Gadolinium-DTPA enhanced magnetic resonance imaging of bone cysts in patients with rheumatoid arthritis

OBJECTIVES: To examine the contents of intraosseous cysts in patients with rheumatoid arthritis (RA) through the signal intensity characteristics on gadolinium-DTPA (Gd-DTPA) enhanced magnetic resonance imaging. METHODS: The hand or foot joints of nine patients with the cystic form of RA (where the initial radiological abnormality consisted of intraosseous cysts without erosions) were imaged before and after intravenous administration of Gd-DTPA. A 0.6 unit, T1 weighted spin echo and T2* weighted gradient echo were used to obtain images in at least two perpendicular planes. RESULTS: Most cysts showed a low signal intensity on the non-enhanced T1 weighted (spin echo) images and a high signal intensity on the T2* weighted (gradient echo) images, consistent with a fluid content. No cyst showed an enhancement of signal intensity on the T1 weighted images after intravenous administration of Gd-DTPA, whereas synovium hyperplasia at the site of bony erosions did show an increased signal intensity after Gd-DTPA. Magnetic resonance imaging detected more cysts (as small as 2 mm) than plain films, and the cysts were located truly intraosseously. In six patients no other joint abnormalities were identified by magnetic resonance imaging; the three other patients also showed, after Gd-DTPA administration, an enhanced synovium at the site of bony erosions. CONCLUSIONS: It is suggested that intraosseous bone cysts in patients with RA do not contain hyperaemic synovial proliferation. The bone cysts in patients with the cystic form of RA may be the only joint abnormality.     

Cross-linking of porous gel-spun ultra-high molecular weight polyethylene by means of electron beam irradiation

Summary Porous gel-spun ultra-high molecular weight polyethylene (UHMWPE) fibres, consisting of large folded chain lamellae linked to each other by means of tie molecules, have been Irradiated at room temperature by means of high energy electrons.From a discrepancy in yield of cross-links per unit of absorbed irradiation energy as calculated from sol-gel measurements and equilibrium swelling experiments, it was concluded that the tie molecules are preferentially scissioned, and thereby separating the different lamellae. At high irradiation doses the lamellae are linked again by cross-links between consecutive lamellae.     

A simple fixpoint argument without the restriction to continuity

Summary In programming language semantics, the introduction of unbounded nondeterminacy, which amounts to the introduction of noncontinuous predicate transformers, is needed for dealing with such concepts as fair interleaving. With the semantics of the repetition given as the strongest solution of a fixpoint equation, the weakest precondition expressed in closed form would then require transfinite ordinals. Here, however, it is shown that, even in the case of unbounded nondeterminacy, the fundamental theorem about the repetition can be proved by a simple and quite elementary argument.     

Toward sustainable production of protein-rich foods: appraisal of eight crops for Western Europe. Part I. Analysis of the primary links of the production chain

Increased production of plant protein is required to support the production of protein-rich foods that can replace meat in the human diet to reduce the strain that intensive animal husbandry poses to the environment. The suitability of lupin (Lupinus spp.), pea (Pisum sativum), quinoa (Chenopodium quinoa Willd.), triticale (x Triticosecale), lucerne (Medicago sativa), grasses (Lolium and Festuca spp.), rapeseed/canola (Brassica napus), and potato (Solanum tuberosum) for protein production in Western Europe was studied on the basis of a chain approach. The aspects considered are the familiarity of farmers with the cultivation of the crop, prospects for rapid crop improvement, protein production (kg/ha), protein quality (absence of unwanted substances) and familiarity with the usage for human food in Western Europe. Pea, lucerne, and grasses are the most promising, fair prospects are foreseen for lupin, triticale, rapeseed, and potato, whereas the possibilities for quinoa are judged to lag far behind. Estimated protein production for pea, lucerne, and grasses is 1250, 2500, and 2500 kg/ha, respectively.     

