Long-term results of clear lens extraction combined with piggyback intraocular lens implantation to correct high hyperopia

<b>AIM:</b> To assess the refractive outcome of clear lensectomy combined with piggyback intraocular lens implantation in highly hyperopic patients.<b>METHODS:</b> This case review included 19 eyes of 10 patients with high hyperopia and axial length less than 21mm. Intraocular lens power was calculated for emmetropia using the Holladay II formula in 17 eyes, and SRK/T formula in 2 eyes following clear lens extraction and piggyback intraocular lens implantation. Patients were examined periodically over 24 months for visual acuity and spherical equivalent (SE).<b>RESULTS:</b> The mean postoperative SE at 24 months was 0.20±1.39D (range, -3.00 to 2.50D), better than preoperative 9.81±2.62D (range, +6.00 to +14.50D) (<i>P</i><0.001). Five eyes had SE within ±0.5D of emmetropia and 11 eyes within ±1.00D at postoperative 24 months. The mean postoperative uncorrected visual acuity (UCVA) at 24 months was 0.60±0.36, significantly improved compared to preoperative 1.39±0.33 (<i>P</i><0.001). The mean best-corrected visual acuity (BCVA) at 24 months was 0.49±0.35, not statistically different compared to preoperative 0.38±0.30 (<i>P</i>=0.34). Twelve eyes maintained and 1 gained 1 or more Snellen line of BCVA, 4 eyes lost 1 line, and 2 eyes lost 2 lines at 24 postoperative months. Twelve eyes best-corrected near visual acuity (BCNVA) achieved J1 at postoperative 24 months compared to preoperative 7 eyes and the other 7 eyes better than J3.<b>CONCLUSION:</b> Clear lens extraction combined piggyback intraocular lens implantation appears to be an effective procedure to correct high hyperopia but mild overcorrection and intralenticular opacification may require secondary procedure

Gamma rays and neutrinos from dark matter annihilation in galaxy clusters

The $\gamma$-ray and neutrino emissions from dark matter (DM) annihilation in galaxy clusters are studied. After about one year operation of Fermi-LAT, several nearby clusters are reported with stringent upper limits of GeV $\gamma$-ray emission. We use the Fermi-LAT upper limits of these clusters to constrain the DM model parameters. We find that the DM model distributed with substructures predicted in cold DM (CDM) scenario is strongly constrained by Fermi-LAT $\gamma$-ray data. Especially for the leptonic annihilation scenario which may account for the $e^{\pm}$ excesses discovered by PAMELA/Fermi-LAT/HESS, the constraint on the minimum mass of substructures is of the level $10^2-10^3$ M$_{\odot}$, which is much larger than that expected in CDM picture, but is consistent with a warm DM scenario. We further investigate the sensitivity of neutrino detections of the clusters by IceCube. It is found that neutrino detection is much more difficult than $\gamma$-rays. Only for very heavy DM ($\sim 10$ TeV) together with a considerable branching ratio to line neutrinos the neutrino sensitivity is comparable with that of $\gamma$-rays.Comment: 21 pages, 8 figures and 1 table; extended discussion about the uncertainties of concentration and subhalo models, figures replotted for better read; references updated; accepted for publication by Phys. Rev.

Learning From Biased Soft Labels

Knowledge distillation has been widely adopted in a variety of tasks and has achieved remarkable successes. Since its inception, many researchers have been intrigued by the dark knowledge hidden in the outputs of the teacher model. Recently, a study has demonstrated that knowledge distillation and label smoothing can be unified as learning from soft labels. Consequently, how to measure the effectiveness of the soft labels becomes an important question. Most existing theories have stringent constraints on the teacher model or data distribution, and many assumptions imply that the soft labels are close to the ground-truth labels. This paper studies whether biased soft labels are still effective. We present two more comprehensive indicators to measure the effectiveness of such soft labels. Based on the two indicators, we give sufficient conditions to ensure biased soft label based learners are classifier-consistent and ERM learnable. The theory is applied to three weakly-supervised frameworks. Experimental results validate that biased soft labels can also teach good students, which corroborates the soundness of the theory

(2′-Amino-4,4′-bi-1,3-thia­zol-2-aminium-κ2 N,N′)aqua­[citrato(4−)-κ3 O,O′,O′′)chromium(III) dihydrate

In the title compound, [Cr(C6H7N4S2)(C6H4O7)(H2O)]·2H2O, the CrIII atom is in a distorted octa­hedral environment, coordinated by one water mol­ecule, two N atoms from a protonated diamino­bithia­zole ligand and three O atoms from a citrate(4−) anion. The complex is zwitterionic, with the H atom from the uncoordinated carboxyl­ate group of the citrate anion transferred to one amino group of the diamino­bithia­zole ligand. O—H⋯O and N—H⋯O hydrogen bonds link the complexes into layers including the two uncoordinated water mol­ecules

N-(2-Chloro­pyrimidin-4-yl)-2-methyl-2H-indazol-6-amine methanol monosolvate

In the title compound, C12H10ClN5·CH3OH, the indazole ring system and the pyrimidine ring make a dihedral angle of 23.86 (4)°. In the crystal, the components are linked by N—H⋯O and O—H⋯N hydrogen bonds into chains propagated in [010]. Inter­molecular π–π inter­actions [centroid–centroid distances = 3.6404 (9), 3.6725 (9) and 3.4566 (9) Å] between the rings of neighbouring chains also stabilize the crystal packing

Enhanced mechanical, thermal and flame retardant properties by combining graphene nanosheets and metal hydroxide nanorods for Acrylonitrile–Butadiene–Styrene copolymer composite

Three metal hydroxide nanorods (MHR) with uniform diameters were synthesized, and then combined with graphene nanosheets (GNS) to prepare acrylonitrile–butadiene–styrene (ABS) copolymer composites. An excellent dispersion of exfoliated two-dimensional (2-D) GNS and 1-D MHR in the ABS matrix was achieved. The effects of combined GNS and MHR on the mechanical, thermal and flame retardant properties of the ABS composites were investigated. With the addition of 2 wt% GNS and 4 wt% Co(OH)2, the tensile strength, bending strength and storage modulus of the ABS composites were increased by 45.1%, 40.5% and 42.3% respectively. The ABS/GNS/Co(OH)2 ternary composite shows the lowest maximum weight loss rate and highest residue yield. Noticeable reduction in the flammability was achieved with the addition of GNS and Co(OH)2, due to the formation of more continuous and compact charred layers that retarded the mass and heat transfer between the flame and the polymer matrix