Viscosity and mutual diffusion of deuterium-tritium mixtures in the warm-dense-matter regime

We have calculated viscosity and mutual diffusion of deuterium-tritium (DT) in the warm, dense matter regime for densities from 5 to 20 g/cm{3} and temperatures from 2 to 10 eV, using both finite-temperature Kohn-Sham density-functional theory molecular dynamics (QMD) and orbital-free molecular dynamics (OFMD). The OFMD simulations are in generally good agreement with the benchmark QMD results, and we conclude that the simpler OFMD method can be used with confidence in this regime. For low temperatures (3 eV and below), one-component plasma (OCP) model simulations for diffusion agree with the QMD and OFMD calculations, but deviate by 30% at 10 eV. In comparison with the QMD and OFMD results, the OCP viscosities are not as good as for diffusion, especially for 5 g/cm{3} where the temperature dependence is significantly different. The QMD and OFMD reduced diffusion and viscosity coefficients are found to depend largely, though not completely, only on the Coulomb coupling parameter Γ , with a minimum in the reduced viscosity at Γ≈25 , approximately the same position found in the OCP simulations. The QMD and OFMD equations of state (pressure) are also compared with the hydrogen two-component plasma model.

Guidelines for an integrated diagnostic approach of chronic lymphoproliferative disorders in the routine laboratory of haematology in Belgium

This paper summarizes the minimal workout of chronic lymphoproliferative disorders in a routine laboratory of haematology as recommended by a team of experienced laboratory supervisors in Belgium, taking into account the specific organisation of healthcare in Belgium, the innovations in the field of molecular analyses and related reimbursement. The starting point was essentially based upon clinical and/or haematological indications and it is emphasized that conclusions should be drawn in close dialogue with the clinician and experts in cytogenetics and histopathology. Reports made in the laboratory should be based upon an integration of cytomorphological, immunophenotypical and molecular data. These guidelines are not intended to be used as universal 'diagnostic pathways', but should be useful in developing local diagnostic pathways. It is well understood that this consensus, being valid anno 2009, may rapidly change with new technologies being introduced and new targets discovered.

Proxies and measurement techniques for mineral dust in Antarctic ice cores

To improve quantitative interpretation of ice core aeolian dust records, a systematic methodological comparison was made. This involved methods for water-insoluble particle counting (Coulter counter and laser-sensing particle detector), soluble ion analysis (ion chromatography and continuous flow analysis), elemental analysis (inductively coupled plasma mass spectroscopy at pH 1 and after full acid digestion), and water-insoluble elemental analysis (proton induced X-ray emission). Antarctic ice core samples covering the last deglaciation from the EPICA Dome C (EDC) and the EPICA Dronning Maud Land (EDML) cores were used. All methods correlate very well among each other, but the ratios of glacial age to Holocene concentrations, which are typically a factor approximately 100, differ between the methods by up to a factor of 2 with insoluble particles showing the largest variability. The recovery of ICP-MS measurements depends on the digestion method and is differentfor different elements and during different climatic periods. EDC and EDML samples have similar dust composition, which suggests a common dust source or a common mixture of sources for the two sites. The analyzed samples further reveal a change of dust composition during the last deglaciation.

Direct verification of mixing rules in the hot and dense regime

We perform orbital-free molecular dynamics simulations in the hot and dense regime for two mixtures: equimolar helium-iron and asymmetric deuterium-copper plasmas. For thermodynamic properties, we test two isobaric-isothermal mixing rules whose definitions involve either the equality of total pressures or the equality of the so-defined excess pressures of the components; the pressure and internal energy obtained by direct simulations are in very good agreement with those given by the mixing rule involving the equality of excess pressures. The viscosity of the deuterium-copper mixture is also extracted from a direct simulation and compared to the result given by a mixing rule applied to the viscosities of the pure elements. Finally, for structural properties, the effective charges given by the isobaric-isothermal mixing rule for the average atom model, used in the binary ionic mixture model, yield partial pair distribution functions in good agreement with those obtained by a direct simulation.

Ab initio molecular dynamics simulations of dense boron plasmas up to the semiclassical Thomas-Fermi regime

We build an "all-electron" norm-conserving pseudopotential for boron which extends the use of ab initio molecular dynamics simulations up to 50 times the normal density rho0. This allows us to perform ab initio simulations of dense plasmas from the regime where quantum mechanical effects are important to the regime where semiclassical simulations based on the Thomas-Fermi approach are, by default, the only simulation method currently available. This study first allows one to establish, for the case of boron, the density regime from which the semiclassical Thomas-Fermi approach is legitimate and sufficient. It further brings forward various issues pertaining to the construction of pseudopotentials aimed at high-pressure studies.

