Broad Applicability (broad + applicability)

Distribution by Scientific Domains

Selected Abstracts

Stereodivergent Syntheses of Highly Substituted Enantiopure 4-Alkoxy-3,6-dihydro-2H -1,2-oxazines by Addition of Lithiated Alkoxyallenes to Carbohydrate-Derived Aldonitrones

Matthias Helms
Abstract Additions of lithiated alkoxyallenes to D -glyceraldehyde-based nitrones 1 and 2 did not provide the expected hydroxylamine derivatives. Instead, a novel [3+3] cyclization process furnished 4-alkoxy-3,6-dihydro-2H -1,2-oxazines 9,14 with excellent syn selectivities and in moderate to good yields. Through precomplexation of the nitrones the corresponding anti -configured 1,2-oxazines 9, 10 and 13 could be obtained with high stereoselectivity. The reactions of nitrones 3,6, derived from D -erythrose or D -threose, generally proceeded less diastereoselectively, but reasonable yields of anti -configured 1,2-oxazines such as anti - 17 and anti - 19 could be obtained under Lewis acid promotion conditions. This was also the case for reactions of the D -arabinose-derived nitrone 7, which provided the anti -1,2-oxazines 23 and 24 with excellent diastereoselectivity and in good yields. Bis-nitrone 8 and lithiated methoxyallene furnished a mixture of six compounds, among which the major componentwas the C2 -symmetric syn/syn -1,2-oxazine 29. The diastereoselectivities of these reactions are interpreted on the basis of Dondoni's model for reactions between organolithium compounds and nitrones. The mechanisms for formation of 1,2-oxazines and of side products are discussed. The method introduced here seems to be of broad applicability and an excellent tool for diastereoselective chain elongation of carbohydrate derivatives, affording stereodefined precursors of aminopolyols and other highly functionalized compounds. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]

Azeotropic Binary Solvent Mixtures for Preparation of Organic Single Crystals

Xiaoran Li
Abstract Here, a new approach is introduced to prepare large single crystals of ,-conjugated organic molecules from solution. Utilizing the concept of azeotropism, single crystals of tri-isopropylsilylethynyl pentacene (TIPS-PEN) with dimensions up to millimeters are facilely self-assembled from homogeneous solutions comprising two solvents with opposing polarities and a positive azeotropic point. At solvent compositions close to the azeotropic point, an abrupt transition of morphology from polycrystalline thin-films to large single crystals is found. How to adjust the initial ratio of the binary solvents so that the change in solvent composition during evaporation favors the specific H-aggregation and promotes an efficient self-assembly of TIPS-PEN is explained. The charge-carrier (hole) mobilities are substantially enhanced by a factor of 4 from the morphology of thin-films to large single crystals used as active layer in field-effect transistors. Additionally, this approach is extended to other ,,, stacked organic molecules to elucidate its broad applicability. [source]

High efficiency site-specific genetic engineering of the mosquito genome

D. D. Nimmo
Abstract Current techniques for the genetic engineering of insect genomes utilize transposable genetic elements, which are inefficient, have limited carrying capacity and give rise to position effects and insertional mutagenesis. As an alternative, we investigated two site-specific integration mechanisms in the yellow fever mosquito, Aedes aegypti. One was a modified CRE/lox system from phage P1 and the other a viral integrase system from Streptomyces phage phi C31. The modified CRE/lox system consistently failed to produce stable germline transformants but the phi C31 system was highly successful, increasing integration efficiency by up to 7.9-fold. The ability to efficiently target transgenes to specific chromosomal locations and the potential to integrate very large transgenes has broad applicability to research on many medically and economically important species. [source]

Synthesis and Bioaccessibility of Fe-Pheophytin Derivatives from Crude Spinach Extract

