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Find video protocols related to scientific articles indexed in Pubmed.
Molecular Adhesion at Clay Nanocomposite Interfaces Depends on Counterion Hydration - Molecular Dynamics Simulation of Montmorillonite/Xyloglucan.
Biomacromolecules
PUBLISHED: 11-13-2014
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Nacre-mimetic clay/polymer nanocomposites with clay platelet orientation parallel to the film surface show interesting gas barrier and mechanical properties. In moist conditions, interfacial adhesion is lowered and mechanical properties are reduced. Molecular dynamic simulations (MD) have been performed to investigate the effects of counter ions on molecular adhesion at montmorillonite clay (Mnt)-xyloglucan (XG) interfaces. We focus on the role of both monovalent cations K+, Na+, Li+ and the divalent cation Ca2+ for the mediating and stabilizing the Mnt/XG complex formation. The conformation of adsorbed XG is strongly influenced by the choice of counterion, and so is the simulated work of adhesion. Free energy profiles that are used to estimate molecular adhesion show stronger interaction between XG and clay in the monovalent cation system than in divalent cation system, following a decreasing order of K-Mnt, Na-Mnt, Li-Mnt and Ca-Mnt. The Mnt clay hydrates differently in the presence of different counter ions, leading to a chemical potential of water that is highest in the case of K-Mnt, followed by Na-Mnt and Li-Mnt, and lowest in the case of Ca-Mnt. This means that water is most easily displaced from the interface in the case of K-Mnt, which contributes to the relatively high work of adhesion. In all systems, the penalty of replacing polymer with water at the interface gives a positive contribution to the work of adhesion of between 19% and 35%. Our work confirms the important role of counter ions in mediating the adsorption of biopolymer XG to Mnt clays and predicts potassium or sodium as the best choice of counter ions for a Mnt-based bio-composite design.
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Prevalence of exercise-induced bronchoconstriction and exercise-induced laryngeal obstruction in a general adolescent population.
Thorax
PUBLISHED: 11-09-2014
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Exercise-induced respiratory symptoms are common among adolescents. Exercise is a known stimulus for transient narrowing of the airways, such as exercise-induced bronchoconstriction (EIB) and exercise-induced laryngeal obstruction (EILO). Our aim was to investigate the prevalence of EIB and EILO in a general population of adolescents.
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Strong and Moldable Cellulose Magnets with High Ferrite Nanoparticle Content.
ACS Appl Mater Interfaces
PUBLISHED: 10-22-2014
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A major limitation in the development of highly functional hybrid nanocomposites is brittleness and low tensile strength at high inorganic nanoparticle content. Herein, cellulose nanofibers were extracted from wood and individually decorated with cobalt-ferrite nanoparticles and then for the first time molded at low temperature (<120 °C) into magnetic nanocomposites with up to 93 wt % inorganic content. The material structure was characterized by TEM and FE-SEM and mechanically tested as compression molded samples. The obtained porous magnetic sheets were further impregnated with a thermosetting epoxy resin, which improved the load-bearing functions of ferrite and cellulose material. A nanocomposite with 70 wt % ferrite, 20 wt % cellulose nanofibers, and 10 wt % epoxy showed a modulus of 12.6 GPa, a tensile strength of 97 MPa, and a strain at failure of ca. 4%. Magnetic characterization was performed in a vibrating sample magnetometer, which showed that the coercivity was unaffected and that the saturation magnetization was in proportion with the ferrite content. The used ferrite, CoFe2O4, is a magnetically hard material, demonstrated by that the composite material behaved as a traditional permanent magnet. The presented processing route is easily adaptable to prepare millimeter-thick and moldable magnetic objects. This suggests that the processing method has the potential to be scaled-up for industrial use for the preparation of a new subcategory of magnetic, low-cost, and moldable objects based on cellulose nanofibers.
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Multipurpose ultra and superhydrophobic surfaces based on oligodimethylsiloxane-modified nanosilica.
ACS Appl Mater Interfaces
PUBLISHED: 10-14-2014
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Nonfluorinated hydrophobic surfaces are of interest for reduced cost, toxicity, and environmental problems. Searching for such surfaces together with versatile processing, A200 silica nanoparticles are modified with an oligodimethylsiloxane and used by themselves or with a polymer matrix. The goal of the surface modification is controlled aggregate size and stable suspensions. Characterization is done by NMR, microanalysis, nitrogen adsorption, and dynamic light scattering. The feasibility of the concept is then demonstrated. The silica aggregates are sprayed in a scalable process to form ultrahydrophobic and imperceptible coatings with surface topographies of controlled nanoscale roughness onto different supports, including nanofibrillated cellulose. To improve adhesion and wear properties, the organosilica was mixed with polymers. The resulting composite coatings are characterized by FE-SEM, AFM, and contact angle measurements. Depending on the nature of the polymer, different functionalities can be developed. Poly(methyl methacrylate) leads to almost superhydrophobic and highly transparent coatings. Composites based on commercial acrylic car paint show "pearl-bouncing" droplet behavior. A light-emitting polyfluorene is synthesized to prepare luminescent and water repellent coatings on different supports. The interactions between polymers and the organosilica influence coating roughness and are critical for wetting behavior. In summary, the feasibility of a facile, rapid, and fluorine-free hydrophobization concept was successfully demonstrated in multipurpose antiwetting applications.
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Preparation of double Pickering emulsions stabilized by chemically tailored nanocelluloses.
Langmuir
PUBLISHED: 07-29-2014
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Nanocelluloses are bio-based nanoparticles of interest as stabilizers for oil-in-water (o/w) Pickering emulsions. In this work, the surface chemistry of nanocelluloses of different length, nanofibrillated cellulose (NFC, long) and cellulose nanocrystals (CNC, short), was successfully tailored by chemical modification with lauroyl chloride (C12). The resulting nanofibers were less hydrophilic than the original and able to stabilize water-in-oil (w/o) emulsions. The combination of the two types of nanocelluloses (C12-modified and native) led to new surfactant-free oil-in-water-in-oil (o/w/o) double emulsions stabilized by nanocellulose at both interfaces. Characterization was performed with respect to droplet size distribution, droplet stability over time, and stability after centrifugation. Nanocellulose-based Pickering emulsions can be designed with a substantial degree of control, as demonstrated by the stability of the chemically tailored NFC double emulsions. Furthermore, it was demonstrated that increased nanofiber length leads to increased stability.
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Sustained effects of a nurse coaching intervention via telehealth to improve health behavior change in diabetes.
Telemed J E Health
PUBLISHED: 07-25-2014
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Diabetes educators and self-management programs are scarce in rural communities, where diabetes is the third highest-ranking health concern. The goal of this study was to evaluate the benefits of nurse telehealth coaching for persons with diabetes living in rural communities through a person-centered approach using motivational interviewing (MI) techniques.
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Level-adjusted funnel plots based on predicted marginal expectations: an application to prophylactic antibiotics in gallstone surgery.
Stat Med
PUBLISHED: 06-26-2014
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Funnel plots are widely used to visualize grouped data, for example, in institutional comparison. This paper extends the concept to a multi-level setting, displaying one level at a time, adjusted for the other levels, as well as for covariates at all levels. These level-adjusted funnel plots are based on a Markov chain Monte Carlo fit of a random effects model, translating the estimated model parameters to predicted marginal expectations. Working within the estimation framework, we accommodate outlying institutions using heavy-tailed random effects distributions. We also develop computer-efficient methods to compute predicted probabilities in the case of dichotomous outcome data and various random effect distributions. We apply the method to a data set on prophylactic antibiotics in gallstone surgery.
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Both habitual short sleepers and long sleepers are at greater risk of obesity: a population-based 10-year follow-up in women.
Sleep Med.
PUBLISHED: 06-12-2014
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To assess how change in sleep duration is related to subsequent obesity.
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Nanostructured membranes based on native chitin nanofibers prepared by mild process.
