Mode Of Illumination Research Articles

Optimal Illumination: The BFF Light

Background: Optimal illumination for procedures performed without the operating microscope remains challenging for the surgeon within some subspecialties. We present a novel device that provides unmatched illumination for such procedures and highlight its use during scleral buckle placement. Methods: A mode of illumination prioritizing precision, flexibility, portability, and compatibility in various procedural settings was developed. Using such a prototype, a proof-of-concept assessment quantified the number of manual light adjustments vs ceiling-mounted spotlight adjustments required during scleral buckle placement. Results: The Brodie-Fekrat Flex (BFF) Light, an ultrabright LED light connected to a flexible gooseneck, can mount on surgical microscopes, wrist-rests, ceiling-mounted spotlight handles, and even exam chairs. During scleral buckle placement, the BFF Light did not require intraoperative re-adjustment once positioned, whereas ceiling-mounted spotlights were repositioned 5 times on average. Conclusions: The BFF light provides reliable, bright illumination during procedures that do not require the operating microscope. This versatile device may also have applications in the clinic setting, even beyond ophthalmology.

Fertility detection of unincubated chicken eggs by hyperspectral transmission imaging in the Vis-SWNIR region

Detection of infertile eggs prior to incubation can lead to an increase in the hatchability rate and prevent the wastage of billions of non-fertile eggs ended up by failed incubation. In this study, the feasibility of a line-scan hyperspectral imaging system in the visible and short-wavelength near-infrared region was assessed for early detection of non-fertile eggs on day 0 before incubation. A total of 227 white-shell eggs including 131 fertile and 96 infertile eggs were collected from a flock with similar conditions in terms of hen age, feeding, and management. Hyperspectral images of eggs were captured on day 0 before incubation in a transmittance mode of illumination and then the eggs were incubated in a commercial incubator. The edge detection method was used to segment the egg, including both the white and yolk, from the background, and the image spectral information was extracted from the egg region. After applying various pretreatment methods, different classifiers including soft independent modeling of class analogy (SIMCA), linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), and artificial neural networks (ANN) classifiers were utilized to extract the predictive models. Following the acceptable results of SIMCA analysis accomplished by 1st derivative pretreatment (accuracy of 86.67%), the discrimination power plot was used to select the most informative wavebands. The results showed that by using fewer variables in effective wavebands better performance (precision and accuracy of 92.59% and 93.33%, respectively) could be obtained in comparison with the ANN classifier based on the whole spectral data (precision and accuracy of 89.29% and 91.11%, respectively). This study revealed the potential application of hyperspectral transmittance imaging in the Vis-SWNIR region to discern the fertile and infertile eggs before starting the incubation process.

ИСПОЛЬЗОВАНИЕ ВИДИМОГО СПЕКТРА ИСКУССТВЕННОГО ОСВЕЩЕНИЯ ДЛЯ КОРОВ ДОЙНОГО СТАДА

The article presents the results of experiments using the developed energy-efficient LED lighting device for lighting a horizontal work surface in livestock premises. The implementation of maintaining the magnitude and mode of illumination was carried out using programmable logic controllers. The results on the influence of the developed LED lamp on the health and productivity of black-and-white dairy cows are presented. The main indicators of milk quality in the control and in the experimental group were determined after 30, 60 and 90 days. It has been established that the use of the visible spectrum of artificial light radiation with an adjustable amount of illumination does not have a negative effect on the body of cows, but on the contrary stimulates its activity, which contributes to more abundant feed consumption and an increase in milk yield, and, accordingly, reduces the cost of production. The maintenance of the magnitude and mode of lighting is implemented using programmable logic controllers of the German company Schneider Electric.

I-scope: a compact automated fluorescence microscope for cell counting applications in low resource settings

Fluorescence microscopy has widespread applications across biological sciences. It has been routinely used for cell counting, which provides a preliminary diagnostic test for many infectious diseases. Conventional fluorescence microscopes are bulky, expensive, time-intensive and laborious. They often require trained operators to acquire and analyze data. We report a compact automated digital fluorescence microscopy system, i-scope, for cell counting applications. The i-scope employs a total internal reflection fluorescence (TIRF) mode of sample illumination, along with a brightfield mode. It has a magnification of 30X, an optical resolution of ∼0.2 μm/pixel and offers sample scanning over 20 mm × 20 mm. A custom-written program enables automated image acquisition and analysis, thereby enhancing ease of operation. It has a compact form-factor and has been developed into a standalone system with a processing unit, screen, and other accessories to offer a portable and economic point-of-care diagnostic solution in low-resource settings. We analysed the performance of the i-scope for milk somatic cell enumeration and benchmarked it against that of a conventional fluorescence microscope.

