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61.
Intr-individual correlations for cranial, mandibular and dental measurements made on lateral skull radiographs of Macaca nemestrina were systematically higher in 30 adult females than in 31 adult males by an average of 0.11 to 0.15, depending upon method of computation. Clearly, for the adult pig-tailed monkey as in Homo during both prenatal and postnatal life, developmental and dimensional communalities are systematically higher in the female indicating a general principle or trend. 相似文献
62.
63.
Insulin was discovered over 100 years ago. Whilst the first half century defined many of the physiological effects of insulin, the second emphasised the mechanisms by which it elicits these effects, implicating a vast array of G proteins and their regulators, lipid and protein kinases and counteracting phosphatases, and more. Potential growth-promoting and protective effects of insulin on the heart emerged from studies of carbohydrate metabolism in the 1960s, but the insulin receptors (and the related receptor for insulin-like growth factors 1 and 2) were not defined until the 1980s. A related third receptor, the insulin receptor-related receptor remained an orphan receptor for many years until it was identified as an alkali-sensor. The mechanisms by which these receptors and the plethora of downstream signalling molecules confer cardioprotection remain elusive. Here, we review important aspects of the effects of the three insulin receptor family members in the heart. Metabolic studies are set in the context of what is now known of insulin receptor family signalling and the role of protein kinase B (PKB or Akt), and the relationship between this and cardiomyocyte survival versus death is discussed. PKB/Akt phosphorylates numerous substrates with potential for cardioprotection in the contractile cardiomyocytes and cardiac non-myocytes. Our overall conclusion is that the effects of insulin on glucose metabolism that were initially identified remain highly pertinent in managing cardiomyocyte energetics and preservation of function. This alone provides a high level of cardioprotection in the face of pathophysiological stressors such as ischaemia and myocardial infarction. 相似文献
64.
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66.
Creatine and the creatine transporter: A review 总被引:6,自引:0,他引:6
67.
68.
The temporal availability of propagules is a critical factor in sustaining pioneer riparian tree populations along snowmelt-driven
rivers because seedling establishment is strongly linked to seasonal hydrology. River regulation in semi-arid regions threatens
to decouple seed development and dispersal from the discharge regime to which they evolved. Using the lower Tuolumne River
as a model system, we quantified and modeled propagule availability for Populus fremontii (POFR), Salix gooddingii (SAGO), and Salix exigua (SAEX), the tree and shrub species that dominate near-channel riparian stands in the San Joaquin Basin, CA. A degree-day
model was fit to field data of seasonal seed density and local temperature from three sites in 2002–2004 to predict the onset
of the peak dispersal period. To evaluate historical synchrony of seed dispersal and seasonal river hydrology, we compared
peak spring runoff timing to modeled peak seed release periods for the last 75 years. The peak seed release period began on
May 15 for POFR (range April 23–June 10), May 30 for SAGO (range May 19–June 11) and May 31 for SAEX (range May 8–June 30).
Degree-day models for the onset of seed release reduced prediction error by 40–67% over day-of-year means; the models predicted
best the interannual, versus site-to-site, variation in timing. The historical analysis suggests that POFR seed release coincided
with peak runoff in almost all years, whereas SAGO and SAEX dispersal occurred during the spring flood recession. The degree-day
modeling approach reduce uncertainty in dispersal timing and shows potential for guiding flow releases on regulated rivers
to increase riparian tree recruitment at the lowest water cost. 相似文献
69.
Studies of proteins synthesized in vitro by messenger RNA (mRNA) extracted from tobacco protoplasts showed that the changes
in protein synthesis and especially the lack of certain proteins observed previously in isolated protoplasts did not result
from a failure of translation. 相似文献
70.
Thymidylate synthase (TS), an essential enzyme for catalyzing the biosynthesis of thymidylate, is a critical therapeutic target in cancer therapy. Recent studies have shown that TS functions as an RNA-binding protein by interacting with two different sequences on its own mRNA, thus, repressing translational efficiency. In this study, peptides binding TS RNA with high affinity were isolated using mRNA display from a large peptide library (>1013 different sequences). The randomized library was subjected up to twelve rounds of in vitro selection and amplification. Comparing the amino acid composition of the selected peptides (12th round, R12) with those from the initial random library (round zero, R0), the basic and aromatic residues in the selected peptides were enriched significantly, suggesting that these peptide regions might be important in the peptide-TS mRNA interaction. Categorizing the amino acids at each random position based on their physicochemical properties and comparing the distributions with those of the initial random pool, an obvious basic charge characteristic was found at positions 1, 12, 17 and 18, suggesting that basic side chains participate in RNA binding. Secondary structure prediction showed that the selected peptides of R12 pool represented a helical propensity compared with R0 pool, and the regions were rich in basic residues. The electrophoretic gel mobility shift and in vitro translation assays showed that the peptides selected using mRNA display could bind TS RNA specifically and inhibit the translation of TS mRNA. Our results suggested that the identified peptides could be used as new TS inhibitors and developed to a novel class of anticancer agents. 相似文献