A multicentre placebo-controlled clinical trial on the efficacy of oral ciclosporin A in the treatment of canine idiopathic sebaceous adenitis in comparison with conventional topical treatment

Canine idiopathic sebaceous adenitis (ISA) is an inflammatory reaction of sebaceous glands, potentially resulting in their complete loss. It is considered a T-cell mediated disease, but its precise pathogenesis is still unknown. Topical treatment is an effective but laborious treatment. Ciclosporin A (CsA) has recently been shown to ameliorate the clinical picture of ISA. It is, however, an expensive treatment option. The objective of this multicentre, partially double-blinded, randomized controlled study was to evaluate the efficacy of CsA, either alone or with topical therapy, in comparison to topical treatment alone, as measured by the primary end-points alopecia and scaling, and multiple histological secondary objectives. 34 dogs with an established diagnosis were treated for 4-6 months and were evaluated before, during and after therapy. Both CsA and topical therapy demonstrated efficacy in this study. Differences between the treatment protocols were marginal. Topical treatment, both alone and in combination with CsA, appeared to reduce scaling more effectively than CsA alone. Both therapies reduced alopecia. There is evidence of a synergistic benefit on both scaling and alopecia, if both treatment options are combined. Inflammation of the sebaceous glands is also best reduced by a combination of both CsA and topical therapy. There is evidence that regeneration of sebaceous glands is best achieved by CsA, either given alone or in combination with topical treatment. Die idiopathische Sebadenitis des Hundes (ISA) ist eine gegen die Talgdrüsen gerichtete Entzündungsreaktion, die zu deren kompletten Verlust führen kann. Die exakte Pathogenese ist noch unklar, man geht von einer T-Zell-vermittelten Immunreaktion aus. Die topische Behandlung ist effektiv, aber zeit- und arbeitsaufwendig. Ciclosporin A (CsA) führte in einer Pilotstudie zu einer deutlichen klinischen Verbesserung von ISA. Es handelt sich jedoch um eine teure Behandlung. Das Ziel dieser Multizenter, Plazebo-kontrollierten, teilweise Doppelblindstudie war die Untersuchung von CsA auf die ISA im Vergleich zur topischen Therapie und der Kombination von beiden. Alopezie und Hyperkeratose dienten als primäre Parameter, während die histologischen Befunde sekundäre Parameter waren. 34 Hunde mit der Diagnose ISA wurden über 4 bis 6 Monate behandelt und vor, während und nach der Therapie untersucht. Sowohl CsA als auch die topische Therapie zeigten eine klinische Verbesserung. Die Unterschiede im Erfolg waren marginal. Die topische Therapie alleine als auch in Kombination mit CsA, zeigte einen besseren Rückgang der Schuppen als CsA alleine. Die Kombination beider Therapien zeigte einen synergistischen Effekt auf Schuppenbildung und Alopezie. Die Entzündung der Talgdrüsen ließ sich ebenfalls am besten durch die Kombination beider reduzieren. Es konnte gezeigt werden, dass eine Behandlung mit CsA sowohl alleine als auch in Kombination zu einer Regeneration der Talgdrüsen führte

A second superconducting energy gap of Nb_3Sn observed by breakjunction point-contact spectroscopy

We report on investigations of the superconducting energy gap of the A15 superconductor Nb_3Sn by point-contact spectroscopy of breakjunctions. The voltage-dependent differential conductance dI/dV reveals features of a second energy gap besides the energy gap known from previous tunnel measurements with maxima at \Delta_1=3.92 +/- 0.16 meV and \Delta_2=0.85 +/- 0.17 meV as derived from a histogram summarizing the data of more than 60 contacts. These findings are the first spectroscopic evidence that Nb_3Sn belongs to the class of two-band superconductors and they are in line with low-temperature specific-heat measurements on Nb_3Sn

Thermodynamic evidence for pressure-induced bulk superconductivity in the Fe-As pnictide superconductor CaFe2As2

We report specific-heat and resistivity experiments performed in parallel in a Bridgman-type of pressure cell in order to investigate the nature of pressure-induced superconductivity in the iron pnictide compound CaFe2As2. The presence of a pronounced specific-heat anomaly at Tc reveals a bulk nature of the superconducting state. The thermodynamic transition temperature differs dramatically from the onset of the resistive transition. Our data indicates that superconductivity occurs in the vicinity of a crystallographic phase transition. We discuss the discrepancy between the two methods as caused by strain-induced superconducting precursors formed above the bulk thermodynamic transition due to the vicinity of the structural instability

Doping dependence of the critical fluctuation regime in the Fe-based superconductor Ba1−x_{1-x}Kx_xFe2_2As2_2