Southern Ocean sea-ice extent, productivity and iron flux over the past eight glacial cycles

Sea ice and dust flux increased greatly in the Southern Ocean during the last glacial period. Palaeorecords provide contradictory evidence about marine productivity in this region, but beyond one glacial cycle, data were sparse. Here we present continuous chemical proxy data spanning the last eight glacial cycles (740,000 years) from the Dome C Antarctic ice core. These data constrain winter sea-ice extent in the Indian Ocean, Southern Ocean biogenic productivity and Patagonian climatic conditions. We found that maximum sea-ice extent is closely tied to Antarctic temperature on multi-millennial timescales, but less so on shorter timescales. Biological dimethylsulphide emissions south of the polar front seem to have changed little with climate, suggesting that sulphur compounds were not active in climate regulation. We observe large glacial-interglacial contrasts in iron deposition, which we infer reflects strongly changing Patagonian conditions. During glacial terminations, changes in Patagonia apparently preceded sea-ice reduction, indicating that multiple mechanisms may be responsible for different phases of CO2 increase during glacial terminations. We observe no changes in internal climatic feedbacks that could have caused the change in amplitude of Antarctic temperature variations observed 440,000 years ago.

[Microsurgery: History of instrumental vascular anastomoses, our experience with eversion-stapling using VCS forceps]

One century, after Carrel in 1906, technics of vascular surgery are the same. After two world wars, peace surgery has been improved by war surgery. Microscopy surgery gave a new way for vascular surgery which became microsurgery with specific instrumentation. We have move from the developing period of microsurgery in the 1970s, to the fully matured period of microsurgery in the 1980s and the the development of clinical free flaps. The 1990s must be the turning point from autogenous tissue transplantation to allogenic transplantation. Ethic comity keeps keys of future! About microvascular anastomoses, many instrumental technics are explored but no-one is better than the classic manual suture. For us, the best instrumental technic is the anastomose with titanium clips VCS((R)) but we only use it in good situation without difficulties.

PCC-FISH in Skin Fibroblasts for Local Dose Assessment: Biodosimetric Analysis of a Victim of the Georgian Radiological Accident

We propose a new method of biodosimetry that could be applied in cases of localized irradiation. The approach is based on excess chromosome segments determination by the PCC-FISH technique in fibroblasts isolated from skin biopsy. Typically, 0 to 10 Gy ex vivo gamma-irradiated human skin biopsies were dissociated and fibroblasts were isolated and grown for several days. Cells next underwent PCC-FISH painting of whole chromosome 4, and the number of excess chromosome segments per metaphase was determined. An ex vivo reference curve correlating the number of excess chromosome segments per metaphase to the radiation dose was established and used to assess the dose delivered to the skin of one of the victims of the radiological accident that occurred at Lia in Georgia in December 2001. Specifically, the victim suffering from moist desquamation underwent skin excision in Hospital Percy (France). Measurement of excess chromosome segments per metaphase was done in fibroblasts isolated and grown from removed wounded skin and subsequent conversion to radiation doses was performed. The radiation dose map obtained was shown to be in accordance with clinical data and physical dosimetry as well as with conventional biodosimetry. These results demonstrated that PCC-FISH painting applied to skin fibroblasts may be a suitable technique for dose estimation. To assess its worth, this approach needs to be extended to future accidents involving localized radiation exposure.

Eight glacial cycles from an Antarctic ice core

The Antarctic Vostok ice core provided compelling evidence of the nature of climate, and of climate feedbacks, over the past 420,000 years. Marine records suggest that the amplitude of climate variability was smaller before that time, but such records are often poorly resolved. Moreover, it is not possible to infer the abundance of greenhouse gases in the atmosphere from marine records. Here we report the recovery of a deep ice core from Dome C, Antarctica, that provides a climate record for the past 740,000 years. For the four most recent glacial cycles, the data agree well with the record from Vostok. The earlier period, between 740,000 and 430,000 years ago, was characterized by less pronounced warmth in interglacial periods in Antarctica, but a higher proportion of each cycle was spent in the warm mode. The transition from glacial to interglacial conditions about 430,000 years ago (Termination V) resembles the transition into the present interglacial period in terms of the magnitude of change in temperatures and greenhouse gases, but there are significant differences in the patterns of change. The interglacial stage following Termination V was exceptionally long--28,000 years compared to, for example, the 12,000 years recorded so far in the present interglacial period. Given the similarities between this earlier warm period and today, our results may imply that without human intervention, a climate similar to the present one would extend well into the future.

