Ionic liquid-reconstituted cellulose composites as solid support matrices for biocatalyst immobilization

Preparation of cellulose-polyamine composite films and beads, which provide high loading of primary amines on the surface allowing direct one-step bioconjugation of active species, is reported using an ionic liquid (IL) dissolution and regeneration process. Films and bead architectures were prepared and used as immobilization supports for laccase as a model system demonstrating the applicability of this approach. Performance of these materials, compared to commercially available products, has been assessed using millimeter-sized beads of the composites and the lipase-catalyzed transesterification of ethyl butyrate.

Production of bioactive cellulose films reconstituted from ionic liquids

A new method for introducing enzymes into cellulosic matrixes which can be formed into membranes, films, or beads has been developed using a cellulose-in-ionic-liquid dissolution and regeneration process. Initial results on the formation of thin cellulose films incorporating dispersed laccase indicate that active enzyme-encapsulated films can be prepared using this methodology and that precoating the enzyme with a second. hydrophobic ionic liquid prior to dispersion in the cellulose/ionic liquid solution can provide an increase in enzyme activity relative to that of untreated films, presumably by providing a stabilizing microenvironment for the enzyme.

Fruit and vegetable consumption in older individuals in Northern Ireland: levels and patterns

Low intakes of fruit and vegetables have previously been reported in the older population of Great Britain, particularly among certain socio-demographic groups. Levels and patterns of consumption in the older population of Northern Ireland, however, remain unknown. A representative sample of 1000 members of the older population of Northern Ireland were contacted by telephone to assess average intake of all fruits and vegetables and various demographic details. Data from 426 individuals (representative of the whole population) reported a mean consumption of 4.0 (SD 1-3) and 4.1 (SD 1-3) portions of fruit and vegetables per weekday and per weekend day respectively. Regression analyses revealed greater consumption on weekdays by females (B 0.53; P

Preparation and characterization of Poly(vinyl alcohol) nanocomposites made from cellulose nanofibers

A method using a combination of ball milling, acid hydrolysis, and ultrasound was developed to obtain a high yield of cellulose nanofibers from flax fibers and microcrystalline cellulose (MCC). Poly(vinyl alcohol) (PVA) nanocomposites were prepared with these additives by a solution-casting technique. The cellulose nanofibers and nanocomposite films that were produced were characterized with Fourier transform infrared spectrometry, X- ray diffraction, thermogravimetric analysis, scanning electron microscopy, and transmission electron microscopy. Nanofibers derived from MCC were on average approximately 8 nm in diameter and 111 nm in length. The diameter of the cellulose nanofibers produced from flax fibers was approximately 9 nm, and the length was 141 nm. A significant enhancement of the thermal and mechanical properties was achieved with a small addition of cellulose nanofibers to the polymer matrix. Interestingly, the flax nanofibers had the same reinforcing effects as MCC nanofibers in the matrix. Dynamic mechanical analysis results indicated that the use of cellulose nanofibers (acid hydrolysis) induced a mechanical percolation phenomenon leading to outstanding and unusual mechanical properties through the formation of a rigid filler network in the PVA matrix. X-ray diffraction showed that there was no significant change in the crystallinity of the PVA matrix with the incorporation of cellulose nanofibers. © 2009 Wiley Periodicals, Inc.

The effect of increased dietary fruit and vegetable consumption on endothelial activation, inflammation and oxidative stress in hypertensive volunteers

Background and aims

Public health campaigns recommend increased fruit and vegetable (FV) consumption as an effective means of cardiovascular risk reduction. During an 8 week randomised control trial among hypertensive volunteers, we noted significant improvements in endothelium-dependent vasodilatation with increasing FV consumption. Circulating indices of inflammation, endothelial activation and insulin resistance are often employed as alternative surrogates for systemic arterial health. The responses of several such biomarkers to our previously described FV intervention are reported here.
Methods and results

Hypertensive volunteers were recruited from medical outpatient clinics. After a common 4 week run-in period during which FV consumption was limited to 1 portion per day, participants were randomised to 1, 3 or 6 portions daily for 8 weeks. Venous blood samples for biomarker analyses were collected during the pre and post-intervention vascular assessments. A total of 117 volunteers completed the 12 week study. Intervention-related changes in circulating levels of high sensitivity C-reactive protein (hsCRP), soluble intracellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), von Willebrand factor (vWF) and plasminogen activator inhibitor-1 (PAI-1) did not differ significantly between FV groups. Similarly, there were no significant between group differences of change in homeostasis model assessment (HOMA) scores.
Conclusions

Despite mediating a significant improvement in acetylcholine induced vasodilatation, increased FV consumption did not affect a calculated measure of insulin resistance or concentrations of the circulating biomarkers measured during this study. Functional indices of arterial health such as endothelium-dependent vasomotion are likely to provide more informative cardiovascular end-points during short-term dietary intervention trials.

