Surface Defect Formation and Passivation in Formamidinium Lead Triiodide (FAPbI3) Perovskite Solar Cell Absorbers.

Formamidinium lead iodide based hybrid perovskite materials with improved efficiency and stability still lack well-understood surface defect formation mechanisms. Controlling the surface termination and defects has the potential to improve the performance of both conventional 3D and latterly reduced-dimensional perovskites photovoltaics. Here, we characterized the termination and all possible defect formations in FAPbI3 surface by the first-principles calculations. We found that, among the surfaces we considered, FAI-termination exhibits the most stable surface with a high defect tolerance. The PbI2-terminated surface is also found to be relatively stable; however, certain defects, such as electron-donating FA-interstitial and Pb-interstitial defects, can create deep-level stable charge-traps, potentially limiting the optoelectronic performance. We further investigate the surface treatment on these deep defects by model small molecule additives. We found that benzene additive with delocalized electron distribution can effectively passivate the deep FA-interstitial and Pb-interstitial defects by electron donating to the surface defect through charge-transfer.

Severe pulmonary toxicity associated with fludarabine and possible contribution of rituximab.

Fludarabine is a nucleoside analogue used in the treatment of low-grade lymphoproliferative disorders and in conditioning regimens of non-myeloablative allogeneic stem cell transplantation. This is a relatively safe drug for clinical use but may cause side effects, some of which may be life-threatening. Here a case of severe pulmonary toxicity associated with fludarabine and a possible contribution of rituximab is presented and the literature reviewed.

Latex allergy risk assessment in children and adolescents with type I diabetes mellitus.

An increased frequency of allergic reactions to latex has been reported in specific populations with chronic latex exposure. However, relevance of latex allergy to children and adolescents with type I diabetes mellitus (DM1) has not been studied yet. The aim of the studty is to assess latex allergy risk in children and adolescents with DM1. Thirty-nine children with DM1 and 35 controls were enrolled. In a case-control study, we applied to all subjects a standard questionnaire, and specific Immunoglobulin E (IgE) concentrations for latex, common aeroallergens, and food-allergens were measured in serum samples. Latex exposure rates by means of medical procedures, operations, and latex glove usage were not different between DM1 and controls. Symptoms due to latex exposure were not determined in both groups. Three (7.7%) subjects in DM1 tested positive for latex-specific antibodies (LSIE), whereas no subject in controls. Diabetics that tested positive for latex-specific antibodies had the disease for three, 5 and 8 years. Nine (23.1%) of diabetics, and two (5.7%) of controls were atopic (p = 0.04). In our investigation, we found that children and adolescents with DM1 are not a risk group for latex allergy, and LSIE in children with DM1 was not accompanied by symptoms of latex allergy, or, presumably, increased risk of latex anaphylaxis.

Thrombotic thrombocytopenic purpura in southern Turkey: a single-center experience of 29 cases.

In this retrospective, nonrandomized study, we describe our experience in the management of 29 consecutive patients with thrombotic thrombocytopenic purpura (TTP) treated with a combined therapy of plasma exchange (PE) and steroids at a single center. We compared the effectiveness of high-dose steroids (20-25 mg/kg methyl prednisolone) as first-line treatment in combination with PE therapy with the combination of standard-dose steroids (1 mg/kg methyl prednisolone) and PE in adult patients with TTP. Clinical, laboratory data and treatment outcomes such as response rate, median time to recovery and survival were evaluated retrospectively. Overall (OR) and complete (CR) response rates were 69 and 52% respectively. Similar response rates were found in patients treated with pulse or conventional dose steroids; however, the median time to response was delayed in the high-dose methyl prednisolone (HDP) group. The median time from the initiation of symptoms to initiation of treatment was approximately 15 days (range: 0-30). Delayed treatment in our patients because of delayed referral to our center resulted in poor response to treatment. In all, four of 14 (27%) complete responders experienced relapses. The predicted relapse rate was 48% at a median of 30 months. All the relapses presented with a combination of thrombocytopenia and microangiopathic hemolytic anemia. This analysis showed that high-dose steroid treatment did not prove to be beneficial for TTP patients as firstline therapy combined with PE. Moreover, pulse steroid interventions might have resulted in delayed responses and our data suggest that initiation of treatment with PE should not be delayed.