Presence of spinal B7.2 (CD86) but not B7.1 (CD80) co-stimulatory molecules following peripheral nerve injury: role of nondestructive immunity in neuropathic pain

Previous work in our laboratory demonstrated spinal neuroimmune activation and leukocyte trafficking into the central nervous system (CNS) parenchyma in a rat model of neuropathic pain. Recent studies suggest that co-stimulatory molecules B7.1 (CD80) and B7.2 (CD86) play a differential role in the effect of beneficial versus deleterious CNS autoimmune responses. In the present study, we determined the lumbar spinal expression of the co-stimulatory molecules B7.1 and B7.2 in a rat model of neuropathy. We observed intense B7.2 microglial immunoreactivity in the lumbar spinal cord following the injury but no expression of B7.1. These data suggest a role of protective CNS autoimmunity following peripheral nerve injury.

A quantitative study of peripheral blood stem cell contamination in diffuse large-cell non-Hodgkin's lymphoma: one-half of patients significantly mobilize malignant cells

Autologous transplantation using peripheral blood stem cells (PBSCs) collected after chemotherapy, followed by growth factor administration (ASCT), is increasingly used in the treatment of non-Hodgkin's lymphoma (NHL). However, quantitative data regarding contaminating malignant cells in the harvests are still scarce. We prospectively investigated 37 diffuse large-cell lymphomas (DLCLs) in complete remission (CR) that were treated according to multicentric protocols at our centre. DNA was extracted from the diagnostic lymph node. The complementarity-determining region (CDR) III was sequenced and a patient-specific oligomer synthesized. Contamination was evaluated semiquantitatively by polymerase chain reaction (PCR) and was confirmed by a limiting dilution analysis. PBSCs collected at regeneration after administration of granulocyte colony-stimulating factor (G-CSF), steady-state bone marrow (BM) and peripheral blood samples at CR were compared. DNA was available in 37 patients, from which 22 rearrangements could be sequenced. Patients (n = 15) who had both the required follow-up samples and a suitable clonal marker were investigated. In two cases, the patient-specific PCR assay set up at diagnosis later gave false-negative results in samples in which clonal DNA was still detectable by other sets of primers. PBSC contamination was highly variable: 7 out of 15 patients showed a PBSC/BM ratio of NHL cells greater than 1 log, whereas 8 out of 15 patients showed no difference and could vary from one apheresis to another. Eight ASCTs were performed, five of which used highly contaminated PBSCs: four patients relapsed early, three with disseminated lymphoma. Thus, 50% of DLCLs in CR seem to mobilize significantly malignant cells at regeneration under G-CSF. Considering the higher numbers of cells reinfused, this translates into a much higher number of lymphoma cells reinfused when compared with autologous bone marrow transplantation (ABMT). However, their clonogenic potential remains unknown and, despite concerning observations in certain cases, it is still unclear whether this has an impact upon the outcome of ASCT.

Severe mechanical dysfunction in pharyngeal muscle from adult mdx mice

The mdx mouse is a widely used animal model of human muscular dystrophy. Although diaphragm muscle exhibits severe muscle weakness throughout the life of the animal, the limb muscle function of mdx mice spontaneously recovers by 6 mo of age. Pharyngeal dilator muscles such as sternohyoid (SH) contribute to upper airway patency during breathing. We hypothesized that SH muscle function was impaired in 6-mo-old mdx mice. Mechanical properties and myosin heavy chain (MHC) composition were investigated in isolated SH from 6-mo-old control (C, n = 10) and mdx (n = 10) mice. As compared with C, peak tetanic tension (Pmax) and maximum shortening velocity were 50% and 16% lower in mdx mice (p < 0.001 and p < 0.05, respectively). Peak mechanical power was lower in mdx than in C (19.0 +/- 3.2 versus 57.4 +/- 5.1 mW g(-)(1), p < 0.001). Both C and mdx SH were composed exclusively of fast myosin isoforms. As compared with C, mdx SH presented a higher proportion of IIX-MHC and a reduction in IIB-MHC (each p < 0.001). In conclusion, our results demonstrated severe SH muscle dysfunction in 6-mo-old mdx mice, that is, at a time when limb muscle function has recovered. Thus, SH muscle of the mdx mouse may be an excellent muscle for studying Duchenne muscular dystrophy.

