Rhenium-Loaded TiO2 : A Highly Versatile and Chemoselective Catalyst for the Hydrogenation of Carboxylic Acid Derivatives and the N-Methylation of Amines Using H2 and CO2.

Herein, we report a heterogeneous TiO2 -supported Re catalyst (Re/TiO2 ) that promotes various selective hydrogenation reactions, which includes the hydrogenation of esters to alcohols, the hydrogenation of amides to amines, and the N-methylation of amines, by using H2 and CO2 . Initially, Re/TiO2 was evaluated in the context of the selective hydrogenation of 3-phenylpropionic acid methyl ester to afford 3-phenylpropanol (pH2 =5 MPa, T=180 °C), which revealed a superior performance over other catalysts that we tested in this study. In contrast to other typical heterogeneous catalysts, hydrogenation reactions with Re/TiO2 did not produce dearomatized byproducts. DFT studies suggested that the high selectivity for the formation of alcohols in favor of the hydrogenation of aromatic rings is ascribed to the higher affinity of Re towards the COOCH3 group than to the benzene ring. Moreover, Re/TiO2 showed a wide substrate scope for the hydrogenation reaction (19 examples). Subsequently, this Re/TiO2 catalyst was applied to the hydrogenation of amides, the N-methylation of amines, and the N-alkylation of amines with carboxylic acids or esters.

Ultrathin inorganic molecular nanowire based on polyoxometalates.

The development of metal oxide-based molecular wires is important for fundamental research and potential practical applications. However, examples of these materials are rare. Here we report an all-inorganic transition metal oxide molecular wire prepared by disassembly of larger crystals. The wires are comprised of molybdenum(VI) with either tellurium(IV) or selenium(IV): {(NH4)2[XMo6O21]}n (X=tellurium(IV) or selenium(IV)). The ultrathin molecular nanowires with widths of 1.2 nm grow to micrometre-scale crystals and are characterized by single-crystal X-ray analysis, Rietveld analysis, scanning electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, thermal analysis and elemental analysis. The crystals can be disassembled into individual molecular wires through cation exchange and subsequent ultrasound treatment, as visualized by atomic force microscopy and transmission electron microscopy. The ultrathin molecular wire-based material exhibits high activity as an acid catalyst, and the band gap of the molecular wire-based crystal is tunable by heat treatment.

A high-temperature in situ cell with a large solid angle for fluorescence X-ray absorption fine structure measurement.

We present the design and performance of a high-temperature in situ cell with a large solid angle for fluorescence X-ray absorption fine structure (XAFS) spectra. The cell has a large fluorescence XAFS window (116 mm(ϕ)) near the sample in the cell, realizing a large half-cone angle of 56°. We use a small heater (25 × 35 mm(2)) to heat the sample locally to 873 K. We measured a Pt-SnO2 thin layer on a Si substrate at reaction conditions having a high activity. In situ measurement enables the analysis of the difference XAFS spectra between before and during the reaction to reveal the structure change during the operation.

A new spectroelectrochemical cell for in situ measurement of Pt and Au K-edge X-ray absorption fine structure.

A new spectroelectrochemical cell to investigate the structure of Pt/Au nanoclusters using Pt and Au K-edge X-ray absorption fine structure (XAFS) measurements under the electrochemical conditions is developed. K-edge XAFS measurements for Pt and Au require a sample as thick as 1-2 cm, which prevents homogeneous potential distribution. We can measure in situ Pt and Au K-edge XAFS spectra and determine reasonable electrochemical surface areas using our developed spectroelectrochemical cell. This work provides a new approach to analyze Pt/Au core-shell nanoclusters. The new cell is designed to be applied to both spectra with high absorption-edge energies such as the K-edge of Pt and Au and those with low absorption-edge energy such as Pt L-edge.

Preparation and structure of a single Au atom on the TiO2(110) surface: control of the Au-metal oxide surface interaction.