Carbohydr Polym
PUBLISHED: 05-27-2014
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Procedures for chitin nanofiber or nanocrystal extraction from Crustaceans modify the chitin structure significantly, through surface deacetylation, surface oxidation and/or molar mass degradation. Here, very mild conditions were used to disintegrate chitin fibril bundles and isolate low protein content individualized chitin nanofibers, and prepare nanostructured high-strength chitin membranes. Most of the strongly 'bound' protein was removed. The degree of acetylation, crystal structure as well as length and width of the native chitin microfibrils in the organism were successfully preserved. Atomic force microscopy and scanning transmission electron microscopy, showed chitin nanofibers with width between 3 and 4 nm. Chitin membranes were prepared by filtration of hydrocolloidal nanofiber suspensions. Mechanical and optical properties were measured. The highest data so far reported for nanostructured chitin membranes was obtained for ultimate tensile strength, strain to failure and work to fracture. Strong correlation was observed between low residual protein content and high tensile properties and the reasons for this are discussed.
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Treatment options for hypertriglyceridemia: from risk reduction to pancreatitis.
Best Pract. Res. Clin. Endocrinol. Metab.
PUBLISHED: 05-21-2014
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While there has been considerable focus on the role and treatment of LDL cholesterol levels, a definitive role of triglycerides in the management of cardiovascular disease has been uncertain. Notably, with increasing triglyceride levels, there is a parallel increase in cholesterol levels carried by triglyceride-rich lipoproteins, which has prompted interest in the use of non-HDL cholesterol levels as a tool guiding interventions. Recent studies have provided evidence for an independent role of triglyceride levels as a cardiovascular risk factor, and recently, an Endocrine Society guideline was published for treatment of hypertriglyceridemia. In contrast to the relative uncertainty regarding triglycerides and cardiovascular disease, a role of very high triglyceride levels as a risk factor for pancreatitis has been well known. The present paper summarizes the underlying evidence for a risk role for triglyceride levels in cardiovascular disease and pancreatitis, current treatment recommendations and areas of future research.
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Ductile all-cellulose nanocomposite films fabricated from core-shell structured cellulose nanofibrils.
Biomacromolecules
PUBLISHED: 05-16-2014
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Cellulosic materials have many desirable properties such as high mechanical strength and low oxygen permeability and will be an important component in a sustainable biomaterial-based society, but unfortunately they often lack the ductility and formability offered by petroleum-based materials. This paper describes the fabrication and characterization of nanocomposite films made of core-shell modified cellulose nanofibrils (CNFs) surrounded by a shell of ductile dialcohol cellulose, created by heterogeneous periodate oxidation followed by borohydride reduction of the native cellulose in the external parts of the individual fibrils. The oxidation with periodate selectively produces dialdehyde cellulose, and the process does not increase the charge density of the material. Yet the modified cellulose fibers could easily be homogenized to CNFs. Prior to film fabrication, the CNF was shown by atomic force microscopy to be 0.5-2 ?m long and 4-10 nm wide. The films were fabricated by filtration, and besides uniaxial tensile testing at different relative humidities, they were characterized by scanning electron microscopy and oxygen permeability. The strength-at-break at 23 °C and 50% RH was 175 MPa, and the films could, before rupture, be strained, mainly by plastic deformation, to about 15% and 37% at 50% RH and 90% RH, respectively. This moisture plasticization was further utilized to form a demonstrator consisting of a double-curved structure with a nominal strain of 24% over the curvature. At a relative humidity of 80%, the films still acted as a good oxygen barrier, having an oxygen permeability of 5.5 mL·?L/(m(2)·24 h·kPa). These properties indicate that this new material has a potential for use as a barrier in complex-shaped structures and hence ultimately reduce the need for petroleum-based plastics.
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Cellulose nanofiber/nanocrystal reinforced capsules: a fast and facile approach toward assembly of liquid-core capsules with high mechanical stability.
Biomacromolecules
PUBLISHED: 04-28-2014
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Liquid-core capsules of high mechanical stability open up for many solid state-like applications where functionality depending on liquid mobility is vital. Herein, a novel concept for fast and facile improvement of the mechanical properties of walls of liquid-core capsules is reported. By imitating nature's own way of enhancing the mechanical properties in liquid-core capsules, the parenchyma plant cells found in fruits and vegetables, a blend of short cellulose nanofibers (<1 ?m, NFC) and nanocrystals (CNC) was exploited in the creation of the capsule walls. The NFC/CNC blend was prepared from a new version of the classical wood pulp hydrolysis. The capsule shell consisted of a covalently (by aromatic diisocyanate) cross-linked NFC/CNC structure at the outer capsule wall and an inner layer dominated by aromatic polyurea. The mechanical properties revealed an effective capsule elastic modulus of 4.8 GPa at 17 wt % NFC/CNC loading, about six times higher compared to a neat aromatic polyurea capsule (0.79 GPa) and 3 orders of magnitude higher than previously reported capsules from regenerated cellulose (0.0074 GPa). The outstanding mechanical properties are ascribed to the dense nanofiber structure, present in the outer part of the capsule wall, that is formed by oriented NFC/CNC of high average aspect ratio (L/d ? 70) and held together by both covalent (urethane bonds) and physical bonds (hydrogen bonds).
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Significant associations between lipoprotein(a) and corrected apolipoprotein B-100 levels in African-Americans.
Atherosclerosis
PUBLISHED: 04-26-2014
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Lipoprotein(a), Lp(a), represents an apolipoprotein (apo) B-carrying lipoprotein, yet the relationship between Lp(a) and apoB levels has not been fully explored.
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Superior mechanical performance of highly porous, anisotropic nanocellulose-montmorillonite aerogels prepared by freeze casting.
J Mech Behav Biomed Mater
PUBLISHED: 04-25-2014
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Directionally solidified nanofibrillated cellulose (NFC)-sodium-montmorillonite (MMT) composite aerogels with a honeycomb-like pore structure were compared with non-directionally frozen aerogels with equiaxed pore structure and identical composition and found to have superior functionalities. To explore structure-property correlations, three different aerogel compositions of 3wt% MMT, and 0.4wt%, 0.8wt%, and 1.2wt% NFC, respectively, were tested. Young?s modulus, compressive strength and toughness were found to increase with increasing NFC content for both architectures. The modulus increased from 25.8kPa to 386kPa for the isotropic and from 2.13MPa to 3.86MPa for the anisotropic aerogels, the compressive yield strength increased from 3.3kPa to 18.0kPa for the isotropic and from 32.3kPa to 52.5kPa for the anisotropic aerogels, and the toughness increased from 6.3kJ/m(3) to 24.1kJ/m(3) for the isotropic and from 22.9kJ/m(3) to 46.2kJ/m(3) for the anisotropic aerogels. The great range of properties, which can be achieved through compositional as well as architectural variations, makes these aerogels highly attractive for a large range of applications, for which either a specific composition, or a particular pore morphology, or both are required. Finally, because NFC is flammable, gasification experiments were performed, which revealed that the inclusion of MMT increased the heat endurance and shape retention functions of the aerogels dramatically up to 800°C while the mechanical properties were retained up to 300°C.
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Highly conducting, strong nanocomposites based on nanocellulose-assisted aqueous dispersions of single-wall carbon nanotubes.
ACS Nano
PUBLISHED: 02-14-2014
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It is challenging to obtain high-quality dispersions of single-wall nanotubes (SWNTs) in composite matrix materials, in order to reach the full potential of mechanical and electronic properties. The most widely used matrix materials are polymers, and the route to achieving high quality dispersions of SWNT is mainly chemical functionalization of the SWNT. This leads to increased cost, a loss of strength and lower conductivity. In addition full potential of colloidal self-assembly cannot be fully exploited in a polymer matrix. This may limit the possibilities for assembly of highly ordered structural nanocomposites. Here we show that nanofibrillated cellulose (NFC) can act as an excellent aqueous dispersion agent for as-prepared SWNTs, making possible low-cost exfoliation and purification of SWNTs with dispersion limits exceeding 40 wt %. The NFC:SWNT dispersion may also offer a cheap and sustainable alternative for molecular self-assembly of advanced composites. We demonstrate semitransparent conductive films, aerogels and anisotropic microscale fibers with nanoscale composite structure. The NFC:SWNT nanopaper shows increased strength at 3 wt % SWNT, reaching a modulus of 13.3 GPa, and a strength of 307 MPa. The anisotropic microfiber composites have maximum conductivities above 200 S cm(-1) and current densities reaching 1400 A cm(-2).
