Superconducting properties of hole doped Ba(0.6)Li(0.4)Fe2As2 single crystal.

We report the emergence of superconductivity in Li doped Ba-122 single crystals grown by the Bridgman method. The superconducting transition temperature Tc,onset is around 19 K. The specific heat capacity C/T shows a weak anomaly near Tc. The value of ΔC/γnTc is smaller than the value predicted in BCS theory indicating a multigap nature of the sample. The magnetic measurements show that the lower critical field Hc1(T) exhibits a linear temperature dependence, with a pronounced change of the Hc1(T) curvature around 0.4Tc and Hc1(0) ≈ 430 Oe in the Ba0.6Li0.4Fe2As2 single crystal. Furthermore, temperature dependence of the penetration depth λ(T) follows a power law (~T(n)) below 0.4Tc which predicts possible S±-wave pairing in a Ba0.6Li0.4Fe2As2 superconductor. Over a wide range of temperatures, the Jc(H) exhibits a relation J(c)[proportionality] H(-α) with α = 0.5 ~ 0.6 for H || c and H || ab which indicates random defects in the sample. We found that the temperature dependence of the critical current density Jc(T) can be fitted well with the δl-type pinning model, whose origin is attributed to spatial variations of charge carrier mean free path l. We suggest that the large mismatch in the ionic radius of Ba and Li can affect the irreversible magnetic properties of the Ba0.6Li0.4Fe2As2 single crystal without any structural transition.

Narrowband ultraviolet B phototherapy for patients with refractory uraemic pruritus: a randomized controlled trial.

BACKGROUND: Pruritus is very common in uraemic patients, but the treatment remains challenging. Studies regarding narrowband ultraviolet B (NB-UVB) phototherapy for uraemic pruritus are rare. OBJECTIVES: To investigate whether or not NB-UVB phototherapy is an effective treatment for uraemic pruritus. METHODS: We conducted a single-blind, randomized, controlled trial for patients with refractory uraemic pruritus. The treatment group received NB-UVB phototherapy three times per week for 6 weeks. The dose of NB-UVB started from 210 mJ cm(-2) and was increased by 10% each time. The control group received time-matched exposures to long-wave UVA radiation. A visual analogue scale (VAS) score was evaluated weekly for pruritus intensity for 12 weeks. The characteristics of pruritus were also assessed by a questionnaire at baseline and after 6 weeks of phototherapy. RESULTS: Both the NB-UVB and control groups had significant and comparable improvement in the pruritus intensity VAS scores during the period of phototherapy and follow-up. Compared with the control group, the NB-UVB group showed a significant improvement in the involved body surface area affected by pruritus (P = 0·006), but not in sleep quality. More detailed regression and estimating analysis revealed that the patients in the NB-UVB group had lower pruritus intensity scores at week 6, week 10 and week 12. This may indicate a beneficial difference at certain time points, but the effect seems marginal. CONCLUSIONS: NB-UVB phototherapy does not show a significant effect in reducing pruritus intensity compared with a control group for refractory uraemic pruritus. Further studies are warranted.

Inhibition of BRCA1 in breast cell lines causes the centrosome duplication cycle to be disconnected from the cell cycle.

BRCA1-dependent ubiquitination activity regulates centrosome number in several tissue culture cell lines derived from breast cells. In these experiments, we asked how BRCA1 inhibits centrosome amplification. In general, supernumerary centrosomes can accumulate by three mechanisms: (1) failed cytokinesis and the accumulation of centrosomes by duplication in a repeated S-phase of the cell cycle, (2) disruption of the licensing of centrosome doubling such that they duplicate at inappropriate times in the cell cycle, or (3) fragmentation of the centrosomes. In this study, we found that inhibition of BRCA1 caused premature separation of centrioles and reduplication. By blocking cells in early S-phase before centrosome amplification secondary to BRCA1 inhibition could occur and then releasing, we found that inhibition of BRCA1 caused centrosome amplification between late S-phase and G2/M before the cell divided. These results suggest that normal BRCA1 function is critical in these cell lines to prevent centriole separation and centrosome reduplication before mitosis.

Closure of chronic abdominal wall defects: a long-term evaluation of the components separation method.

