Monocular Microscope Research Articles

Investigation of the fracture characteristics of mixed-mode I/III crack by using two kinds of sandstone specimens

This study aims to identify specimens that are more suitable for examining the failure properties of I/III mixed-mode cracks under static loads. We employed single-edge notched bending (SENB) and edge-notched disc bending (ENDB) specimens, and used ABAQUS finite element method software to calculate the stress intensity factors for modes I and III at various crack inclination angles θ. Fracture toughness was tested using three-point bending experiments on two types of sandstone specimens. The evolution of mixed-mode I/III fracture morphology and failure patterns was investigated with a monocular microscope. Additionally, the evolution of the strain field and crack tip opening displacement was analyzed using the digital image correlation method. Our findings indicate that the fracture toughness of the ENDB specimens surpassed that of the SENB specimens. The effective fracture toughness of both SENB and ENDB specimens initially increased with crack inclination angle θ but then decreased. The fracture mode correlated with energy release; the energy release rate of the ENDB specimens exceeded that of the SENB specimens, making the former more brittle. For SENB specimens, crack initiation was primarily intergranular, while ENDB specimens exhibited predominantly transgranular fractures. The crack initiation moments for both specimen types increased with higher crack inclination angles. Furthermore, at the same crack inclination angle, ENDB specimens cracked earlier than SENB specimens.

A Workshop on the Utilization of Light Microscope for Biology Education Pre-Service Students of FKIP ULM through the Use of Wet Mount Preparations

Microscopes in learning biology are very important as a tool for students in studying microscopic organisms and objects that cannot be seen by the eye directly. The results of the needs analysis show that biology education students in the Year of 2022 have never received training in the use and maintenance of microscopes and have never used a microscope with a magnification of 1000x. therefore, 98% of the survey results to participants indicate the need for training in the use of microscopes. The training on the use of light microscope was trained to make wet mount preparations of Rhoeo discolor leaf stomata and Hibiscus rosa-sinensis flower pollen. The microscopes used were monocular microscope and electric binocular microscope. The microscope magnifications used were 10x10; 10x40; and 10x100. The training results show that students are able to use all microscope magnifications and figures of the results of microscope observations well and clearly. The results of the microscope proficiency test were 21.06%, very good; 45.61% good/adequate grades; 24.56 adequate grades, but there were 8.7% still getting poor grades. The next service can be trained in making preparations with the whole mount preparation method, squash method for mitosis observation, slice preparation method without embedding and slice preparation method with paraffin method.

Non-Contact 3D Characterization System of Scratch-Induced Surface Damage on Monolithic Glass Panel

Glass material has been widely used in modern architecture. Scratch-induced surface damage of aged monolithic glass panel leads to the strength degradation of material and thus threatens the glass safety. Therefore, in order to accurately evaluate the strength of aged glass elements, it is crucial to extract key damage features including the damage location and depth in a precise way. This study aims to develop a non-contact stage-wise scanning method to extract 3D damage characteristics on glass surface, which can further facilitate the investigation into the associated influences on the flexural strength of glass. Coaxial double ring tests on annealed glass specimens under various magnitudes of applied loads were performed, which aimed to explore the influence of the surface damage on the flexural strength. Monocular microscope equipped with an industrial camera was used to detect damage area throughout the glass panel in the first stage rapidly. It was then followed by a chromatic confocal scanner to precisely measure the damage depth within local damage area. The results via confocal microscope scanning were considered as the reference values. It shows that the proposed method can be a potentially alternative solution instead of confocal microscope for damage quantification.

In-situ 3D reconstruction of worn surface topography via optimized photometric stereo

Since worn surfaces contain rich information of the wear mechanisms, in-situ measurements of surface topography can characterize ongoing wear degradation in machines. With the help of photometric stereo vision, three-dimensional (3D) topography of worn surfaces is obtained with a monocular microscope. However, the accuracy of the reconstructed surfaces remains low due to the non-Lambertian reflections of worn surfaces and noise in the image acquisition equipment. To address this issue, an optimized photometric stereo approach is proposed for the improvement of worn surface reconstruction. To accommodate the non-Lambertian reflections, a multi-branch network is constructed to estimate normal vectors from both the photometric images and the incident illumination directions. The estimated normal vectors are adopted to reconstruct worn surface topography by embedding prior knowledge. With this design, the overall distortion caused by image noise is effectively suppressed. The proposed method is verified by comparing with the Laser Scanning Confocal Microscopy (LSCM). As the main result, over 88% similarity on the worn surface roughness can be obtained.