R.E. Nelson
ABSTRACT:, Heme iron is recognized as a highly bioavailable source of iron suitable for treatment of iron deficiency anemia. However, the animal origin of purified heme limits its broad applicability due to religious, personal, and food safety issues. Development of chlorophyll-derived heme mimetics offers opportunities to expand current iron fortification strategies. The objective of this study was the synthesis of Fe-pheophytin (FePhe) derivatives from natural chlorophyll and subsequent evaluation of their digestive behavior and bioaccessibility in vitro. FePhe a and a, were synthesized from crude spinach extracts by treatment with 1.3 M iron(II)chloride and 0.25 M Na-acetate dissolved in glacial acetic acid at 80 °C for 30 min. FePhe-rich extracts (approximately 1 mM) were formulated into corn starch based test meals (7.5% lipid) and subjected to a 2-step in vitro digestion designed to simulate in vivo gastric and small intestinal conditions. Recovery of FePhe following digestion and transfer of FePhe and pheophytins (Phe) from test meal matrix to mixed micelles was assessed by RP C18-HPLC to determine the digestive stability and micellarization efficiency (bioaccessibility). FePhe a and a, derivatives were moderately stable to digestive conditions with recoveries of 52.3% and 58.7%, respectively. Residual Phe a was stable to digestion. Micellarization efficiency of FePhe a (4%) and a, (3.4%) was significantly (P < 0.05) lower than Phe a (25.8%) from test meals. While digestive stability and micellarization efficiency are limiting, the presence of lipophilic FePhe derivatives in mixed micelles suggests that these compounds would be available for subsequent absorption in the intestinal tract. [source]


Article first published online: 24 SEP 200
Dawes, C. J. Department of Biology, University of South Florida, Tampa, Florida 33620 The goal of my presentation is to review several studies that have enhanced our understanding of the effects of abiotic factors on coastal and estuarine seaweed populations. Accordingly, I will introduce a few key papers dealing with five major abiotic factors-i.e. salinity, temperature, desiccation, water motion, and illumination. Foremost, the salinity tolerance studies of Russell and Bolton (1975) have broad applicability to estuarine seaweeds, while the osmoregulatory studies of Bisson and Kirst (1979) are also significant. Biebl's (1972) review of his earlier studies on temperature tolerances in diverse seaweeds were pivotal. Johnston and Raven's (1986) studied the effects of desiccation on the fucoid brown alga Ascophyllum nodosum, while similar studies on the saccate brown seaweed Colpomenia peregrina were conducted by Oates (1985). Lewis (1968) conducted early synoptic evaluations of the effects of water movement on rocky shore communities, while Kitching and Ebling (1967) gave detailed assessments of seaweed populations within estuarine tidal rapids in Ireland. Basically estuarine tidal rapids represent areas of enhanced nutrients, oxygen and light availability, plus reduced sedimentation (Mathieson et al. (1983). The physiological effects of light have probably been evaluated more than any single abiotic factor and two areas of importance are cited here. The critical papers by Levring (1947) on submarine illumination and those of Ramus (1978) and Littler and Littler (1980) on algal form and light response. Several areas of future studies are also suggested, which may further enhance our understanding of seaweed adaptations. In summary, five major abiotic factors affecting coastal and estuarine seaweed populations will be discussed, their importance to seaweeds noted, and "key" findings for several significant papers summarized. [source]

The feasibility and reliability of using circular electrode for sphincter of Oddi electromyography in anaesthetised rabbits

F. Chen
Abstract, Sphincter of Oddi manometry (SOM) is the gold standard for assessing sphincter of Oddi dysfunction (SOD), but is considered a diagnostic sensitivity of 30,80% and associated with significant complications of pancreatitis. Electromyography (EMG) of sphincter of Oddi (SO) using a circular electrode (CE) may be useful in improving diagnostic accuracy and reducing complications. To evaluate the feasibility and reliability of the CE, we record myoelectric activity of SO in rabbits using the CE to compare with the traditional needle electrode (NE). The CE was prepared using a double-channel biogel catheter with two silver rings at the head of the catheter. The CE was then inserted into the lumen of the SO through the duodenal papilla, and myoelectric activity was recorded in the SO in 30 rabbits. An EMG recorded using an NE was performed at the same time, when the SO was in basal state, after injection of cholecystokinin and N-butylscopolamine bromide. Electromyographs recorded by the two methods were then evaluated. Satisfactory SO EMGs were acquired using the CE without any injury. Simultaneous recording revealed a very similar traces and one-to-one correspondence of SO spike bursts (SOSB). Linear regression analysis showed a significant direct correlation between the two methods for SOSB duration and amplitude. The results suggested that CE was comparable with NE in terms of recording efficacy. The CE also has advantages of easy fixation, accurate localisation, broad applicability and ease of achieving satisfactory outcomes without trauma, compared with the NE. [source]

