Calcium-catalysed synthesis of amines through imine hydrosilylation: an experimental and theoretical study.

A method to reduce aldimines through hydrosilylation is reported. The catalytic system involves calcium triflimide (Ca(NTf2)2) and potassium hexafluorophosphate (KPF6) which have been shown to act in a synergistic manner. The expected amines are obtained in fair to very high yields (40-99%) under mild conditions (room temperature in most cases). To illustrate the potential of this method, a bioactive molecule with antifungal properties was prepared on the gram scale and in high yield in environmentally friendly 2-methyltetrahydrofuran. Moreover, it is shown in this example that the imine can be prepared in situ from the aldehyde and the amine without isolating the imine. The mechanism involved has been explored experimentally and through DFT calculations, and the results are in accordance with an electrophilic activation of the silane by the calcium catalyst.

Early-onset Neovascular Inflammatory Vitreoretinopathy Due to Two de Novo CAPN5 Mutations in Chinese Patients: A Case Series.

PURPOSE: To explore the clinical and molecular characteristics, diagnosis, and treatment of early-onset autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV) in Chinese patients. METHODS: A retrospective, interventional case series was assembled from three ADNIV patients. RESULTS: The three ADNIV cases harbored de novo CAPN5 mutations (p.Arg289Trp and p.Leu73Val). The ages of onset ranged from 11 months to 2 years. All the cases presented with vitreous opacity and subretinal inflammatory exudations. During the postoperative follow-up, all the patients manifested with exaggerated postoperative inflammatory responses. An intravitreal Ozurdex injection could not effectively control ocular inflammation in ADNIV. Laser spots after panretinal photocoagulation were partly visible. CONCLUSIONS: Two de novo CAPN5 mutations (p.Leu73Val and p.Arg289Trp) could cause early-onset ADNIV. Panretinal photocoagulation during vitrectomy and an intravitreal Ozurdex injection could not significantly stop the progression of subretinal exudations and ocular inflammation in early-onset ADNIV patients.

Intraoperative Perfluorocarbon Liquid Tamponade Technique for Treatment of Extensive Retinal Detachment Secondary to a Myopic Macular Hole.

BACKGROUND/PURPOSE: To report an intraoperative perfluorocarbon liquid (PFCL) tamponade technique in treating extensive retinal detachment secondary to a myopic macular hole (MH) through pars plana vitrectomy. METHODS: The technique was applied in nine eyes with MH-RD extending two quadrants or more areas. The procedures for pars plana vitrectomy included: 1). thorough drainage of subretinal fluid through the MH with fluid-air exchange; 2). PFCL tamponade on the macular area for more than 10 minutes; and 3). repairing the MH after PFCL was removed. RESULTS: All nine eyes gained intraoperative retinal reattachment after PFCL tamponade for 22.22 ± 8.01 minutes and removal of PFCL. Procedures for MH closure included internal limiting membrane peeling in eight eyes, with internal limiting membrane free flap insertion (four eyes), internal limiting membrane inverted flap insertion (two eyes), or lens capsular flap transplantation (three eyes). All eyes received C3F8 tamponade. During 9.11 ± 3.89 months of follow-up, eight of the nine eyes (89%) achieved retinal reattachment and MH closure; one eye achieved anatomical success after reoperations. All eyes had vision improvement at the last follow-up. CONCLUSION: This new technique in pars plana vitrectomy may promote anatomical and functional recovery in the treatment of extensive retinal detachment secondary to a myopic MH.

Repeated intravitreal ranibizumab for reactivated retinopathy of prematurity after intravitreal ranibizumab monotherapy: vascular development analysis.

PURPOSE: To evaluate the retinal vascularization of repeated intravitreal ranibizumab (IVR) for reactivated retinopathy of prematurity (ROP) treated with IVR monotherapy. METHODS: The retrospective study reviewed ROP infants who accepted IVR injection as the first treatment in our department from January 2017 to December 2018. The ratio of the distance from the center of the optic disc to the border of the vascularized zone (DB) to the distance from the center of the disc to the fovea (DF) was used for the vascular outgrowth analysis. RESULTS: Seventy-eight infants were included in the study. A total of 54.3% of the reactivated ROP patients could achieve complete vascularization after repeated IVR injections. Gestational age (GA) > 29 weeks and a temporal DB/DF ratio ≥ 3 in the first IVR were potential predictors for complete retinal vascularization after IVR monotherapy. The temporal DB/DF ratio ≥ 3.6 in the second IVR injection was a potential predictor for complete retinal vascularization after repeated IVR for ROP reactivation. CONCLUSIONS: Reactivated ROP after IVR monotherapy can be treated successfully with repeated IVR injections. GA and temporal DB/DF ratio are potential predictors of complete retinal vascularization in ROP infants treated with IVR.