Evaluation of disability glare caused by headlights of most common vehicles in Iran

Background and Objectives: Road traffic accident is one of the leading causes of death in some countries such as Iran. Disability glare due to headlights of vehicles can increase the risk of crashes and make dangerous conditions. This study aimed to investigate the level of glare induced by the headlights of most common vehicles in Iran. Materials and Methods: This cross-sectional study was conducted in a suburban road of Ilam province in 2019. The disability glare resulted from the headlights of Pride Saba GTX, Pride 131SL, Samand Soren, Peugeot 405, Megan, and Peugeot Pars was measured at the distances of 10–100 m away from the headlights. The Threshold Elevation index under the high-beam and low-beam conditions (headlight's operation modes) was obtained for the background luminance condition including 1 and 50 cd/m2 for the age groups of 20, 35, 70, and 83 years old. Results: When the background luminance was 1 cd/m2, the mean glare level caused by the high-beam mode of illumination exceeded the recommended disability glare thresholds of all age groups. When the background luminance was 50 cd/m2, at certain longitudinal distances, glare level exceeded the disability glare thresholds of the elderly drivers (aged 70 and 83 years). At the background luminance of 1 cd/m2, low-beam mode of illumination caused disability glare at certain distances but not in general. At the background luminance of 50 cd/m2, low-beam mode of illumination did not cause disability glare at any distance. Conclusion: The results showed the mutual effect of luminance and the angle of line of sight with respect to glare source on the emergence of disability glare. The age also exhibited a significant association with the disability glare, as the highest glare levels were obtained for older drivers.

These Stories Must Be Told: Preliminary Observations by a Black Scholar Practitioner on Silences in the Archive

As a scholar practitioner, a trained philosophical theologian, Methodist clergywoman, and social enterprise founder who is conducting oral histories as part of my doctoral internship in the IUPUI Arts and Humanities Institute, my scholarly lens and methodological skills are being defined as I interrogate the COVID-19 archive. In this article I attempt to offer some preliminary reflections on my oral history curation focused on how Black and brown artists and activists, primarily based in Indianapolis, IN, frame their lived experiences of death, dying, mourning, and bereavement in the wake of COVID-19 utilizing critical archival practices: those practices that take seriously the methods of critical race theory, critical gender theory, Womanist, mujerista, and feminist methodologies, to name a few. The COVID-19 archive is a collection of oral histories, stories and artifacts depicting the times in which we are living, through the lenses of storytellers grappling with the pandemics of systemic racism, COVID-19, distrust in government, and various relics representing the idea of the United States of America in 2020, as such, I conclude with a brief exploration of how art emerges as both an outlet for creators and a mode of illumination for consumers.

РОЗРОБКА ІНСТРУМЕНТАЛЬНОГО МЕТОДУ ДОСЛІДЖЕННЯ ФАКТУРИ ТКАНИНИ


 
 
 Modern consumers attach increasing importance to tactile sensations and the general perception of the surface of fabrics, therefore, the study of the structure and properties of woven textures is an urgent task of textile production. In textile technologies, organoleptic research methods are used mainly, which give a subjective visual and tactile assessment of the surface of the tissues. Therefore, there was a need to develop an instrumental method for determining the texture of fabrics, which was implemented on the basis of the existing method for studying the texture of hard surfaces. It is based on the idea of creating a constant mode of illumination of the object of observation, which is a tissue sample. The proposed method is based on the use of a special optical device for determining the qualitative and quantitative characteristics of textures and is a viewing chamber containing a mechanism for changing the lighting mode and a mechanism for capturing tissue images. For an objective assessment of the state of the surface of the tissues, the invoice indicator is calculated − the invoice coefficient. The implementation of the developed method allows to increase the efficiency of the processes of design-design of fabrics, to predict the appearance of fabrics and to ensure compliance with the texture of the fabric of the model of the garment.
 
 

Automation of artificial lighting design for dairy herd cows

The article presents the results of experiments with the use of the developed energy-efficient LED-based lighting device for illuminating the horizontal working surface in livestock houses. The implementation of maintaining the magnitude and mode of illumination was carried out using programmable logic controllers. The results of the effect of the developed LED luminaire on the health and productivity of black-and-white dairy cows are given. The main indicators of the quality of milk in the control and experimental group after 30, 60 and 90 days were determined. It has been established that the use of the visible spectrum of artificial light emission with an adjustable amount of light does not adversely affect the cows’ organism, but rather stimulates its activity, which contributes to more abundant feed consumption and an increase in milk yield, and, accordingly, a reduction in production costs. The maintenance of the magnitude and mode of illumination using programmable logic controllers of the German company Schneider Electric has been implemented.