Kinetic models applied to the growth of Saccharomyces boulardii

Predictive microbiology is an interesting tool that allows evaluating the behavior of biomass and metabolites in different culture media, providing multiple benefits, whether scientific or industrial, for these and other reasons the objective of this research was to evaluate applied sigmoidal kinetic models to the growth of Saccharomyces boulardii in milk. For this purpose, flasks were prepared with 200 mL of fresh cow's milk, previously sterilized at 121 ° C x 15 min, then the strains were inoculated at a temperature of 37 ° C and incubated at the same temperature under constant shaking of 20 revolutions per minute (rpm) in a water bath with shaking, for 7 h; To construct the curves and obtain the growth constants, colony-forming units were counted per milliliter (cfu / ml) at one-hour intervals, with a monocular microscope and Neubauer chamber. Also, the pH and titratable acidity expressed in lactic acid were measured. The data obtained were converted to a logarithmic scale to apply the sigmoidal equations of Gompertz, Logistic, Modified Logistic and Weibull. The results of the kinetic modeling gave us that the modified Logistics and Logistics models presented a better fit compared to the rest. Likewise, the Weibull model presented the lowest value of adjustment, on the other hand, in the analysis of the statistical criteria, all models except Weibull present similarity. Finally, each sigmoidal model allowed to evaluate the growth of Saccharomyces boulardii with each of its kinetic constants.

Microplastic abundance in the water, seagrass, and sea hare Dolabella auricularia in Pramuka Island, Seribu Islands, Jakarta Bay, Indonesia

This research focused on the amount of abundance of microplastics in the sea hare Dolabella auricularia as well as the seagrass fields along the southern coast of Pramuka Island. Sampling of 8 individuals of Dolabella auricularia along with seagrass Cymodocea rotundata leafblades was done at the southern coast of Pramuka Island, after which the samples were preserved and brought to a laboratorium in Depok for microplastic analysis. The sea hares’ digestive tracts were extracted and dissolved in strong nitric acid. A 1 cm2 portion of a seagrass leaf blade was cut for observation. Prepared samples were observed under a monocular microscope and further analysis was done. Microplastic fibers and film particles were found in highest abundance within the digestive tracts of each sample of Dolabella auricularia as well as on the seagrass surface where the sea hare obtains its algae from, with fragment particles found in much lower amounts. Overall, number of microplastics was found between 40.1 to 73.7 particles/g weight of sea hare digestive tract and the estimated amount of microplastic found at seagrass leafblade was 185 particles/cm2. Results provide evidence that microplastics in the ocean brought by water currents could adsorb on to algae through which it enters the food chain as it is consumed by marine biota.

Position Measurements of the Space Manipulator based on Monocular Microscope Vision

In this paper, an inspection manipulator with a micro-camera at the end was designed for in-situ microscopic observation of samples on the material exposure platform. In order to achieve the positioning requirements, a novel position measurement method for the manipulator was proposed based on monocular microscope vision. First, a planar target was designed for feature detection. Next, the measurement task was performed in two steps respectively. On the image plane, a motion-based active calibration method was used to measure the translation. For the rotation around Z axis, the relationship between the image blur b and the rotation θ was fitted to estimate the rotation from images. In final, the proposed approach was tested in term of accuracy and robustness in ground experimental conditions. The focusing error of the piezoelectric motor was about 1μm and the obtained average alignment accuracies were less than 10μm in X, Y, and 0.002° around Z, respectively, which satisfied the positioning requirements of the in-situ observation.

Intraoperative identification of parathyroid tissue: a comparative validity study of frozen section, cytology, and reflected-light diagnostic methods

Background Surgery is the main line of treatment for hyperparathyroidism, but preliminary localization of the lesion is essential. This could be accomplished preoperatively by radiographic methods (isotope scans and ultrasonography) or intraoperatively by pathologic methods, namely, frozen section, cytology, and reflected-light microscopy. Aim To compare the diagnostic accuracy of the intraoperative pathologic methods when used singly or combined. The study was done on 30 (10 parathyroid tissue and 20 nonparathyroid tissue) tissue samples, obtained from nine patients. Modifications were made on a monocular microscope to allow transmitted-light, reflected-light, and digital photography. Results When used alone, the diagnostic accuracy was 96.6% for frozen section, 86.6% for cytology, and 80% for reflected-light microscopy. The combined use of cytology with reflected-light microscopy increased the diagnostic accuracy to 93.3%, with good concordance with the accuracy of frozen section combined with cytology (κ ratio 0.651). Diagnostic errors were mainly owing to the difficulty to differentiate thyroid from parathyroid tissue. Conclusion In specialized centers, frozen section combined with cytology is the method of choice for the intraoperative diagnosis of parathyroid tissue. Conversely, in developing countries, where frozen section equipment is usually not available, combination of reflected-light microscopy and cytology is a good, inexpensive, rapid and effective alternative. However, proper training is needed for these methods to ensure an accurate diagnosis.