Competing endogenous RNA network associated with oxygen-induced retinopathy: Expression of the network and identification of the MALAT1/miR-124-3p/EGR1 regulatory axis.

Retinopathy of prematurity (ROP) is a severe retinal dysfunction in prematurely born babies. The relationship between non-coding RNAs and retinopathy of prematurity (ROP) remain unclear. Microarray analysis of lncRNAs, miRNAs, and mRNAs was conducted in a mouse model of ROP. A competing endogenous RNA (ceRNA) network was constructed. The relationship among MALAT1, miR-124-3p, and Early growth response protein 1 (EGR1) was assessed in hypoxia-induced primary human umbilical vein endothelial cells (HUVECs) and ROP mouse model. In the study, we found 2252 lncRNAs, 1239 mRNAs, and 36 miRNAs were differentially regulated. ceRNA network consisting of 21 lncRNAs, 10 miRNAs, and 19 mRNAs was established. Of the most down-regulated miRNAs, miR-124-3p was selected for additional study. miR-124-3p ceased the migration and proliferation of primary HUVECs in hypoxic conditions, and directly suppressed EGR1. Additionally, MALAT1 directly sponged miR-124-3p. Knockdown of MALAT1 decreased EGR1 expression and inhibited the migration and proliferation of primary HUVECs in hypoxia. Furthermore, these changes were rescued by depletion of miR-124-3p. In vivo, intravitreal injection of miR-124-3p, shMALAT1 decreased EGR1 expression and markedly suppressed retinal neovascularization in OIR models. Intravitreal injection of shMALAT1 and miR-124-3p antagomir at the same time can promote retinal neovascularization, which reversed the suppression of retinal neovascularization functioned by shMALAT1. In conclusion, the expression profiles of lncRNAs and miRNAs and the ceRNA network in a mouse model of ROP may be indicative of the underlying mechanisms of retinal angiogenesis and neural activity. The MALAT1/miR-124-3p/EGR1 regulatory axis is partly responsible for retinal neovascularization, which may provide a novel theoretical basis for the pathogenesis of ROP.

A lactam-functionalized copper bent diisophthalate framework displaying significantly enhanced adsorption of CO2 and C2H2 over CH4.

The design and construction of porous materials for high-efficient adsorption-based separation of CH4 from C2H2 and CO2 is a fundamental goal in the chemical industry. In this work, a lactam-functionalized bent diisophthalate linker, 5,5'-(1-methylpyridin-2(1H)-one-3,5-diyl) diisophthalic acid, was judiciously designed and utilized to construct a dicopper paddlewheel-based MOF under solvothermal conditions. Single-crystal X-ray diffraction revealed that the resulting solid is a three-dimensional mfj-type network incorporating Lewis-acidic copper sites and accessible lactam groups as two different kinds of functional sites. Furthermore, gas adsorption studies indicated that the material exhibited great promise for C2H2/CH4 and CO2/CH4 separations. In particular, compared to the unmodified parent compound, the resultant MOF exhibits 9.4% and 12.9% higher C2H2 and CO2 uptake capacities and 48.0% and 28.3% higher C2H2/CH4 and CO2/CH4 adsorption selectivities for the equimolar gas mixtures at 298 K and 1 atm, despite the lower specific surface area and pore volume. This work reported the first lactam-functionalized MOF displaying significantly enhanced adsorption of CO2 and C2H2 over CH4.

Diagnosis of complicated FEVR preoperatively and intra-/post-operatively: characteristics and risk factors for diagnostic timing.

BACKGROUND: To delineate the characteristics of complicated familial exudative vitreoretinopathy (FEVR) patients diagnosed before surgery or intra-/post-operatively and to analyze the risk factors for the diagnostic timing. METHODS: Forty-eight patients who underwent surgery and were diagnosed as FEVR in our department were retrospectively reviewed. Data were collected including the demographic and clinical characteristics of these patients. FEVR patients were divided into 2 groups according to the diagnostic timing: FEVR diagnosed pre-operatively (23 patients), FEVR diagnosed intra-/post-operatively (25 patients). Multivariable analysis was applied for analyzing the risk factors for diagnostic timing. RESULTS: The clinical characteristics of the FEVR patients were of great variability, including retinal detachment (RD), disappear of anterior chamber, retrolental membrane, epiretinal membrane (ERM), vitreous hemorrhage (VH), myopic foveoschisis (MF), lamellar macular hole (LMH), high myopia (HM). And the referral diagnosis or pre-operative diagnosis were always non-specific. The majority of the referral or preoperative diagnosis were unilateral RD (52.1%), bilateral RD (8.3%), unilateral persistent fetal vasculature (PFV) (8.3%), bilateral PFV (4.2%). There are two risk factors for the complicated FEVR cases diagnosed as FEVR preoperatively: pre-operative ocular manifestations with RD only (OR, 0.104; p-value, 0.022), positive parent's fluorescein angiography (FA) (OR, 0.105; p-value, 0.035). CONCLUSIONS: The phenotypes of FEVR were greatly variable, they can mimic many non-specific vitreoretinal disorders. The most non-specific referral diagnosis/pre-operative diagnosis was unilateral RD, bilateral RD, unilateral PFV, bilateral PFV. A positive family history or a simple ocular presentation with RD only could contribute to diagnose FEVR preoperatively.

