Demonstration of Tokamak ohmic flux saving by transient coaxial helicity injection in the national spherical torus experiment

Transient coaxial helicity injection (CHI) started discharges in the National Spherical Torus Experiment (NSTX) have attained peak currents up to 300 kA and when coupled to induction, it has produced up to 200 kA additional current over inductive-only operation. CHI in NSTX has shown to be energetically quite efficient, producing a plasma current of about 10 A/J of capacitor bank energy. In addition, for the first time, the CHI-produced toroidal current that couples to induction continues to increase with the energy supplied by the CHI power supply at otherwise similar values of the injector flux, indicating the potential for substantial current generation capability by CHI in NSTX and in future toroidal devices.

Sentinel lymphadenectomy for the staging of clinical axillary node-negative breast cancer before neoadjuvant chemotherapy

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Background: Several authors reported sentinel lymph node biopsy after neoadjuvant chemotherapy. Nevertheless, the ideal time of sentinel lymph node biopsy is still a matter of debate. Methods: We evaluated the feasibility and the accuracy of sentinel lymph node biopsy before neoadjuvant chemotherapy using a combined procedure (blue dye and radio-labelled detection) in a homogeneous cohort study with clinically axillary node-negative breast cancer. Study candidates were patients referred to the Institut Paoli-Calmettes Cancer Center (Marseille, France) for the treatment of invasive breast cancer. Patients were included in the study if they had tumor more than 3 cm in diameter without palpable axillary lymph node for which a neoadjuvant chemotherapy was indicated in order to enhance the likelihood of breast conservation. An axillary lymph node dissection was performed after completion of neoadjuvant chemotherapy. Results: From September 2005 to September 2007, thirty-one women with T2 or T3 invasive breast cancer without palpable axillary lymph node underwent sentinel lymph node biopsy before neoadjuvant chemotherapy and an axillary lymph node dissection after neoadjuvant chemotherapy. Among the 20 women who had metastatic sentinel lymph node biopsy (65%), 4 (20%) had additional metastatic node on axillary lymph node dissection. By contrast, all the 11 women who had no metastatic sentinel lymph node biopsy had no involved nodes in the axillary lymph node dissection. The sentinel lymph node biopsy identification rate before neoadjuvant chemotherapy was 100% with any false negative. Conclusions: Sentinel lymph node biopsy before neoadjuvant chemotherapy is a feasible and an accurate diagnostic tool to predict the pre-therapeutic axilla status. These findings suggest that axillary lymph node dissection may be avoided in patients with a negative sentinel lymph node biopsy performed before neoadjuvant chemotherapy.

No significant financial relationships to disclose.

Elevated IL-6 levels in the synovial fluid of osteoarthritis patients stem from plasma cells

OBJECTIVE

To analyse the levels of interleukin-6 (IL-6) in the synovial fluids and sera of patients with osteoarthritis (OA) and to identify the IL-6-secreting cells.

METHODS

Serum, synovial fluid, synovial tissue, and articular cartilage samples were collected from 49 OA patients with end-stage knee or hip OA who underwent joint replacement surgery. Serum and synovial fluid levels of IL-6 were measured by enzyme-linked immunosorbent assay (ELISA) and IL-6-secreting cells were identified by immunohistochemistry.

RESULTS

Eight out of 49 patients (16%) exhibited elevated IL-6 levels in the synovial fluids, averaging at 2022+/-526 pg/mL, while the levels in the rest of the patients averaged at 132+/-19 pg/mL. The sera levels of all patients were comparable in the 10 pg/mL range. Immunohistochemical analyses revealed plasma cells in the synovial lining of the high producers as the source of IL-6.

CONCLUSIONS

Synovial fluid IL-6 levels may help to classify OA patients and may point to a subgroup with a particular impact from their immune system.

Efficient generation of closed magnetic flux surfaces in a large spherical tokamak using coaxial helicity injection

A method of coaxial helicity injection has successfully produced a closed flux current without the use of the central solenoid in the NSTX device, on a size scale closer to a spherical torus reactor, for a proof-of-principle demonstration of this concept. For the first time, a remarkable 60 times current multiplication factor was achieved. Grad-Shafranov plasma equilibrium reconstructions are used to verify the existence of closed flux current. In some discharges the generated current persists for a surprisingly long time approximately 400 ms.

Rotational and Vibrational Relaxation of Methane Excited to 2ν3 in CH4/H2 and CH4/He Mixtures at 296 and 193 K from Double-Resonance Measurements

