Propylamine hydrobromide passivated tin-based perovskites to efficient solar cells

The development of tin-based devices with low toxicity is critical for the commercial viability of perovskite solar cells.However because tin halide is a stronger Lewis acid,its crystallization rate is extremely fast,resulting in the formation of numerous defects that affect the device performance of tin-based perovskite solar cells.Herein,propylamine hydrobromide(PABr)was added to the perovskite precursor solution as an additive to passivate defects and fabricate more uniform and dense perovskite films.Because propylamine cations are too large to enter the perovskite lattices,they only exist at the grain boundary to passivate surface defects and promote crystal growth in a preferred orientation.The PABr additive raises the average short-circuit current density from 19.45 to 25.47 mA·cm^(-2)by reducing carrier recombination induced by defects.Furthermore,the device’s long-term illumination stability is improved after optimization,and the hysteresis effect is negligible.The addition of PABr results in a power conversion efficiency of 9.35%.

Alverine citrate induced acute hepatitis

Alverine dtrate is a commonly used smooth muscle relaxant agent.A MEDLINE search on January 2004 revealed only 1 report implicating the hepatotoxicity of this agent.A 34- year-old woman was investigated because of the finding of elevated liver function tests on biochemical screening.Other etiologies of hepatitis were appropriately ruled out and elevated enzymes were ascribed to alverine citrate treatment. Although alverine citrate hepatotoxicity was related to an immune mechanism in the first case,several features such as absence of predictable dose-dependent toxicity of alverine citrate in a previous study and absence of hypersensitivity manifestations in our patient are suggestive of a metabolic type of idiosyncratic toxicity.

Organic coating of 1-2-nm-size silicon nanoparticles： Effect on particle properties

Photoluminescent silicon nanoparticles 1-2 nm in size were synthesized by a wet chemical procedure and derivatized with propylamine （NH2SiNP）. Surface NH2 groups were used as linkers for additional poly（ethylene glycol） （PEG） and folic acid （Fo） attachment （PEG-NHSiNP and Fo-NHSiNP, respectively） to enable efficient targeting of the particles to tumors and inflammatory sites. The particles were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, ζ potential, dynamic light scattering, and time-resolved anisotropy. The photophysical properties and photosensitizing capacity of the particles and their interaction with proteins was dependent on the nature of the attached molecules. While PEG attachment did not alter the photophysical behavior of NH2SiNP, the attachment of Fo diminished particle photoluminescence. Particles retained the capacity for 1O2 generation; however, efficient 1O2 quenching by the attached surface groups may be a drawback when using these particles as 1O2photosensitizers. In addition, Fo attachment provided particles with the capacity to generate the superoxide anion radical （O2-）. The particles were able to bind tryptophan residues of bovine serum albumin （BSA） within quenching distances. NH2SiNP and PEG-NHSLNP ground state complexes with BSA showed binding constants of （3.1 ± 0.3） × 10^4 and （1.3 ±0.4） × 10^3 M-1, respectively. The lower value observed for PEG-NHSiNP complexes indicates that surface PEGylation leads to a reduction in protein adsorption, which is required to prevent opsonization. An increase in particle luminescence upon BSA binding was attributed to the hydrophobic environment generated by the protein. NH2SiNP-BSA complexes were also capable of resonance energy transfer.