Role of Microstructure in Oxygen Induced Photodegradation of Methylammonium Lead Triiodide Perovskite Films

This paper investigates the impact of microstructure on the degradation rate of methylammonium lead triiodide (MAPbI₃) perovskite films upon exposure to light and oxygen. By comparing the oxygen induced degradation of perovskite films of different microstructure–fabricated using either a lead acetate trihydrate precursor or a solvent engineering technique–it is demonstrated that films with larger and more uniform grains and better electronic quality show a significantly reduced degradation compared to films with smaller, more irregular grains. The effect of degradation on the optical, compositional, and microstructural properties of the perovskite layers is characterized and it is demonstrated that oxygen induced degradation is initiated at the layer surface and grain boundaries. It is found that under illumination, irreversible degradation can occur at oxygen levels as low as 1%, suggesting that degradation can commence already during the device fabrication stage. Finally, this work establishes that improved thin‐film microstructure, with large uniform grains and a low density of defects, is a prerequisite for enhanced stability necessary in order to make MAPbI₃ a promising long lived and low cost alternative for future photovoltaic applications.     

Preparation of polymers containing Fe(0)-coordinated 2,5-diethynylsilole units

UV irradiation of poly(organosilanylene-2,5-diethynylenesiloles) in benzene with an excess of Fe(CO)₅ led to the formation of Fe(CO)₃-coordinated silole units in the polymer backbone. The Fe(CO)₃-coordinated polymers exhibited suppressed π-conjugation, relative to the parent non-coordinated polymers. Hole-transporting properties of poly(organosilanylene-2,5-diethynylenesiloles) were examined by the performance of EL devices containing the polymer layer as the hole-transport and Alq3 layer as the electron-transporting emitter.     

A simple filtration device for separating nonadherent microorganisms from mammalian cells in in vitro studies on microbial adherence

In adherence studies, the removal of nonadherent microorganisms is essential for the valid enumeration of microorganisms that adhere to host cells. Although filtration devices are available commercially for the removal of nonadherent microorganisms, these are expensive and not reusable. In this article, we describe a simple, inexpensive, and reusable filtration device composed of two chambers of nylon, a nylon membrane of desired pore size, a rubber washer, and supporting stainless steel mesh. The device was effective in in vitro adherence assays for removing nonadherent endospores of Rhinosporidium seeberi from human buccal epithelial cells, providing valid counts of adherent microorganisms.     

INVO: a simple, low cost effective assisted reproductive technology

⁵Correspondence address. E-mail: clauderanoux{at}bioxcell.com INVO procedure is a simple and effective infertility treatmentthat uses a new device, the INVOcell. INVO can be performedin a physician's office or in a satellite facility of an IVFcenter. The INVO procedure consists of fertilization of oocyte(s)and early embryo development in the INVOcell placed into thematernal vaginal cavity for incubation. The vaginal cavity replacesthe complex in vitro fertilization (IVF) laboratory. This studypresents the specially designed device, INVOcell that has receivedCE Certification. INVOcell overcomes the disadvantages of thepreviously used prototype and makes the procedure simpler andreproducible. INVO is a proven procedure that has demonstratedcomparable results to conventional IVF when comparative studieswere performed. Over 800 cycles have been published worldwidethat showed a clinical pregnancy rate of 19.6%. The INVO technologycan be performed in an office setting with minor capital equipment.INVO is a simple low-cost procedure that can be available almosteverywhere. INVO allows the treatment of a new population ofinfertile couples who could not benefit from IVF due to costand availability. The participation of the patient in the processof fertilization and early embryo development is a psychologicalbenefit that creates a high level of acceptance of INVO.     

Bear deterrence with scare devices,a non-lethal tool in the use-of-force continuum

Wild animals eating agricultural products and coming close to people's residences are primary causes of human–wildlife conflict worldwide. When carnivores eat anthropogenic foods and cause human safety concerns, it often results in the removal of the animals and public demand for reduced wildlife populations. The use of remote methods, such as scare devices, to deter carnivores has been touted in the literature; however, efficacy evidence remains thin. I test the efficacy of a widely available motion-activated solar alarm lamp to deter grizzly bears (Ursus arctos) from farms in Montana, USA. When scare devices were activated, there was a 46% reduction in the odds bears would access an attractant. For every additional scare device, there was an additional 44% reduction in the odds of a bear getting the food. Additionally, scare devices caused bears to be more vigilant and increase movement behavior. More bears in a group led to loss of deterrence efficacy, and there was no evidence for habituation to the aversive stimuli. This deterrence method was most effective in August and for fungicide-treated wheat. Out of 21 farms, scare devices stopped bears from returning to 11 sites. Overall, scare devices can be a cheap and easy first step to preventing, or resolving, some grizzly bear issues in the use-of-force continuum, which hierarchically organizes conflict responses from non-lethal to more severe.     

DPP-4 inhibitor des-F-sitagliptin treatment increased insulin exocytosis from db/db mice β cells

Incretin promotes insulin secretion acutely. Recently, orally-administered DPP-4 inhibitors represent a new class of anti-hyperglycemic agents. Indeed, inhibitors of dipeptidyl peptidase-IV (DPP-4), sitagliptin, has just begun to be widely used as therapeutics for type 2 diabetes. However, the effects of sitagliptin-treatment on insulin exocytosis from single β-cells are yet unknown. We therefore investigated how sitagliptin-treatment in db/db mice affects insulin exocytosis by treating db/db mice with des-F-sitagliptin for 2 weeks. Perfusion studies showed that 2 weeks-sitagliptin treatment potentiated insulin secretion. We then analyzed insulin granule motion and SNARE protein, syntaxin 1, by TIRF imaging system. TIRF imaging of insulin exocytosis showed the increased number of docked insulin granules and increased fusion events from them during first-phase release. In accord with insulin exocytosis data, des-F-sitagliptin-treatment increased the number of syntaxin 1 clusters on the plasma membrane. Thus, our data demonstrated that 2-weeks des-F-sitagliptin-treatment increased the fusion events of insulin granules, probably via increased number of docked insulin granules and that of syntaxin 1 clusters.     

Shoulder Joint Dislocation as an Unusual Complication of Defibrillation Threshold Testing Following Subcutaneous Implantable Cardioverter-Defibrillator Implantation

A 53-year-old man underwent implantation of a totally subcutaneous ICD (S-ICD; Boston Scientific). He was positioned supine, with the left arm abducted, externally rotated (i.e. palm up) and strapped to the arm extender. The generator was placed in the left mid-axillary line along the 5th-6th intercostal spaces and the defibrillation coil was tunneled anterior to the sternum. Defibrillation threshold (DFT) testing with 65 Jcaused a forceful pectoralis twitch. The patient woke up with a painful anteriorly dislocated left shoulder. Glenohumeral dislocation due to DFT testing has not been previously reported. It is likely that this complication is specific to the S-ICD implantation, and is related to positioning with the arm abducted, externally rotated, and immobilized, and use of greater defibrillation energy with current pathway through the bulk of the pectoralis muscle.Precautions may include extending the arm palm down, strapping the arm loosely, and adduction of the arm for DFT testing.