1,222 research outputs found
Jerzy ĆoĆ Positional Calculus and the Origin of Temporal Logic
Most accounts, including leading textbooks, credit Arthur Norman Prior with the invention of temporal (tense logic). However, (i) Jerzy ĆoĆ delivered his version of temporal logic in 1947, several years before Prior; (ii) Henrk HiĆŒâs review of ĆoĆâs system in Journal of Symbolic Logic was published as early as 1951; (iii) there is evidence to the effect that, when constructing his tense calculi, Prior was aware of ĆoĆâs system. Therefore, although Prior is certainly a key figure in the history tense logic, as well as modal logic in general, it should be accepted both in the literature that temporal logic was invented by Jerzy ĆoĆ
Snapshot spectrally encoded fluorescence imaging through a fiber bundle
Fiber optic endomicroscopy is a valuable tool
for clinical diagnostics and animal studies because it can
capture images of tissue in vivo with subcellular resolution.
Current configurations for endomicroscopes have either
limited spatial resolution or require a scanning mechanism
at the distal end of the fiber, which can slow imaging speed
and increase the probe size. We present a novel configuration
that provides high contrast 350 Ă 350 pixel images at
7.2 frames per second, without the need for mechanical
scanning at the proximal or distal end of the fiber. The proofof-
concept benchtop system is tested in fluorescence mode
and can resolve 1.5 ÎŒm features of a high resolution 1951
USAF target
Lenslet array tunable snapshot imaging spectrometer (LATIS) for hyperspectral fluorescence microscopy
Snapshot hyperspectral imaging augments pixel dwell time and acquisition speeds over existing scanning systems, making it a powerful tool for fluorescence microscopy. While most snapshot systems contain fixed datacube parameters (x,y,λ), our novel snapshot system, called the lenslet array tunable snapshot imaging spectrometer (LATIS), demonstrates tuning its average spectral resolution from 22.66 nm (80x80x22) to 13.94 nm (88x88x46) over 485 to 660 nm. We also describe a fixed LATIS with a datacube of 200x200x27 for larger field-of-view (FOV) imaging. We report <1 sec exposure times and high resolution fluorescence imaging with minimal artifacts
Quantitative evaluation of performance of three-dimensional printed lenses
We present an analysis of the shape, surface quality, and imaging capabilities of custom three-dimensional (3-D) printed lenses. 3-D printing technology enables lens prototypes to be fabricated without restrictions on surface geometry. Thus, spherical, aspherical, and rotationally nonsymmetric lenses can be manufactured in an integrated production process. This technique serves as a noteworthy alternative to multistage, labor-intensive, abrasive processes, such as grinding, polishing, and diamond turning. Here, we evaluate the quality of lenses fabricated by Luxexcel using patented Printoptical© technology that is based on an inkjet printing technique by comparing them to lenses made with traditional glass processing technologies (grinding, polishing, etc.). The surface geometry and roughness of the lenses were evaluated using white-light and Fizeau interferometers. We have compared peak-to-valley wavefront deviation, root mean square (RMS) wavefront error, radii of curvature, and the arithmetic roughness average (Ra) profile of plastic and glass lenses. In addition, the imaging performance of selected pairs of lenses was tested using 1951 USAF resolution target. The results indicate performance of 3-D printed optics that could be manufactured with surface roughness comparable to that of injection molded lense
Dislocation of the mandible in a 47 year old patient
Dislocation of mandible is relatively uncommon disorder of temporomandibular joints. Disorder can occur during extreme dilation of mouth such as yawing, during dental treatments or endoscopic examination. 47- year old patient was admitted to the Department of Maxillo-facial Surgery in case of bilateral mandible dislocation. In this case the reposition in general anaesthesia was performed but ended up with failure
Achromatization method for multichannel fluorescence imaging systems
An achromatization method optimized for dual-channel imaging is developed. Dichroic mirrors are employed to split and recombine narrowband signals, and separation between catoptric components is used to minimize the longitudinal chromatic shift. An achromatic system based on this principle could be built from singlet lenses, since refractive element properties such as dispersion and power are not utilized to optimize wavelength-dependent performance. To demonstrate the validity of the proposed solution, a prototype miniature fluorescence microscope optimized for two emission lines of acridine orange (525 and 650 nm) is built. To reduce the cost and accelerate assembly, the system is built from commercially available optical components. The optical train consisted of two plastic singlet lenses combined with a pair of dichroic mirrors. Optical performance of the prototype is evaluated by imaging a bar line target at both design wavelengths. To demonstrate the potential of the proposed design strategy, the achromatic system prototype is used to measure a two-part white blood cells differential count on a venous blood sample. Data from the prototype fluorescence microscope are compared against results from a commercially available blood analyzer, and the difference between both instruments is within 20%
Dislocation of mandible in 48 year old patient - the continuation of a therapy
Dislocation of a temporomandible joint (TMJ) is a rare disfunction, which has multiform background divided into imbalance in the function of neuromascular component or structural deficit.