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Obesity and lifespan health--importance of the fetal environment.
Nutrients
PUBLISHED: 01-07-2014
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A marked increase in the frequency of obesity at the population level has resulted in an increasing number of obese women entering pregnancy. The increasing realization of the importance of the fetal environment in relation to chronic disease across the lifespan has focused attention on the role of maternal obesity in fetal development. Previous studies have demonstrated that obesity during adolescence and adulthood can be traced back to fetal and early childhood exposures. This review focuses on factors that contribute to early developmental events, such as epigenetic modifications, the potential for an increase in inflammatory burden, early developmental programming changes such as the variable development of white versus brown adipose tissue, and alterations in organ ontogeny. We hypothesize that these mechanisms promote an unfavorable fetal environment and can have a long-standing impact, with early manifestations of chronic disease that can result in an increased demand for future health care. In order to identify appropriate preventive measures, attention needs to be placed both on reducing maternal obesity as well as understanding the molecular, cellular, and epigenetic mechanisms that may be responsible for the prenatal onset of chronic disease.
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Omentectomy in addition to gastric bypass surgery and influence on insulin sensitivity: A randomized double blind controlled trial.
Clin Nutr
PUBLISHED: 01-02-2014
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Accumulation of visceral adipose tissue is associated with insulin resistance and cardio-vascular disease. The aim of this study was to elucidate whether removal of a large amount of visceral fat by omentectomy in conjunction with Roux en-Y gastric bypass operation (RYGB) results in enhanced improvement of insulin sensitivity compared to gastric bypass surgery alone.
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High-strength nanocellulose-talc hybrid barrier films.
ACS Appl Mater Interfaces
PUBLISHED: 11-22-2013
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Hybrid organic-inorganic films mimicking natural nacre-like composite structures were fabricated from cellulose nanofibers obtained from sequential periodate-chlorite oxidation treatment and talc platelets, using a simple vacuum-filtration method. As a pretreatment, commercial talc aggregates were individualized into well-dispersed talc platelets using a wet stirred media mill with high-shear conditions to promote the homogeneity and mechanical characteristics of hybrids. The nanofiber-talc hybrids, which had talc contents from 1 to 50 wt %, were all flexible in bending, and possessed tensile strength and Youngs modulus values up to 211 ± 3 MPa and 12 ± 1 GPa, respectively, the values being remarkably higher than those reported previously for nanofibrillated cellulose-talc films. Because of the lamellar and well-organized structure of hybrids in which the talc platelets were evenly embedded, they possessed a small pore size and good oxygen barrier properties, as indicated by the preliminary results. The talc platelets decreased the moisture adsorption of highly talc-loaded hybrids, although they still exhibited hydrophilic surface characteristics in terms of contact angles.
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Nacre-mimetic clay/xyloglucan bionanocomposites: a chemical modification route for hygromechanical performance at high humidity.
Biomacromolecules
PUBLISHED: 10-22-2013
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Nacre-mimetic bionanocomposites of high montmorillonite (MTM) clay content, prepared from hydrocolloidal suspensions, suffer from reduced strength and stiffness at high relative humidity. We address this problem by chemical modification of xyloglucan in (XG)/MTM nacre-mimetic nanocomposites, by subjecting the XG to regioselective periodate oxidation of side chains to enable it to form covalent cross-links to hydroxyl groups in neighboring XG chains or to the MTM surface. The resulting materials are analyzed by FTIR spectroscopy, thermogravimetric analysis, carbohydrate analysis, calorimetry, X-ray diffraction, scanning electron microscopy, tensile tests, and oxygen barrier properties. We compare the resulting mechanical properties at low and high relative humidity. The periodate oxidation leads to a strong increase in modulus and strength of the materials. A modulus of 30 GPa for cross-linked composite at 50% relative humidity compared with 13.7 GPa for neat XG/MTM demonstrates that periodate oxidation of the XG side chains leads to crucially improved stress transfer at the XG/MTM interface, possibly through covalent bond formation. This enhanced interfacial adhesion and internal cross-linking of the matrix moreover preserves the mechanical properties at high humidity condition and leads to a Youngs modulus of 21 GPa at 90%RH.
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Multifunctional nanoclay hybrids of high toughness, thermal, and barrier performances.
ACS Appl Mater Interfaces
PUBLISHED: 07-22-2013
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To address brittleness of nanoclay hybrids of high inorganic content, ductile polymers (polyethylene oxide and hydroxyethyl cellulose) and montmorillonite (MTM) have been assembled into hybrid films using a water-based filtration process. Nacre-mimetic layered films resulted and were characterized by FE-SEM and XRD. Mechanical properties at ambient condition were studied by tensile test, while performance at elevated temperature and moisture conditions were evaluated by TGA, dynamic vapor sorption, and dynamic thermomechanical and hygromechanical analyses. Antiflammability and barrier properties against oxygen and water vapor were also investigated. Despite their high MTM content in the 60-85 wt % range, the hybrids exhibit remarkable ductility and a storage modulus above 2 GPa even in severe conditions (300°C or 94% RH). Moreover, they present fire-shielding property and are amongst the best oxygen and water vapor barrier hybrids reported in the literature. This study thus demonstrates nanostructure property advantages for synergistic effects in hybrids combining inexpensive, available, and environmentally benign constituents.
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Deoxyguanosine phosphate mediated sacrificial bonds promote synergistic mechanical properties in nacre-mimetic nanocomposites.
Biomacromolecules
PUBLISHED: 07-11-2013
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We show that functionalizing polymer-coated colloidal nanoplatelets with guanosine groups allows synergistic increase of mechanical properties in nacre-mimetic lamellar self-assemblies. Anionic montmorillonite (MTM) was first coated using cationic poly(diallyldimethylammonium chloride) (PDADMAC) to prepare core-shell colloidal platelets, and subsequently the remaining chloride counterions allowed exchange to functional anionic 2-deoxyguanosine 5-monophosphate (dGMP) counterions, containing hydrogen bonding donors and acceptors. The compositions were studied using elemental analysis, scanning and transmission electron microscopy, wide-angle X-ray scattering, and tensile testing. The lamellar spacing between the clays increases from 1.85 to 2.14 nm upon addition of the dGMP. Adding dGMP increases the elastic modulus, tensile strength, and strain 33.0%, 40.9%, and 5.6%, respectively, to 13.5 GPa, 67 MPa, and 1.24%, at 50% relative humidity. This leads to an improved toughness seen as a ca. 50% increase of the work-to-failure. This is noteworthy, as previously it has been observed that connecting the core-shell nanoclay platelets covalently or ionically leads to increase of the stiffness but to reduced strain. We suggest that the dynamic supramolecular bonds allow slippage and sacrificial bonds between the self-assembling nanoplatelets, thus promoting toughness, still providing dynamic interactions between the platelets.
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Predicting disagreement between physicians and patients on depression response and remission.
Int Clin Psychopharmacol
PUBLISHED: 03-15-2013
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Demographic, personality, and disease-related factors all contribute when patients disagree with physicians on the severity of subjective symptoms. This study aims to create a model, on the basis of patient factors at treatment initiation, for longitudinal prediction of disagreement on treatment response and remission in depressed patients. Four hundred patients with major depressive disorder were studied during a clinical drug trial. Repeated assessments with the Montgomery-Åsberg Depression Rating Scale (MADRS) and the self-rating version (MADRS-S) were used to indicate response or remission. Factors at baseline and week 2 were tested for inclusion in a model for the prediction of discordance on remission and response between patients and physicians at week 8. The models were then tested, in the same population, at weeks 12, 16, and 24. Model AUCs ranged from 0.71 to 0.74 for week 8. The models that were validated at weeks 12, 16, and 24 indicated stability in the predictive value of the models. The risk for longitudinal disagreement in the evaluation of depression treatment response and remission in clinical practice and drug trials can be predicted using factors at study initiation and at week 2.
