Normal Room Light Conditions Research Articles

SURG-57. FLUORESCENCE LIFETIME IMAGING (FLIM) PROVIDES HIGHLY ACCURATE, DYE-FREE TUMOR MARGIN DETECTION DURING GLIOMA RESECTIONS

Abstract INTRODUCTION Fluorescence guided tumor margin detection is an important tool to enhance the extent of resection for gliomas. Existing dyes, such as 5-ALA, require planned administration, surgical resection in dark conditions, and are only effective for high-grade tumors. We have developed a novel laser scanning probe to assess tissue autofluorescence decay (lifetime) which allows tumor margin detection without exogenous dyes and under normal room light conditions. This technology has been optimized for margin detection in low-grade and high-grade gliomas. METHODS Patients undergoing craniotomy for resection of gliomas were enrolled. During resection of the final tumor margin, multiple 1x1 mm regions were scanned with FLIm and biopsied for evaluation by a neuropathologist. FLIm data and ground truth pathology were processed by a machine-learning algorithm to develop classifiers for the FLIm data. Classifiers were then applied to the full data set to determine the accuracy of FLIm predictions. RESULTS 12 patients with non-enhancing (LGG) and 25 patients with enhancing (HGG) tumors were enrolled, with a total of 228 biopsies obtained. For LGG, sensitivity of FLIm for detection of residual tumor was 0.89 (95% CI 0.8-0.98) with a specificity of 0.92 (95% CI 0.86-0.97), resulting in a positive predictive value of 0.76 and negative predictive value of 0.96 with an overall accuracy of 0.91. For HGG, sensitivity of FLIm for detection of residual tumor was 0.92 (95% CI 0.84-1.0) with a specificity of 0.95 (95% CI 0.91-0.99), resulting in a positive predictive value of 0.90 and negative predictive value of 0.96 with an overall accuracy of 0.94, exceeding reported values for 5-ALA. CONCLUSION FLIm can distinguish between residual low and high-grade glioma and normal brain at resection margins with very high sensitivity and specificity. This quantitative technology does not require administration of exogenous dyes and can be used under normal room light illumination.

Effect of a light-darkness cycle on the body weight gain of preterm infants admitted to the neonatal intensive care unit

The Continuous bright light conditions to which premature infants are subjected while hospitalized in Neonatal Intensive Care Units (NICU) can have deleterious effects in terms of growth and development. This study evaluates the benefits of a light/darkness cycle (LDC) in weight and early hospital discharge from the NICU. Subjects were recruited from three participating institutions in Mexico. Eligible patients (n = 294) were premature infants who were hospitalized in the low-risk and high-risk neonatal units classified as stable. The subjects randomized to the experimental group (n = 150) were allocated to LDC conditions are as follows: light from 07:00 to 19:00 and darkness (25 lx) from 19:00 to 07:00. The control group (n = 144) was kept under normal room light conditions (CBL) 24 h a day. Main outcome was weight gain and the effect of reducing the intensity of nocturnal light in development of premature infants. Infants to the LDC gained weight earlier, compared with those randomized to CBL, and had a significant reduction in length of hospital stay. These results highlight those premature infants subjected to a LDC exhibit improvements in physiological development, favoring earlier weight gain and consequently a decrease in hospital stays. ClinicalTrials.gov; 02/09/2020 ID: NCT05230706.

American Sign Language to Text - Speech using Background Subtraction using Running Averages

This Paper Proposes A System Which Converts American Sign Language Hand Gestures Into Text Cum Speech And Helps To Bridge The Communication Gap Between DeafMute People And Rest Of The Society. Any System For This Purpose Generally Has Four Modules: Segmentation, Feature Extraction, Classification And Text-To-Speech. This Paper Focuses On An Improved Method For The Segmentation And The Feature Extraction Processes To Get More Better Resultswhile Using The Standard Techniques On The Other Two Modules. Proposed Algorithm Captures Initial 30 Frames Of The Live Video From The Web Cam Of The System To Construct The Background Model. It Then Finds The Absolute Difference Between The Current Frame And The Background Model In Order To Get The Foreground. Various Features Are Extracted To Classify The Gestures Like Contour, Convexity Hull Etc.. Proposed Algorithm Has Been Tested Under Low And Normal Room Light Conditions. The Overall Performance Of The Proposed Model Will Be Very High And Will Produce Far More Better Resultsdue To Improved Proposed Algorithms For The Initial Two Modules In Comparison To Other Standard Techniques Used Like Hsv, Ycbcr The Above System Can Be Incorporated Into Simple Web Applications, Mobile Applications And Many Other Applications Translating Gestures In The Conversations In Real Time.

