroidolina, Siphonophorae, Leptothecata, Aplanulata, Filifera II, Filifera III, Capitata and Pseudothecata taxon novum, the latter supported by four morphological synapomorphies. The monophyly of several families was not supported, viz. Bougainvilliidae, Cordylophoridae, Oceaniidae, Rathkeidae and Pandeidae. Some of the genera typically considered in Bougainvilliidae, including Bougainvillia, fell into the clade Pseudothecata, which is consistently reconstructed as the sister group of Leptothecata. We formally suggest that Dicoryne be removed from Bougainvilliidae and placed in the resurrected family Dicorynidae. The exoskeleton was a key feature in the diversification of Hydroidolina, especially with the transition from the bare hydranth to one completely enveloped within the exoskeleton. In this context, bougainvilliids exhibit several intermediate states in the development of the exosarc. Although the concatenated analysis unravels some interesting hypotheses, taxon sampling is still deficient and therefore more data are necessary for achieving a more complete understanding of the evolution and ecology of bougainvilliids and their allies.  相似文献   

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Cerium (IV) initiated “graft‐from” polymerization reactions were employed to convert M‐PVA magnetic particles into polyacrylic acid‐fimbriated magnetic cation exchange supports displaying ultra‐high binding capacity for basic target proteins. The modifications, which were performed at 25 mg and 2.5 g scales, delivered maximum binding capacities (Qmax) for hen egg white lysozyme in excess of 320 mg g?1, combined with sub‐micromolar dissociation constants (0.45–0.69 µm) and “tightness of binding” values greater than 49 L g?1. Two batches of polyacrylic acid‐fimbriated magnetic cation exchangers were combined to form a 5 g pooled batch exhibiting Qmax values for lysozyme, lactoferrin, and lactoperoxidase of 404, 585, and 685 mg g?1, respectively. These magnetic cation exchangers were subsequently employed together with a newly designed “rotor–stator” type HGMF rig, in five sequential cycles of recovery of lactoferrin and lactoperoxidase from 2 L batches of a crude sweet bovine whey feedstock. Lactoferrin purification performance was observed to remain relatively constant from one HGMF cycle to the next over the five operating cycles, with yields between 40% and 49% combined with purification and concentration factors of 37‐ to 46‐fold and 1.3‐ to 1.6‐fold, respectively. The far superior multi‐cycle HGMF performance seen here compared to that observed in our earlier studies can be directly attributed to the combined use of improved high capacity adsorbents and superior particle resuspension afforded by the new “rotor–stator” HGMS design. Biotechnol. Bioeng. 2013; 110: 1714–1725. © 2013 Wiley Periodicals, Inc.  相似文献   

4.
Rechargeable aqueous Zn‐based batteries are attractive candidates as energy storage technology, but the uncontrollable Zn dendrites, low stripping/plating coulombic efficiency, and inefficient utilization of Zn metal limit the battery reliability and energy density. Herein, for the first time, a novel presodiated TiS2 (Na0.14TiS2) is proposed and investigated as an intercalated anode for aqueous Zn‐ion batteries, showing a capacity of 140 mAh g?1 with a suitable potential of 0.3 V (vs Zn2+/Zn) at 0.05 A g?1 and superior cyclability of 77% retention over 5000 cycles at 0.5 A g?1. The remarkable performance originates from the buffer phase formation of Na0.14TiS2 after chemically presodiating TiS2, which not only improves the structural reversibility and stability but also enhances the diffusion coefficient and electronic conductivity, and lowers cation migration barrier, as evidenced by a series of experimental and theoretical studies. Moreover, an aqueous “rocking‐chair” Zn‐ion full battery is successfully demonstrated by this Na0.14TiS2 anode and ZnMn2O4 cathode, which delivers a capacity of 105 mAh g?1 (for anode) with an average voltage of 0.95 V at 0.05 A g?1 and preserves 74% retention after 100 cycles at 0.2 A g?1, demonstrating the feasibility of Zn‐ion full batteries for energy storage applications.  相似文献   

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Phototherapy Miniaturization of electronics, small enough to be integrated into textiles, offer new opportunities for medical technology and phototherapy. Measuring physiological body functions and the use of semiconductors like light emitting diodes (LEDs) actively influencing physiology are examples for these kinds of innovations.  相似文献   

