A critical examination of the evidence relating high fructose corn syrup and weight gain

The use of high fructose corn syrup (HFCS) has increased over the past several decades in the United States while overweight and obesity rates have risen dramatically. Some scientists hypothesize that HFCS consumption has uniquely contributed to the increasing mean body mass index (BMI) of the U.S. population. The Center for Food, Nutrition, and Agriculture Policy convened an expert panel to discuss the published scientific literature examining the relationship between consumption of HFCS or "soft drinks" (proxy for HFCS) and weight gain. The authors conducted original analysis to address certain gaps in the literature. Evidence from ecological studies linking HFCS consumption with rising BMI rates is unreliable. Evidence from epidemiologic studies and randomized controlled trials is inconclusive. Studies analyzing the differences between HFCS and sucrose consumption and their contributions to weight gain do not exist. HFCS and sucrose have similar monosaccharide compositions and sweetness values. The fructose:glucose (F:G) ratio in the U.S. food supply has not appreciably changed since the introduction of HFCS in the 1960s. It is unclear why HFCS would affect satiety or absorption and metabolism of fructose any differently than would sucrose. Based on the currently available evidence, the expert panel concluded that HFCS does not appear to contribute to overweight and obesity any differently than do other energy sources. Research recommendations were made to improve our understanding of the association of HFCS and weight gain.     

Endogenous amino acid flow at the terminal ileum of adult humans determined following the ingestion of a single protein-free meal

The study sought to determine endogenous total nitrogen and amino acid flows at the terminal ileum of adult humans. Six adults (65 ± 10 kg bodyweight) with well-established ileostomics fasted for 14 h before consuming a single protein-free meal (240 g) containing Celite (acid-insoluble ash) as an indigestible marker. Ileal digesta were collected for 8 h after the meal and endogenous flows were determined by reference to the marker. The mean (±SE) total 8 h output of digesta dry matter was 9.1 (± 3.51) g. The mean ileal flow of total nitrogen was 4.38 (± 0.770). with the mean amino acid flows ranging from 0.17 (± 0.009) for methionine to 2.26 (± 0.258) for glutamic acid (mg g^?1 food dry matter intake).     

Toughening and reinforcement of poly(vinylidene fluoride) nanocomposites with “bud-branched” nanotubes

Bud-branched nanotubes, fabricated by growing metal particles on the surface of multi-wall carbon nanotubes (MWCNTs), were used to prepare poly(vinylidene fluoride) (PVDF) based nanocomposites. The results of differential scanning calorimetry (DSC) showed that the introduction of the MWCNTs and bud-branched nanotubes both increased the crystallization temperature, while no significant variation of T_m (melting temperature), ΔH_c (melting enthalpy) and ΔH_m (crystallization enthalpy) occurred. The results of wide angle X-ray diffraction (WAXD) tests showed that α-phase was the dominated phase for both pure PVDF and its nanocomposites, indicating the addition of the MWCNTs and bud-branched nanotubes did not alter the crystal structures. Dynamic mechanical analysis (DMA) tests showed that bud-branched nanotubes were much more efficient in increasing storage modulus than the smooth MWCNTs. In addition, no significant variation of the T_g (glass transition temperature) was observed with the addition of MWCNTs and bud-branched nanotubes. Tensile tests showed that the introduction of MWCNTs and bud-branched nanotubes increased the modulus. However, a dramatic decrease in the fracture toughness was observed for PVDF/MWCNTs nanocomposites. For PVDF/bud-branched nanotubes nanocomposites, a significant improvement in the fracture toughness was observed compared with PVDF/MWCNTs nanocomposites.     

11β-Hydroxysteroid Dehydrogenase Type 1 within Osteoclasts Mediates the Bone Protective Properties of Therapeutic Corticosteroids in Chronic Inflammation

Therapeutic glucocorticoids (GCs) are powerful anti-inflammatory tools in the management of chronic inflammatory diseases such as rheumatoid arthritis (RA). However, their actions on bone in this context are complex. The enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is a mediator of the anti-inflammatory actions of therapeutic glucocorticoids (GCs) in vivo. In this study we delineate the role of 11β-HSD1 in the effects of GC on bone during inflammatory polyarthritis. Its function was assessed in bone biopsies from patients with RA and osteoarthritis, and in primary osteoblasts and osteoclasts. Bone metabolism was assessed in the TNF-tg model of polyarthritis treated with oral GC (corticosterone), in animals with global (TNF-tg^11βKO), mesenchymal (including osteoblast) (TNF-tg^{11βflx/tw2cre}) and myeloid (including osteoclast) (TNF-tg^{11βflx/LysMcre}) deletion. Bone parameters were assessed by micro-CT, static histomorphometry and serum metabolism markers. We observed a marked increase in 11β-HSD1 activity in bone in RA relative to osteoarthritis bone, whilst the pro-inflammatory cytokine TNFα upregulated 11β-HSD1 within osteoblasts and osteoclasts. In osteoclasts, 11β-HSD1 mediated the suppression of bone resorption by GCs. Whilst corticosterone prevented the inflammatory loss of trabecular bone in TNF-tg animals, counterparts with global deletion of 11β-HSD1 were resistant to these protective actions, characterised by increased osteoclastic bone resorption. Targeted deletion of 11β-HSD1 within osteoclasts and myeloid derived cells partially reproduced the GC resistant phenotype. These data reveal the critical role of 11β-HSD1 within bone and osteoclasts in mediating the suppression of inflammatory bone loss in response to therapeutic GCs in chronic inflammatory disease.     

Evaluating the performance of designed terpolymers for polymer flooding

In this work, polymeric materials designed for enhanced oil recovery (EOR) were evaluated for their intended application. Properties including viscosity, flow through porous media (resistance factor and residual resistance factor), and heavy oil displacement (incremental oil recovery) were assessed for designed terpolymers of 2-acrylamido-2-methylpropane sulphonic acid (AMPS), acrylamide (AAm), and acrylic acid (AAc). The same properties were evaluated for two commercially available reference materials (e.g., partially hydrolyzed polyacrylamides or HPAM) with similar characteristics, which allowed for direct comparison between the newly designed terpolymers and materials that are currently on the market for the polymer flooding application. The incremental oil recovery directly associated with polymer flooding, which includes both the polymer flooding and post-polymer waterflooding stages (excluding the initial waterflooding injection (or secondary) oil recovery), demonstrates that the designed terpolymers provided a higher incremental recovery (42% and 58%) than the reference materials (33% and 46%). Therefore, the terpolymers provided a higher contribution to incremental (or enhanced) oil recovery than the typical HPAM. Additionally, both designed terpolymers showed better injectivity in unconsolidated porous media and are less likely to cause plugging than the commercially available reference materials. Therefore, using a targeted design approach ultimately led to polymeric materials with excellent performance for EOR polymer flooding applications.