A 48-year-old woman was admitted to the Department of Maxillo-Facial Surgery of the Medical University of Lublin due to continuation of a treatment of TMJ dislocation. Previous hospitalization was performed a few months earlier. Reposition in general anaesthesia was used as a treatment, however it ended up with defeat. Current hospitalization with open surgery reposition was scheduled. Bilateral condylectomy was prosecuted. After surgery correct movability and proper anterior-posterior placement of mandible were achieved
Real-time video mosaicing with a high-resolution microendoscope
Microendoscopes allow clinicians to view subcellular features in
vivo and in real-time, but their field-of-view is inherently limited by the
small size of the probe's distal end. Video mosaicing has emerged as an
effective technique to increase the acquired image size. Current
implementations are performed post-procedure, which removes the benefits
of live imaging. In this manuscript we present an algorithm for real-time
video mosaicing using a low-cost high-resolution microendoscope. We
present algorithm execution times and show image results obtained from in
vivo tissue
Development of a multimodal foveated endomicroscope for the detection of oral cancer
A multimodal endomicroscope was developed for cancer detection that combines hyperspectral and confocal imaging through a single foveated objective and a vibrating optical fiber bundle. Standard clinical examination has a limited ability to identify early stage oral cancer. Optical detection methods are typically restricted by either achievable resolution or a small field-of-view. By combining high resolution and widefield spectral imaging into a single probe, a device was developed that provides spectral and spatial information over a 5 mm field to locate suspicious lesions that can then be inspected in high resolution mode. The device was evaluated on ex vivo biopsies of human oral tumors
Differentiating between live and deadïŸ Mycobacterium smegmatisïŸ using autofluorescence
While there have been research efforts to find faster and more efficient diagnostic techniques for tuberculosis (TB), it is equally important to monitor a patient's response to treatment over time, especially with the increasing prevalence of multi-drug resistant (MDR) and extensively-drug resistant (XDR) TB. Between sputum smear microscopy, culture, and GeneXpert, only culture can verify viability of mycobacteria. However, it may take up to six weeks to grow Mycobacterium tuberculosis (Mtb), during which time the patient may have responded to treatment or the mycobacteria are still viable because the patient has MDR or XDR TB. In both situations, treatment incurs increased patient costs and makes them more susceptible to host-drug effects such as liver damage. Coenzyme Factor 420 (F420) is a fluorescent coenzyme found naturally in mycobacteria, with an excitation peak around 420 nm and an emission peak around 470 nm. Using Mycobacterium smegmatis, we show that live and dead mycobacteria undergo different rates of photobleaching over a period of 2 min. These preliminary experiments suggest that the different photobleaching rates could be used to help monitor a patient's response to TB treatment. In future studies, we propose to describe these experiments with Mtb as both M. smegmatis and Mtb use F420
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