Incisional hernias and abdominal wall defects are frequently iatrogenic problems that have been found to complicate as many as 11% of all abdominal operations. Current techniques for closure of large, chronic abdominal wall defects have limitations. The use of local musculofascial flaps rather than fascial patches (i.e., the tensor fascia lata) or synthetic material for the repair of chronic abdominal wall defects is preferable. The superiority of innervated muscle flaps that provide dynamic abdominal support has been demonstrated. This report focuses on patients with chronic abdominal wall defects in whom previous techniques have failed. An algorithmic approach to planned reconstruction is presented utilizing the "components separation" technique as its foundation. Thirty-seven patients who underwent abdominal reconstruction following this algorithm are reviewed and their clinical course is outlined. The components separation technique provides a compound innervated and vascularized muscle flap for dynamic support of the reconstructed abdominal wall. The experience documented here and by others suggests that this technique is a safe and effective method for reconstructing the abdominal wall in patients with recurrent herniation. Enterocutaneous fistulas, however, continue to present a challenge to the surgeon.

Plastic ankle-foot orthoses: evaluation of function.

Plastic ankle-foot orthoses (PAFOs) are worn by persons with hemiplegia to correct gait abnormalities such as foot drop during swing and insufficient pushoff during stance. A PAFO should resist plantarflexion sufficiently to provide toe clearance during the swing phase of gait without excessively increasing the knee bending moment during heelstrike. It should resist dorsiflexion during late stance to raise the heel to simulate gastrocnemiussoleus muscle group function. Five PAFOs were evaluated as to the amount of plantarflexion-dorsiflexion resistance that was provided when worn by hemiplegic and able-bodied subjects. A self-aligning goniometer measured ankle angle as the subject walked, and a gait event marker system recorded occurrences of gait events. The Seattle design polypropylene orthosis which enclosed the malleoli was the least flexible; it provided the greatest plantarflexion resistance to ensure against toe drag during swing for patients with severe plantarflexion spasticity. It offered the greatest dorsiflexion resistance to provide a good substitute for the gastrocnemiussoleus during the latter part of stance as required by patients with flaccid plantarflexors and full ankle range of motion. Progressive trimming of the Seattle design polypropylene orthosis made it more flexible and comparable in function to the commercially available Engen and Teufel orthoses. The latter 2 orthoses did not provide a pushoff substitute as well as the Seattle design orthosis which enclosed the malleoli, but they did provide an adequate amount of toe clearance during swing. The more flexible orthoses would be appropriate for subjects with mild to moderate plantarflexor spasticity.

Knee moments: origin in normal ambulation and their modification by double-stopped ankle-foot orthoses.

While the primary function of an ankle-foot orthosis is to stabilize the ankle complex, these devices often cause an unstable knee joint. The effect of a double upright ankle-foot orthosis on knee stability was evaluated during the stance phase of the walking cycle. The external moments applied to the knee in the anteroposterior plane were determined by measuring the ground reaction forces and the position of the knee with respect to these forces. Total knee moment and individual moment contributions of the fore/aft shear and vertical ground reaction forces were analyzed. Moments generated during normal ambulation were compared with those generated by an ankle-foot orthosis with an adjustable double stop. Knee moment components due to fore/aft shear and vertical ground reaction forces tended to counterbalance each other, minimizing the magnitudes of total knee moment. Fore/aft shear moment was most affected by the magnitude of the fore/aft shear force and had the major effect on total knee moment when the fore/aft shear force was peaking during the heel-strike and push-off phases. The vertical force moment was most affected by the length of the moment arm (position of knee center with respect to force) rather than magnitude of force, and had the major effect on total knee moment during midstance phase.

Double-stopped ankle-foot orthosis in flaccid peroneal and tibial paralysis: evaluation of function.

This study was undertaken to evaluate how effectively an ankle-foot orthosis can substitute for paralyzed musculature, and to determine the forces it sustains in so doing. Timing of the events of gait, the ground reaction forces, their magnitude and location, and the brace moments were studied. Midstance phase was found lengthened at the expense of push-off phase. During push-off, vertical loading and posterior shear were markedly reduced by tibial block. Also, the dorsiflexion moment in the orthosis was correspondingly increased. The orthosis was found to substitute for muscle function in that it approximates the foot-ankle motion of heel-strike and allows a push-off substitute.