Influence of active layer thickness on contribution of hole and electron trapping to threshold voltage instability in organic field effect transistors

Effect of active layer thickness on threshold voltage stability was studied. Threshold voltage instability was found to be minimum for an optimum thickness of 15nm when operated under normal room light conditions. Influence of active layer thickness on individual contribution of hole and electron trapping effect to hysteresis was estimated. Hole and electron trap concentrations were found to exhibit different pattern of variation with thickness compared to each other. Film with 15nm thickness exhibited minimum hole trapping and maximum electron trapping effect. This could be attributed to reduced grain boundary density and availability of large photogenerated carrier concentration at the dielectric/semiconductor interface. Along with electron trap, hole trap concentrations were also shown to be significantly influenced by photogenerated carrier concentration at the interface. For further increase in thickness, increase in hole trapping and reduction in electron trapping were observed again. This could be attributed to (a) increase in grain boundary density due to volume effect and (b) lesser number of photogenerated carriers at the interface due to limitations in exciton quenching length. Hole and electron trapping effect were suggested to be mutually affecting each other, depending on active layer thickness. Effect of active layer thickness was further confirmed with frequency and voltage dependent capacitance measurements.

Influence of light and time on bilirubin degradation in CSF spectrophotometry for subarachnoid haemorrhage

Aim. Investigation of the influence of light on bilirubin degradation over time in cerebrospinal fluid (CSF) specimens from patients with computed tomography (CT) positive subarachnoid haemorrhage (SAH).Methods. Twenty-nine CSF samples were analysed from 23 patients with CT-positive SAH. Samples were divided into two cohorts – one half being stored in the dark, the other in normal room light conditions. Samples were assayed by spectrophotometry 0, 1, 2, 6, 19, 24 and 48 h post-storage. Net bilirubin absorbance (NBA) was measured in absorbance units (AU) by determining the optical density at 476 nm.Results. In 27 of 28 (96%) samples stored in light conditions and 21 of 29 (72%) samples stored in dark, a decline in the amount of bilirubin detected in CSF over time was observed. The rate of bilirubin degradation over 24 h for CSF samples stored in the light ranged from 0.0001 to 0.0048 AU/h (mean 0.0020 AU/h), and was significantly greater (p < 0.01) than the rate of degradation in the dark, which ranged from 0 to 0.0024 AU/h (mean 0.0005 AU/h).Conclusion. CSF bilirubin samples are susceptible to the same photodegradation as shown in serum bilirubin samples. The rate of degradation is not predictable or consistent. This photodegradation may potentially produce false-negative results in the diagnosis of SAH. If spectrophotometry cannot be carried out immediately, all such CSF samples should at least be centrifuged immediately, the supernatant protected from light as soon as possible and the collection and analysis times provided in the report.

Efficacy of brimonidine tartrate 0.2% ophthalmic solution in reducing halos after laser in situ keratomileusis

To quantitatively evaluate the effect of brimonidine tartrate 0.2% (Alphagan) on halo and pupil size in patients who had symptomatic night-vision difficulties after laser in situ keratomileusis (LASIK). Nune Eye Hospital, Seoul, Korea. This study comprised 28 eyes of 14 patients with symptomatic night-vision difficulties after LASIK. Pupil diameter was measured with a Colvard pupillometer (Oasis Medical, Inc.). Quantitative analysis of halos was performed by measuring the area using a new computerized method. Pupil size and halo size were evaluated under scotopic and normal room light conditions. Alphagan was administered, and the effect was measured after 30 minutes and 1, 6, 12, and 24 hours. There was a statistically significant correlation between pupil size and halo size (r = 0.527; P<.0001; slope = 691.6 pixel/mm). Pupil size and halo size decreased significantly 30 minutes after Alphagan instillation under both luminance conditions (all P< .0001). Under normal room light, the pupil and halo remained decreased until the last measurement at 24 hours. Under scotopic conditions, the pupil returned to its preinstillation size at 24 hours while the halo remained decreased. The maximum effect on halos was observed after 6 hours, when the mean reduction over preinstillation size was 28.2% and 29.1% under normal room light conditions and scotopic conditions, respectively. Alphagan effectively reduced halo size and pupil size in postoperative LASIK patients with night-vision symptoms.

SEEMORE: combining color, shape, and texture histogramming in a neurally inspired approach to visual object recognition.