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Low serum adiponectin concentrations are associated with insulin sensitivity independent of obesity in Sudanese subjects with type 2 diabetes mellitus.
Diabetol Metab Syndr
PUBLISHED: 03-07-2013
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Prevalence of Type 2 diabetes mellitus among Sudanese population was found to be 3.4% and associated with high rates of complications and obesity. Different adipocytokines are secreted from adipose tissues, among them adiponectin, which was shown to have insulins ensitizing properties and anti-inflammatory, anti-atherogenic effect. The aim of this study was to characterize type 2 diabetes in Sudanese diabetic subjects and controls in respect to hormones influencing or influenced by glucose metabolism.
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Indices of fatty acid desaturase activity in healthy human subjects: effects of different types of dietary fat.
Br. J. Nutr.
PUBLISHED: 02-18-2013
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?9-Desaturase (stearoyl-CoA desaturase 1, SCD-1) regulates the desaturation of SFA, mainly stearic and palmitic, to MUFA. ?6-Desaturase (D6D) and ?5-desaturase (D5D) are involved in the metabolism of linoleic and ?-linolenic acid to polyunsaturated metabolites. The objective of the present study was to study the effects of different types of dietary fat on indices of fatty acid desaturase (FADS) activity (evaluated as product:precursor ratios) in plasma and skeletal muscle in human subjects. A high SCD-1 index has been related to obesity and metabolic disorders, while the D5D index is associated with insulin sensitivity. Fatty acid composition of serum and skeletal muscle lipids was analysed by GLC during a randomised, controlled, 3-month dietary intervention in healthy subjects. A comparison of the effects of a diet containing butter fat (SFA, n 17) with a diet containing monounsaturated fat (MUFA, n 17), keeping all other dietary components constant, showed a reduced SCD-1 activity index by 20% on the MUFA diet compared with the SFA diet assessed in serum cholesteryl esters. The D6D and D5D indices remained unaffected. Supplementation with long-chain n-3 fatty acids reduced the SCD-1 index by a similar magnitude while the D6D index decreased and the D5D index increased. It is concluded that changes in the type of fat in the diet affect the indices of FADS activity in serum and skeletal muscle in human subjects. The desaturase activity indices estimated from the serum lipid ester composition are significantly related to corresponding indices studied in skeletal muscle phospholipids.
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Effects of sugar-sweetened beverages on plasma acylation stimulating protein, leptin and adiponectin: Relationships with Metabolic Outcomes.
Obesity (Silver Spring)
PUBLISHED: 02-14-2013
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The effects of fructose and glucose consumption on plasma acylation stimulating protein (ASP), adiponectin, and leptin concentrations relative to energy intake, body weight, adiposity, circulating triglycerides, and insulin sensitivity were determined.
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Antimüllerian hormone levels are strongly associated with live-birth rates after assisted reproduction.
J. Clin. Endocrinol. Metab.
PUBLISHED: 02-13-2013
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Context: Previous studies have suggested that antimüllerian hormone (AMH) levels are positively associated with in vitro fertilization (IVF) outcome through their relationship with oocyte yield and not by reflecting oocyte or embryo quality. Objective: The aim was to investigate whether AMH levels are associated with pregnancy and live-birth rates and whether the results may also reflect qualitative aspects of oocytes and embryos. Design: The study was a prospective cohort study between April 2008 and June 2011. Setting: The study was done at a university-affiliated private infertility center. Patients: The study cohort consisted of 892 consecutive women undergoing 1230 IVF-intracytoplasmic sperm injection cycles. Intervention(s): AMH levels, analyzed using the DSL ELISA kit, were statistically adjusted for repeated treatments and age and analyzed for associations with treatment outcome. Main Outcome Measures: Pregnancy rates, live-birth rates, and stimulation outcome parameters were measured. Results: AMH was log-normally distributed with a mean (SD) of 2.3 (2.5) ng/mL. Live-birth rates per started cycle (mean [95% confidence interval]) increased log-linearly from 10.7% [7.2-14.1] for AMH < 0.84 ng/mL (25th percentile) to 30.8% [25.7-36.0] for AMH > 2.94 ng/mL (75th percentile), Ptrend < .0001, being superior in women with polycystic ovaries. These findings were significant also after adjustments were made for age and oocyte yield. AMH was also associated with ovarian response variables and embryo scores. Conclusions: AMH is strongly associated with live-birth rates after IVF-intracytoplasmic sperm injection. AMH may therefore serve as a prognostic factor for the chance of a pregnancy and live birth. Treatment outcome was superior in patients with polycystic ovaries. The findings also indicate that AMH may partially comprise information about oocyte quality.
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High-sensitive cardiac troponin T and its relations to cardiovascular risk factors, morbidity, and mortality in elderly men.
Am. Heart J.
PUBLISHED: 02-07-2013
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Cardiac troponin is emerging as risk indicator in community-dwelling populations. In this study, we investigated the associations of cardiac troponin T (cTnT) to cardiovascular (CV) disease and outcome in elderly men.
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Using the ovarian sensitivity index to define poor, normal, and high response after controlled ovarian hyperstimulation in the long gonadotropin-releasing hormone-agonist protocol: suggestions for a new principle to solve an old problem.
Fertil. Steril.
PUBLISHED: 01-03-2013
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To explore the utility of using the ratio between oocyte yield and total dose of FSH, i.e., the ovarian sensitivity index (OSI), to define ovarian response patterns.
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GDF-15 for Prognostication of Cardiovascular and Cancer Morbidity and Mortality in Men.
PLoS ONE
PUBLISHED: 01-01-2013
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The objective was to evaluate the hypothesis that growth-differentiation factor 15 (GDF-15) is an independent marker of the long-term risk for both cardiovascular disease and cancer morbidity beyond clinical and biochemical risk factors. Plasma obtained at age 71 was available from 940 subjects in the Uppsala Longitudinal Study of Adult Men (ULSAM) cohort. Complete mortality and morbidity data were obtained from public registries. At baseline there were independent associations between GDF-15 and current smoking, diabetes mellitus, biomarkers of cardiac (high-sensitivity troponin-T, NT-proBNP) and renal dysfunction (cystatin-C) and inflammatory activity (C-reactive protein), and previous cardiovascular disease (CVD). During 10 years follow-up there occurred 265 and 131 deaths, 115 and 46 cardiovascular deaths, and 185 and 86 events with coronary heart disease mortality or morbidity in the respective total cohort (n=940) and non-CVD (n=561) cohort. After adjustment for conventional cardiovascular risk factors, one SD increase in log GDF-15 were, in the respective total and non-CVD populations, associated with 48% (95%CI 26 to 73%, p<0.001) and 67% (95%CI 28 to 217%, p<0.001) incremental risk of cardiovascular mortality, 48% (95%CI 33 to 67%, p<0.001) and 61% (95%CI 38 to 89%, p<0.001) of total mortality and 36% (95%CI 19 to 56%, p<0.001) and 44% (95%CI 17 to 76%, p<0.001) of coronary heart disease morbidity and mortality. The corresponding incremental increase for cancer mortality in the respective total and non-cancer disease (n=882) population was 46% (95%CI 21 to 77%, p<0.001) and 38% (95%CI 12 to 70%, p<0.001) and for cancer morbidity and mortality in patients without previous cancer disease 30% (95%CI 12 to 51%, p<0.001). In conclusion, in elderly men, GDF-15 improves prognostication of both cardiovascular, cancer mortality and morbidity beyond established risk factors and biomarkers of cardiac, renal dysfunction and inflammation.
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Seasonal variations of insulin sensitivity from a euglycemic insulin clamp in elderly men.
Ups. J. Med. Sci.
PUBLISHED: 11-09-2011
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Seasonal variations in hemoglobin-A1c have been reported in diabetic patients, but the underlying mechanisms have not been elucidated.
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Circulating concentrations of monocyte chemoattractant protein-1, plasminogen activator inhibitor-1, and soluble leukocyte adhesion molecule-1 in overweight/obese men and women consuming fructose- or glucose-sweetened beverages for 10 weeks.
