Papillary and follicular cancers of the thyroid

MANAGEMENT STRATEGIES: Management of papillary and follicular cancer of the thyroid varies somewhat between centers because of the generally good prognosis and the absence of well-controlled therapeutic trials. The internationally recognized TNM system is widely used to modulate treatment and follow-up to the individual situation. PRIMARY TREATMENT: Surgery is indicated in well-differentiated thyroid cancer. Total thyroidectomy is required for clinically patent tumors (> or = 1 cm) and small tumors (< 1 cm) recognized prior to surgery. For small tumors found at histology examination, reoperation is discussed in terms of prognosis. Post-operative 131-iodine is indicated when surgical resection is incomplete or in case of unfavorable prognosis. External radiotherapy is currently reserved for exceptional cases with unremoved tumoral tissue unresponsive to 131-iodine. FOLLOW-UP: All operated patients are given L-thyroxine to achieve euthyroidism and low TSH levels (< 0.1 microU/ml). Early detection of relapse is based on combined thyroglobulin assay and whole body 131-iodine scintigraphy. Both are performed during the first year of follow-up after a period of thyroid hormone withdrawal. Human recombinant TSH will soon be available allowing selection of patients with a detectable thyroglobulin level after stimulation; these patients should have a 131-iodine scintigram. If thyroglobulin remains undetectable during L-thyroxine treatment, an annual dosage is indicated and other exams are unwarranted. RELAPSE: Surgery is indicated in case of small areas of active recurrent tumoral tissue in a cervical location. If a high-sensitivity scintigram does not show iodine uptake, the surgical procedure is completed by radiotherapy or possibly chemotherapy with doxorubicin. Small recurrent tumors in other areas respond to 131-iodine (3.7 GBq). Surgery, 131-iodine and radiotherapy are usually indicated for large ectopic recurrences. Chemotherapy is ineffective. CURRENT PROTOCOLS: Standard primary therapy generally provides cure and most patients are followed by annual thyroglobulin and TSH assays. Other explorations beginning with a whole-body 131-scintigram may be indicated in selected patients.     

NMR Time Reversal Experiments in Highly Polarised Liquid 3He-4He Mixtures

Long-range magnetic interactions in highly magnetised liquids (laser-polarised ³He-⁴He dilute mixtures at 1 K in our experiment) introduce a significant non-linear and non-local contribution to the evolution of nuclear magnetisation that leads to instabilities during free precession. We recently demonstrated that a multi-echo NMR sequence, based on the magic sandwich pulse scheme developed for solid-state NMR, can be used to stabilise the magnetisation against the effect of distant dipolar fields. Here, we report investigations of echo attenuation in an applied field gradient that show the potential of this NMR sequence for spin diffusion measurements at high magnetisation densities.      

Biomarkers of Genotoxicity in Medical Workers Exposed to Low-Dose Ionizing Radiation: Systematic Review and Meta-Analyses

Medical staff represent the largest group of workers occupationally exposed to ionizing radiation (IR). Chronic exposure to low-dose IR may result in DNA damage and genotoxicity associated with increased risk of cancer. This review aims to identify the genotoxicity biomarkers that are the most elevated in IR-exposed vs. unexposed health workers. A systematic review of the literature was performed to retrieve relevant studies with various biomarkers of genotoxicity. Subsequent meta-analyses produced a pooled effect size for several endpoints. The search procedure yielded 65 studies. Chromosome aberrations (CA) and micronuclei (MN) frequencies were significantly different between IR-exposed and unexposed workers (θ_pooled = 3.19, 95% CI 1.46–4.93; and θ_pooled = 1.41, 95% CI 0.97–1.86, for total aberrant cells and MN frequencies, respectively), which was not the case for ring chromosomes and nucleoplasmic bridges. Although less frequently used, stable translocations, sister chromatid exchanges (SCE) and comet assay endpoints were also statistically different between IR-exposed and unexposed workers. This review confirms the relevance of CA and MN as genotoxicity biomarkers that are consistently elevated in IR-exposed vs. unexposed workers. Other endpoints are strong candidates but require further studies to validate their usefulness. The integration of the identified biomarkers in future prospective epidemiological studies is encouraged.     

What are the challenges of setting up a biomass fueled dimethylether plant in Växjö?

