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31.
ABSTRACT. The unusual nature of mitosis and ancestral organization of the dinoflagellate nucleus prompted the question of whether the cdc 2-like histone H1 kinase, a presumed ubiquitous cell cycle regulator in eukaryotes, is present in these primitive organisms. Western blotting of Crypthecodinium cohnii protein extracts using antibody against the Pro-Ser-Thr-Ala-Ile-Arg-Glu (=PSTAIRE) amino acid sequence motif, conserved in all cdc 2 homologues known, revealed one prominent band corresponding to a protein with an apparent relative molecular weight ≈ 34,000, identical in mobility to that from HeLa cells and Physarum polycephalum , higher and lower eukaryotic controls, respectively. Incubation of C. cohnii cell lysates with p13 suc 1-sepharose beads, which preferentially, though not exclusively, bind p34 cdc 2, resulted in precipitation of a 34-kDa protein which was reactive with anti-PSTAIRE antibody, selectively competed for by the PSTAIRE peptide and able to phosphorylate histone H1 in vitro. We conclude that the dinoflagellate C. cohnii contains a protein very similar to the cdc 2 gene product from fission yeast and its homologues in all eukaryotes studied thus far.  相似文献   
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1. An ecological model was developed using genetic programming (GP) to predict the time‐series dynamics of the diatom, Stephanodiscus hantzschii for the lower Nakdong River, South Korea. Eight years of weekly data showed the river to be hypertrophic (chl. a, 45.1 ± 4.19 μg L−1, mean ± SE, n = 427), and S. hantzschii annually formed blooms during the winter to spring flow period (late November to March). 2. A simple non‐linear equation was created to produce a 3‐day sequential forecast of the species biovolume, by means of time series optimization genetic programming (TSOGP). Training data were used in conjunction with a GP algorithm utilizing 7 years of limnological variables (1995–2001). The model was validated by comparing its output with measurements for a specific year with severe blooms (1994). The model accurately predicted timing of the blooms although it slightly underestimated biovolume (training r2 = 0.70, test r2 = 0.78). The model consisted of the following variables: dam discharge and storage, water temperature, Secchi transparency, dissolved oxygen (DO), pH, evaporation and silica concentration. 3. The application of a five‐way cross‐validation test suggested that GP was capable of developing models whose input variables were similar, although the data are randomly used for training. The similarity of input variable selection was approximately 51% between the best model and the top 20 candidate models out of 150 in total (based on both Root Mean Squared Error and the determination coefficients for the test data). 4. Genetic programming was able to determine the ecological importance of different environmental variables affecting the diatoms. A series of sensitivity analyses showed that water temperature was the most sensitive parameter. In addition, the optimal equation was sensitive to DO, Secchi transparency, dam discharge and silica concentration. The analyses thus identified likely causes of the proliferation of diatoms in ‘river‐reservoir hybrids’ (i.e. rivers which have the characteristics of a reservoir during the dry season). This result provides specific information about the bloom of S. hantzschii in river systems, as well as the applicability of inductive methods, such as evolutionary computation to river‐reservoir hybrid systems.  相似文献   
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The trace fossil Sinusichnus sinuosus Gibert 1996 is described and interpreted as an open burrow system, attributed to a crustacean tracemaker, that shares some features with fodinichnial networks, such as Thalassinoides and Ophiomorpha , and with graphoglyptid burrows, such as Protopaleodictyon and Cosmorhaphe. These similarities suggest that Sinusichnus could have been produced by an animal combining deposit-feeding and farming (or trapping) strategies. The Sinusichnus record has yielded juvenile and adult burrows, often in close association. On account of minor morphologic differences between the two, juvenile tracemakers could have employed an agrichnial feeding strategy, whereas adults could have employed fodinichnial feeding.  相似文献   
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The aleocharine subtribe Homalotina Heer represents one of the most diverse lineages of Staphylinidae. Despite its wide distribution and diversity, the phylogenetic relationships of the subtribe remain poorly understood. Here, we present the first cladistic analysis of the Homalotina based on morphological data. The subtribe is hypothesized to be a monophyletic group consisting of seven genera (Anomognathus Solier, Cephaloxynum Bernhauer, Holisomimus Cameron, Homalota Mannerheim, Neomalota Cameron, Stenomastax Cameron, and Thecturota Casey). The dataset for phylogenetic analysis comprised 83 characters representing 245 character states derived from adult morphology. These data were analysed using equal weighting and implied weighting schemes (k = 1–6) and results support the monophyly of the subtribe based on two synapomorphic characters (complete postoccipital sutures on head, posterolateral margin of metacoxae with macrosetae) and three homoplastic characters (medial setae on prementum not extended to apex of ligula, medial setae on labium contiguous, posterolateral angle of elytron slightly sinuate). Generic relationships differ in each analysis within the Homalotina (EW, IW with k = 1, 2–4, 5–6) although there are some identical topologies among the IW trees. Clades A, B, C, D, H, J and G were resolved as monophyletic in all weighting regimes. The monophyly of the genera is relatively well supported except for the genera Homalota and Stenomastax. Homalota species were recovered in four independent clades (clade C, D, I, K) and the Stenomastax species were recovered in two independent lineages. Candidates for the possible new genera are discussed. We herein transfer Homalota flavomaculata Bernhauer to the genus Stenomastax, resulting in the new combination [Stenomastax flavomaculata (Bernhauer)]. Our preliminary character correlation tests using phylogenetic pairwise comparisons did not support the hypothesis of association between flattened body form, and subcortical habitat and anterior shift of antennal insertion in Homalotini.  相似文献   