J. Clin. Endocrinol. Metab.
PUBLISHED: 09-28-2011
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Results from animal studies suggest that consumption of large amounts of fructose can promote inflammation and impair fibrinolysis. Data describing the effects of fructose consumption on circulating levels of proinflammatory and prothrombotic markers in humans are unavailable.
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Strong and tough cellulose nanopaper with high specific surface area and porosity.
Biomacromolecules
PUBLISHED: 09-09-2011
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In order to better understand nanostructured fiber networks, effects from high specific surface area of nanofibers are important to explore. For cellulose networks, this has so far only been achieved in nonfibrous regenerated cellulose aerogels. Here, nanofibrillated cellulose (NFC) is used to prepare high surface area nanopaper structures, and the mechanical properties are measured in tensile tests. The water in NFC hydrogels is exchanged to liquid CO2, supercritical CO2, and tert-butanol, followed by evaporation, supercritical drying, and sublimation, respectively. The porosity range is 40-86%. The nanofiber network structure in nanopaper is characterized by FE-SEM and nitrogen adsorption, and specific surface area is determined. High-porosity TEMPO-oxidized NFC nanopaper (56% porosity) prepared by critical point drying has a specific surface area as high as 482 m(2) g(-1). The mechanical properties of this nanopaper structure are better than for many thermoplastics, but at a significantly lower density of only 640 kg m(-3). The modulus is 1.4 GPa, tensile strength 84 MPa, and strain-to-failure 17%. Compared with water-dried nanopaper, the material is softer with substantiallly different deformation behavior.
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Lipoprotein(a): genotype-phenotype relationship and impact on atherogenic risk.
Metab Syndr Relat Disord
PUBLISHED: 07-12-2011
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In 2010, more than 45 years after the initial discovery of lipoprotein(a) [Lp(a)] by Kare Berg, an European Atherosclerosis Society Consensus Panel recommended screening for elevated Lp(a) in people at moderate to high risk of atherosclerotic cardiovascular disease (CVD). This recommendation was based on extensive epidemiological findings demonstrating a significant association between elevated plasma Lp(a) levels and coronary heart disease, myocardial infarction, and stroke. In addition to those patients considered to be at moderate to high risk of heart disease, statin-treated patients with recurrent heart disease were also identified as targeted for screening of elevated Lp(a) levels. Taken together, recent findings have significantly strengthened the notion of Lp(a) as a causal risk factor for CVD. It is well established that Lp(a) levels are largely determined by the size of the apolipoprotein a [apo(a)] gene; however, recent studies have identified several other LPA gene polymorphisms that have significant associations with an elevated Lp(a) level and a reduced copy number of K4 repeats. In addition, the contribution of other genes in regulating Lp(a) levels has been described. Besides the strong genetic regulation, new evidence has emerged regarding the impact of inflammation as a modulator of Lp(a) risk factor properties. Thus, oxidized phospholipids that possess a strong proinflammatory potential are preferentially carried on Lp(a) particles. Collectively, these findings point to the importance of both phenotypic and genotypic factors in influencing apo(a) proatherogenic properties. Therefore, studies taking both of these factors into account determining the amount of Lp(a) associated with each individual apo(a) size allele are valuable tools when assessing a risk factor role of Lp(a).
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Age as a modulator of inflammatory cardiovascular risk factors.
Arterioscler. Thromb. Vasc. Biol.
PUBLISHED: 06-23-2011
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Levels of acute phase reactants are affected by age. The extent to which cardiovascular risk associated with aging is due to an increase in the inflammatory burden is not known. We assessed the relationship with age of inflammatory markers, representing (1) systemic (C-reactive protein, fibrinogen, and serum amyloid-A) and (2) vascular (lipoprotein-associated phospholipase A(2) and pentraxin-3) inflammation.
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Metabolic responses to prolonged consumption of glucose- and fructose-sweetened beverages are not associated with postprandial or 24-h glucose and insulin excursions.
Am. J. Clin. Nutr.
PUBLISHED: 05-25-2011
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Consumption of sugar-sweetened beverages has been shown to be associated with dyslipidemia, insulin resistance, fatty liver, diabetes, and cardiovascular disease. It has been proposed that adverse metabolic effects of chronic consumption of sugar-sweetened beverages are a consequence of increased circulating glucose and insulin excursions, ie, dietary glycemic index (GI).
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Fatty fish in the diet of patients with type 2 diabetes: comparison of the metabolic effects of foods rich in n-3 and n-6 fatty acids.
Am. J. Clin. Nutr.
PUBLISHED: 05-25-2011
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Dietary advice, including modification of dietary fat quality, is the basis of treatment of diabetes, but there is some uncertainty about the optimal amount of polyunsaturated fatty acids of the n-6 (omega-6) and n-3 (omega-3) series.
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Colloidal ionic assembly between anionic native cellulose nanofibrils and cationic block copolymer micelles into biomimetic nanocomposites.
Biomacromolecules
PUBLISHED: 05-10-2011
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We present a facile ionic assembly between fibrillar and spherical colloidal objects toward biomimetic nanocomposites with majority hard and minority soft domains based on anionic reinforcing native cellulose nanofibrils and cationic amphiphilic block copolymer micelles with rubbery core. The concept is based on ionic complexation of carboxymethylated nanofibrillated cellulose (NFC, or also denoted as microfibrillated cellulose, MFC) and micelles formed by aqueous self-assembly of quaternized poly(1,2-butadiene)-block-poly(dimethylaminoethyl methacrylate) with high fraction of the NFC reinforcement. The adsorption of block copolymer micelles onto nanocellulose is shown by quartz crystal microbalance measurements, atomic force microscopy imaging, and fluorescent optical microscopy. The physical properties are elucidated using electron microscopy, thermal analysis, and mechanical testing. The cationic part of the block copolymer serves as a binder to NFC, whereas the hydrophobic rubbery micellar cores are designed to facilitate energy dissipation and nanoscale lubrication between the NFC domains under deformation. We show that the mechanical properties do not follow the rule of mixtures, and synergistic effects are observed with promoted work of fracture in one composition. As the concept allows wide possibilities for tuning, the work suggests pathways for nanocellulose-based biomimetic nanocomposites combining high toughness with stiffness and strength.
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Agreement between physicians and patients ratings on the Montgomery-Åsberg Depression Rating Scale.
J Affect Disord
PUBLISHED: 05-06-2011
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Self-rating scales developed for monitoring depression severity are potentially informative and cost effective tools. There is an increasing tendency to use the Montgomery-Åsberg Depression Rating Scale (MADRS) and the self-rating version (MADRS-S) interchangeably.
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Cellulose nanocomposite biopolymer foam--hierarchical structure effects on energy absorption.
ACS Appl Mater Interfaces
PUBLISHED: 04-26-2011
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Starch is an attractive biofoam candidate as replacement of expanded polystyrene (EPS) in packaging materials. The main technical problems with starch foam include its hygroscopic nature, sensitivity of its mechanical properties to moisture content, and much lower energy absorption than EPS. In the present study, a starch-based biofoam is for the first time able to reach comparable mechanical properties (E = 32 MPa, compressive yield strength, 630 kPa) to EPS at 50% relative humidity and similar relative density. The reason is the nanocomposite concept in the form of a cellulose nanofiber network reinforcing the hygroscopic amylopectin starch matrix in the cell wall. The biofoams are prepared by the freezing/freeze-drying technique and subjected to compressive loading. Cell structure is characterized by FE-SEM of cross sections. Mechanical properties are related to cell structure and cell wall nanocomposite composition. Hierarchically structured biofoams are demonstrated to be interesting materials with potential for strongly improved mechanical properties.
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Antral follicle counts are strongly associated with live-birth rates after assisted reproduction, with superior treatment outcome in women with polycystic ovaries.
Fertil. Steril.
PUBLISHED: 04-14-2011
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To evaluate the association of antral follicle count (AFC) with in vitro fertilization/intracytoplasmic sperm injection (IVF-ICSI) outcome in a large unselected cohort of patients covering the entire range of AFC.