Cultured epithelial autografts in extensive burn coverage of severely traumatized patients: a five year single-center experience with 30 patients

OBJECTIVE

We report recent five-year experience in a large, single center series of severely burned and otherwise traumatized patients given cultured epithelial autografts (CEA) from a single commercial laboratory.

SUMMARY BACKGROUND DATA

Initial optimism over CEA application has been tempered by subsequent reports asserting that this modality is unreliable and expensive. Discussion continues over its clinical role.

METHODS

From 1991 to 1996, CEA were applied to a mean 37+/-17% of total body surface area (TBSA) of 30 patients. These patients had 78+/-10% average burn size, 65+/-16% average third-degree burn size, 90% prevalence of endoscopically confirmed inhalation injury and 37% prevalence of other serious conditions.

RESULTS

CEA achieved permanent coverage of a mean 26+/-15% of TBSA, an area greater than that covered by conventional autografts (a mean 25+/-10% of TBSA). Survival was 90% in these severely burned and otherwise traumatized patients. Final CEA take was a mean 69+/-23%. In subset analyses, only younger age was significantly associated with better CEA take (p = 0.0001 in univariate analysis, p<0.04 in multivariate analysis, Student's t-test).

CONCLUSIONS

Epicel CEA successfully provided extensive, permanent burn coverage in severely traumatized patients, proving an important adjunct to achievement of a high survival rate in a patient population whose prognosis previously had been poor. In our experience CEA appear to have a very high beneficial value in the management of bur ns >60% TBSA. In some cases studied it is very likely that CEA was a life-saving treatment.

Myosin molecular motor dysfunction in dystrophic mouse diaphragm

Cross-bridge properties and myosin heavy chain (MHC) composition were investigated in isolated diaphragm from 6-mo-old control (n = 12) and mdx (n = 12) mice. Compared with control, peak tetanic tension fell by 50% in mdx mice (P < 0.001). The total number of cross bridges per square millimeter (x10(9)), the elementary force per cross bridge, and the peak mechanical efficiency were lower in mdx than in control mice (each P < 0.001). The duration of the cycle and the rate constant for cross-bridge detachment were significantly lower in mdx than in control mice. In the overall population, there was a linear relationship between peak tetanic tension and either total number of cross bridges per square millimeter or elementary force per cross bridge (r = 0.996 and r = 0.667, respectively, each P < 0.001). The mdx mice presented a higher proportion of type IIA MHC (P < 0.001) than control mice and a reduction in type IIX MHC (P < 0.001) and slow myosin isoforms (P < 0.01) compared with control mice. We concluded that, in mdx mice, impaired diaphragm strength was associated with qualitative and quantitative changes in myosin molecular motors. It is proposed that reduced force generated per cross bridge contributed to diaphragm weakness in mdx mice.

Impaired skeletal muscle performance in the early stage of cardiac pressure overload in rabbits: beneficial effects of angiotensin-converting enzyme inhibition

Abnormalities of skeletal muscles are frequently observed in patients with congestive heart failure. In these patients, angiotensin-converting enzyme (ACE) inhibitors improve exercise performance. The present study was designed to assess whether skeletal muscle dysfunction develops in the early stage of cardiac overload and if so, whether such functional alterations can be prevented by ACE inhibition. Mechanical performance, cross-bridge (CB) properties, and myosin heavy chain composition were investigated in respiratory and limb skeletal muscles of rabbits with moderate cardiac hypertrophy, and after single therapy with the ACE inhibitor perindopril (PE). After constriction of the aorta, the rabbits were treated during a 10-week period with either PE (1 mg/kg/day; n = 9) or a placebo (PL; n = 15). A third group of sham-operated animals received PL (n = 10). Analyses were performed on isolated diaphragm and soleus strips. Compared with sham-operated animals (shams), peak tetanic tension in PL fell by 40% in diaphragm and 34% in soleus. There were no significant differences in peak tetanic tension and the maximum shortening velocity between PE and shams. In both muscles, the total number of CBs was significantly lower in PL than in shams, but did not differ between shams and PE. The elementary force per CB did not differ between groups. In both muscles, the myosin heavy chain composition did not differ between groups. The study demonstrated that intrinsic performance of diaphragm and soleus muscles was affected early in the development of chronic pressure overload. Single therapy with PE tended to preserve muscle strength, essentially by limiting the loss of CBs.