The application of colloidal gas aphrons in the recovery of fine cellulose fibres from paper mill wastewater

Colloidal gas aphrons (CGAs) are micron-sized gas bubbles of 25–30 µm in diameter produced by a high-speed stirrer in a vessel containing dilute surfactant solution. These bubbles, because of their small size, exhibit some colloidal properties. In this work, CGAs were used to separate fine fibres from a lean slurry of cellulosic pulp in a flotation column. The pulp fibres were recovered as foamate from the top. Sodium dodecyl sulphate at a concentration of 2.0 kg/m3 was used as a surfactant to generate the CGAs in a spinning disc apparatus. The results indicated that up to 70% flotation efficiency could be obtained within a short column height of 0.3–0.35 m. This technique can be applied to recover fine cellulosic pulp from paper-machine backwater.

Barriers to increasing fruit and vegetable intakes in the older population of Northern Ireland: low levels of liking and low awareness of current recommendations

Objective: To investigate barriers to increasing fruit and vegetable (f + v) intakes in a large sample of the older population of Northern Ireland (NI), in relation to current intakes.

Biomarkers of fruit and vegetable intake in Human intervention studies a systematic review

Observational evidence consistently shows that consumption of a diet rich in fruit and vegetables may offer protection against diseases such as cardiovascular disease and cancer. Assessment of dietary intake is complex and prone to many sources of error. More objective biomarkers of fruit and vegetable intake are therefore of interest. The aim of this review is to examine the usefulness of the main biomarkers of fruit and vegetable intake to act as objective indicators of compliance in dietary intervention studies. A comprehensive search of the literature was conducted using six databases. Suitable papers were selected and relevant data extracted. The papers were categorized into 3 sub-groups: whole diet interventions; mixed fruit and vegetable interventions; and studies involving individual varieties of fruits or vegetables. Ninety-six studies were included in the review. Overall, the most commonly measured, and most consistently responsive, biomarkers were the carotenoids and vitamin C. Based on the results of this systematic review, it remains prudent to measure a panel of biomarkers in fruit and vegetable intervention studies. The only possible exception to this is “fruit only” intervention studies where assessment of vitamin C alone may suffice.

Preparation and characterisation of cellulose nanofibres

Two different procedures were compared for the preparation of cellulose nanofibres from flax and microcrystalline cellulose (MCC). The first involved a combination of high energy ball milling, acid hydrolysis and ultrasound, whilst the second employed a high pressure homogenisation technique, with and without various pre-treatments of the fibrous feedstock. The geometry and microstructure of the cellulose nanofibres were observed by SEM and TEM and their particle size measured using image analysis and dynamic light scattering. Aspect ratios of nanofibres made by microfluidisation were orders of magnitude greater than those achieved by acid hydrolysis. FTIR, XRD and TGA were used to characterise changes to chemical functionality, cellulose crystallinity and thermal stability resulting from the approaches used for preparing the cellulose nanofibres. Hydrolysis using sulphuric acid gave rise to esterification of the cellulose nanofibres, a decrease in crystallinity with MCC, but an increase with flax, together with an overall reduction in thermal stability. Increased shear history of flax subjected to multiple passes through the microfluidiser, raised both cellulose nanofibril crystallinity and thermal stability, the latter being strongly influenced by acid, alkaline and, most markedly, silane pretreatment.

Effect of fruit and vegetable intake on oxidative stress and inflammation in COPD: a randomised controlled trial

Epidemiological evidence supports a positive relationship between fruit and vegetable (FV) intake, lung function and chronic obstructive pulmonary disease (COPD). Increasing FV intake may attenuate the oxidative stress and inflammation associated with COPD.

An exploratory randomised controlled trial to examine the effect of increased consumption of FV on oxidative stress and inflammation in moderate-to-severe COPD was conducted. 81 symptomatically stable patients with a habitually low FV intake (two or fewer portions of FV per day) were randomised to the intervention group (five or more portions of FV per day) or the control group (two or fewer portions of FV per day). Each participant received self-selected weekly home deliveries of FV for 12 weeks.

75 participants completed the intervention. There was a significant between-group change in self-reported FV intake and biomarkers of FV intake (zeaxanthin (p=0.034) and ß-cryptoxanthin (p=0.015)), indicating good compliance; post-intervention intakes in intervention and control groups were 6.1 and 1.9 portions of FV per day, respectively. There were no significant changes in biomarkers of airway inflammation (interleukin-8 and myeloperoxidase) and systemic inflammation (C-reactive protein) or airway and systemic oxidative stress (8-isoprostane).

This exploratory study demonstrated that patients with moderate-to-severe COPD were able to comply with an intervention to increase FV intake; however, this had no significant effect on airway or systemic oxidative stress and inflammation.