Spin relaxation in (110) and (001) InAs/GaSb superlattices

We report an enhancement of the electron spin relaxation time (T1) in a (110) InAs/GaSb superlattice by more than an order of magnitude (25 times) relative to the corresponding (001) structure. The spin dynamics were measured using polarization sensitive pump probe techniques and a mid-infrared, subpicosecond PPLN OPO. Longer T1 times in (110) superlattices are attributed to the suppression of the native interface asymmetry and bulk inversion asymmetry contributions to the precessional D'yakonov Perel spin relaxation process. Calculations using a nonperturbative 14-band nanostructure model give good agreement with experiment and indicate that possible structural inversion asymmetry contributions to T1 associated with compositional mixing at the superlattice interfaces may limit the observed spin lifetime in (110) superlattices. Our findings have implications for potential spintronics applications using InAs/GaSb heterostructures.Comment: 4 pages, 2 figure

Anti–Neutrophil Extracellular Trap Antibodies in Antiphospholipid Antibody–Positive Patients: Results From the Antiphospholipid Syndrome Alliance for Clinical Trials and InternatiOnal Networking Clinical Database and Repository

OBJECTIVE: This study aimed to elucidate the presence, antigen specificities, and potential clinical associations of anti–neutrophil extracellular trap (anti-NET) antibodies in a multinational cohort of antiphospholipid (aPL) antibody–positive patients who did not have lupus. METHODS: Anti-NET IgG/IgM levels were measured in serum samples from 389 aPL-positive patients; 308 patients met the classification criteria for antiphospholipid syndrome. Multivariate logistic regression with best variable model selection was used to determine clinical associations. For a subset of the patients (n = 214), we profiled autoantibodies using an autoantigen microarray platform. RESULTS: We found elevated levels of anti-NET IgG and/or IgM in 45% of the aPL-positive patients. High anti-NET antibody levels are associated with more circulating myeloperoxidase (MPO)–DNA complexes, which are a biomarker of NETs. When considering clinical manifestations, positive anti-NET IgG was associated with lesions affecting the white matter of the brain, even after adjusting for demographic variables and aPL profiles. Anti-NET IgM tracked with complement consumption after controlling for aPL profiles; furthermore, patient serum samples containing high levels of anti-NET IgM efficiently deposited complement C3d on NETs. As determined by autoantigen microarray, positive testing for anti-NET IgG was significantly associated with several autoantibodies, including those recognizing citrullinated histones, heparan sulfate proteoglycan, laminin, MPO–DNA complexes, and nucleosomes. Anti-NET IgM positivity was associated with autoantibodies targeting single-stranded DNA, double-stranded DNA, and proliferating cell nuclear antigen. CONCLUSION: These data reveal high levels of anti-NET antibodies in 45% of aPL-positive patients, where they potentially activate the complement cascade. While anti-NET IgM may especially recognize DNA in NETs, anti-NET IgG species appear to be more likely to target NET-associated protein antigens

Use of alternative therapies by patients with rheumatic disease in Guadalajara, Mexico: Prevalence, beliefs, and expectations

Objective. To assess the prevalence, practices, beliefs, and expectations of patients with rheumatic diseases in relation to the use of alternative therapies. Methods. We conducted a cross-sectional survey of 300 consecutive patients with rheumatic diseases at 3 outpatient rheumatic disease clinics in Guadalajara, Mexico to evaluate the use of alternative therapies. A face-to-face structured interview was administered by a trained assistant to evaluate the prevalence of use and patient beliefs, perceptions, and expectations in relation to alternative therapies. Results. Two hundred fifty patients (83%) had used a total of 1386 alternative therapies (range 1-19); 203 (68%) patients had used alternative therapy in the previous 12 months. Sixty-one percent received at least one alternative treatment before the first rheumatology consultation, but an additional 18% initiated these therapies after their initial contact with a rheumatologist at our clinics. Only 66 (26%) of the patients using alternative therapy notified their rheumatologist about their use. Thirty-six patients (14%) discontinued formal treatment at least on one occasion in order to receive alternative therapies, and only 8 (22%) notified their rheumatologist. Alternative therapy practitioners recommended discontinuation of conventional therapy on 57% of the occasions when formal treatments were discontinued. Mean expenditures per patient for fees to alternative therapy providers were equivalent to 28 days of the official minimum daily wage, and per patient costs for the remedies themselves were equivalent to 13 days of the official minimum daily wage. Patients who used alternative therapy in the past 12 months had lower education (7 versus 10 years, P < 0.001) and were slightly more disabled (1.7 versus 1.5, modified Health Assessment Questionnaire, P < 0.01). Conclusions. In this survey most patients used alternative therapies for the treatment of their rheumatic disease. Alternative therapies were costly and appeared to decrease adherence to conventional therapy. Health care providers should openly discuss the use of alternative therapy in patients with rheumatic diseases