Unraveling Halogen Role in Two-Step Solution Growth of Organic-Inorganic Hybrid Mixed-Halide Perovskites: Guidelines of Fabricating Single-Phase Perovskites with Predictable Stoichiometry.

The challenge faced in optoelectronic applications of halide perovskites is their degradation. Minimizing material imperfections is critical to averting cascade degradation processes. Identifying causes of such imperfections is, however, hindered by mystified growth processes and is particularly urgent for mixed-halide perovskites because of inhomogeneity in growth and phase segregation under stresses. To unravel two-step solution growth of MAPbBr x I3-x , we monitored the evolution of Br composition and found that the construction of perovskite lattice is contributed by iodine from PbI2 substrate and Br from MABr solution with a 1:1 ratio rather than a 2:1 ratio originally thought. Kinetic analysis based on a derived three-stage model extracted activation energies of perovskite construction and anion exchange. This model is applicable to the growth of PbI2 reacting with a mixed solution of MABr and MAI. Two guidelines of fabricating single-phase MAPbBr x I3-x with predictable stoichiometry thus developed help strategizing protocols to reproducibly fabricate mixed-halide perovskite films tailored to specific optoelectronic applications.

A variant NS1 protein from H5N2 avian influenza virus suppresses PKR activation and promotes replication and virulence in mammals.

Highly pathogenic avian influenza viruses (HPAIVs) frequently receive global attention as threats to public health. The NS1 protein is a key virulence factor known to impair host antiviral responses. The study herein revealed HPAIV H5N2 NS gene encoded additional protein; a truncated NS1 variant, designated NS3, produced by alternative splicing of the NS transcript. To examine the function of NS3 during infection, we generated recombinant viruses expressing either full-length NS1 (RG-AIV-T375G) or NS3 (RG-AIV-NS3). Interestingly, RG-AIV-NS3 virus produced higher titres than RG-AIV-T375G in multiple mammalian cell lines. However, RG-AIV-T375G exhibited a replication advantage over RG-AIV-NS3 in chicken DF-1 cells, indicating that host cell identity dictates the effect of NS3 on viral replication. In mice and mammalian cells, RG-AIV-NS3 infection elicited higher level of cytokines, including IFN-ß, MX and TNF-α, potentially due to its higher replication activity. Based on mini-genome assay, NS3 had pronounced effects on viral replication machinery. Surprisingly, NS3 retained an interaction with PKR and suppressed PKR activation despite its lack of amino-acid residues 126-167. The poor replication ability of RG-AIV-T375G was partially restored in cells deficient in PKR suggesting that full-length NS1 may be insufficient to suppress PKR function. Notably, virulence of the full-length NS1-expressing RG-AIV-T375G virus was highly attenuated in mice when compared to RG-AIV-NS3. In summary, our study reveals the existence and function of a previously unidentified H5N2 viral protein, NS3. We found that NS3 is functionally distinct from NS1 protein, as it enhances viral replication and pathogenicity in mammalian systems, potentially via suppression of PKR activity.

Taohe Chengqi Tang ameliorates acute liver injury induced by carbon tetrachloride in rats.

OBJECTIVE: To clarify the efficacy of Taohe Chengqi Tang (THCQT), a compound traditional Chinese herbal medicine, in protecting liver damage induced by carbon tetrachloride (CCl(4)) in rats. METHODS: Thirty male Wistar rats were divided into normal control group, untreated group, low-dose THCQT group (receiving 0.3 g/kg of THCQT), high-dose THCQT group (receiving 0.5 g/kg of THCQT), and positive control group (receiving silymarin 25 mg/kg). All testing substances were orally administered 1 hour before the intraperitoneal injection of CCl(4) (1.5 mL/kg). Twenty-four hours after CCl(4) injection, the rats were sacrificed to observe liver histopathological changes, and to evaluate activities of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and lipid peroxidation (LPO) and glutathione (GSH) levels in liver tissues. RESULTS: CCl(4) injection elevated the serum AST and ALT activities, but THCQT significantly reversed this effect. The increase of hepatic LPO by CCl(4) was markedly reduced by THCQT. Also, this herbal mixture increased hepatic GSH in the rats. In histopathology analysis, THCQT decreased the fatty accumulation, necrosis and lymphocyte infiltration. The in vitro study in rat brain showed that LPO induced by Fe(2+)/ascorbic acid was dose-dependently reduced by THCQT. According to the biochemical and morphological data, THCQT could protect the liver from CCl(4-)induced injuries. CONCLUSION: THCQT seems helpful for protection of liver damage induced by chemicals depending on its anti-oxidant-like function, and THCQT is more effective than silymarin.

Outcomes of emergency treatment in ruptured hepatocellular carcinoma in the ED.

The choice of emergency treatment of ruptured hepatocellular carcinoma (HCC) remains controversial. This study analyzed the prognostic factors for ruptured HCC seen in an ED. Patients were retrospectively classified into survival and mortality groups. Fifty-five patients were enrolled into this study, and the hospital mortality rate was 38.2%. There were no associations of clinical presentation, tumor characteristics, and emergency treatment method with patients' prognoses. Significantly higher mortality rate was noted in patients with poor liver function. The time between admission and emergency chemoembolization was significantly shorter in the mortality group than in the survival group (mean, 255 vs 394 minutes). The 1-month survival rate was 69% in patients who received conservative treatment and 59% in patients who underwent emergency chemoembolization. Routine emergency chemoembolization did not improve outcome and was associated with higher mortality and complication rates, especially in patients with poor liver function. Conservative therapy may be a preferable option for patients with ruptured HCC if they have baseline poor liver function.