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Endothelial function in resistance and conduit arteries and 5-year risk of cardiovascular disease.
Circulation
PUBLISHED: 03-28-2011
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Impaired endothelial function has been implicated as a cause of cardiovascular disease. Little is known of the relations of measures of endothelial function in resistance and conduit arteries to incident cardiovascular disease in the general population, and available techniques have not been compared.
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The combined contribution of albuminuria and glomerular filtration rate to the prediction of cardiovascular mortality in elderly men.
Nephrol. Dial. Transplant.
PUBLISHED: 02-18-2011
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Cardiovascular risk prediction is particularly important in the primary prevention of cardiovascular disease (CVD). Yet, data on whether the combined addition of albuminuria and estimated glomerular filtration rate (eGFR) improves cardiovascular risk prediction in individuals without CVD in the community is scarce.
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Poor chest compression quality with mechanical compressions in simulated cardiopulmonary resuscitation: a randomized, cross-over manikin study.
Resuscitation
PUBLISHED: 02-14-2011
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Mechanical chest compression devices are being implemented as an aid in cardiopulmonary resuscitation (CPR), despite lack of evidence of improved outcome. This manikin study evaluates the CPR-performance of ambulance crews, who had a mechanical chest compression device implemented in their routine clinical practice 8 months previously. The objectives were to evaluate time to first defibrillation, no-flow time, and estimate the quality of compressions.
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Clay nanopaper with tough cellulose nanofiber matrix for fire retardancy and gas barrier functions.
Biomacromolecules
PUBLISHED: 02-03-2011
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Nacre-mimicking hybrids of high inorganic content (>50 wt %) tend to show low strain-to-failure. Therefore, we prepared clay nanopaper hybrid composite montmorillonite platelets in a continuous matrix of nanofibrillated cellulose (NFC) with the aim of harnessing the intrinsic toughness of fibrillar networks. Hydrocolloid mixtures were used in a filtration approach akin to paper processing. The resulting multilayered structure of the nanopaper was studied by FE-SEM, FTIR, and XRD. Uniaxial stress-strain curves measured in tension and thermal analysis were carried out by DMTA and TGA. In addition, fire retardance and oxygen permeability characteristics were measured. The continuous NFC matrix is a new concept and provides unusual ductility to the nanocomposite, allowing inorganic contents as high as 90% by weight. Clay nanopaper extends the property range of cellulose nanopaper and is of interest in self-extinguishing composites and in oxygen barrier layers.
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Useful tests of usefulness of new risk factors: tools for assessing reclassification and discrimination.
Scand J Public Health
PUBLISHED: 01-26-2011
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New risk factors for various diseases are suggested at an increasing pace, with promise of clinical usefulness for risk prediction, but almost unvaryingly without formal testing of that property. We propose that a risk factor clinically relevant for risk prediction can be defined as one that correctly alters predicted risk to a clinically relevant extent in persons with a relevant absolute risk, such that it affects clinical decision making. We recommend that investigators who suggest a new risk factor for clinical use investigate if the new risk factor adds capacity to discriminate between persons who will subsequently experience the outcome from those who will not. For that purpose, we provide tools for calculating the net reclassification improvement, NRI, and the integrated discrimination improvement, IDI, using major statistical packages.
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Differential associations of serum amyloid A and pentraxin-3 with allele-specific lipoprotein(a) levels in African Americans and Caucasians.
Transl Res
PUBLISHED: 01-05-2011
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Lipoprotein(a) [Lp(a)] is a cardiovascular disease (CVD) risk factor, where inflammation impacts levels differentially across ethnicity. We investigated the effect of systemic [serum amyloid A (SAA)] and vascular [pentraxin-3 (PTX-3)] inflammation on Lp(a) levels across different apolipoprotein(a) [apo(a)] sizes in a biethnic population. Lp(a) and allele-specific apo(a) levels, apo(a) sizes, SAA, and PTX-3 levels were determined in 336 Caucasians and 224 African Americans. We dichotomized subjects into 2 groups using the respective median SAA (29.8 and 41.5 mg/dL for Caucasians and African Americans, respectively) or PTX-3 levels (1.6 and 1.1 ng/mL for Caucasians and African Americans, respectively). Among African Americans, but not in Caucasians, Lp(a) levels were increased (146 vs 117 nmol/L, P = 0.024) in the high versus low SAA group. No difference was observed across PTX-3 groups. Furthermore, among African Americans with smaller (<26 K4 repeats) apo(a) sizes, allele-specific apo(a) levels (111 vs 79 nmol/L, P = 0.020) were increased in the high versus low SAA group. Again, no difference was observed for PTX-3. We did not find any significant associations between allele-specific apo(a) and SAA or PTX-3 levels among Caucasians with smaller (<26 K4) apo(a) sizes. In conclusion, increased levels of SAA, but not PTX-3, were associated significantly with higher Lp(a) levels for smaller (<26 K4) apo(a) sizes in African Americans. Our results implicate that a proinflammatory stimulus may result in an increased cardiovascular risk through a selective increase in Lp(a) levels among African Americans who carry a smaller apo(a) size.
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Enigmatic role of lipoprotein(a) in cardiovascular disease.
Clin Transl Sci
PUBLISHED: 12-21-2010
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Lipoprotein (a), [Lp(a)] has many properties in common with low-density lipoprotein, (LDL) but contains a unique protein apolipoprotein(a), linked to apolipoprotein B-100 by a single disulfide bond. There is a substantial size heterogeneity of apo(a), and generally smaller apo(a) sizes tend to correspond to higher plasma Lp(a) levels, but this relation is far from linear, underscoring the importance to assess allele-specific apo(a) levels. The presence of apo(a), a highly charged, carbohydrate-rich, hydrophilic protein may obscure key features of the LDL moiety and offer opportunities for binding to vessel wall elements. Recently, interest in Lp(a) has increased because studies over the past decade have confirmed and more robustly demonstrated a risk factor role of Lp(a) for cardiovascular disease. In particular, levels of Lp(a) carried in particles with smaller size apo(a) isoforms are associated with coronary artery disease (CAD). Other studies suggest that proinflammatory conditions may modulate risk factor properties of Lp(a). Further, Lp(a) may act as a preferential acceptor for proinflammatory oxidized phospholipids transferred from tissues or from other lipoproteins. However, at present only a limited number of agents (e.g., nicotinic acid and estrogen) has proven efficacy in lowering Lp(a) levels. Although Lp(a) has not been definitely established as a cardiovascular risk factor and no guidelines presently recommend intervention, Lp(a)-lowering therapy might offer benefits in subgroups of patients with high Lp(a) levels.
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Effect of steam treatment on the properties of wood cell walls.
Biomacromolecules
PUBLISHED: 12-06-2010
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Steam treatment is a hygrothermal method of potential industrial significance for improving the dimensional stability and durability of wood materials. The steaming results in different chemical and micromechanical changes in the nanostructured biocomposite that comprise a wood cell wall. In this study, spruce wood ( Picea abies Karst.) that had been subjected to high-temperature steaming up to 180 °C was examined, using imaging Fourier Transform Infrared (FT-IR) microscopy and nanoindentation to track changes in the chemical structure and the micromechanical properties of the secondary cell wall. Similar changes in the chemical components, due to the steam treatment, were found in earlywood and latewood. A progressive degradation of the carbonyl groups in the glucuronic acid unit of xylan and a loss of mannose units in the glucomannan backbone, that is, a degradation of glucomannan, together with a loss of the C?O group linked to the aromatic skeleton in lignin, was found. The development of the hygroscopic and micromechanical properties that occurred with an elevation in the steam temperature correlated well with this pattern of degradation in the constituents in the biocomposite matrix in the cell wall (hemicellulose and lignin).
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Electron-beam-initiated polymerization of poly(ethylene glycol)-based wood impregnants.