Peripheral blood stem cell contamination in mantle cell non-Hodgkin lymphoma: the case for purging?

Intensification using peripheral blood stem cells collected after chemotherapy followed by growth factors is being increasingly investigated as an alternative to conventional chemotherapy for mantle cell non-Hodgkin lymphoma. We investigated 14 grades III-IV, t(11;14)-positive cases for contamination of PBSC collected after a polychemotherapy regimen followed by G-CSF. Patients were first treated with a polychemotherapy regimen. There were four CR, seven PR, two refractory and one early death. Seven patients have been transplanted, in whom PBSC were mobilized, using either cyclophosphamide/VP16 or Dexa-BEAM followed by G-CSF. For all patients, whether actually autografted or not, PB cells were tested at the time of regeneration on G-CSF after the first polychemotherapy or after the mobilizing regimen. PCR evaluation of contamination was performed first by a semi-quantitative approach, using serial dilutions of initial DNA, then confirmed using a limiting-dilution analysis. Two patients were not informative (one early death and one without an available molecular marker). PB cells collected at regeneration contained at least one log more lymphoma cells than steady-state blood or marrow, apart from in two cases. Moreover, where a mobilizing treatment diminished tumor burden in the patient, at the same time it increased PB contamination in most cases. We conclude that advanced mantle cell NHL appears to be largely resistant to significant in vivo purging by conventional chemotherapy. Where treatment brings benefits by reducing tumor load, it may at the same time negate it by mobilizing malignant cells into the collections used to intensify. Although the clonogenic potential of this massive infiltration is unknown (only gene marking studies could provide a definitive answer regarding the source of relapses), strategies aimed at reducing the level of contamination in the graft should be considered when designing future protocols.

Effect of neutron-gamma radiation on dopamine and serotonin metabolism in the rat brain: a regional analysis

The concentrations of dopamine (DA) and its metabolites and the levels of 5-hydroxyindoleacetic acid (5-HIAA), the metabolite of serotonin, were determined in discrete cerebral areas of rats 3 hr after (neutron-gamma) irradiation at 4 and 7 Gy. After the 7 Gy irradiation, no significant effect was observed. After the 4 Gy exposure, the most marked difference between irradiated and control rats was in the levels of DA and its metabolites in the striatum. We observed a decrease of DA, HVA, and DOPAC levels in the striatum and an opposite pattern in the substantia nigra. Whatever the brain area observed, an increase of 5-HIAA levels was noted.

Increased compliance in diaphragm muscle of the cardiomyopathic Syrian hamster

We investigated the hypothesis that diaphragm compliance was abnormal in cardiomyopathic Syrian hamsters (CSH), an experimental model of myopathy. The passive elastic properties of isolated diaphragm muscles were analyzed at both the muscle and sarcomere levels. We used the following passive exponential relationship between stress (sigma) and strain (epsilon): sigma = (Eo/beta) (ebetaepsilon - 1), where Eo is the initial elastic modulus and beta is the stiffness constant. Immunocytochemistry procedures were used to analyze the distribution of two key elastic components of muscle, extracellular collagen and intracellular titin elastic components, as well as the extracellular matrix glycoprotein laminin. Muscle and sarcomere values of beta were nearly twofold lower in CSH (8.7 +/- 1.9 and 8.3 +/- 1.4, respectively) than in control animals (19.7 +/- 1.7 and 16.8 +/- 2.1, respectively) (P < 0.01 for each). Compared with controls, Eo was higher in CSH. Sarcomere slack length was significantly longer in CSH than in control animals (2.1 +/- 0.1 vs. 1.9 +/- 0.1 micrometer, P < 0.05). The surface area of collagen I was significantly larger in CSH (17.4 +/- 1.8%) than in control animals (12.4 +/- 0.7%, P < 0.05). There was no change in the distribution of titin or laminin labelings between the groups. These results demonstrate increased diaphragm compliance in cardiomyopathic hamsters. The increase in CSH diaphragm compliance was observed despite an increase in the surface area of collagen and was not associated with an abnormal distribution of titin or laminin.

Fixation of zygomatic fractures with a new biodegradable copolymer osteosynthesis system. Preliminary results

In a prospective study, a new biodegradable osteosynthesis material for the facial skeleton has been used in 27 patients with zygomatic fractures. In the six-month follow-up period, the first ten patients showed clinically and radiologically uneventful healing of bone. There were no implant-related complications. The main advantages of the new material are its malleability when heated, enabling fast adaptation to the bone surface, and the avoidance of a second operation for implant removal.