Worm-like morphology of semi-rigid substituted poly(<Emphasis Type="Italic">p</Emphasis>-phenylene)

The rheological and dynamic mechanical properties of a semi-rigid substituted poly(p-phenylene) were investigated. At temperatures below the glass transition temperature of 152 °C the amorphous polymer is very stiff compared with flexible chain polymers. Although the material can be processed in the melt, the melt is unusually elastic. Atomic force and transmission electron microscopy revealed a worm-like morphology. Blends with polycarbonate yield transparent materials. Microscopy and X-ray diffraction of these blends indicated that the flexible chain polymer is located in between the worm-like structures of the semi-rigid polymer.     

Dietary energy source in dairy cows in early lactation: energy partitioning and milk composition

Metabolic problems related to negative energy balance suggest a role for the balance in supply of lipogenic and glucogenic nutrients. To test the effect of lipogenic and glucogenic nutrients on energy partitioning, energy balance and nitrogen balance of 16 lactating dairy cows were determined by indirect calorimetry in climate respiration chambers from wk 2 to 9 postpartum. Cows were fed a diet high in lipogenic nutrients or a diet high in glucogenic nutrients from wk 3 prepartum until wk 9 postpartum. Diets were isocaloric (net energy basis) and equal in intestinal digestible protein. There was no effect of diet on metabolizable energy intake and heat production. Cows fed the lipogenic diet partitioned more energy to milk than cows fed the glucogenic diet [1,175 ± 18 vs. 1,073 ± 12 kJ/(kg^0.75·d)] and had a higher milk fat yield (1.89 ± 0.02 vs. 1.67 ± 0.03 kg/d). The increase in milk fat production was caused by an increase in C16:0, C18:0, and C18:1 in milk fat. No difference was found in energy retained as body protein, but energy mobilized from body fat tended to be higher in cows fed the lipogenic diet than in cows fed the glucogenic diet [190 ± 23 vs. 113 ± 26 kJ/(kg^0.75·d)]. Overall, results demonstrate that energy partitioning between milk and body tissue can be altered by feeding isocaloric diets differing in lipogenic and glucogenic nutrient content.     

Integrated pollution control in seed oil refining

In edible oil refining, the various processes in current use lead to different by-products and/or waste products and they may also cause some form of pollution. The processes are reviewed in this paper and current or possible means of disposal of these by-products/waste products are discussed to highlight the areas requiring most attention. These areas turn out to be gum disposal when the degumming operation is carried out at a stand-alone refinery, and soapstock effluent resulting from the alkali refining process. Other waste products and pollution sources are found to be unimportant or manageable. Accordingly, a major step forward in pollution abatement in seed oil refining can be achieved by making two changes. The first one entails carrying out the degumming operation at the oil mill rather than at the refinery. This should be done in such a way that the degummed oil is amenable to physical refining. The acid refining process is recommended for this degumming step and consequently, acid refined oil with appropriate quality guarantees will then become the article of trade. The second one involves a switch from alkali refining crude or waterdegummed oil to the physical refining of acid refined oil. For this latter step, a counter-current process is recommended because of its low stripping steam requirement. Dry condensation of the distillate will further alleviate pollution problems associated with deodorization and physical refining. Finally, some processes, that may contribute to pollution control but that still require development, are mentioned.     

Germination of Arabidopsis Seed in Space and in Simulated Microgravity: Alterations in Root Cell Growth and Proliferation

Changes have been reported in the pattern of gene expression in Arabidopsis on exposure to microgravity. Plant cell growth and proliferation are functions that are potentially affected by such changes in gene expression. In the present investigation, the cell proliferation rate, the regulation of cell cycle progression and the rate of ribosome biogenesis (this latter taken to estimate cell growth) have been studied using morphometric markers or parameters evaluated by light and electron microscopy in real microgravity on the International Space Station (ISS) and in ground-based simulated microgravity, using the Random Positioning Machine and the Magnetic Levitation Instrument. Results showed enhanced cell proliferation but depleted cell growth in both real and simulated microgravity, indicating that the two processes are uncoupled, unlike the situation under normal gravity on Earth in which they are strictly co-ordinated events. It is concluded that microgravity is an important stress condition for plant cells compared to normal ground gravity conditions.