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291.
Liang GB Qian X Feng D Fisher M Crumley T Darkin-Rattray SJ Dulski PM Gurnett A Leavitt PS Liberator PA Misura AS Samaras S Tamas T Schmatz DM Wyvratt M Biftu T 《Bioorganic & medicinal chemistry letters》2008,18(6):2019-2022
Diaryl-(4-piperidinyl)-pyrrole derivatives bearing cyclic amine substituents have been synthesized and evaluated as anticoccidial agents. Improvements in potency of Et-PKG inhibition, such as azetidine derivative 3a, and broad spectrum anticoccidial activities in feed, such as morpholine derivative 8c, have been achieved. 相似文献
292.
This investigation evaluates the performance of juvenile stature (from tibia and radius lengths) and body mass (from breadth of the femoral distal metaphysis) prediction equations based on the Denver Growth Study sample (Ruff C. 2007. Am J Phys Anthropol 133 698-716). The sample used here for evaluation is an independent sample of juveniles brought to the Franklin County (Ohio) Coroner in 1990-1991. The Ohio sample differs somewhat from the Denver reference sample: it includes approximately 25% African-Americans (rather than all European-Americans), a significant number of right limb bones were measured (rather than all left side), it includes a wider range of economic statuses and it includes individuals who died from disease and trauma. As such the composition and measures of the Ohio sample correspond more generally to that seen in skeletal samples so that the accuracy of the estimates from the present sample should approach those found in practical applications of these methods. Results indicate that both juvenile body mass and stature are estimated relatively accurately. Accuracy of body mass estimates for 1-13-year-old juveniles is similar for African-American and European-American males and females. The least accurate estimates are for individuals in the 8-13 years age class (excluding individuals with body mass indices greater than the age specific 95th percentile): n = 9, +/- 2.9 kg, 95% confidence interval 1.4-4.4 kg. Accuracy of stature estimates for 1-17-year-old juveniles is comparable for the tibia and radius and, as with body mass estimates, are similar for African-American and European-American males and females. For combined age, sex, and ancestry groups average accuracies are in the +/-3.5 to +/-6.5 cm range. Some limitations of the methods are discussed. 相似文献
293.
Variation in Prokaryotic Community Composition as a Function of Resource Availability in Tidal Creek Sediments 下载免费PDF全文
Jennifer W. Edmonds Nathanial B. Weston Samantha B. Joye Mary Ann Moran 《Applied microbiology》2008,74(6):1836-1844
In anaerobic coastal sediments, hydrolytic and/or fermentative bacteria degrade polymeric material and produce labile intermediates, which are used by terminal metabolizers to complete the conversion of organic material to CO2. We used molecular approaches to evaluate the response of two bacterial terminal metabolizer groups from a coastal tidal creek sediments, sulfate reducers and methanogens, to controlled changes in carbon resource supply. Tidal creek sediment bioreactors were established in April and August 2004. For each date, intact sediment sections were continuously supplied with flowthrough seawater that was either unamended or amended with the high-molecular-weight polysaccharide dextran. Biogeochemical data indicate that the activity of fermenting bacteria and the terminal metabolizers was limited by organic carbon supply during both experiments, with a significant increase in net volatile fatty acid (VFA) production and rates of sulfate reduction and methanogenesis following dextran addition. Community composition (measured by using terminal restriction fragment length polymorphism analysis, and functional gene [dsrA, mcrA] clone libraries) changed from April to August. However, community composition was not different between amended and unamended cores within each month, despite the change in resource level. Moreover, there was no relationship between community richness and evenness with resource level. This lack of variation in community composition with C addition could be attributed to the dynamic environment these sediment communities experience in situ. Fluctuations in VFA concentrations are most likely very high, so that the dominant bacterial species must be able to outcompete other species at both high and low resource levels. 相似文献
294.
Samantha M Martins Alex Chapeaurouge Sérgio T Ferreira 《European journal of biochemistry》2002,269(22):5484-5491
The structures and stabilities of recombinant chicken muscle troponin I (TnI) and T (TnT) were investigated by a combination of bis-ANS binding and equilibrium unfolding studies. Unlike most folded proteins, isolated TnI and TnT bind the hydrophobic fluorescent probe bis-ANS, indicating the existence of solvent-exposed hydrophobic domains in their structures. Bis-ANS binding to binary or ternary mixtures of TnI, TnT and troponin C (TnC) in solution is significantly lower than binding to the isolated subunits, which can be explained by burial of previously exposed hydrophobic domains upon association of the subunits to form the native troponin complex. Equilibrium unfolding studies of TnT and TnI by guanidine hydrochloride and urea monitored by changes in far-UV CD and bis-ANS fluorescence revealed noncooperative folding transitions for both proteins and the existence of partially folded intermediate states. Taken together, these results indicate that isolated TnI and TnT are partially unstructured proteins, and suggest that conformational plasticity of the isolated subunits may play an important role in macromolecular recognition for the assembly of the troponin complex. 相似文献
295.