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A cladistic analysis of the tribe Agathidiini Westwood is presented. Agathidiines are slime mould specialists and they are hypothesized to be a monophyletic group consisting of 12 genera (Afroagathidium Angelini & Peck, Agathidium Panzer, Anisotoma Panzer, Besuchetionella Angelini & Peck, Cyrtoplastus Reitter, Decuria Miller & Wheeler, Gelae Miller & Wheeler, Liodopria Reitter, Pseudoagathidium Angelini, Sphaeroliodes Portevin, and Stetholiodes Fall), based on three synapomorphies: epipleuron present to apical third, mesoventrite without longitudinal carina and longitudinal setal lines present on the tibiae. The dataset for phylogenetic analysis comprised 72 characters representing 198 character states derived from adult morphology. These data were analysed using equal weighting and implied weighting (k = 1–6) and supported the monophyly of the tribe based on three unique characters (epipleuron present to apical third, mesoventrite without longitudinal carina, longitudinal setal lines present on tibia) and two homoplastic characters [antennomeres 7–10 (or 6–9) asymmetrical, apical shape of terminal antennomere abruptly tapered]. The topology of IW trees with k = 4–6 was identical with one of three EW trees. Decuria was sister group to the remaining agathidiine genera whereas the following groups were resolved as monophyletic: Anisotoma, Gelae + Liodopria, and Pseudoagathidium (Afroagathidium + Besuchetionella). The clade [Sphaeroliodes rufescens (Agathidium bockshini, Agathidium subcostatum)] was supported in all analyses except for the IW (k = 1) cladogram. The monophyly of Agathidium was not supported at all and was rendered paraphyletic by the placements of Sphaeroliodes, Stetholiodes and the Pseudoagathidium (Afroagathidium + Besuchetionella) clade. Sphaeroliodes is synonymized with Agathidium ( syn.n. ) resulting in two new combinations [A. acuminatus (?vec) and A. rufescens (Portevin)]. Contractability is a complex character composed of several morphological features that have evolved independently within the agathidiine tree. Conglobation (the ability to roll the body into a ball) has arisen at least twice in Agathidiini.  相似文献   
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A granular formulation of 1.0% temephos (temephos G) was tested for its efficacy in mosquito larval control, residual effects and effects on non‐target microorganisms. Culex pipiens complex in septic tanks in Yangsan, Republic of Korea were used for this study. Microorganisms in the same septic tanks were used for study of non‐target organisms. After the application of temephos G at the rates of 2.0 and 5.0 mg/L to selected septic tanks, mortalities were recorded for 50 days. The effect of temephos G on non‐target organisms was studied by evaluating its effects on the bacterial populations in the treated septic tanks. It was observed that using 1.0% temephos G at a rate of 2.0 mg/L resulted in 100% mortality against Cx. pipiens larvae by the eighth day after treatment. The residual activity of temephos G was observed to continue for a time; for example 29 days after treatment, average larval mortality rates of >68.0% were observed for both concentrations. At the 50th day after treatment, the mortality rates of the Cx. pipiens larvae were observed to decrease to below 42.7% for both concentrations. Application of temephos G did not have significant effects on the bacteria populations in the septic tanks. Since temephos did not seem to have any major effects on the microorganisms, it was concluded that it is a safe and effective larvicide to use in the septic tanks at a rate of 2.0–5.0 mg/L of 1.0% temephos G.  相似文献   
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Staphylococcus aureus is currently a significant multidrug-resistant bacterium, causing severe healthcare-associated and community-acquired infections worldwide. The current antibiotic regimen against this pathogen is becoming ineffective due to resistance, in addition, they disrupt the normal microbiota. It highlights the urgent need for a pathogen-specific drug with high antibacterial efficacy against S. aureus. α-Viniferin, a bioactive phytochemical compound, has been reported to have excellent anti-Staphylococcus efficacy as a topical agent. However, so far, there were no clinical trials that have been conducted to elucidate its efficacy. The present study aimed to investigate the antibacterial efficacy of α-viniferin against S. aureus in a ten-day clinical trial. Based on the results, α-viniferin showed 50% minimum inhibitory concentrations (MIC50 values) of 7.8 μg/ml in culture broth medium. α-Viniferin was administered in the nares three times a day for ten days using a sterile cotton swab stick. Nasal swab specimens were collected before (0 days) and after finishing the trial (10th day), and then analyzed. In the culture and RT-PCR-based analysis, S. ureus was reduced significantly: 0.01. In addition, 16S ribosomal RNA-based amplicon sequencing analysis showed that S. aureus reduced from 51.03% to 23.99% at the genus level. RNA-seq analysis was also done to gain insights into molecular mechanisms of α-viniferin against S. aureus, which revealed that some gene groups were reduced in 5-fold FC cutoff at two times MIC conditions. The study results demonstrate α-viniferin as a potential S. aureus-specific drug candidate.  相似文献   
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