A H2O2 Oxidation Approach to Ti3C2/TiO2 for Efficient Photocatalytic Removal of Distinct Organic Pollutants in Water.

To develop versatile photocatalysts for efficient degradation of distinct organic pollutants in water is a continuous pursuit in environment remediation. Herein, we directly oxidize Ti3C2 MXene with hydrogen peroxide to produce C-doped anatase TiO2 nanowires with aggregates maintaining a layered architecture of the MXene. The Ti3C2 MXene provides a titanium source for TiO2, a carbon source for in situ C-doping, and templates for nanowire aggregates. Under UV light illumination, the optimized Ti3C2/TiO2 exhibits a reaction rate constant 1.5 times that of the benchmark P25 TiO2 nanoparticles, toward photocatalytic degradations of trace phenol in water. The mechanism study suggests that photogenerated holes play key roles on the phenol degradation, either directly oxidizing phenol molecules or in an indirect way through oxidizing first the surface hydroxyl groups. The unreacted Ti3C2 MXene, although with trace amounts, is supposed to facilitate electron transfer, which inhibits charge recombination. The unique nanostructure of layered aggregates of nanowires, abundant surface oxygen vacancies arising from the carbon doping, and probably the Ti3C2/TiO2 heterojunction guarantee the high photocatalytic efficiency toward removals of organic pollutants in water. The photocatalyst also exhibits an activity superior to, or at least comparable to, the benchmark P25 TiO2 toward photodegradations for typical persistent organic pollutants of phenol, dye molecule of rhodamine B, antibiotic of tetracycline, pharmaceutical wastewater of ofloxacin, and pesticide of N,N-dimethylformamide, when evaluated in total organic carbon removal.

Genetic factors for idiopathic choroidal neovascularization.

Objective: The aim of this study was to investigate genetic factors associated with idiopathic choroidal neovascularization (ICNV). Methods: We conducted a case-control study including 69 cases with ICNV and 114 controls who underwent cataract surgery. Single nucleotide polymorphisms (SNPs) from genes reported to be related to AMD, CNV and uveitis were selected for this study. Results: In an univariate analysis, the rs669676 SNP located in the COL8A1 gene was associated with the proportion of people who has idiopathic CNV ( X2 = 9.3453, corrected p-value = 0.1). For the rs669676 SNP, minor allele homozygotes, in the dominant model of genotype analysis (GG versus AA-GA), it showed significant differences in the ICNV group vs controls (p = .01, OR = 1.219 (95%CI: 1.04-1.429)). Conclusions: The rs669676 SNP located in the COL8A1 gene may contribute to a genetic susceptibility for ICNV.

CONGENITAL CONTRACTILE PERIPAPILLARY STAPHYLOMA WITH RHEGMATOGENOUS RETINAL DETACHMENT.

PURPOSE: To describe the occurrence of a congenital contractile peripapillary staphyloma in association with a rhegmatogenous retinal detachment. METHODS: The clinical course of a 17-year-old patient with a contractile peripapillary staphyloma and undergoing pars plana vitrectomy for repair of an associated retinal detachment was studied. RESULTS: The left eye showed a peripapillary staphyloma which during the ophthalmoscopical examination revealed contractile movements after the presentation of a light stimulus to either eye. The contraction of the peripapillary staphyloma was not correlated with a Valsalva maneuver, neck venous compression, forced lid closure, or respiratory movements. Because of a retinal detachment involving the inferior, nasal, and temporal retina, best-corrected visual acuity was 20/100. During pars plana vitrectomy under systemic anesthesia, the contractions of the peripapillary staphyloma subsided in the early phase of surgery, and reoccurred at approximately 80 minutes after the start of general anesthesia, when the posterior pole was touched with an aspiration syringe. CONCLUSION: The etiology of the movements of the congenital peripapillary staphyloma in our patient may include a misbalance between intraocular pressure and orbital cerebrospinal fluid pressure or contractions of extraocular muscles. The observations may give information about the physiology and pathophysiology of the optic nerve head.

Optical Coherence Tomographic Features and Visual Prognosis after Treatment for Idiopathic Choroidal Neovascularization.

