Trapped field potential of commercial Y-Ba-Cu-O bulk superconductors designed for applications

Bulk high-temperature superconductors (HTSs) that act as a trap field magnet establish a novel type of magnetic field source, which is significantly different from that of a permanent magnet or solenoid; therefore, they can be potentially used in magnetic-force-based applications. However, the primary issues related to the commercial use of the bulk HTS technology are established on the enhancement of trapped magnetic fields, as well as their reliability and reproducibility at temperatures achievable with off-the-shelf cryocoolers. This study presents experimental investigations on the strong trapped magnetic fields observed in commercial Y-Ba-Cu-O bulk HTSs produced as a double-sample stack, a cylindrical bulk, and a ring-shaped bulk. Consequently, a reliable and reproducible magnetic field of 9.5 T at 50 K was trapped in commercial Y-Ba-Cu-O assembled as a double-sample stack. In this case, shrink-fit encapsulation with either aluminum or stainless steel tube ensured equally effective reinforcement. Higher magnetization, although accompanied with partial flux jumps, yielded a trapped field of 16.85 T at 30 K, which is comparable to the reported record trapped fields. Finally, a maximum trapped field of 9.78 T - the strongest trapped field reported to date - was attained in the 6 mm hollow space of the ring-shaped bulk HTS

Clinical practice. Diagnosis and treatment of cow’s milk allergy

Introduction Cow's milk allergy (CMA) is thought to affect 2-3% of infants. The signs and symptoms are nonspecific and may be difficult to objectify, and as the diagnosis requires cow's milk elimination followed by challenge, often, children are considered cow's milk allergic without proven diagnosis. Diagnosis Because of the consequences, a correct diagnosis of CMA is pivotal. Open challenges tend to overestimate the number of children with CMA. The only reliable way to diagnose CMA is by double-blind, placebo-controlled challenge (DBPCFC). Therapy At present, the only proven treatment consists of elimination of cow's milk protein from the child's diet and the introduction of formulas based on extensively hydrolysed whey protein or casein; amino acid-based formula is rarely indicated. The majority of children will regain tolerance to cow's milk within the first 5 years of life. Conclusions Open challenges can be used to reject CMA, but for adequate diagnosis, DBPCFC is mandatory. In most children, CMA can be adequately treated with extensively hydrolysed whey protein or casein formulas

Up-regulation of C5a receptor expression and function on human monocyte derived dendritic cells by prostaglandin E(2)

The expression of the C5a-receptor (C5aR) on dendritic cells, its regulation and function have not been well established thus far. We show that the C5aR is expressed on human monocyte-derived dendritic cells (DC) and can be down-regulated by maturation stimuli such as tumour necrosis factor-α (TNF-α), lipopolysaccharide (LPS) or CD40L and by the T helper 1-cytokine interferon-γ (INF-γ). Prostaglandin E2 (PGE(2)), a proinflammatory mediator supporting dendritic cell activation and necessary for adequate DC migration, leads to the up-regulation of C5aR expression when incubated alone and prevents down-regulation when given in combination with TNF-α or LPS. Stimulation of C5aR on DC triggered F-actin polymerization, indicating the chemotactic potential of DC elicited by C5a. C5a induced F-actin polymerization was increased when C5aR was up-regulated by PGE(2). Stimulation of DC with C5a resulted in interleukin-10 production which was significantly increased after C5aR up-regulation with TNF-α and PGE(2). Therefore, up-regulation of the C5aR on human DC alters their chemotactic and immunologic response to C5a

Detection of anaphylatoxin receptors on CD83(+) dendritic cells derived from human skin