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The internally transcribed spacer (ITS) sequences of 21 Arthrospira clonal strains from four continents and assigned to four different species (A. platensis, A. maxima, A. fusiformis, A. indica) in the culture collections were determined. Two main clusters, I and II, were differentiated by 49 positions out of 475 nt or 477 nt, respectively. Each cluster was further subdivided into two subclusters. Subclusters I.A and I.B were separated by two substitutions, whereas subclusters II.A and II.B were distinguished by four substitutions. After direct sequencing of the PCR products, three dried samples from Chad aged between 3 months and 35 years yielded a sequence belonging to subcluster I.A, as did a recent commercial product. The strains grown in production plants belonged to the same (sub)clusters as strains from culture collections, mainly I.A and II. PCR primers specific for each cluster and subcluster were designed and tested with crude cell lysates of Arthrospira strains. One dried sample (“dihé” 1) and a herbarium sample from Lake Sonachi (Kenya) only contained I.A sequences, whereas the commercial product was a mixture of the four genotypes and the other two dried samples contained minor polymorphisms characteristic of different clusters. Five clonal Arthrospira strains, thought to be duplicates, showed the simultaneous presence of the two forms of the four diagnostic positions that distinguish subclusters genotype II.A and genotype II.B. This is likely to be caused by multiple copies of the rDNA operon, in a intermediate stage of homogenization between subcluster II.A and subcluster II.B. The high conservation of ITS sequences is in contrast with the assignment to four different species, the great morphological variability of the strains, and their wide geographic distribution.  相似文献   

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Preliminary observations were made between October 1982 and May 1983 on the nature, taxonomic composition, spatial distribution, buoyancy behaviour and nutrient requirements of some unusual planktonic algal “jellies” in Oguta Lake in Southeastern Nigeria. These “jellies” are macroscopic, blue-green algal masses whose excessive mucilage of high consistency acts as substrata for other epiphytic components viz. diatoms and green algae. They are more abundant in the lentic areas of the lake, undergo diurnal vertical movements and have their growth enhanced by spikes of nitrogen and phosphorus salts into their aquatic medium. The effects of these “jellies” on the ecology and general water use of the lake are discussed. Speculations on the reasons for their occurrence are given and possible control measures outlined.  相似文献   

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Biophysical methods allow quantitative deductions as to the “bending effectivity” of various stele types and the contribution of different tissues to the stability of upright plant axes. Considering the first occurrence of the different stele types in geological history, a strong tendency towards a higher “bending effectivity” can be observed. It can be shown that Rhynia gwynne-vaughanii, Aglaophyton major (Rhynia major) and Asteroxylon mackiei as well as probably the vast majority of early “vascular” land plants were turgor systems, i.e. that the parenchyma (when fully turgescent) is by far the most important contributory factor towards the bending stability of the upright axes.  相似文献   

10.
We develop nonparametric maximum likelihood estimation for the parameters of an irreversible Markov chain on states from the observations with interval censored times of 0 → 1, 0 → 2 and 1 → 2 transitions. The distinguishing aspect of the data is that, in addition to all transition times being interval censored, the times of two events (0 → 1 and 1 → 2 transitions) can be censored into the same interval. This development was motivated by a common data structure in oral health research, here specifically illustrated by the data from a prospective cohort study on the longevity of dental veneers. Using the self‐consistency algorithm we obtain the maximum likelihood estimators of the cumulative incidences of the times to events 1 and 2 and of the intensity of the 1 → 2 transition. This work generalizes previous results on the estimation in an “illness‐death” model from interval censored observations.  相似文献   

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The results of a detailed morphological analysis of the skull attributed to Mozart are presented which refute a recent claim that the skull as well as several of Mozart's portraits show indications of uncomplicated trigonocephaly. These indications according to the present analysis are within the limits of normal variation and derive from retention of part of the long arm of the anterior fontanelle.  相似文献   

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Electrode stabilization by surface passivation has been explored as the most crucial step to develop long‐cycle lithium‐ion batteries (LIBs). In this work, functionally graded materials consisting of “conversion‐type” iron‐doped nickel oxyfluoride (NiFeOF) cathode covered with a homologous passivation layer (HPL) are rationally designed for long‐cycle LIBs. The compact and fluorine‐rich HPL plays dual roles in suppressing the volume change of NiFeOF porous cathode and minimizing the dissolution of transition metals during LIBs cycling by forming a structure/composition gradient. The structure and composition of HPL reconstructs during lithiation/delithiation, buffering the volume change and trapping the dissolved transition metals. As a result, a high capacity of 175 mAh g?1 (equal to an outstanding volumetric capacity of 936 Ah L?1) with a greatly reduced capacity decay rate of 0.012% per cycle for 1000 cycles is achieved, which is superior to the NiFeOF porous film without HPL and commercially available NiF2‐FeF3 powders. The proposed chemical and structure reconstruction mechanism of HPL opens a new avenue for the novel materials development for long‐cycle LIBs.  相似文献   

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Isothermal recombinase polymerase amplification (RPA) assays for the specific detection of “Candidatus Phytoplasma mali (Ca. P. mali),” the causal agent of apple proliferation, were developed. The assays amplify a fragment of the imp gene and amplimers were detected either by fluorescence in real‐time mode (TwistAmp®exo assay) using a fluorophore‐labelled probe or by direct visualization employing a lateral flow device (TwistAmp®nfo assay/Milenia®HybriDetect). The RPA assays specifically amplified DNA from “Ca. P. mali” strains, and cross‐reactivity with other phytoplasmas or plant DNA was not observed. The limit of detection was determined with a cloned imp standard, and positive results were obtained down to 10 copies with both RPA assay formats. In comparison with a TaqMan real‐time PCR assay based on the same target gene, the RPA assays were equally sensitive, but results were obtained faster. Simplified nucleic acid extraction procedures from plant tissue with Tris‐ and CTAB‐based buffers revealed that crude Tris–DNA extracts were a suitable source for RPA tests while larger concentrations of CTAB were inhibitory. This is the first report of RPA‐based assays for the detection of “Ca. P. mali”. The assays are suitable for high‐throughput screening of plant material and point‐of‐care diagnostic and can be potentially combined with a simplified DNA extraction procedure.  相似文献   