BACKGROUND: The aim of this study was to determine whether pretreatment spectral-domain optical coherence tomographic (SD-OCT) features are associated with visual prognosis after treatment for idiopathic subfoveal choroidal neovascularization (ISCNV) with intravitreal ranibizumab. METHODS: We retrospectively evaluated SD-OCT images of eyes with ISCNV undergoing treatment with intravitreal ranibizumab with a mean follow-up of 7 months. RESULTS: This study included 22 patients (22 eyes) with a mean age of 32.7 ± 8.1 years. In univariate analysis, better final visual acuity expressed in logMAR units was significantly associated with a lower amount of pretreatment ellipsoid zone defects (p = 0.03; standardized correlation coefficient ß = 0.46) and a lower amount of pretreatment external limiting membrane (ELM) damage (p = 0.007; ß = 0.56). All other SD-OCT parameters were not significantly associated with final visual acuity. A higher improvement in visual acuity was marginally significantly associated with larger pretreatment ellipsoid zone defects (p = 0.049; ß = -0.43). CONCLUSIONS: The integrity of the outer retinal layers at baseline, in particular of the ELM, is of importance in predicting the final visual outcome in patients undergoing intravitreal medical therapy for ISCNV.

Choroidal thickness in idiopathic subfoveal choroidal neovascularization.

PURPOSE: To evaluate choroidal thickness in patients with idiopathic choroidal neovascularization. METHODS: The observational case series study included patients who were consecutively diagnosed with idiopathic unilateral choroidal neovascularization as demonstrated by ophthalmoscopy, fluorescein angiography and enhanced depth imaging optical coherence tomography (EDI-OCT). Using EDI-OCT, choroidal thickness was measured at the fovea and at locations in a distance of 500, 1,000 and 1,500 µm temporal and nasal to the fovea. RESULTS: Mean subfoveal choroidal thickness was significantly (p = 0.002) thicker in the study group than in the control group (357 ± 99 vs. 316 ± 83 µm). In a parallel manner, the differences between the study group and the control group in choroidal thickness were significant for all other measurement points, except for the examination at 1,500 µm nasal to the fovea (p = 0.09). The results remained unchanged after adjusting for axial length and age. CONCLUSIONS: Idiopathic unilateral choroidal neovascularization is associated with a thickening of the choroid.

Subfoveal choroidal thickness change after intravitreal ranibizumab for idiopathic choroidal neovascularization.

PURPOSE: To investigate changes in subfoveal choroidal thickness (SFCT) after intravitreal injections of ranibizumab for idiopathic subfoveal choroidal neovascularization (ISCNV). METHODS: The prospective consecutive case series study included 16 patients with unilateral ISCNV. All eyes with ISCNV were treated with a single intravitreal injection of 0.5 mg ranibizumab followed by as-needed dosing. Subfoveal choroidal thickness was measured using enhanced depth imaging optical coherence tomography. RESULTS: The mean total follow-up time was 4.9 ± 1.5 months, and the follow-up after the last intravitreal ranibizumab injection was 4.4 ± 1.3 months. In the treated eyes, the SFCT decreased significantly from 354 ± 84 µm at baseline to 328 ± 79 µm at 1 month later (P < 0.001) and reincreased (P = 0.02) to 342 ± 75 µm at the final visit (P = 0.15 versus baseline value). Change in SFCT was marginally (P = 0.11) associated with the change in retinal foveal thickness. In the contralateral unaffected eyes, the SFCT did not change significantly during follow-up (P = 0.76). CONCLUSION: In patients with unilateral ISCNV, intravitreal ranibizumab therapy was associated with a thinning of an abnormally thick subfoveal choroid, marginally in association with a parallel decrease in retinal foveal thickness. It remained elusive whether the choroidal thinning was due to a direct pharmacological effect of ranibizumab or whether it was secondary due to the foveal retinal thinning. In view of the significant differences in SFCT between affected eyes and unaffected contralateral eyes at baseline and in view of the significant therapy-associated decrease in SFCT, the potential role of SFCT as an additional marker for the diagnosis and follow-up of ISCNV and other neovascular maculopathies may be examined in future studies.