Dendritic cells (DC) are recruited to sites of inflammation for the initiation of immune responses. As the anaphylatoxins C5a and C3a are important mediators of inflammation, we investigated the expression of their receptors (C3aR and C5aR) on human DC. DC were isolated from human skin or generated from purified blood monocytes and were identified by their expression of CD1a or CD83. Freshly isolated or cultured dermal CD1a(+) and CD83(+) DC bound anti-C5aR and anti-C3aR monoclonal antibodies (mAbs), as detected by flow cytometry. C5a induced calcium fluxes in dermal CD1a(+) and CD83(+) DC, which could be inhibited by C17/5, an anti-C5a mAb. C3a did not induce calcium fluxes in these cells. Anaphylatoxin receptor expression was down-regulated on dermal DC by adding tumour necrosis factor-α (TNF-α) to the culture medium. On CD1a(+) CD83(−) cells generated from isolated blood monocytes by culture with 6·25 ng/ml of granulocyte–macrophage colony-stimulating factor (GM-CSF) and 125 U/ml of interleukin-4 (IL-4), expression of both C5aR and C3aR was observed. In these cells, both C5a and C3a induced calcium fluxes. After addition of TNF-α to the culture medium, the majority of the CD1a(+) cells expressed CD83(+). These cells – expressing a phenotype of ‘mature DC’ – down-regulated the expression of the anaphylatoxin receptors and lost their reactivity to the respective ligands. Our results demonstrate the expression of the anaphylatoxin receptors C5aR and C3aR on human skin-derived DC and blood-derived cells expressing the DC-associated membrane molecule, CD1a. Furthermore, the expression of anaphylatoxin receptors on CD83(+) dermal DC is indicative of an intermediate stage of maturation of these cells, which was not observed on in vitro-differentiated CD83(+) cells

Hochstromanwendungen mit Hochtemperatursupraleitern - Technische Leiterentwicklung und Bau von Funktionsmodellen. Drehstrom-Synchronmotor mit Hochtemperatur-Supraleiter (HTSL)-Laeuferwicklung und HTSL-Lagern Abschlussbericht

The project involved the design, construction and testing of a 3000 kW converter-fed synchronous motor as a development prototype with - HTS rotor windings, - closed-circuit cooling system, - stator air-gap winding and -high-gradient HTS magnetic bearing. The project objective was to create the conditions necessary for the construction of an application-oriented model(#approx#2 MW) that would be suitable for field tests and provide a starting point for subsequent series expansion. The main focus was fixed on feasibility and function issues relating to the various components, particularly during operation of the overall system in the test bay. These ambitious targets were achieved within the scope of project-based cooperation. This has been demonstrated especially in test bed operation of the machine since spring 2001, in the course of which the motor produced a maximum continuous rating of 450 kW - significantly above the specified value - while the short-time rating could be increased up to 600 kW. Throughout testing the motor demonstrated excellent performance characteristics that are markedly indifferent to load fluctuations and indicative of important operating advantages to subsequent users of such HTS motors. Loss calculations showed that, in terms of efficiency, this prototype already represents an approximately 1% improvement over the conventional motors or generators currently available. The robustness of the cooling concept developed as part of the project was also convincingly demonstrated during the comprehensive test phase, which has been ongoing since spring 2001. The innovative pulse-tube coolers developed by our partner companies Leybold and TransMIT promise further advantages over current commercial GM-coolers. Despite considerable problems with materials the team successfully built and operated a contactless HTS magnet bearing (based on YBCO stator cylinders from partner company ATZ) that is currently one of the world's largest in terms of bearing capacity. A bearing of this type functions passively; in other words, it does not require any actively controlled electronic components and could therefore be an important development for high-speed machines in future. In the light of these positive results, additional questions were investigated in connection with the scaling-up of findings and procedures in the application-relevant power range of several MW and with the analysis of critical components (including winding technique, torque transmission, cooling). This further improved the prerequisites for successor projects and for subsequent implementation of the development results. (orig.)Available from TIB Hannover: F03B1309 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

Update "Systemic treatment of atopic dermatitis" of the S2k‐guideline on atopic dermatitis

This guideline is an update from August 2020 the S2k-guideline “Atopic dermatitis” published in 2015. The reason for updating this chapter of the guideline were the current developments in the field of systemic therapy of atopic dermatitis. The agreed recommendations for systemic treatment in atopic dermatitis of the present guideline are based on current scientific data. Due to the approval of dupilumab for the treatment of moderate to severe atopic dermatitis, which cannot be treated sufficiently with topical drugs alone, this part of the guideline has now been adapted and newly consented. The indication for systemic therapy and the therapeutic response to topical and systemic treatment should be recorded and documented in a suitable form in clinic and practice. A standardized documentation of the indication for system therapy in atopic dermatitis can be recommended and is also part of the updated chapter of this guideline