Visual and morphological outcomes of vitreomacular traction syndrome in retinitis pigmentosa treated by vitrectomy.

Retrospective review of 13 eyes that had undergone pars plana vitrectomy (PPV) for vitreomacular traction (VMT) syndrome in retinitis pigmentosa (RP) and had a postoperative follow-up period ≥9mo in order to evaluate whether it is necessary to treat VMT in RP by vitrectomy. The 13 RP eyes suffering from VMT were evaluated by means of best corrected visual acuity (BCVA), anterior and posterior binocular examination, spectral-domain optical coherence tomography (SD-OCT) before and after operation. We detected that although vitrectomy could improve the macular morphology in some RP patients with VMT, visual outcomes might be limited and unpredicted most likely because of the long-standing retinal dysfunction, but the vitrectomy is necessary in order to remain or improve the central vision in some cases.

Downregulation of HDAC9 inhibits cell proliferation and tumor formation by inducing cell cycle arrest in retinoblastoma.

Histone deacetylase 9 (HDAC9) is a member of class II HDACs, which regulates a wide variety of normal and abnormal physiological functions. Recently, HDAC9 has been found to be overexpressed in some types of human cancers. However, the role of HDAC9 in retinoblastoma remains unclear. In this study, we found that HDAC9 was commonly expressed in retinoblastoma tissues and HDAC9 was overexpressed in prognostically poor retinoblastoma patients. Through knocking down HDAC9 in Y79 and WERI-Rb-1 cells, the expression level of HDAC9 was found to be positively related to cell proliferation in vitro. Further investigation indicated that knockdown HDAC9 could significantly induce cell cycle arrest at G1 phase in retinoblastoma cells. Western blot assay showed downregulation of HDAC9 could significantly decrease cyclin E2 and CDK2 expression. Lastly, xenograft study in nude mice showed that downregulation of HDAC9 inhibited tumor growth and development in vivo. Therefore, our results suggest that HDAC9 could serve as a novel potential therapeutic target in the treatment of retinoblastoma.

Hydrothermal conversion of one-photon-fluorescent poly(4-vinylpyridine) into two-photon-fluorescent carbon nanodots.

A novel two-photon-fluorescent N,O-heteroatom-rich carbon nanomaterial has been synthesized and characterized. The new carbon nanoparticles were produced by hydrothermal conversion from a one-photon-fluorescent poly(4-vinylpyridine) precursor (P4VP). The carbonized particles (cP4VP dots) with nonuniform particle diameter (ranging from sub-6 to 20 nm with some aggregates up to 200 nm) exhibit strong fluorescence properties in different solvents and have also been investigated for applications in cell culture media. The cP4VP dots retain their intrinsic fluorescence in a cellular environment and exhibit an average excited-state lifetime of 2.0 ± 0.9 ns in the cell. The cP4VP dots enter HeLa cells and do not cause significant damage to outer cell membranes. They provide one-photon or two-photon fluorescent synthetic scaffolds for imaging applications and/or drug delivery.

Hydrothermal core-shell carbon nanoparticle films: thinning the shell leads to dramatic pH response.

Carbon nanoparticles with phenylsulfonate negative surface functionality (Emperor 2000, Cabot Corp.) are coated with positive chitosan followed by hydrothermal carbonization to give highly pH-responsive core-shell nanocarbon composite materials. With optimised core-shell ratio (resulting in an average shell thickness of ca. 4 nm, estimated from SANS data) modified electrodes exhibit highly pH-sensitive resistance, capacitance, and Faradaic electron transfer responses (solution based, covalently bound, or hydrothermally embedded). A shell "double layer exclusion" mechanism is discussed to explain the observed pH switching effects. Based on this mechanism, a broader range of future applications of responsive core-shell nanoparticles are envisaged.