Enhanced current transport at grain boundaries in high-T(c) superconductors.

Large-scale applications of high-transition-temperature (high-T(c)) superconductors, such as their use in superconducting cables, are impeded by the fact that polycrystalline materials (the only practical option) support significantly lower current densities than single crystals. The superconducting critical current density (J(c)) across a grain boundary drops exponentially if the misorientation angle exceeds 2 degrees -7 degrees. Grain texturing reduces the average misorientation angle, but problems persist. Adding impurities (such as Ca in YBa2Cu3O7-delta; YBCO) leads to increased J(c) (refs 9, 10), which is generally attributed to excess holes introduced by Ca2+ substituting for Y3+ (ref. 11). However, a comprehensive physical model for the role of grain boundaries and Ca doping has remained elusive. Here we report calculations, imaging and spectroscopy at the atomic scale that demonstrate that in poly-crystalline YBCO, highly strained grain-boundary regions contain excess O vacancies, which reduce the local hole concentration. The Ca impurities indeed substitute for Y, but in grain-boundary regions under compression and tension they also replace Ba and Cu, relieving strain and suppressing O-vacancy formation. Our results demonstrate that the ionic radii are more important than their electronic valences for enhancing J(c).

Prevention of chemotherapy-induced nausea and vomiting in the real-world setting in Spain.

PURPOSE: Proper monitoring and management of chemotherapy-induced nausea and vomiting (CINV) with antiemetics is crucial for cancer patients. This study aimed to evaluate the use of antiemetics for the treatment of highly emetogenic chemotherapy (HEC) including carboplatin in the real-world setting in Spain. METHODS: A representative panel of cancer specialists was asked to collect information about the antiemetic treatments provided to patients receiving chemotherapy. Records formed part of the Global Oncology Monitor© database (Ipsos Healthcare, London, UK). Chemotherapy data were extrapolated using Ipsos Healthcare's projection methodology. RESULTS: A total of 73 experts were finally included. Data from 9519 patients, estimated to be representative of 202,084 patients, were collected. HEC (and carboplatin-based chemotherapy) was administered to 73,118 (36%) patients, cisplatin-based therapy being the most frequent treatment (n = 34,649, 47.38%). Neurokinin-1 receptor antagonists (NK1RAs) alone or in combination were used as prophylaxis for CINV in 14,762 (20%) patients, while the combination of NK1RA with 5-hydroxytryptamine-3 receptor antagonist (5-HT3RAs) and dexamethasone as recommended by the international guidelines was used in 5849 (8%) patients only. No antiemetic prophylaxis was administered to 8.46% of the patients receiving HEC (n = 6189). Physicians classified cisplatin-, anthracycline-cyclophosphamide (AC-), and carboplatin-based regimens as HEC in 63%, 22% and 4% of the cases, respectively. CONCLUSIONS: The use of NK1RA-containing regimens for CINV prevention in patients treated with HEC was less than expected, suggesting poor adherence to international antiemetic guidelines.

Design rules to achieve high-T(C) ferromagnetism in (Ga, Mn)As alloys.

The Curie temperature T(C) of ferromagnetic semiconductor alloys depends not only on the alloy composition, but also on the spatial configuration of the magnetic impurities. Here we use a set of first-principle-calculated Curie temperatures to uncover-via a statistical, 'data mining' approach-the rules that govern the dependence of T(C) on the configuration of Mn substitutional impurities in GaAs. We find that T(C) is lowered (raised) when the average number of first (third and fourth) nearest-neighbour Mn pairs increases, suggesting simple atom-by-atom strategies to achieve high T(C) in (Ga, Mn)As alloys.

A. Franceschetti--great ophthalmologist and humanitarian.

A. Franceschetti is well known for his work in ocular genetics; however, his role in creating a department that served as a haven for ophthalmologists during World War II is less well known. Franceschetti was an enthusiastic and multitalented researcher whose contributions to ophthalmology are far-reaching.