The use of quality of life measures in oral medicine: a review of the literature

ORAL DISEASES, Issue 5 2010
R Ni Riordain
Oral Diseases (2010) 16, 419,430 Objectives:, To explore the use of patient reported quality of life measures in oral medicine, to highlight the importance of use of these measures in oral medicine practice and to provide guidance for the selection of such measures in the future. Methods:, A detailed literature review was undertaken to investigate the use of quality of life measures in oral medicine. The databases searched were MEDLINE (through PubMed), EMBASE, CINDHL, Web of Science Citation Index and the Cochrane Database of Systematic Reviews and randomised controlled trials. Results:, The initial literature search yielded a total of 5310 citations; however, only 63 of these fulfilled the inclusion criteria. Twenty-two articles were regarding oral mucosal conditions, 14 related to orofacial pain disorders and 27 were regarding salivary gland-related conditions. Conclusions:, The evaluation of quality of life in oral medicine has a broad applicability, providing information in treatment-based studies and population-based studies. A predominance of generic and oral health specific quality of life measures are being used to a limited extent in oral medicine practice. A scarcity of reports of the development, validation or use of disease specific measures is evident. [source]

Individual Orientation Toward Engagement in Social Action

Alexandra F. Corning
The issue of how an activist identity develops is one of the core issues in social psychology and social movement research. Because of problems in the measurement of individuals' propensities to engage in social action, however, findings in this area are often equivocal, and cross,study comparisons and conclusions are difficult to draw. Hence, the aim of these studies was to develop a measure to assess individuals' propensities to engage in social action. This measure, the Activism Orientation Scale (AOS), demonstrates strong psychometric properties and allows assessment of activist propensity across a wide continuum of social action behaviors, ideological positions, and movement issues. Additionally, the broad applicability of the AOS allows for its use by researchers, activists, and policymakers. [source]

Nurturing a strong process safety culture

Shakeel H. Kadri
Process safety management introduced a formal, structured, management systems approach to accident prevention that represented a "step change" improvement in identifying and reducing the potential for major process plant accidents. Although the process safety management elements have proven effective, the overall sustainability remains a challenge. This paper highlights the importance of a strong process safety culture that is needed to sustain a strong process safety performance. We use the Columbia Shuttle disaster incident as a backdrop to focus the attention on the significance of not having an optimal "Safety Culture." Examples have been included from our industry to further exemplify its broad applicability. The paper proposes an approach that will help organizations to self-assess the state of the process safety culture in their organizations, which can be an aid in their ongoing cultural improvement effort. Four important cultural themes are identified and described: (1) Create awareness and buy-in about process safety culture themes, (2) adapt process safety culture themes to your company experience, (3) use suggested indicators to identify specific areas of improvement, and (4) develop a strategic improvement plan to strengthen and sustain process safety culture. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2006 [source]

Resolution of ligand positions by site-directed tryptophan fluorescence in tear lipocalin