ACS Appl Mater Interfaces
PUBLISHED: 11-08-2010
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The current study demonstrates that methacrylate and acrylate poly(ethylene glycol) (PEG) functional oligomers can be effectively impregnated into wood blocks, and cured efficiently to high conversions without catalyst by e-beam radiation, allowing for less susceptibility to leaching, and favorable properties including higher Brinell hardness values. PEG based monomers were chosen because there is a long history of this water-soluble monomer being able to penetrate the cell wall, thus bulking it and decreasing the uptake of water which further protects the wood from fungal attack. Diacrylate, dimethacrylate, and dihydroxyl functional PEG of M(w) 550-575, of concentrations 0, 30, 60, and 100 wt % in water, were vacuum pressure impregnated into Scots Pine blocks of 15 × 25 × 50 mm in an effort to bulk the cell wall. The samples were then irradiated and compared with nonirradiated samples. It was shown by IR, DSC that the acrylate polymers were fully cured to much higher conversions than can be reached with conventional methods. Leaching studies indicated a much lower amount of oligomer loss from the cured vinyl functional PEG chains in comparison to hydroxyl functional PEG indicating a high degree of fastening of the polymer in the wood. The Brinell hardness indicated a significant increase in hardness to hardwood levels in the modified samples compared to the samples of hydroxyl functional PEG and uncured vinyl PEG samples, which actually became softer than the untreated Scots Pine. By monitoring the dimensions of the sample it was found by weight percent gain calculations (WPG %) that water helps to swell the wood structure and allow better access of the oligomers into the cell wall. Further, the cure shrinkage of the wood samples demonstrated infiltration of the oligomers into the cell wall as this was not observed for methyl methacrylate which is well-documented to remain in the lumen. However, dimensional stability of the vinyl polymer modified blocks when placed in water was not observed to the same extent as PEG.
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Ultrastructure and mechanical properties of populus wood with reduced lignin content caused by transgenic down-regulation of cinnamate 4-hydroxylase.
Biomacromolecules
PUBLISHED: 09-14-2010
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Several key enzymes in lignin biosynthesis of Populus have been down-regulated by transgenic approaches to investigate their role in wood lignification and to explore their potential for lignin modification. Cinnamate 4-hydroxylase is an enzyme in the early phenylpropanoid pathway that has not yet been functionally analyzed in Populus . This study shows that down-regulation of cinnamate 4-hydroxylase reduced Klason lignin content by 30% with no significant change in syringyl to guaiacyl ratio. The lignin reduction resulted in ultrastructural differences of the wood and a 10% decrease in wood density. Mechanical properties investigated by tensile tests and dynamic mechanical analysis showed a decrease in stiffness, which could be explained by the lower density. The study demonstrates that a large modification in lignin content only has minor influences on tensile properties of wood in its axial direction and highlights the usefulness of wood modified beyond its natural variation by transgene technology in exploring the impact of wood biopolymer composition and ultrastructure on its material properties.
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Plasma parathyroid hormone and risk of congestive heart failure in the community.
Eur. J. Heart Fail.
PUBLISHED: 08-26-2010
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In experimental studies parathyroid hormone (PTH) has been associated with underlying causes of heart failure (HF) such as atherosclerosis, left ventricular hypertrophy, and myocardial fibrosis. Individuals with increased levels of PTH, such as primary or secondary hyperparathyroidism patients, have increased risk of ischaemic heart disease and HF. Moreover, increasing PTH is associated with worse prognosis in patients with overt HF. However, the association between PTH and the development HF in the community has not been reported.
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HIV protease inhibitors and obesity.
Curr Opin Endocrinol Diabetes Obes
PUBLISHED: 08-19-2010
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To review the current scientific literature and recent clinical trials on HIV protease inhibitors and their potential role in the pathogenesis of lipodystrophy and metabolic disorders.
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Plasma vitamin D and mortality in older men: a community-based prospective cohort study.
Am. J. Clin. Nutr.
PUBLISHED: 08-18-2010
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Vitamin D status is known to be important for bone health but may also affect the development of several chronic diseases, including cancer and cardiovascular diseases, which are 2 major causes of death.
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Integrated role of two apoliprotein E polymorphisms on apolipoprotein B levels and coronary artery disease in a biethnic population.
Metab Syndr Relat Disord
PUBLISHED: 08-17-2010
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Apolipoprotein E (ApoE) plays a major role in lipoprotein metabolism and genetic variability of ApoE confers susceptibility to coronary artery disease (CAD). Beyond variability in the coding region, promoter polymorphisms in the ApoE gene impact on ApoE transcription.
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Fast preparation procedure for large, flat cellulose and cellulose/inorganic nanopaper structures.
Biomacromolecules
PUBLISHED: 08-12-2010
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Nanostructured materials are difficult to prepare rapidly and as large structures. The present study is thus significant because a rapid preparation procedure for large, flat, smooth, and optically transparent cellulose nanopaper structures is developed using a semiautomatic sheet former. Cellulose/inorganic hybrid nanopaper is also produced. The preparation procedure is compared with other approaches, and the nanopaper structures are tested in uniaxial tensile tests. Optical transparency and high tensile strength are demonstrated in 200 mm diameter nanopaper sheets, indicating well-dispersed nanofibrils. The preparation time is 1 h for a typical nanopaper thickness of 60 ?m. In addition, the application of the nanopaper-making strategy to cellulose/inorganic hybrids demonstrates the potential for "green" processing of new types of nanostructured functional materials.
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Androgen levels, insulin sensitivity, and early insulin response in women with polycystic ovary syndrome: a long-term follow-up study.
Fertil. Steril.
PUBLISHED: 05-25-2010
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Thirty-four women with polycystic ovary syndrome who previously had participated in studies with intravenous glucose tolerance test and hyperinsulinemic, euglycemic clamp between 1987 and 1995 underwent anthropometric, endocrine (T and sex-hormone binding globulin serum concentration), and metabolic (intravenous glucose tolerance test, hyperinsulinemic, euglycemic clamp, and androgens) measurements. Free androgen levels and ?-cell function decreased over time in women with polycystic ovary syndrome, but insulin sensitivity remained unaltered.
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Usefulness of apolipoprotein B/apolipoprotein A-I ratio to predict coronary artery disease independent of the metabolic syndrome in African Americans.
Am. J. Cardiol.
PUBLISHED: 05-11-2010
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Studies have demonstrated that the apolipoprotein B/apolipoprotein A-I (apoB/apoA-I) ratio predicts cardiovascular risk better than any of the cholesterol indexes. A number of factors that define the metabolic syndrome (MS) differ across African-American and European-American ethnicities. We assessed the relation of the apoB/apoA-I ratio to MS and coronary artery disease (CAD) in 224 African Americans and 304 European Americans. The MS was defined using the revised National Cholesterol Education Program Adult Treatment Panel III criteria, and CAD was assessed as ?50% stenosis or a continuous cardiovascular score (0 to 75). The European Americans had a greater apoB/apoA-I ratio than the African Americans (1.15 vs 1.07, p = 0.008). The apoB/apoA-I ratio was associated with presence of the MS in both European Americans (odds ratio 5.9, 95% confidence interval 2.53 to 13.57, p <0.001) and African Americans (odds ratio 8.3, 95% confidence interval 3.52 to 19.25, p <0.001) and was greater in subjects with the MS than in those without the MS (1.21 vs 1.04, p <0.001, for European Americans and 1.20 vs 0.94, p <0.001, for African Americans). A stepwise increase was seen in the prevalence of the MS across the apoB/apoA-I ratio tertiles in both ethnic groups (chi-square = 13.1, p <0.001, for European Americans and chi-square = 19.6, p <0.001, for African Americans). On multiple regression analyses, the apoB/apoA-I ratio independently predicted CAD in African Americans (? = 0.242, p = 0.011). The cardiovascular score was significantly increased across the apoB/apoA-I ratio tertiles in the European-American subjects with the MS (p = 0.001). However, this association was seen in the African-American subjects without the MS (p = 0.023). In conclusion, the apoB/apoA-I ratio differed across ethnicities and was associated with presence of the MS in both groups. Among African Americans, an elevated apoB/apoA-I ratio independently predicted a greater risk of CAD.
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Postprandial lipoproteins and cardiovascular disease risk in diabetes mellitus.