The main challenges of setting up a 400 kt y^?1 biomass fueled dimethylether plant in the city of Växjö consist not only of evaluating social and economic impact but also exploring ways to initiate and develop the market for DME. One way of initiating and developing the market for DME is by mixing DME with LPG. In the longer perspective, DME can be a substitute to diesel which, however, requires a consistent orchestrated strategy. For the raw material situation it is indicated that the main bulk of logging residues and stumps can be obtained near the city and to a lesser extent from adjacent regions supplemented with marginal imports. The employment effects are considerable; a positive net effect of 550–750 full-time jobs is expected. The geographical localization of jobs will to a large extent be in or near Växjö (for operation of the plant), and nearby regions (for collection of raw material and transports).     

The Microstructure,Texture and Mechanical Properties of Friction Stir Welded Aluminum Alloy

Russian Journal of Non-Ferrous Metals - The microstructure and texture of 7075-T6 FSW weld with optimal parameters are investigated using optical microscopy, electron back scatter diffraction and...     

Quantitative infrared analysis of welding processes: temperature measurement during RSW and CMT-MIG welding

This article deals with temperature characterisation by infrared thermography during welding. To demonstrate the versatility of this technique, two welding processes were investigated with different materials: cold metal transfer metal inert gas welding of al alloy and resistance spot welding of galvanised steel. Two experimental methods were used to characterise temperature without requiring implementation of thermocouples. The validity of these methods is demonstrated by metallurgical characterisations. The error on the measured values of temperature is assessed regarding the initial uncertainty on the apparent surface emissivity. The results show that it is possible to obtain absolute temperature values, cooling rates and informative visualisation of temperature gradients with a reasonable uncertainty.     

Tetramer-dimer equilibrium of oxyhemoglobin mutants determined from auto-oxidation rates

One of the main difficulties with blood substitutes based on hemoglobin (Hb) solutions is the auto-oxidation of the hemes, a problem aggravated by the dimerization of Hb tetramers. We have employed a method to study the oxyHb tetramer-dimer equilibrium based on the rate of auto-oxidation as a function of protein concentration. The 16-fold difference in dimer and tetramer auto-oxidation rates (in 20 mM phosphate buffer at pH 7.0, 37 degrees C) was exploited to determine the fraction dimer. The results show a transition of the auto-oxidation rate from low to high protein concentrations, allowing the determination of the tetramer-dimer dissociation coefficient K4,2 = [Dimer] 2/[Tetramer]. A 14-fold increase in K4,2 was observed for addition of 10 mM of the allosteric effector inositol hexaphosphate (IHP). Recombinant hemoglobins (rHb) were genetically engineered to obtain Hb with a lower oxygen affinity than native Hb (Hb A). The rHb alpha2beta2 [(C7) F41Y/(G4) N102Y] shows a fivefold increase in K4,2 at pH 7.0, 37 degrees C. An atmosphere of pure oxygen is necessary in this case to insure fully oxygenated Hb. When this condition is satisfied, this method provides an efficient technique to characterize both the tetramer-dimer equilibrium and the auto-oxidation rates of various oxyHb. For low oxygen affinity Hb equilibrated under air, the presence of deoxy subunits accelerates the auto-oxidation. Although a full analysis is complicated, the auto-oxidation studies for air equilibrated samples are more relevant to the development of a blood substitute based on Hb solutions. The double mutants, rHb alpha2beta2 [(C7) F41Y/(G4) N102A] and rHb alpha2beta2 [(C7) F41Y/(E10) K66T], show a lower oxygen affinity and a higher rate of oxidation than Hb A. Simulations of the auto-oxidation rate versus Hb concentration indicate that very high protein concentrations are required to observe the tetramer auto-oxidation rate. Because the dimers oxidize much more rapidly, even a small fraction dimer will influence the observed oxidation rate.     

Influence of FSSW parameters on fracture mechanisms of 5182 aluminium welds

The influence of the tool rotational speed, the probe plunge depth and the shoulder penetration depth on weld microstructure and on the weld strength have been studied. The shear tests showed that the friction stir spot welds fail by nugget pullout. Three microstructural factors play a determinant role on the weld's strength: the size and location of the stir zone, and the unwelded interface tip slope. With increasing rotational speed, the shear strength increases because of the larger size of the stir zone. By changing the probe plunge depth the location of the stir zone can be controlled in order to maximize the bonded distance between the interface tip and the central hole left by the probe. The shoulder penetration depth must be sufficient to ensure a horizontal interface tip and therefore avoid fracture by the opening mode (mode I) during shear loading.