Oktay K. Gasymov
Abstract The lipocalin superfamily of proteins functions in the binding and transport of a variety of important hydrophobic molecules. Tear lipocalin is a promiscuous lipid binding member of the family and serves as a paradigm to study the molecular determinants of ligand binding. Conserved regions in the lipocalins, such as the G strand and the F-G loop, may play an important role in ligand binding and delivery. We studied structural changes in the G strand of holo- and apo-tear lipocalin using spectroscopic methods including circular dichroism analysis and site-directed tryptophan fluorescence. Apo-tear lipocalin shows the same general structural characteristics as holo-tear lipocalin including alternating periodicity of a ,-strand, orientation of amino acid residues 105, 103, 101, and 99 facing the cavity, and progressive depth in the cavity from residues 105 to 99. For amino acid residues facing the internal aspect of cavity, the presence of a ligand is associated with blue shifted spectra. The collisional rate constants indicate that these residues are not less exposed to solvent in holo-tear lipocalin than in apo-tear lipocalin. Rather the spectral blue shifts may be accounted for by a ligand induced rigidity in holo-TL. Amino acid residues 94 and 95 are consistent with positions in the F-G loop and show greater exposure to solvent in the holo- than the apo-proteins. These findings are consistent with the general hypothesis that the F-G loop in the holo-proteins of the lipocalin family is available for receptor interactions and delivery of ligands to specific targets. Site-directed tryptophan fluorescence was used in combination with a nitroxide spin labeled fatty acid analog to elucidate dynamic ligand interactions with specific amino acid residues. Collisional quenching constants of the nitroxide spin label provide evidence that at least three amino acids of the G strand residues interact with the ligand. Stern-Volmer plots are inconsistent with a ligand that is held in a static position in the calyx, but rather suggest that the ligand is in motion. The combination of site-directed tryptophan fluorescence with quenching by nitroxide labeled species has broad applicability in probing specific interactions in the solution structure of proteins and provides dynamic information that is not attainable by X-ray crystallography. [source]

Increasing the activity of monoclonal antibody therapeutics by continuous chromatography (MCSGP)

T. Müller-Späth
Abstract The charged monoclonal antibody (mAb) variants of the commercially available therapeutics Avastin®, Herceptin® and Erbitux® were separated by ion-exchange gradient chromatography in batch and continuous countercurrent mode (MCSGP process). Different stationary phases, buffer conditions and two MCSGP configurations were used in order to demonstrate the broad applicability of MCSGP in the field of charged protein variant separation. Batch chromatography and MCSGP were compared with respect to yield, purity, and productivity. In the case of Herceptin®, also the biological activity of the product stream was taken into account as performance indicator. The robustness of the MCSGP process against feed composition variations was confirmed experimentally and by model simulations. Biotechnol. Bioeng. 2010;107:652,662. © 2010 Wiley Periodicals, Inc. [source]

Aberrant processing of deviant stimuli in schizophrenia revealed by fusion of fMRI and EEG data

Vince D. Calhoun
Calhoun VD, Wu L, Kiehl KA, Eichele T, Pearlson GD. Aberrant processing of deviant stimuli in schizophrenia revealed by fusion of fMRI and EEG data. Background: Aberrant electrophysiological and haemodynamic processing of auditory oddball stimuli is among the most robustly documented findings in patients with schizophrenia. However, no study to date has directly examined linked patterns of electrical and haemodynamic differences in patients and controls. Methods: In a recent paper we demonstrated a data-driven approach, joint independent component analysis (jICA) to fuse together functional magnetic resonance imaging (fMRI) and event-related potential (ERP) data and elucidated the chronometry of auditory oddball target detection in healthy control subjects. In this paper we extend our fusion method to identify specific differences in the neuronal chronometry of target detection for chronic schizophrenia patients compared to healthy controls. Results: We found one linked source, consistent with the N2 response, known to be related to cognitive processing of deviant stimuli, spatially localized to bilateral fronto-temporal regions. This source showed significant between-group differences both in amplitude response and in the fMRI/ERP distribution pattern. These findings are consistent with previous work showing N2 amplitude and latency abnormalities in schizophrenia, and provide new information about the linkage between the two. Conclusions: In summary, we use a novel approach to isolate and identify a linked fMRI/ERP component which shows marked differences in chronic schizophrenia patients. We also show that jointly using both fMRI and ERP measures provides a fully picture of the underlying haemodynamic and electrical changes which are present in patients. Our approach also has broad applicability to other diseases such as autism, Alzheimer's disease, or bipolar disorder. [source]

