96 research outputs found
\u3cem\u3eg\u3c/em\u3e Factor of the 2\u3csup\u3e+\u3c/sup\u3e\u3csub\u3e1\u3c/sub\u3e State of \u3csup\u3e172\u3c/sup\u3eHf
The g factor of the 2+1 state of 172Hf was measured using the perturbed angular correlation technique in a static external magnetic field. The result, g(2+1) = 0.25(5), is discussed in relation to the systematics of the previously reported g factors in the Hf isotopes and compared with the predictions of several models. An interesting outcome of the analysis presented in this paper is the agreement between the calculated g factors within the interacting boson approximation (IBA) and the results of a large-scale shell model calculation. This agreement supports the emphasis in the IBA on the valence space. The undershooting of the empirical g factors near midshell in both models suggests that they underestimate the role of the saturation of collectivity, which is explicitly incorporated into a phenomenological model that agrees better with the data
Estradiol differentially affects auditory recognition and learning according to photoperiodic state in the adult male songbird, European starling ( Sturnus vulgaris
Comparative aspects of canine and human inflammatory breast cancer
Inflammatory breast cancer (IBC) in humans is the most aggressive form of mammary gland cancer and shares clinical, pathologic, and molecular patterns of disease with canine inflammatory mammary carcinoma (CIMC). Despite the use of multimodal therapeutic approaches, including targeted therapies, the prognosis for IBC/CIMC remains poor. The aim of this review is to critically analyze IBC and CIMC in terms of biology and clinical features. While rodent cancer models have formed the basis of our understanding of cancer biology, the translation of this knowledge into improved outcomes has been limited. However, it is possible that a comparative “one health” approach to research, using a natural canine model of the disease, may help advance our knowledge on the biology of the disease. This will translate into better clinical outcomes for both species. We propose that CIMC has the potential to be a useful model for developing and testing novel therapies for IBC. Further, this strategy could significantly improve and accelerate the design and establishment of new clinical trials to identify novel and improved therapies for this devastating disease in a more predictable way
High Value Antioxidants from Softwood Bark and Foliage
In the development of renewable sources of fuels and polymers, the forest industry will continue to be the source of the most abundant natural renewable carbon-rich resource on the planet. The development of efficient extraction and isolation methods could yield large quantities of high-value antioxidants from wood bark and foliage to supplement the fuels and chemicals derived from the hemi-cellulose, cellulose, and lignin in the forestry industry. Current research has focused on new methods of extracting and isolating cellulose, hemi-cellulose, and lignin. While focusing on these biopolymers is important to utilizing the high carbon content of wood, the extractives that make up the secondary metabolites of plants have gained increased interest due to their potent antioxidant activity and represents a new potential source of revenue for the pulp and paper, biorefinery, and timber industries. There are numerous secondary metabolites within tree bark and foliage that were extracted using an accelerated solvent extractor, ASE. Among these secondary metabolites are the stilbene and flavonoid compounds, which are derived through the stilbene and chalcone synthase enzymatic pathway, respectively. Resveratrol and piceatannol, two major stilbene compounds, were identified in black spruce, Norway spruce, white spruce, red spruce, and Eastern white pine bark and foliage and were quantified for the first time using HPLC-UV-MS and GC-MS techniques. Resveratrol has shown the ability to increase the lifespan in some model species and may be a high-value extractive. Relatively high concentrations of resveratrol (350-600 ppm) and piceatannol (400-650 ppm) were found in spruce bark. This concentration of resveratrol was equal to the values reported for Japanese knotweed (the main commercial source of resveratrol) and was up to 10-100 times more concentrated than grapes, wine, cocoa, peanuts, and blueberries. Catechin, epicatechin, and quercetion (flavonoid compounds) were also identified and quantified in spruce, pine, and fir species with white spruce bark containing the most abundant source of catechin (3600 ± 100 ppm). Bark, which is currently burned as wood fuel in pulp processing, may be a good source of high-value chemicals and antioxidants. Spruce bark, in particular, shows promise for its high stilbene and flavonoid content. The antioxidant potential of these species (tamarack, balsam fir, Eastern white pine, red pine, black spruce, Norway spruce, white spruce, and red spruce), which are important to the Maine forest industry, were all tested through various colorimetric assays based on food and beverage procedures (Folin-Ciocalteu\u27s total phenolic assay, B-carotene bleaching assay, DPPH free radical scavenging assay) and showed greater antioxidant activity than most vegetables and fruits reported in the literature. The use of bark and foliage extracts as functional food additives would enable the forestry industry to enter a market that has shown 10-15% growth per year over that last decade and provide additional revenues to support the continued progress of a complete biorefinery