Severe architectural and timing constraints within the primate visual system support the conjecture that the early phase of object recognition in the brain is based on a feedforward feature-extraction hierarchy. To assess the plausibility of this conjecture in an engineering context, a difficult three-dimensional object recognition domain was developed to challenge a pure feedforward, receptive-field-based recognition model called SEEMORE. SEEMORE is based on 102 viewpoint-invariant nonlinear filters that as a group are sensitive to contour, texture, and color cues. The visual domains consists of 100 real objects of many different types, including rigid (shovel), nonrigid (telephone cord), and statistical (maple leaf cluster) objects and photographs of complex scenes. Objects were individually presented in color video images under normal room lighting conditions. Based on 12 to 36 training views, SEEMORE was required to recognize unnormalized test views of objects that could vary in position, orientation in the image plane and in depth, and scale (factor of 2); for nonrigid objects, recognition was also tested under gross shape deformations. Correct classification performance on a test set consisting of 600 novel object views was 97 percent (chance was 1 percent) and was comparable for the subset of 15 nonrigid objects. Performance was also measured under a variety of image degradation conditions, including partial occlusion, limited clutter, color shift, and additive noise. Generalization behavior and classification errors illustrated the emergence of several striking natural shape categories that are not explicitly encoded in the dimensions of the feature space. It is concluded that in the light of the vast hardware resources available in the ventral stream of the primate visual system relative to those exercised here, the appealingly simple feature-space conjecture remains worthy of serious consideration as a neurobiological model.

Chemical Stability of Suramin in Commonly used Infusion Fluids

The chemical stability of suramin in NaCl 0.9%, dextrose 5%, and lactated Ringer's injection was investigated. The admixtures were stored in glass infusion bottles at 4 degrees C in the dark, and at room temperature (22 degrees C) both protected from light and under normal room fluorescent light conditions in a day-night rhythm. The initial concentration of suramin was approximately 1 mg/mL. Samples withdrawn immediately after preparation and at four hours, one, two, three, five, and seven days were analyzed by HPLC with ultraviolet (UV) detection. Samples were also inspected for visual changes and tested for changes in pH. Accelerated stability studies in NaCl 0.9% injection were executed at 90 degrees C. The drug appeared to be stable under the chosen storage conditions with no visual changes or changes in pH. The accelerated experiments revealed that suramin degrades in NaCl 0.9% at 90 degrees C with a half-life of about 5.5 hours. It is concluded that suramin 1 mg/mL is stable in NaCl 0.9%, dextrose 5%, and lactated Ringer's injections when stored in glass infusion bottles at 4 degrees C in the dark and at 22 degrees C under normal room light conditions in a day-night rhythm or protected from light for at least seven days.

A 35 mm Hologram Camera

AbstractThe measurement facilities available from holographic interferometry are well known. It is, however, an inconvenient technique to operate and its use may be precluded when contemplating work outside the confines of a vibration isolated table located in a blacked out room.Based on a standard 35 mm rdlex camera the interference camera described here circumvents these difficulties. Using the principles of common path interferometry and white light holography, interferograms can be taken under normal room lighting conditions. Apart from the laser required to illuminate the object under study, operation of the camera is similar to ordinary photography there being no need for elaborate vibration isolation. An economic advantage is also realized by using acetate-based roll film in place of the usual glass backed plates.

A holographic interference camera

Describes a regular 35 mm reflex camera modified to incorporate the principles of the Lippmann-Bragg diffraction effect and focused image holography. This modification enables holographic interferometry to be executed in normal room lighting conditions without the need for elaborate vibration isolation.

Bilirubin Dynamics in the Gunn Rat during Phototherapy

Bilirubin dynamics were studied in homozygous Gunn rats under normal room lighting conditions and under conditions simulating phototherapy. A kinetic model was developed for the formation, distribution, and elimination of bilirubin. The decrease in plasma bilirubin concentration during illumination with low intensity [300 footcandles (fc)] and high intensity (1000–1100fc) light was studied. The plasma bilirubin concentration in the rats decreased under phototherapy until a new steady-state concentration was reached, the decline being more rapid under high intensity light conditions. Gunn rats were also injected with a tracer dose of 14C-bilirubin following a period during which the rats were illuminated with low or high intensity light. The distribution and elimination of the labeled bilirubin were followed under continuous illumination. The chosen kinetic model, when adapted to the set of data under investigation, fit all of the data concerning bilirubin kinetics in Gunn rats under continuous illumination.