Three-dimensional Au structures on bare and organic-compound-modified TiO2(110) surfaces were interrogated by Au L3-edge polarization dependent total reflection fluorescence X-ray absorption fine structure (PTRF-XAFS) spectroscopy. On the bare TiO2(110) surface, icosahedral Au55 nanoclusters were the main product found. When the surfaces were modified with ortho or meso mercaptobenzoic acid (o-MBA or m-MBA), Au was atomically dispersed. Sulfur atoms in the o- and m- MBA formed strong covalent bonds with Au to produce stable Au-MBA (o- and m- forms) surface complexes. On the other hand, only oxygen atoms on the surface did not make a strong enough interaction to stabilize the Au species. We discuss how the Au species formed on the modified TiO2(110) surface and the possibility to control the Au structure by the surface modification method.

Fine tuning and orientation control of surface Cu complexes on TiO2(110) premodified with mercapto compounds: the effect of different mercapto group positions.

Three-dimensional structures of vacuum-deposited Cu species formed on TiO2(110) surfaces premodified with three mercaptobenzoic acid (MBA) isomers were studied using polarization-dependent total reflection fluorescence X-ray absorption fine structure (PTRF-XAFS). We explored the possibility of fine tuning and orientation control of the surface Cu structures, including their coordination and configuration against the surface, according to the different mercapto group positions of the three MBA isomers (o-, m-, and p-MBA). Almost linear S-Cu-O (lattice O of TiO2) surface compounds were formed on the three MBA-modified TiO2(110) surfaces; however, the orientation of the Cu species on the o- and m-MBA-modified TiO2(110) surfaces (40-45° inclined from the surface normal) was different from that on the p-MBA-modified TiO2(110) surface (60° from the surface normal). This work suggests that the selection of a different MBA isomer for premodification of a single crystal TiO2(110) surface enables fine tuning and orientation control of surface Cu complexes.

One-year results of three monthly ranibizumab injections and as-needed reinjections for polypoidal choroidal vasculopathy in Japanese patients.

PURPOSE: To investigate the 1-year outcomes of monthly intravitreal injections of ranibizumab for 3 months followed by an as-needed reinjection schedule to treat polypoidal choroidal vasculopathy (PCV) in Japanese patients. DESIGN: Prospective, consecutive case series. METHODS: Eighty-five eyes of 82 consecutive Japanese patients with naïve symptomatic PCV received monthly intravitreal injections of ranibizumab for 3 months followed by an as-needed reinjection schedule. Eighty-one eyes (95%) followed for 1 year were studied. RESULTS: A mean of 4.2 ± 1.3 (mean ± standard deviation) injections were administered over 1 year. Twenty-three of 81 eyes (28%) did not require additional injections and 32 eyes (40%) required only 1 injection after the 3 monthly injections. The mean (± standard error) logarithm of minimal angle of resolution (logMAR) visual acuity (VA) at baseline was 0.59 ± 0.37 and improved to 0.37 ± 0.30 (P = .001). Thirty eyes (37%) and 5 eyes (6%), respectively, had improved and decreased VA of 0.3 or more logMAR unit. Indocyanine green angiography showed that the polypoidal lesions resolved in 21 eyes (26%) and 32 eyes (40%) 3 months and 1 year after the first injection, respectively. Abnormal choroidal vessels remained in all eyes. CONCLUSIONS: Monthly injections of ranibizumab for 3 months to treat PCV improved the VA, and a reinjection schedule based on need maintained the improved VA. The polypoidal lesions tended to improve over 1 year, whereas abnormal choroidal vessels remained in all eyes. Further long-term follow-up is needed to determine the efficacy of ranibizumab therapy for PCV.

Incidence of retinal breaks in eyes undergoing 23-gauge or 20-gauge vitrectomy with induction of posterior vitreous detachment.

PURPOSE: To compare the incidence rates of retinal breaks in eyes in which posterior vitreous detachment was induced during 23-gauge and 20-gauge vitrectomies to treat macular holes or preretinal membranes. METHODS: We retrospectively reviewed 122 eyes of 115 patients with a macular hole or preretinal membrane who underwent induction of posterior vitreous detachment during 23-gauge vitrectomy (23-gauge group) and 61 eyes of 58 consecutive patients with the disorders who underwent induction of posterior vitreous detachment during 20-gauge vitrectomy performed by 1 surgeon. RESULTS: No difference was found in the incidence rates of intraoperative retinal breaks between the 23-gauge (16% [20/122]) and 20-gauge (16% [10/61]) groups. A postoperative rhegmatogenous retinal detachment developed in 2 (2%) eyes in the 23-gauge group, whereas no eyes in the 20-gauge group had postoperative retinal breaks or rhegmatogenous retinal detachment. The incidence rates of retinal breaks in eyes with a macular hole and preretinal membrane did not differ significantly. CONCLUSION: Posterior vitreous detachment induced during vitrectomy frequently results in intraoperative retinal breaks, the incidence of which may be independent of the gauge of the vitreous instruments. Surgeons should be alert to the development of retinal breaks.

