125,236 research outputs found
Visual examination apparatus
An automated visual examination apparatus for measuring visual sensitivity and mapping blind spot location including a projection system for displaying to a patient a series of visual stimuli. A response switch enables him to indicate his reaction to the stimuli, and a recording system responsive to both the visual stimuli per se and the patient's response. The recording system thereby provides a correlated permanent record of both stimuli and response from which a substantive and readily apparent visual evaluation can be made
Visual examination apparatus
An automated visual examination apparatus for measuring visual sensitivity and mapping blind spot location is described. The apparatus includes a projection system for displaying to a patient a series of visual stimuli, a response switch enabling him to indicate his reaction to the stimuli, and a recording system responsive to both the visual stimuli per se and the patient's response. The recording system provides a correlated permanent record of both stimuli and response from which a substantive and readily apparent visual evaluation can be made
A Computational Methodology to Screen Activities of Enzyme Variants
We present a fast computational method to efficiently screen enzyme activity.
In the presented method, the effect of mutations on the barrier height of an
enzyme-catalysed reaction can be computed within 24 hours on roughly 10
processors. The methodology is based on the PM6 and MOZYME methods as
implemented in MOPAC2009, and is tested on the first step of the amide
hydrolysis reaction catalyzed by Candida Antarctica lipase B (CalB) enzyme. The
barrier heights are estimated using adiabatic mapping and are shown to give
barrier heights to within 3kcal/mol of B3LYP/6-31G(d)//RHF/3-21G results for a
small model system. Relatively strict convergence criteria
(0.5kcal/(mol{\AA})), long NDDO cutoff distances within the MOZYME method
(15{\AA}) and single point evaluations using conventional PM6 are needed for
reliable results. The generation of mutant structure and subsequent setup of
the semiempirical calculations are automated so that the effect on barrier
heights can be estimated for hundreds of mutants in a matter of weeks using
high performance computing
Recommended from our members
Reliability of Semiautomated Kinetic Perimetry (SKP) and Goldmann Kinetic Perimetry in Children and Adults With Retinal Dystrophies.
PurposeTo investigate the precision of visual fields (VFs) from semiautomated kinetic perimetry (SKP) on Octopus 900 perimeters, for children and adults with inherited retinal degenerations (IRDs). Goldmann manual kinetic perimetry has long been used in the diagnosis and follow-up of these patients, but SKP is becoming increasingly common. Octopus VFs (OVFs) and Goldmann VFs (GVFs) were both mapped on two occasions.MethodsNineteen females and 10 males with IRDs were tested on OVFs and GVFs, with two targets per test (V4e and one smaller target). Tests were performed in the same (randomized) order at two visits about 1 week apart. The VFs were digitized to derive isopter solid angles. Comparisons, within and between visits, were performed with paired t-tests and Bland-Altman plots.ResultsMedian age was 20 years (range, 7-70; 10 participants aged ≤17 years old). There were no significant differences in solid angles between OVFs and GVFs (P ≥ 0.06) or between the two visits' solid angles on either perimeter (P ≥ 0.30). Between-visit test-retest variability for GVFs and OVFs was similar (P ≥ 0.73), with median values of approximately 9% to 13%. Overall variability was lower for children than adults (medians of 7.5% and 12.8%, respectively).ConclusionsOctopus SKP and Goldmann perimetry produced VFs of similar size and variability.Translational relevanceOur study indicates that SKP provides a viable alternative to traditional Goldmann perimetry in clinical trials or care involving both children and adults with IRDs
Active Site Mapping of Xylan-Deconstructing Enzymes with Arabinoxylan Oligosaccharides Produced by Automated Glycan Assembly
Xylan-degrading enzymes are crucial for the deconstruction of hemicellulosic biomass, making the hydrolysis products available for various industrial applications such as the production of biofuel. To determine the substrate specificities of these enzymes, we prepared a collection of complex xylan oligosaccharides by automated glycan assembly. Seven differentially protected building blocks provided the basis for the modular assembly of 2-substituted, 3-substituted, and 2-/3-substituted arabino- and glucuronoxylan oligosaccharides. Elongation of the xylan backbone relied on iterative additions of C4-fluorenylmethoxylcarbonyl (Fmoc) protected xylose building blocks to a linker-functionalized resin. Arabinofuranose and glucuronic acid residues have been selectively attached to the backbone using fully orthogonal 2-(methyl)naphthyl (Nap) and 2-(azidomethyl)benzoyl (Azmb) protecting groups at the C2 and C3 hydroxyls of the xylose building blocks. The arabinoxylan oligosaccharides are excellent tools to map the active site of glycosyl hydrolases involved in xylan deconstruction. The substrate specificities of several xylanases and arabinofuranosidases were determined by analyzing the digestion products after incubation of the oligosaccharides with glycosyl hydrolases.Fil: Senf, Deborah. Max Planck Institut für Kolloid und Grenzflächenforschung; Alemania. Freie