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The proximate composition, nutrient and trace elements of the planktonic algal “jellies” of Lake Oguta in Southern Nigeria, are provided as guides to their utilization and control, using flood (rainy) and dry season samples. These “jellies” are an unusual, macroscopic planktonic algal community in the lake, made up mostly of blue-green algae (Microcystis, Anabaena, Chroococcus) with some green algae (e. g. Spirogyra) and pennate diatoms (e.g. Navicula) rather epiphytic on the mucous jellies of the blue-green algae. Water content was high (98.2% mean, range 97.5-99.5%). Ash, protein and fat had values of 41.7 (39.0-46.2%), 16.9 (15.6-19.4%), and 2.0 (1.7-2.1%) respectively. Crude fibre and carbohydrates were high (25.8% and 12.4%). The levels of phosphorus and nitrogen were rather high, so were the major cations whose order of dominance (Ca > K > Mg > Na) differed from that of the lake water. Macronutrients increased in their concentrations during the rainy flood season while the reverse was the case with the micronutrients. Diagenesis of the endogenic minerals rather than anthropogenic factors are thought to be the reason for the seasonal changes in the ionic concentrations. Possible uses of the algal jellies are discussed as well as their control options.  相似文献   

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The coccoid glaucophyte genus Glaucocystis is characterized by having a thick cell wall, which has to date prohibited examination of the native ultrastructural features of the protoplast periphery. Recently, however, the three‐dimensional (3‐D) ultrastructure of the protoplast periphery was revealed in two divergent Glaucocystis species, with the world's most powerful ultra‐high voltage electron microscope (UHVEM). The two species exhibit morphological diversity in terms of their 3‐D ultrastructural features. However, these two types do not seem to encompass actual ultrastructural diversity in the genetically diverse genus Glaucocystis. Here, we report a new type of peripheral 3‐D ultrastructure resolved in “G. incrassata” SAG 229‐2 cells by 3‐D modeling based on UHVEM tomography using high‐pressure freezing and freeze‐substitution fixation. The plasma membrane and underlying flattened vesicles in “G. incrassata” SAG 229‐2 exhibited grooves at intervals of 200–600 nm, and the flattened vesicles often overlapped one another at the protoplast periphery. This 3‐D ultrastructure differs from those of the two types previously reported in other species of Glaucocystis. The possibility of classification of Glaucocystis species based on the 3‐D ultrastructure of the protoplast periphery is discussed.  相似文献   

19.
“Bryndza” is a traditional Slovak dairy product (type of soft cheese) made from sheep cheese which was ripened for 14 days. Because its manufacture, transporting and/or storing represent conditions which facilitate contamination, the effect of enterocin CCM4231 in “bryndza” was investigated with the aim to reduce the contaminant agents. “Bryndza” was divided into equal portions (50 g). The experimental sample (ES) as well as the control sample one (C1) were inoculated with Listeria innocua Li1 strain. The other control samples C2 and C3 were without Li1 strain. C3 control was selected as a reference control. ES and C2 portions were treated with purified enterocin CCM4231 in a concentration of 6400 AU/ml. Before the experimental inoculation, “bryndza” was checked for the presence of contaminant agents. The experiment lasted 1 week and the samples were stored in the refrigerator at 4 °C. Sampling was performed on day 1, on day 4 and on day 7. The control samples C2 and C3 were checked only on day 1 and then after 1 week. The following contaminant agents were detected in “bryndza” before its experimental inoculation with L. innocua Li1 strain: Escherichia coli in the amount 103 cfu/ml/g, Staphylococcus aureus (102 cfu/ml/g) and enterococci (104 cfu/ml/g). In the control sample C2, the number of E. coli was reduced to 102 cfu/ml/g. Enterococci and staphylococci were totally eliminated there. Concerning C3 control, natural decrease of bacteria was found and/or their unchanged counts. The value of pH (5) was stable during the whole experiment. In the experimental sample inoculated with Li1 strain, its counts were decreased immediately after enterocin CCM4231 addition approximately by one order of magnitude. This inhibitory effect was also detectable on day 4 by the difference of one order of magnitude between ES and C1. On day 7, 103 cfu/ml/g of Li1 strain were detected in both samples (ES, C1). The difference by one order of magnitude indicated, an inhibitory effect of enterocin CCM4231 in “bryndza”. However, bacteriocin activity was not determined by laboratory analyses.  相似文献   

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