Surgical outcomes of 23- and 20-gauge vitrectomies for rhegmatogenous retinal detachment associated with posterior vitreous detachment.

BACKGROUND AND OBJECTIVE: To compare the outcomes of 23- and 20-gauge vitrectomies 1 year after primary repair of rhegmatogenous retinal detachments (RRDs) associated with a posterior vitreous detachment (PVD). PATIENTS AND METHODS: One hundred seventy-five consecutive eyes were reviewed that had undergone 23- or 20-gauge vitrectomy for RRDs associated with PVD. RESULTS: Retinal reattachment during the year after the first vitrectomy occurred in 88 (91%) of 97 eyes in the 23-gauge group and 70 (90%) of 78 eyes in the 20-gauge group. All eyes in both groups achieved anatomic success after another procedure. The surgical time in the 23-gauge group was significantly (P = .03) shorter than in the 20-gauge group. No significant difference was found between the preoperative and postoperative visual acuities in both groups. CONCLUSION: Twenty-three-gauge vitrectomy can obtain anatomic and visual acuity results similar to those obtained with 20-gauge vitrectomy after primary repair of RRDs and may be a surgical option for treating the disorder.

23- and 20-gauge vitrectomy with air tamponade with combined phacoemulsification for idiopathic macular hole: a single-surgeon study.

PURPOSE: To compare the results of 23- and 20-gauge vitrectomies combined with phacoemulsification and aspiration and intraocular lens implantation (phacoemulsification surgery) 1 year after repair of idiopathic macular holes. DESIGN: Retrospective, consecutive, comparative case series. METHODS: The medical charts of 100 consecutive eyes were reviewed that had undergone either 23- or 20-gauge vitrectomy combined with phacoemulsification surgery to treat an idiopathic macular hole performed by 1 surgeon. The rate of improvement of the logarithm of the minimal angle of resolution visual acuity (VA) was calculated using the formula: (postoperative value - preoperative value) × 100/(1-year postoperative value - preoperative value). RESULTS: The macular holes closed successfully after the primary vitrectomy in all eyes in both groups. Although the VAs did not differ significantly before surgery or 1 year after surgery between the 2 groups, the VA improvement was significantly greater 1 and 3 months after surgery (P = .02, for both) in the 23-gauge group compared with the 20-gauge group. The induced corneal astigmatism levels 1 week and 1 and 3 months after surgery were significantly lower (P = .01, P = .01, and P = .03, respectively) and the surgical time was significantly shorter (P = .01) in the 23-gauge group than in the 20-gauge group. No apparent complications developed in either group. CONCLUSIONS: Since 23-gauge vitrectomy combined with phacoemulsification surgery is advantageous because the VA improved rapidly after treating the macular holes with an acceptable safety profile, idiopathic macular holes are a good indication for 23-gauge vitrectomy combined with phacoemulsification surgery.

Factors predictive of visual acuity outcomes 1 year after photodynamic therapy in Japanese patients with polypoidal choroidal vasculopathy.

PURPOSE: The purpose of this study was to determine the factors predictive of visual acuity (VA) outcomes 1 year after photodynamic therapy (PDT) for polypoidal choroidal vasculopathy. METHODS: We prospectively studied 220 eyes of 210 Japanese patients with polypoidal choroidal vasculopathy treated with primary application of PDT. A stepwise logistic regression model was used to estimate the independent factors predictive of better VA and improvement of VA 1 year after the primary PDT. RESULTS: Visual acuities at the various follow-up evaluations improved significantly compared with baseline (P = 0.001 for all comparisons). The VA improved and decreased more than 0.3 logarithm of minimum angle of resolution unit 1 year after the primary PDT in 55 (25%) and 21 (10%) eyes, respectively. Stepwise logistic regression analysis showed that younger age, smaller greatest linear dimension, better baseline VA, and less baseline hemorrhage were significant and independent factors predictive of better VA 1 year after PDT, and younger age, smaller greatest linear dimension, better baseline VA, less hemorrhaging, and the presence of a serous macular detachment at baseline were significant and independent factors predictive of VA improvement. CONCLUSION: Photodynamic therapy stabilized eyes anatomically and functionally. Clinical characteristics at baseline were predictors of favorable VA outcomes after PDT. These findings may help establish the strategy of treatment for polypoidal choroidal vasculopathy.