Using a portable Raman spectrometer to detect carotenoids of halophilic prokaryotes in synthetic inclusions in NaCl, KCl, and sulfates.

Cell suspensions of the haloarchaea Halorubrum sodomense and Halobacterium salinarum and the extremely halophilic bacterium Salinibacter ruber (Bacteroidetes) in saturated solutions of chlorides and sulfates (NaCl, KCl, MgSO4·7H2O, K2SO4, and (NH4)Al(SO4)2·12H2O) were left to evaporate to produce micrometric inclusions in laboratory-grown crystals. Raman spectra of these pinkish inclusions were obtained using a handheld Raman spectrometer with green excitation (532nm). This portable instrument does not include any microscopic tool. Acceptable Raman spectra of carotenoids were obtained in the range of 200-4000cm-1. This detection achievement was related to the mode of illumination and collection of scattered light as well as due to resonance Raman enhancement of carotenoid signals under green excitation. The position of diagnostic Raman carotenoid bands corresponds well to those specific carotenoids produced by a given halophile. To our best knowledge, this is the first study of carotenoids included in the laboratory in crystalline chlorides and sulfates, using a miniature portable Raman spectrometer. Graphical abstract ᅟ.

Abstract IA15: Molecular navigation for cancer diagnosis and surgery: Imaging tumors and nerves

Abstract Although treatment algorithms vary, surgery is the primary treatment modality for most solid cancers. The fundamental goal of a curative oncologic surgery is complete cancer removal but equally important from the patient's point of view is function preservation and pain control. Currently, there is an increasing trend to adopt minimally invasive technologies such as endoscopic and robotic surgery in order to decrease patient morbidity. However, the ability for surgeons to distinguish between normal and diseased tissue by texture or consistency is significantly reduced with these techniques (due to lack of ability to physically touch the tissue) and is limited to visual inspection alone. Using white light reflectance which is the current standard mode of illumination in operating rooms, the visual difference between normal and cancerous tissue can be imperceptible. The inability of surgeons to visually distinguish between tumor and normal tissue leads to residual cancer cells left behind at the edges of resection, i.e. positive surgical margins and can be as high as 20-40% in breast cancer lumpectomy, 21% for radical prostatectomy, and 13% for HNSCC. Molecular imaging with fluorescence provides enhanced visual definition between diseased and normal tissue and have been shown to decrease PSM in both animal models and patients. Molecular imaging with fluorescence can also provide enhanced visualization of important structures such as nerves to improve preservation and minimize inadvertent injury. Our laboratory has extensive experience in development of both nerve and tumor injectable markers for surgical visualization. In presentation we will discuss the development of nerve and tumor markers combinations to improve intraoperative visualization---aka color-coded surgery. Citation Format: Quyen T. Nguyen. Molecular navigation for cancer diagnosis and surgery: Imaging tumors and nerves [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; April 23-25, 2017; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(23_Suppl):Abstract nr IA15.

Low spatial coherence electrically pumped semiconductor laser for speckle-free full-field imaging

The spatial coherence of laser sources has limited their application to parallel imaging and projection due to coherent artifacts, such as speckle. In contrast, traditional incoherent light sources, such as thermal sources or light emitting diodes (LEDs), provide relatively low power per independent spatial mode. Here, we present a chip-scale, electrically pumped semiconductor laser based on a novel design, demonstrating high power per mode with much lower spatial coherence than conventional laser sources. The laser resonator was fabricated with a chaotic, D-shaped cavity optimized to achieve highly multimode lasing. Lasing occurs simultaneously and independently in ∼1,000 modes, and hence the total emission exhibits very low spatial coherence. Speckle-free full-field imaging is demonstrated using the chaotic cavity laser as the illumination source. The power per mode of the sample illumination is several orders of magnitude higher than that of a LED or thermal light source. Such a compact, low-cost source, which combines the low spatial coherence of a LED with the high spectral radiance of a laser, could enable a wide range of high-speed, full-field imaging and projection applications.