Delledonne Massimo Allegro Gianni Belenghi Beatrice Balestrazzi Alma Picco Franco Levine Alex Zelasco Samantha Calligari Paolo Confalonieri Massimo 《Molecular breeding : new strategies in plant improvement》2001,7(1):35-42
Transgenic white poplar (Populus alba L.) plants expressing a novel Arabidopsis thaliana cysteine proteinase inhibitor (Atcys) gene have been produced using Agrobacterium tumefaciens-mediated gene transfer. Internodal stem segments of cv. Villafranca were co-cultivated with the EHA105 pBI-Atcys A. tumefaciens strain. Sixteen putative transgenic plant lines were regenerated from different calli with a transformation efficiency of 11%. The integration and expression of the cysteine proteinase inhibitor (Atcys) gene into the plant genome was confirmed by Southern and northern blot analyses. Papain inhibitory activity was detected in poplar transgenic tissues by means of a specific in vitro assay. Such activity was sufficient to inhibit most of the digestive proteinase activity of chrysomelid beetle (Chrysomela populi L.) and confer resistance to C. populi larvae on selected transgenic plants. A close correspondence between the inhibition of papain and resistance to poplar leaf beetle was observed in all tested transgenic lines. Our results indicate that Atcys could be succesfully employed in breeding programmes aimed at the selection of new poplar genotypes resistant to major insect pests. 相似文献
296.
297.
Kristen W. Yeom Matus Straka Michael Iv Michael E. Moseley Patrick D. Barnes Stefan Skare Samantha J. Holdsworth 《PloS one》2015,10(6)
Here we investigate the utility of a dual-echo Echo-Planar Imaging (DE-EPI) Diffusion Weighted Imaging (DWI) approach to improve lesion conspicuity in pediatric imaging. This method delivers two ‘echo images’ for one diffusion-preparation period. We also demonstrate how the echoes can be utilized to remove transmit/receive coil-induced and static magnetic field intensity modulations on both echo images, which often mimic pathology and thereby pose diagnostic challenges. DE-EPI DWI data were acquired in 18 pediatric patients with abnormal diffusion lesions, and 46 pediatric patient controls at 3T. Echo1 [TE = 45ms] and Echo2 [TE = 86ms] were corrected for signal intensity variation across the images by exploiting the images equivalent coil-sensitivity and susceptibility-induced modulations. Two neuroradiologists independently reviewed Echo1 and Echo2 and their intensity-corrected variants (cEcho1 and cEcho2) on a 7-point Likert scale, with grading on lesion conspicuity diagnostic confidence. The apparent diffusion coefficient (ADC) map from Echo1 was used to validate presence of true pathology. Echo2 was unanimously favored over Echo1 for its sensitivity for detecting acute brain injury, with a mean respective lesion conspicuity of 5.7/4.4 (p < 0.005) and diagnostic confidence of 5.1/4.3 (p = 0.025). cEcho2 was rated higher than cEcho1, with a mean respective lesion conspicuity of 5.5/4.3 (p < 0.005) and diagnostic confidence of 5.4/4.4 (p < 0.005). cEcho2 was favored over all echoes for its diagnostic reliability, particularly in regions close to the head coil. This work concludes that DE-EPI DWI is a useful alternative to conventional single-echo EPI DWI, whereby Echo2 and cEcho2 allows for improved lesion detection and overall higher diagnostic confidence. 相似文献
298.
299.
The zinc metalloenzyme carbonic anhydrase plays a critical role in inorganic carbon acquisition in marine diatoms, thus conferring on zinc a key role in oceanic carbon cycling. As a first step in determining the location and function of carbonic anhydrase (CA) in Bacillariophyceae, we purified and partially sequenced CA from T. weissflogii (Gru) Fryxell et Hasle (TWCA1) and cloned the corresponding cDNA (twca1). The twca1 sequence is different from other known algal carbonic anhydrase genes, and encodes a protein of roughly 34 kDa. The amino terminal amino acids sequenced from purified TWCA1 are 72 residues downstream of the putative starting methionine predicted by twca1. This difference may be due to the presence of a short-lived signal sequence designed to guide the enzyme to the correct cellular location. The absence of any homology between TWCA1 and previously sequenced CAs from Chlorophyceae may indicate either convergent evolution or that carbon acquisition represents a fundamental physiological difference among algal phyla. 相似文献
300.
Individual elements of many extinct and extant North American rhinocerotids display osteopathologies, particularly exostoses, abnormal textures, and joint margin porosity, that are commonly associated with localized bone trauma. When we evaluated six extinct rhinocerotid species spanning 50 million years (Ma), we found the incidence of osteopathology increases from 28% of all elements of Eocene Hyrachyus eximius to 65–80% of all elements in more derived species. The only extant species in this study, Diceros bicornis, displayed less osteopathologies (50%) than the more derived extinct taxa. To get a finer-grained picture, we scored each fossil for seven pathological indicators on a scale of 1–4. We estimated the average mass of each taxon using M1-3 length and compared mass to average pathological score for each category. We found that with increasing mass, osteopathology also significantly increases. We then ran a phylogenetically-controlled regression analysis using a time-calibrated phylogeny of our study taxa. Mass estimates were found to significantly covary with abnormal foramen shape and abnormal bone textures. This pattern in osteopathological expression may reflect a part of the complex system of adaptations in the Rhinocerotidae over millions of years, where increased mass, cursoriality, and/or increased life span are selected for, to the detriment of long-term bone health. This work has important implications for the future health of hoofed animals and humans alike. 相似文献