Universität; AlemaniaFil: Ruprecht, Colin. Max Planck Institut für Kolloid und Grenzflächenforschung; AlemaniaFil: de Kruijff, Goswinus H. M.. Max Planck Institut für Kolloid und Grenzflächenforschung; Alemania. Freie Universität; Alemania. University Mainz. Institute of Institute of Organic Chemistry, Johannes Gutenberg; AlemaniaFil: Simonetti, Sebastián Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina. Max Planck Institut für Kolloid und Grenzflächenforschung; AlemaniaFil: Schuhmacher, Frank. Max Planck Institut für Kolloid und Grenzflächenforschung; Alemania. Freie Universität; AlemaniaFil: Seeberger, Peter H.. Max Planck Institut für Kolloid und Grenzflächenforschung; Alemania. Freie Universität; AlemaniaFil: Pfrengle, Fabian. Max Planck Institut für Kolloid und Grenzflächenforschung; Alemania. Freie Universität; Alemani
Model Reduction Tools For Phenomenological Modeling of Input-Controlled Biological Circuits
We present a Python-based software package to automatically obtain phenomenological models of input-controlled synthetic biological circuits that guide the design using chemical reaction-level descriptive models. From the parts and mechanism description of a synthetic biological circuit, it is easy to obtain a chemical reaction model of the circuit under the assumptions of mass-action kinetics using various existing tools. However, using these models to guide design decisions during an experiment is difficult due to a large number of reaction rate parameters and species in the model. Hence, phenomenological models are often developed that describe the effective relationships among the circuit inputs, outputs, and only the key states and parameters. In this paper, we present an algorithm to obtain these phenomenological models in an automated manner using a Python package for circuits with inputs that control the desired outputs. This model reduction approach combines the common assumptions of time-scale separation, conservation laws, and species' abundance to obtain the reduced models that can be used for design of synthetic biological circuits. We consider an example of a simple gene expression circuit and another example of a layered genetic feedback control circuit to demonstrate the use of the model reduction procedure
Designing algorithms to aid discovery by chemical robots
Recently, automated robotic systems have become very efficient, thanks to improved coupling between sensor systems and algorithms, of which the latter have been gaining significance thanks to the increase in computing power over the past few decades. However, intelligent automated chemistry platforms for discovery orientated tasks need to be able to cope with the unknown, which is a profoundly hard problem. In this Outlook, we describe how recent advances in the design and application of algorithms, coupled with the increased amount of chemical data available, and automation and control systems may allow more productive chemical research and the development of chemical robots able to target discovery. This is shown through examples of workflow and data processing with automation and control, and through the use of both well-used and cutting-edge algorithms illustrated using recent studies in chemistry. Finally, several algorithms are presented in relation to chemical robots and chemical intelligence for knowledge discovery
A Hybridised Optimisation of an Automated Photochemical Continuous Flow Reactor
A new hybridized algorithm that combines process optimisation with response surface mapping was developed and applied in an automated continuous flow reaction. Moreover, a photochemical cascade CSTR was developed and characterised by chemical actinometry, showing photon flux density of ten times greater than previously reported in batch. The success of the algorithm was then evaluated in the aerobic oxidation of sp3 C–H bonds using benzophenone as photosensitizer in the newly developed photo reactor
Annotation of SBML Models Through Rule-Based Semantic Integration
*Motivation:* The creation of accurate quantitative Systems Biology Markup Language (SBML) models is a time-intensive, manual process often complicated by the many data sources and formats required to annotate even a small and well-scoped model. Ideally, the retrieval and integration of biological knowledge for model annotation should be performed quickly, precisely, and with a minimum of manual effort. Here, we present a method using off-the-shelf semantic web technology which enables this process: the heterogeneous data sources are first syntactically converted into ontologies; these are then aligned to a small domain ontology by applying a rule base. Integrating resources in this way can accommodate multiple formats with different semantics; it provides richly modelled biological knowledge suitable for annotation of SBML models.
*Results:* We demonstrate proof-of-principle for this rule-based mediation with two use cases for SBML model annotation. This was implemented with existing tools, decreasing development time and increasing reusability. This initial work establishes the feasibility of this approach as part of an automated SBML model annotation system.
*Availability:* Detailed information including download and mapping of the ontologies as well as integration results is available from "http://www.cisban.ac.uk/RBM":http://www.cisban.ac.uk/RB
Biochemical network matching and composition
This paper looks at biochemical network matching and compositio
- …