Zinc oxide loaded MWCNT buckypaper for the efficient photocurrent generation

We successfully demonstrate the preparation of surface loaded zinc oxide (ZnO) nanoparticles into the multiwalled carbon nanotube buckypaper by using the process of dispersion and filtration. The ZnO particles stay near the top surface of the network were clearly observed using X-ray diffraction and field emission scanning electron microscopy. The experimental results exhibits that, under zero bias the network composite demonstrated a superior ON/OFF photoresponse under two (full and gradient) illumination conditions. The device produced a peak value of 7μA in the generation of photocurrent under the gradient mode of illumination.

Study on the Photo-Electro-Catalytic Oxidation of Methane

Emission control of methane from landfills has received considerable attentions in recent years. Photo-electro-catalytic oxidation of methane was carried out at the mode of continuous electrolysis and intermittent illumination with TiO2-coated titanium mesh plate as pholocatalyst and electrode in combination with ionic liquid as electrolyte under UV light irradiation. The result showed that the rapid conversion of methane was achieved under ambient pressure and temperature through photocatalytic oxidation combining with electrolysis. Under the mode of intermittent illumination (on:off = 10 min : 10 min) and continuous electrolysis (II-CE), the highest oxidation rate of methane (280 mg/(m3min)) was obtained. Under fixed off time and total illumination time, the oxidation quantity of methane linearly increased with the intermittent frequency. Photo-electro-catalytic oxidation of methane can be described by the first-order kinetics, and the apparent kinetic constant increased with the intermittent frequency.

Using of algorithm of superposition micropulse lighting for cultivation of phototrophic microorganisms

The authors analyzed light sources and lighting modes for the cultivation of phototrophic microorganisms. Preliminary studies on the application of the superposition mode of illumination are conducted.

Effects of the Chromatic Defocus Caused by Interchange of Two Monochromatic Lights on Refraction and Ocular Dimension in Guinea Pigs

To investigate refractive and axial responses to the shift of focal plane resulting from the interchange of two monochromatic lights separately corresponding to the peak wavelengths of the cones absorption spectrum in retina, fifty 2-week-old pigmented guinea pigs were randomly assigned to five groups based on the mode of illumination: short-wavelength light (SL), middle-wavelength light (ML) and broad-band white light (BL) for 20 weeks, SL for 10 weeks followed by ML for 10 weeks (STM), as well as ML for 10 weeks followed by SL for 10 weeks (MTS). Biometric and refractive measurements were then performed every 2 weeks. After 10 weeks, SL and STM groups became more hyperopic and had less vitreous elongation than BL group. However, ML and MTS groups became more myopic and had more vitreous elongation. After interchange of the monochromatic light, the refractive error decreased rapidly by about 1.93D and the vitreous length increased by 0.14 mm in STM group from 10 to 12 weeks. After that, there were no significant intergroup differences between STM and BL groups. The interchange from ML to SL quickly increased the refractive error by about 1.53D and decreased the vitreous length by about 0.13 mm in MTS group after two weeks. At this time, there were also no significant intergroup differences between MTS and BL groups. The guinea pig eye can accurately detect the shift in focal plane caused by interchange of two monochromatic lights and rapidly generate refractive and axial responses. However, an excessive compensation was induced. Some properties of photoreceptors or retina may be changed by the monochromatic light to influence the following refractive development.

Test installation to determine parameters of superposition modes of lighting of phototrophic microorganisms

The authors developed and tested an installation for selection of an optimal setting of durations of light and dark periods in studies of superposition (two-frequency intermittent) mode of illumination on the growth of phototrophic microorganisms.

Light exposure and cell viability in fluorescence microscopy

Test systems for measuring cell viability in optical microscopy (based on colony formation ability or lysosomal integrity) were established and applied to native cells as well as to cells incubated with fluorescence markers or transfected with genes encoding for fluorescent proteins. Human glioblastoma and Chinese hamster ovary cells were irradiated by various light doses, and maximum doses where at least 90% of the cells survived were determined. These tolerable light doses were in the range between 25 J cm⁻² and about 300 J cm⁻² for native cells (corresponding to about 250-3000 s of solar irradiance and depending on the wavelength as well as on the mode of illumination, e.g. epi- or total internal reflection illumination) and decreased to values between 50 J cm⁻² and less than 1 J cm⁻² upon application of fluorescent markers, fluorescent proteins or photosensitizers. In high-resolution wide field or laser scanning microscopy of single cells, typically 10-20 individual cell layers needed for reconstruction of a 3D image could be recorded with tolerable dose values. Tolerable light doses were also maintained in fluorescence microscopy of larger 3D samples, e.g. cell spheroids exposed to structured illumination, but may be exceeded in super-resolution microscopy based on single molecule detection.