We investigate the importance of superconducting order parameter fluctuations in the 122 family of Fe-based superconductors, using high-resolution specific heat and thermal expansion data of various Ba$_{1-x}$K$_x$Fe$_2$As$_2$ single crystals covering a large range of the phase diagram from the strongly underdoped to the overdoped regime. By applying scaling relations of the 3d-XY and the 3d-Lowest-Landau-Level (3d-LLL) fluctuation models to data measured in different magnetic fields, we demonstrate that a strong increase of the critical fluctuation regime is responsible for the transition broadening in magnetic fields, which is a direct consequence of a magnetic-field-induced finite size effect due to a reduction of the effective dimensionality by a decreasing magnetic length scale related to the mean vortex separation and the confinement of quasiparticles in low Landau levels. The fluctuations are stronger in the underdoped and overdoped regimes and appear to be weakest at optimal doping

High-Pressure Evolution of the Specific Heat of a Strongly Underdoped Ba(Fe0.963Co0.037)As2 Iron-Based Superconductor

We report specific-heat experiments under the influence of high pressure on a strongly underdoped Co-substituted BaFe2As2 single crystal. This allows us to study the phase diagram of this iron pnictide superconductor with a bulk thermodynamic method and pressure as a clean control parameter. The data show large specific-heat anomalies at the superconducting transition temperature, which proves the bulk nature of pressure-induced superconductivity. The transitions in the specific heat are sharper than in resistivity, which demonstrates the necessity of employing bulk thermodynamic methods to explore the exact phase diagram of pressure-induced Fe-based superconductors. The Tc at optimal pressure and the superconducting condensation energy are found to be larger than in optimally Co-doped samples at ambient pressure, which we attribute to a weak pair breaking effect of the Co ions.Comment: To appear in Physical Review

The role of the coherence length for the establishment of global phase coherence in three-dimensional arrays of ultra-thin quasi-one-dimensional superconducting Pb and NbN nanowires

We have fabricated 5 nm ultra-thin NbN nanowires that form a dense and regular array in the linear channels of mesoporous SBA-15 silica substrates. Bulk NbN is a well-known classical superconductor with Tc of 16 K. We show that, by being incorporated into this nanostructure, the composite material exhibits typical quasi-one-dimensional characteristics. We compare the superconducting properties with those of superconducting Pb nanowires of same dimensionality in identical configuration within the linear SBA-15 pores. While Pb nanowire arrays show a pronounced crossover from 1D superconductivity at high temperatures to a 3D bulk superconducting state in the low temperature regime with true zero resistance triggered by transversal Josephson interaction, this transition appears to be completely absent in the NbN nanowire array. The small coherence length in NbN, which strongly suppresses the Josephson coupling is discussed as the origin of this difference

Thermodynamic evidence for the Fulde-Ferrell-Larkin-Ovchinnikov state in the KFe2As2 superconductor

We have investigated the magnetic phase diagram near the upper critical field of KFe2As2 by magnetic torque and specific heat experiments, using a high-resolution piezo-rotary positioner to precisely control the parallel orientation of the magnetic field with respect to the FeAs layers. We observe a clear double transition when the field is oriented strictly in-plane, and a characteristic upturn of the upper critical field line well beyond the Pauli limit at 4.7 T. This provides firm evidence that an FFLO state is realized in this iron-based KFe2As2 superconductor

The Fulde-Ferrell-Larkin-Ovchinnikov State in the Organic Superconductor k-(BEDT-TTF)2Cu(NCS)2 as Observed in Magnetic Torque Experiments

We present magnetic-torque experiments on the organic superconductor k-(BEDT-TTF)2Cu(NCS)2 for magnetic fields applied parallel to the 2D superconducting layers. The experiments show a crossover from a second-order to a first-order transition when the upper critical field reaches 21 T. Beyond this field, which we interpret as the Pauli limit for superconductivity, the upper critical field line shows a pro-nounced upturn and a phase transition line separates the superconducting state into a low- and a high-field phase. We interpret the data in the framework of a Fulde-Ferrell-Larkin-Ovchinnikov state.Comment: 2 pages, 1 figur

‘Fragile Superconductivity': A Kinetic Glass Transition in the Vortex Matter of the High-temperature Superconductor YBa2 Cu3O7-δ

Using high-resolution thermal expansion and magnetization measurements, we provide experimental evidence for a kinetic glass transition in the vortex matter of YBa2Cu3O7-δ with some disorder. This transition, which represents the true superconducting transition in a magnetic field, exhibits many of the features of the usual glass transition found in supercooled structural liquids such as window glass. We demonstrate, using both kinetic and thermodynamic criteria, that this vortex matter is the most fragile system known to date, which we argue makes it possible to investigate the behavior very close to the Kauzmann temperature. Vortex matter, we suggest, may be a model system to study glassy behavior in general, which is expected to lead to a better understanding of the strong-fragile behavior in structural glasse