Improvement of angiographic findings of polypoidal choroidal vasculopathy after intravitreal injection of ranibizumab monthly for 3 months.

PURPOSE: To evaluate the efficacy of 1 intravitreal injection of ranibizumab monthly for 3 months in eyes with polypoidal choroidal vasculopathy (PCV), with attention to changes on indocyanine green angiography (ICGA) with confocal scanning laser ophthalmoscopy (cSLO). DESIGN: Prospective, consecutive case series. METHODS: Fifty consecutive eyes of 50 patients with symptomatic PCV who had not been treated previously received 1 intravitreal injection of 0.5 mg ranibizumab monthly for 3 months. Changes in ICGA findings with cSLO 3 months after the primary injection were evaluated. RESULTS: The mean visual acuity (VA) at baseline (0.25; range, 0.1-0.8) improved to 0.38 (P = .001) 3 months after the primary injection. Nineteen eyes (38%) had an improvement in VA of 0.3 or more logMAR unit, and 5 eyes (10%) had a decrease in VA of 0.3 or more logMAR unit. Polypoidal lesions disappeared on ICGA in 13 eyes (26%) and the number of lesions decreased but did not disappear in 26 eyes (52%), with absorption of the accompanying fluid on optical coherence tomography. The remaining 11 eyes (22%) had unchanged or worsened polypoidal lesions. A branching vascular network remained in all 48 eyes in which the network was detected at baseline. Although resolution of the branching vascular networks or decreased diameter of the branching vascular network occurred in 11 eyes (23%), the branching vascular network was unchanged or worse in 37 eyes (77%). CONCLUSION: Although a limitation of this study is the short-term follow-up, polypoidal lesions tended to respond to ranibizumab therapy, but the branching vascular network responded poorly.

Surface-mediated visible-light photo-oxidation on pure TiO(2)(001).

We used STM to observe visible light photo-oxidation reactions of formic acid on the ordered lattice-work structure of a TiO(2)(001) surface for the first time. The nanostructured surface makes the band gap significantly smaller than 3.0 eV only at the surface layer, and the surface state of the crystal enables a visible light response.

Comparison of one-year outcomes between 23- and 20-gauge vitrectomy for preretinal membrane.

PURPOSE: To compare the outcomes of transconjunctival sutureless 23-gauge vitrectomy and conventional 20-gauge vitrectomy 1 year after removal of preretinal membrane. DESIGN: Retrospective, consecutive, comparative case series. METHODS: One hundred consecutive eyes with a preretinal membrane underwent either 23- and 20-gauge vitrectomy. The rate of improvement of the logarithm minimum angle of resolution visual acuity (VA) was calculated by the formula: (various postoperative values-preoperative values) x 100/ (1 year postoperative values-preoperative values). RESULTS: No significant differences were found between the groups in the preoperative and postoperative VAs. The VA improvement was higher and the surgically induced corneal astigmatism was lower 1 week postoperatively in the 23-gauge group compared with the 20-gauge group (P = .006 and P = .001, respectively). The flare values in the anterior chamber measured by laser flare meter preoperatively and 1 week postoperatively did not differ between the groups. The surgical time was significantly (P = .023) shorter in the 23-gauge group than in the 20-gauge group. No apparent complications developed in either group. CONCLUSION: Transconjunctival sutureless 23-gauge vitrectomy appears effective for preretinal membrane surgery with an acceptable safety profile. Transconjunctival sutureless 23-gauge vitrectomy may be a treatment option for preretinal membranes.

Causes of macular serous retinal detachments in Japanese patients 40 years and older.