A series of time-resolved IR-IR double-resonance experiments have been conducted where methane molecules are excited into a selected rovibrational level of the 2nu3(F2) vibrational substate of the tetradecad and where the time evolution of the population of the various energy levels is probed by a tunable continuous wave laser. The rotational relaxation and vibrational energy transfer processes occurring in methane upon inelastic CH4-H2 and CH4-He collisions have been investigated by this technique at room temperature and at 193 K. By probing transitions in which either the lower or the upper level is the laser-excited level, rotational depopulation rates in the 2nu3(F2) substate were measured. The rate constants for CH4-H2 collisions were found to be 17.7 +/- 2.0 and 18.9 +/- 2.0 micros(-1) Torr(-1) at 296 and 193 K, respectively, and for CH(4)-He collisions they are 12.1 +/- 1.5 and 16.0 +/- 2.0 micros(-1) Torr(-1) at the same temperatures. The vibrational relaxation was investigated by probing other stretching transitions such as 2nu3(F2) - nu3, nu3 + 2nu4 - 2nu4, and nu3 + nu4 - nu4. A kinetic model, taking into account the main collisional processes connecting energy levels up to 6000 cm(-1), that has been developed to describe the various relaxation pathways allowed us to calculate the temporal evolution of populations in these levels and to simulate double-resonance signals. The different rate coefficients of the vibrational relaxation processes involved in these mixtures were determined by fitting simulated signals to the observed signals corresponding to assigned transitions. For vibration to translation energy transfer processes, hydrogen is a much more efficient collision partner than helium, nitrogen, or methane itself at 193 K as well as at room temperature.

Sexual dimorphism in the osteoarthritis of STR/ort mice may be linked to articular cytokines

BACKGROUND

STR/ort mice spontaneously develop degenerative changes of the knee joints resembling human osteoarthritis (OA), with the males being more severely affected than the females.

OBJECTIVE

To analyse the early changes leading to OA by examining the articular cytokine expression and degenerative changes in STR/ort mice.

METHODS

122 STR/ort mice of both sexes aged between 2 and 15.5 months were included. Thin sections of the knees were analysed for osteoarthritic changes by haematoxylin/eosin staining. The articular cytokine expression was investigated by immunohistochemical staining using monoclonal antibodies specific for interleukin (IL)6, tumour necrosis factor alpha, transforming growth factor beta1 (TGFbeta1), IL1beta, IL4, and IL10, respectively.

RESULTS

Both cartilage degeneration and articular cytokine expression differ between the sexes. The protection from cartilage degeneration in the female mice correlates with an increased expression of TGFbeta1 and IL4 at 2 months of age.

CONCLUSION

The increased expression of TGFbeta1 and IL4 in young STR/ort female mice suggests that the sexual dimorphism is mediated through the articular expression of cytokines involved in cartilage metabolism.

Angiotensin-I-converting enzyme insertion/deletion polymorphism and high urinary albumin concentration in French Type 2 diabetes patients

AIMS

Family-based studies suggest a genetic basis for nephropathy in Type 2 diabetes. The angiotensin-I-converting enzyme (ACE) gene is a candidate gene for Type 1 diabetes nephropathy. We assessed the association between high urinary albumin concentration and ACE insertion/deletion (I/D) polymorphism, in French Type 2 diabetes patients.

METHODS

We studied 3139 micro/macroalbuminuric French patients recruited in the DIABHYCAR Study, an ACE inhibition trial in Type 2 diabetes patients with renal and cardiovascular outcomes. The main inclusion criteria were age >/= 50 years, urinary albumin concentration >/= 20 mg/l assessed centrally during two consecutive screening visits, and plasma creatinine concentration </= 150 micro mol/l. These patients were compared with 605 normoalbuminuric (NA; urinary albumin concentration < 10 mg/l at first screening for the DIABHYCAR Study) French patients. ACE I/D genotype was determined by nested polymerase chain reaction.

RESULTS

The ACE I/D polymorphism was in Hardy-Weinberg equilibrium. The distribution of genotypes did not differ significantly between micro/macroalbuminuric and NA patients: 552 and 115 II, 1468 and 282 ID, 1119 and 208 DD (P = 0.67). However, the ACE D allele was more frequent among normotensive micro/macroalbuminuric patients than among NA patients (P = 0.039).

CONCLUSIONS

The ACE I/D polymorphism was not associated with high urinary albumin concentration in French Type 2 diabetes patients.

Association of HLA-DRB1*02 with osteoarthritis in a cohort of 106 patients

OBJECTIVE

We have previously shown that the inflammatory cytokines tumour necrosis factor alpha (TNF-alpha) and interleukin (IL) 6 or IL-1beta are up-regulated in chondrocytes of patients with osteoarthritis (OA). However, the inflammatory responses associated with OA are of low grade and restricted. To investigate the involvement of the immune system in the pathogenesis of OA, we analysed patients for their HLA-DRB1 haplotypes.

METHODS

Combining single-stranded oligo or sequence-specific primer typing procedures, 139 randomly selected controls and 106 OA patients were typed for their HLA-DRB1 alleles.

RESULTS

The OA cohort showed statistically significant differences in the frequencies of the DR2 and DR5 alleles compared with the controls. While the frequency of the DR2 allele was elevated among the OA patients, the DR5 allele was negatively associated with the disease. The P values for differences from the controls were 0.0431 for DR2 and 0.0386 for DR5 and the odds ratios for the two alleles were 1.58 and 0.54 respectively.

CONCLUSION

The association of DR2 and DR5 with OA hints at linkage disequilibrium between HLA-DRB1 genes and genes involved in the pathogenesis of OA. Alternatively, DR2 has a direct role in restricting immunological responses to the low-grade inflammation characteristic of OA.