Photocatalytic degradation of phenol in a rotating annular reactor

Batch photocatalytic degradation studies of phenol were conducted in an annular slurry reactor, to evaluate its performance under different operating and design conditions. The reactor had two concentric cylinders with the inner one rotating at specified revolutions per minute. The reactor also had provisions for aerating the slurry present in the annular gap. The inner cylinder housed the UV-lamps. The effects of catalyst loading (0–8 g/L), inner cylinder rotation speed (0–50 rpm), annular gap-width (7.5, 17.5 and 32.5 mm), initial pollutant concentration (10–50 mg/L) and mode of illumination (continuous or periodic) were studied. Light intensity received by the slurry was measured using Actinometry. Depending on the catalyst loading, annular gap-width and number of illuminated lamps the intensity values ranged from 0.58×10 −4 to 6.4×10 −4 Einsteins/L min. Under well mixed conditions, the reactor performance was found to increase with increase in catalyst loading. At low/medium annular gap width configurations, agitation induced by continuous aeration was found to provide sufficient mixing even when the inner cylinder was stationary. Rotation of the inner cylinder was required only in the high gap width configuration at high catalyst loadings. Scale-up of the reactor was investigated by increasing the gap-width of the annulus and hence increasing the quantity of feed processed. Controlled periodic illumination created by Taylor vortices did not show any improved performance over the regular continuous illumination. Modeling of reaction kinetics was investigated with different approaches and their efficacy in fitting the concentration–time trends of both the primary pollutant and the intermediates are discussed.

Millisecond timescale slimfield imaging and automated quantification of single fluorescent protein molecules for use in probing complex biological processes

Fluorescence microscopy offers a minimally perturbative approach to probe biology in vivo. However, available techniques are limited both in sensitivity and temporal resolution for commonly used fluorescent proteins. Here we present a new imaging system with a diagnostic toolkit that caters for the detection and quantification of fluorescent proteins for use in fast functional imaging at the single-molecule level. It utilizes customized microscopy with a mode of illumination we call "slimfield" suitable for rapid (approximately millisecond) temporal resolution on a range of common fluorescent proteins. Slimfield is cheap and simple, allowing excitation intensities approximately 100 times greater than those of widefield imaging, permitting single-molecule detection at high speed. We demonstrate its application on several purified fluorescent proteins in standard use as genetically-encoded reporter molecules. Controlled in vitro experiments indicate single protein molecules over a field of view of approximately 30 microm(2) area, large enough to encapsulate complete prokaryotic and small eukaryotic cells. Using a novel diagnostic toolkit we demonstrate automated detection and quantification of single molecules with maximum imaging rates for a 128 x 128 pixel array of approximately 500 frames per second with a localization precision for these photophysically poor fluorophores to within 50 nm. We report for the first time the imaging of the dim enhanced cyan fluorescent protein (ECFP) and CyPet at the single-molecule level. Applying modifications, we performed simultaneous dual-colour slimfield imaging for use in co-localization and FRET. We present preliminary in vivo imaging on bacterial cells and demonstrate approximately millisecond timescale functional imaging at the single-molecule level with negligible photodamage.

Thermal effect of illumination on microsurgical transfer of free flaps: Experimental study and clinical implications

The light source of a modern operating microscope gives a clear operative field, but the possibility of thermal impairment by the strong light is substantial. We aimed to elucidate the potential risk of such strong light on transfer of free flaps and the optimal application of light. First, the thermal effect of clinically used microsurgical illumination was examined by direct irradiation of a thermometer. Secondly, the thermal influence on living tissue of microsurgical light was evaluated using a model of vascularised and non-vascularised pedicled groin flaps in rats. Thirdly, the influence of strong light on the transfer of free flaps was investigated using a model of a free groin flap in rats. Fourthly, histological alteration was investigated by a light microscopy and scanning electron microscopy. With direct irradiation of a thermometer, temperatures reached values in excess of 80 degrees C with maximal xenon light illumination from 20 cm. The mode of illumination significantly influenced the results of free flaps. Prolonged irradiation of the vascular pedicle in particular resulted in an increase in the number of failures, supposedly caused by venous occlusion. Bright illumination contributed to efficient microvascular procedures, but we confirmed its potential risk. Our findings may benefit all surgeons engaged in transfer of free flaps, as potential impairment caused by excessive operative irradiation is prevented simply by recognition of its harm.