PURPOSE: To investigate the causes of macular serous retinal detachment without hemorrhage at the macula in patients 40 years and older. METHODS: Seventy-one eyes of 71 consecutive Japanese patients 40 years and older with the disease were examined using optical coherence tomography, digital simultaneous fluorescein and indocyanine green angiographies with a confocal laser scanning system. RESULTS: Of 71 eyes, 17 eyes (24%) had central serous chorioretinopathy, including three eyes with chronic central serous chorioretinopathy, 40 eyes (56%) had polypoidal choroidal vasculopathy (PCV), 10 eyes (14%) had occult choroidal neovascularization secondary to age-related macular degeneration, one had Harada disease, and another had retinal macroaneurysms. In two eyes, the diagnosis could not be established because of difficulty differentiating among chronic central serous chorioretinopathy, PCV, and occult choroidal neovascularization. Thirty-eight of 59 (64%) eyes of patients in the sixth decade of life and older had PCV. CONCLUSIONS: Polypoidal choroidal vasculopathy is a primary cause of macular serous retinal detachment without hemorrhage in Japanese patients over 50 years of age. Since clinical and fluorescein angiographic findings are indistinguishable among central serous chorioretinopathy, PCV, and occult choroidal neovascularization, indocyanine green angiography might help to establish a more definitive diagnosis.

[Combined intravitreal triamcinolone and photodynamic therapy for retinal angiomatous proliferation after photodynamic therapy].

PURPOSE: To investigate the 1-year results of treatment for retinal angiomatous proliferation (RAP), especially focused on the combination therapy of intravitreal injection of tiamcinolone acetonide with photodynamic therapy (IVTA-PDT). METHODS: Between July 2004 and July 2005, IVTA-PDT was performed in 7 patients (9 eyes) with RAP at the Ohtsuka Eye Hospital. We reviewed the records of 4 of these patients (5 eyes) who had received IVTA-PDT during follow-up. RESULTS: PDT was effective in only 1 of the 9 eyes. During IVTA-PDT, leakage from neovascularization was observed on angiography, and retinal edema and retinal pigment epithelial detachment (RPED) were observed on optical coherence tomography (OCT), even though PDT had been performed several times in all 5 eyes receiving IVTA-PDT. Complete resolution of angiographic leakage and improvement of retinal edema and RPED were observed at the examination 3 months after IVTA-PDT. At 1 year after IVTA-PDT, the fundus findings remained stable in 4 eyes, but angiographic leakage and RPED had progressed slightly in one eye. Visual acuity 1 year after IVTA had decreased compared with that at the primary PDT, but was almost the same as that at the beginning of IVTA-PDT. CONCLUSIONS: IVTA-PDT for eyes with RAP, in which PDT had been performed several times, may be effective for improvement or elimination of retinal edema, achieving rapid regression of neovascularization, and stabilizing visual acuity.

Improvement of visual acuity one-year after vitreous surgery in eyes with residual triamcinolone acetonide at the macular hole.

PURPOSE: To investigate whether triamcinolone acetonide in the macular hole after surgery interferes with anatomic macular hole repair or visual acuity improvement. DESIGN: Prospective, interventional case series with historical comparison. METHODS: Pars plana vitrectomy and triamcinolone acetonide-assisted internal limiting membrane peeling were performed in 26 eyes (24 patients) with stage 3 or 4 idiopathic macular hole. The visual acuities one-year after surgery were compared between eyes with and without residual triamcinolone acetonide after surgery. RESULTS: The macular holes were closed successfully in all 26 eyes. Nine eyes (35%) had residual triamcinolone acetonide in the macular hole at the end of the surgery and in the fovea on day 3 after surgery. The mean preoperative logarithm of the minimum angle of resolution (logMAR) visual acuity +/- standard deviation was 0.73 +/- 0.36 and improved significantly to 0.20 +/- 0.29 one-year after surgery (P = .010). In the nine eyes with residual triamcinolone acetonide, the preoperative mean logMAR triamcinolone acetonide was 0.81 +/- 0.33, which improved to 0.20 +/- 0.19 one-year after surgery (P = .013). In the remaining 17 eyes, the mean visual acuity also improved from 0.71 +/- 0.38 before surgery to 0.21 +/- 0.28 after surgery (P = .001). No significant difference was found between the groups in preoperative and postoperative logMAR visual acuities. CONCLUSIONS: Residual triamcinolone acetonide in the macular hole does not interfere with anatomic or visual improvement.