Curr. Diab. Rep.
PUBLISHED: 04-29-2010
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Diabetes mellitus is associated with increased risk for atherosclerotic cardiovascular disease (CVD). Recent prospective studies in healthy individuals suggest that the postprandial triglyceride (TG) level is a better independent predictor for assessing future CVD events than fasting TG levels. In contrast, results have been more controversial among diabetic patients, as some studies report a positive association between postprandial TG and CVD. This raises the issue of to what extent postprandial TG levels may be of predictive value in the diabetic population. One possibility impacting on the predictive power of postprandial TG in identifying CVD risk may be the presence of other risk factors, including alterations in lipid and lipoprotein metabolism, which could make it more difficult to identify the impact of postprandial lipemia on cardiovascular risk. The findings provide a challenge to develop a better approach to assess the impact of postprandial lipemia on CVD risk under diabetic conditions.
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Translational nutrition research at UC Davis--the key role of the Clinical and Translational Science Center.
Ann. N. Y. Acad. Sci.
PUBLISHED: 04-15-2010
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The National Institutes of Healths Clinical and Translational Science Award (CTSA) program has had a profound impact on clinical research and training methods at the University of California, Davis (UC Davis). UC Davis was among the first 12 institutions to receive NIH funding for this award, and created its Clinical and Translational Science Center (CTSC) in 2006. The funding accelerated and further integrated an existing conscientious and careful planning effort for translational research with a stepwise approach to gradually increase our institutional competencies, capabilities, and resources in this area. The development of our CTSC has led us to develop new ways of bringing together a diverse faculty and facilitating research. The CTSC has impacted virtually every area and infrastructure resource involved in promoting clinical and translational research at our institution.
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Plasma 25-hydroxyvitamin D levels and fracture risk in a community-based cohort of elderly men in Sweden.
J. Clin. Endocrinol. Metab.
PUBLISHED: 03-23-2010
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Blood levels of 25-hydroxyvitamin D [25(OH)D] is the generally accepted indicator of vitamin D status, but no universal reference level has been reached.
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Large-area, lightweight and thick biomimetic composites with superior material properties via fast, economic, and green pathways.
Nano Lett.
PUBLISHED: 03-12-2010
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Although remarkable success has been achieved to mimic the mechanically excellent structure of nacre in laboratory-scale models, it remains difficult to foresee mainstream applications due to time-consuming sequential depositions or energy-intensive processes. Here, we introduce a surprisingly simple and rapid methodology for large-area, lightweight, and thick nacre-mimetic films and laminates with superior material properties. Nanoclay sheets with soft polymer coatings are used as ideal building blocks with intrinsic hard/soft character. They are forced to rapidly self-assemble into aligned nacre-mimetic films via paper-making, doctor-blading or simple painting, giving rise to strong and thick films with tensile modulus of 45 GPa and strength of 250 MPa, that is, partly exceeding nacre. The concepts are environmentally friendly, energy-efficient, and economic and are ready for scale-up via continuous roll-to-roll processes. Excellent gas barrier properties, optical translucency, and extraordinary shape-persistent fire-resistance are demonstrated. We foresee advanced large-scale biomimetic materials, relevant for lightweight sustainable construction and energy-efficient transportation.
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Association of lipoprotein-associated phospholipase A2 with coronary artery disease in African-Americans and Caucasians.
J. Clin. Endocrinol. Metab.
PUBLISHED: 03-01-2010
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Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) is bound predominately to low-density lipoprotein and has been implicated as a risk factor for coronary artery disease (CAD).
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Reengineering the national clinical and translational research enterprise: the strategic plan of the National Clinical and Translational Science Awards Consortium.
Acad Med
PUBLISHED: 02-26-2010
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Advances in human health require the efficient and rapid translation of scientific discoveries into effective clinical treatments; this process, in turn, depends on observational data gathered from patients, communities, and public health research that can be used to guide basic scientific investigation. Such bidirectional translational science, however, faces unprecedented challenges due to the rapid pace of scientific and technological development, as well as the difficulties of negotiating increasingly complex regulatory and commercial environments that overlap the research domain. Further, numerous barriers to translational science have emerged among the nations academic research centers, including basic structural and cultural impediments to innovation and collaboration, shortages of trained investigators, and inadequate funding.To address these serious and systemic problems, in 2006 the National Institutes of Health created the Clinical and Translational Science Awards (CTSA) program, which aims to catalyze the transformation of biomedical research at a national level, speeding the discovery and development of therapies, fostering collaboration, engaging communities, and training succeeding generations of clinical and translational researchers. The authors report in detail on the planning process, begun in 2008, that was used to engage stakeholders and to identify, refine, and ultimately implement the CTSA programs overarching strategic goals. They also discuss the implications and likely impact of this strategic planning process as it is applied among the nations academic health centers.
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Linking scientific discovery and better health for the nation: the first three years of the NIHs Clinical and Translational Science Awards.
Acad Med
PUBLISHED: 02-26-2010
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A comprehensive system for translating basic biomedical research into useful and effectively implemented clinical diagnostic, preventive, and therapeutic practices is essential to the nations health. The state of clinical and translational research (CTR) in the United States, however, has been characterized as fragmented, slow, expensive, and poorly coordinated. As part of its Roadmap Initiative, the National Institutes of Health instituted the Clinical and Translational Science Awards (CTSA), a sweeping and ambitious program designed to transform the conduct of biomedical research in the United States by speeding the translation of scientific discoveries into useful therapies and then developing methods to ensure that those therapies reach the patients who need them the most. The authors review the circumstances of the U.S. biomedical research enterprise that led to the creation of the CTSA and discuss the initial strategic plan of the CTSA, which was developed from the first three years of experience with the program and was designed to overcome organizational, methodological, and cultural barriers within and among research institutions. The authors also describe the challenges encountered during these efforts and discuss the promise of this vital national health care initiative, which is essential to creating a pipeline for the scientific workforce needed to conduct research that will, in turn, provide a rational evidence base for better health in the United States.
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Association of Lp-PLA(2) activity with allele-specific Lp(a) levels in a bi-ethnic population.
Atherosclerosis
PUBLISHED: 02-24-2010
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Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) and lipoprotein(a) [Lp(a)] have been implicated as cardiovascular disease risk factors, and are differentially regulated across ethnicity. We investigated the association between Lp-PLA(2) activity and allele-specific apolipoprotein(a) [apo(a)] levels in a bi-ethnic population.
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Determining vitamin D status: a comparison between commercially available assays.
PLoS ONE
PUBLISHED: 01-27-2010
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Vitamin D is not only important for bone health but can also affect the development of several non-bone diseases. The definition of vitamin D insufficiency by serum levels of 25-hydroxyvitamin D depends on the clinical outcome but might also be a consequence of analytical methods used for the definition. Although numerous 25-hydroxyvitamin D assays are available, their comparability is uncertain. We therefore aim to investigate the precision, accuracy and clinical consequences of differences in performance between three common commercially available assays.
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Increased stroke risk and lipoprotein(a) in a multiethnic community: the Northern Manhattan Stroke Study.
Cerebrovasc. Dis.
PUBLISHED: 01-11-2010
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Elevated lipoprotein(a) [Lp(a)] is associated with ischemic stroke (IS) among Whites, but data is sparse for non-White populations.
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Early insulin response and insulin sensitivity are equally important as predictors of glucose tolerance after correction for measurement errors.
Diabetes Res. Clin. Pract.
PUBLISHED: 08-11-2009
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We estimated measurement error (ME) corrected effects of insulin sensitivity (M/I), from euglycaemic insulin clamp, and insulin secretion, measured as early insulin response (EIR) from oral glucose tolerance test (OGTT), on fasting plasma glucose, HbA1c and type 2 diabetes longitudinally and cross-sectional.
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High basal LH levels in combination with low basal FSH levels are associated with high success rates at assisted reproduction.
Hum. Reprod.
PUBLISHED: 07-17-2009
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The objective of this study was to evaluate the associations of basal gonadotrophins with pregnancy and delivery rates at IVF/ICSI.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.