2,560 research outputs found
Discovery and the Doctor: Expansion of Rule 35(b)
Discovery And The Doctor: Expansion Of Rule 35(b
Electroconvulsive therapy: we are hesitant to use the most effective treatment for severe depression
An attempt to optimize the outcome of penetrating keratoplasty in congenital aniridia-associated keratopathy (AAK)
Purpose
To propose an optimized microsurgical and medical approach to reduce the risk of complications after penetrating keratoplasty (PKP) in patients with aniridia-associated keratopathy (AAK).
Methods
Retrospective observational case series of 25 PKP performed in 16 patients with AAK. Preoperative indications were endothelial decompensation and vascularized scars (68%) or graft failure (32%) due to limbal stem cell deficiency. The optimized approach included a combination of a small corneal graft size (around 7.0 mm), interrupted 10–0nylon sutures, simultaneous AMT as a patch, large bandage contact lens, temporary lateral tarsorrhaphy, postoperative autologous serum eye drops, and systemic immunosuppression. Main outcome measures included: visual acuity, transplant survival, and complications encountered during follow-up of 107 weeks on average.
Results
A complete modified keratoplasty scheme was used in 10 of 25 PKP (group 1), while at least one of the modifications was missing in the other 15 PKP (group 2). After 8 weeks of follow-up, the epithelium was closed in 23 eyes. Visual acuity improved in 19 eyes at 6 months of follow-up, and remained stable in six eyes. None of the eyes showed a decrease in visual acuity. At the last post-operative follow-up, this visual improvement persisted in 14 eyes and graft survival rate after 156 weeks (3 years) was 69% in group 1 versus 44% in group 2 (p = 0.39, log-rank test). Secondary corneal neovascularization (8%), scarring (4%), ulcer (4%), or graft rejection (8%) happened mostly in the second group which was missing at least one of the suggested modifications.
Conclusions
PKP in congenital aniridia must be considered as a high-risk keratoplasty. An optimized therapeutic approach seems to be promising in order to reduce the postoperative complication rate in these most difficult eyes
Multiparallel Three-Dimensional Optical Microscopy
Multiparallel three-dimensional optical microscopy is a method of forming an approximate three-dimensional image of a microscope sample as a collection of images from different depths through the sample. The imaging apparatus includes a single microscope plus an assembly of beam splitters and mirrors that divide the output of the microscope into multiple channels. An imaging array of photodetectors in each channel is located at a different distance along the optical path from the microscope, corresponding to a focal plane at a different depth within the sample. The optical path leading to each photodetector array also includes lenses to compensate for the variation of magnification with distance so that the images ultimately formed on all the photodetector arrays are of the same magnification. The use of optical components common to multiple channels in a simple geometry makes it possible to obtain high light-transmission efficiency with an optically and mechanically simple assembly. In addition, because images can be read out simultaneously from all the photodetector arrays, the apparatus can support three-dimensional imaging at a high scanning rate
Discovery of a Very Nearby Brown Dwarf to the Sun: A Methane Rich Brown Dwarf Companion to the Low Mass Star SCR 1845-6357
We present VLT/NACO SDI images of the very nearby star SCR 1845-6357
(hereafter SCR 1845). SCR 1845 is a recently discovered (Hambly et al. 2004)
M8.5 star just 3.85 pc from the sun (Henry et al. 2006). Using the capabilities
of the unique SDI device, we discovered a substellar companion to SCR 1845 at a
separation of 4.5 AU (1.170''+-0.003'' on the sky) and fainter by 3.57+-0.057
mag in the 1.575 um SDI filter. This substellar companion has an H magnitude of
13.16+0.31-0.26 (absolute H magnitude of 15.30+0.31-0.26), making it likely the
brightest mid-T dwarf known. The unique Simultaneous Differential Imager (SDI)
consists of 3 narrowband filters placed around the 1.6 um methane absorption
feature characteristic of T-dwarfs (Teff < 1200 K). The flux of the substellar
companion drops by a factor of 2.7+-0.1 between the SDI F1(1.575 um) filter and
the SDI F3(1.625 um) filter, consistent with strong methane absorption in a
substellar companion. We estimate a spectral type of T5.5+-1 for the companion
based on the strength of this methane break. The chances that this object is a
background T dwarf are vanishing small -- and there is no isolated background
T-dwarf in this part of the sky according to 2MASS. Thus, it is a bound
companion, hereafter SCR 1845-6357B. For an age range of 100 Myr - 10 Gyr and
spectral type range of T4.5-T6.5, we find a mass range of 9 - 65 MJup for SCR
1845B from the Baraffe et al. 2003 COND models. SCR 1845AB is the 24th closest
stellar system to the Sun (at 3.85 pc); the only brown dwarf system closer to
the Sun is Eps Indi Ba-Bb (at 3.626 pc). In addition, this is the first T-dwarf
companion discovered around a low mass star.Comment: 8 pages, 3 figures. Accepted to the Astrophysical Journal Letter
Data management routines for reproducible research using the G-Node Python Client library
Structured, efficient, and secure storage of experimental data and associated meta-information constitutes one of the most pressing technical challenges in modern neuroscience, and does so particularly in electrophysiology. The German INCF Node aims to provide open-source solutions for this domain that support the scientific data management and analysis workflow, and thus facilitate future data access and reproducible research. G-Node provides a data management system, accessible through an application interface, that is based on a combination of standardized data representation and flexible data annotation to account for the variety of experimental paradigms in electrophysiology. The G-Node Python Library exposes these services to the Python environment, enabling researchers to organize and access their experimental data using their familiar tools while gaining the advantages that a centralized storage entails. The library provides powerful query features, including data slicing and selection by metadata, as well as fine-grained permission control for collaboration and data sharing. Here we demonstrate key actions in working with experimental neuroscience data, such as building a metadata structure, organizing recorded data in datasets, annotating data, or selecting data regions of interest, that can be automated to large degree using the library. Compliant with existing de-facto standards, the G-Node Python Library is compatible with many Python tools in the field of neurophysiology and thus enables seamless integration of data organization into the scientific data workflow
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