The conformational landscape of RNA translational regulators and their potential as drug discovery targets
RNA is an underutilized target for drug discovery. Once thought to be a passive carrier of genetic information, RNA is now known to play a critical role in essentially all aspects of biology including signaling, gene regulation, catalysis, and retroviral infection. It is now well-established that RNA does not exist as a single static structure, but instead populates an ensemble of energetic minima along a free-energy landscape. Knowledge of this structural landscape has become an important goal for understanding its diverse biological functions. In this case, NMR spectroscopy has emerged as an important player in the characterization of RNA structural ensembles, with solution-state techniques accounting for almost half of deposited RNA structures in the PDB, yet the rate of RNA structure publication has been stagnant over the past decade. Several bottlenecks limit the pace of RNA structure determination by NMR: the high cost of isotopic labeling, tedious and ambiguous resonance assignment methods, and a limited database of RNA optimized pulse programs. We have addressed some of these challenges to NMR characterization of RNA structure with applications to various RNA-drug targets. These approaches will increasingly become integral to designing new therapeutics targeting RNA
An Efficient Method for the Synthesis of Substituted 4-Acetoxynaphthalene-2-Carboxylate Esters, Ethyl 4-Acetoxybenzofuran-6-Carboxylate, and Ethyl 4-Acetoxybenzothiophene-6-Carboxylate
A descriptive cross-sectional international study to explore current practices in the assessment, prevention and treatment of skin tears
This study presents the results of a descriptive, cross-sectional, online international survey in order to explore current practices in the assessment, prediction, prevention and treatment of skin tears (STs). A total of 1127 health care providers (HCP) from 16 countries completed the survey. The majority of the respondents (69·6%, n = 695) reported problems with the current methods for the assessment and documentation of STs with an overwhelming majority (89·5%, n = 891) favouring the development of a simplified method of assessment. Respondents ranked equipment injury during patient transfer and falls as the main causes of STs. The majority of the samples indicated that they used non-adhesive dressings (35·89%, n = 322) to treat a ST, with the use of protective clothing being the most common method of prevention. The results of this study led to the establishment of a consensus document, classification system and a tool kit for use by practitioners. The authors believe that this survey was an important first step in raising the global awareness of STs and to stimulate discussion and research of these complex acute wounds
Isotope-Labeled RNA Building Blocks for NMR Structure and Dynamics Studies
RNA structural research lags behind that of proteins, preventing a robust understanding of RNA functions. NMR spectroscopy is an apt technique for probing the structures and dynamics of RNA molecules in solution at atomic resolution. Still, RNA analysis by NMR suffers from spectral overlap and line broadening, both of which worsen for larger RNAs. Incorporation of stable isotope labels into RNA has provided several solutions to these challenges. In this review, we summarize the benefits and limitations of various methods used to obtain isotope-labeled RNA building blocks and how they are used to prepare isotope-labeled RNA for NMR structure and dynamics studies
Extraction and Purification of (E)-Resveratrol from the Bark of Conifer Species
(E)-Resveratrol is a naturally occurring polyphenolic compound in plants with a variety of widely studied health benefits. The bark of Northern American, Canadian, and Northern European conifer species, which is an underutilized by-product generated by forest industries, is a source of (E)-resveratrol, providing a potential value-added product for these industries. Bark may serve as a good alternative to the invasive plant Japanese knotweed (Polygonum cuspidatum), which currently is the leading commercial source of (E)-resveratrol. This work describes a method to extract and purify (E)-resveratrol from conifer bark with high yield and high purity and investigates the relationship between the amount of (E)-resveratrol and the total phenolic contents in the bark of common conifer species. In this work, barks of four conifer species were extracted and the total phenolic contents were determined by Folin–Cicoalteu’s assay. The (E)-resveratrol content was determined by HPLC-MS. A purification method that utilizes solvent extraction and column chromatography was developed to isolate (E)-resveratrol in high yield from black spruce (Picea mariana) bark. The quantitative analysis of bark samples suggests the presence of (E)-resveratrol in black spruce (Picea mariana) and Norway spruce (Picea abies), in comparable amounts to Japanese knotweed. Based on HPLC-MS and HPLC-UV analyses, the purification method isolates the compound with a yield of 84% and purity of 99%. Hence, our method extracts and isolates (E)-resveratrol from conifer bark in high purity and high yield. The results do not support any correlation between the total phenolic content and the amount of (E)-resveratrol
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