Spiro Skeletons: A Class of Privileged Structure for Chiral Ligand Design

Kuiling Ding Prof.
Abstract This Focus Review highlights the exciting results obtained in the area of asymmetric catalysis using spirobiindane- or spirobifluorene-based chiral ligands. The spiro, mono, and bidentate ligands have been successfully applied in a wide range of transition-metal-catalyzed asymmetric reactions, including hydrogenations, carbon,carbon and carbon,heteroatom coupling reactions, with superior or comparable enantioselectivities to those obtained by using the related ligands bearing other backbones, thus proving that the spiro skeleton is a type of privileged structure for chiral ligand design. It is expected that the spiro concept for chiral ligand design will stimulate the future efforts to understand the features that account for their broad applicability and to apply this understanding to seek new privileged chiral ligands and catalysts. [source]

Developments in allergen-specific immunotherapy: from allergen extracts to allergy vaccines bypassing allergen-specific immunoglobulin E and T cell reactivity

M. Focke
Summary Allergen-specific immunotherapy (SIT) is the only specific and disease-modifying approach for the treatment of allergy but several disadvantages have limited its broad applicability. We argue that the majority of the possible disadvantages of SIT such as unwanted effects, poor efficacy and specificity as well as inconvenient application are related to the poor quality of natural allergen extracts, which are the active ingredients of all currently available allergy vaccines. Because of the progress made in the field of molecular allergen characterization, new allergy vaccines based on recombinant allergens, recombinant hypoallergenic allergen derivatives and allergen-derived T cell peptides have entered clinical testing and hold promise to reduce the side-effects and to increase the specificity as well as the efficacy of SIT. Here, we present a refined immunotherapy concept, which is based on the use of peptides derived from allergen surfaces that exhibit reduced, allergen-specific IgE as well as T cell reactivity. These peptides when fused to non-allergenic carriers give rise to allergen-specific protective IgG responses with T cell help from a non-allergenic carrier molecule. We summarize the experimental data demonstrating that such peptide vaccines can bypass allergen-specific IgE as well as T cell activation and may be administered at high doses without IgE- and T cell-mediated side-effects. Should these peptide vaccines prove efficacious and safe in clinical trials, it may become possible to develop convenient, safe and broadly applicable forms of SIT as true alternatives to symptomatic, drug-based allergy treatment. Cite this as: M. Focke, I. Swoboda, K. Marth and R. Valenta, Clinical & Experimental Allergy, 2010 (40) 385,397. [source]

Laboratory tools and strategies for methicillin-resistant Staphylococcus aureus screening, surveillance and typing: state of the art and unmet needs

M. J. Struelens
Abstract The public health burden caused by methicillin-resistant Staphylococcus aureus (MRSA) infections is now widely recognized, and is a cause of public alarm. Effective MRSA risk management in the healthcare system as well as in the community should rely on accurate detection of reservoirs and sources of transmission, as well as on close monitoring of the impact of interventions on disease incidence and bacterial dissemination. MRSA carrier screening and disease surveillance, coupled with molecular typing, are key information tools for integrated MRSA control and individual risk assessment. These tools should be tailored to the distinct needs of local interventions and national prevention programmes. Surveillance schemes should primarily inform local staff and serve as quality assurance about MRSA risk management. New technologies, including the use of selective culture media and real-time PCR assays, allow faster detection of MRSA carriers upon admission or during stay in healthcare institutions. More research is needed to ascertain their cost-effectiveness for MRSA control. Likewise, tremendous progress has been made concerning molecular typing methods, with optimization and standardization of sequence-based technologies offering broad applicability and high throughput. However, no single S. aureus typing method is yet providing fully reliable information within the range of discrimination needed for public health action. Further refinement of genotyping methods and international harmonization of surveillance and typing schemes must be achieved to facilitate global MRSA control. [source]