Developing Tools for STEM Education: The Foldscope, a Very Inexpensive Monocular Microscope for Biological Research.

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Depth-from-Focus-Based 3D Reconstruction of Asphalt Pavement Micro-Texture

Abstract Three-dimensional image reconstruction is one of the basic methods to obtain the micro-texture characteristics of body surface. In this study, a novel 3D-reconstruction measurement technique is proposed to rapidly and reliably capture the features of asphalt pavement micro-texture. This technique is based on the depth-from-focus principle. Sequential images of pavement texture are hierarchically photographed using a monocular stereo microscope installed perpendicularly to the surface of asphalt specimen. These images focus on different depths of the pavement surface, and each pixel on the clear area of the images are orientated and combined into a fused image through the new proposed algorithm, which introduces the improved Laplacian focus operator. The three-dimensional picture of micro-texture can be reconstructed utilizing the MATLAB software with the altitude data of the pixels obtained through the Gaussian interpolation. Laboratory tests are described and the results exhibit that the proposed method can accurately reconstruct the three-dimensional micro-texture of asphalt pavement.

Evolution and clinical application of microsurgery

Evolution and clinical application of microsurgery

A history of urine microscopy.

The naked-eye appearance of the urine must have been studied by shamans and healers since the Stone Age, and an elaborate interpretation of so-called Uroscopy began around 600 AD as a form of divination. A 1000 years later, the first primitive monocular and compound microscopes appeared in the Netherlands, and along with many other objects and liquids, urine was studied from around 1680 onwards as the enlightenment evolved. However, the crude early instruments did not permit fine study because of chromatic and linear/spherical blurring. Only after complex multi-glass lenses which avoided these problems had been made and used in the 1820s in London by Lister, and in Paris by Chevalier and Amici, could urinary microscopy become a practical, clinically useful tool in the 1830s. Clinical urinary microscopy was pioneered by Rayer and his pupils in Paris (especially Vigla), in the late 1830s, and spread to UK and Germany in the 1840s, with detailed descriptions and interpretations of cells and formed elements of the urinary sediment by Nasse, Henle, Robinson and Golding Bird. Classes were held, most notably by Donné in Paris. After another 50 years, optical microscopy had reached its apogee, with magnifications of over 1000 times obtainable free of aberration, using immersion techniques. Atlases of the urinary sediment were published in all major European countries and in the US. Polarised light and phase contrast was used also after 1900 to study urine, and by the early 20th century, photomicroscopy (pioneered by Donné and Daguerre 50 years previously, but then ignored) became usual for teaching and recording. In the 1940s electron microscopy began, followed by detection of specific proteins and cells using immunofluorescent antibodies. All this had been using handheld methodology. Around 1980, machine-assisted observations began, and have dominated progress since.

Towards malaria microscopy at the point-of-contact: an assessment of the diagnostic performance of the Newton Nm1 microscope in Uganda.

Malaria microscopy in sub-Saharan Africa is often restricted by access to light microscopes. To address this gap, a novel portable inverted monocular microscope, the Newton Nm1, was designed and is now commercially available. Its diagnostic performance was assessed in a blinded-slide trial at ×1000 (oil) of Giemsa-stained thick blood films against a conventional microscope as undertaken by four Ugandan Ministry of Health technicians. With the Newton Nm1, diagnostic performance was: sensitivity 93.5% (95% confidence interval (CI) 78.6-99.2%), specificity 100.0% (95% CI 82.4-100.0%), positive predictive value 100.0% (95% CI 88.1-100.0%) and negative predictive value 90.5% (95% CI 69.6-98.8%). Discordance was due to a systematic error underestimating parasitaemia by ~45%; when counting Plasmodium parasites against 200 white blood cells, blood films with low parasitaemia (i.e. <100 μL(-1) of blood) could be overlooked and misclassified. By contrast, specificity was excellent with no false positives encountered. Whilst proven useful, especially in resource-poor environments, it is still unclear how we can ensure the uptake of the Newton Nm1 within sub-Saharan Africa.

Clinical metabolomics: the next stage of clinical biochemistry.

Centuries of scientific advances have paved the way for the relatively recent great strides in clinical biochemistry, a field which mainly relies upon biochemical analyses of various body fluids, prime amongst which are urine1, blood and cerebrospinal fluid2. Technological innovation, through the introduction of cutting edge instrumentation has enabled decades of substantial improvements in the field of standard analytical chemistry in the clinical setting. At its dawn, clinical biochemistry relied on rudimental approaches, such as in the case of Richard Bright’s (1789–1858) test for proteinuria in cases of suspected renal disease, in which a candle flame was used to heat urine in a tablespoon3. Only minor technological improvements could date back to the early twentieth century. As reported by Olukoga et al.4, the equipment of a clinical pathology laboratory within a 200-bedded American hospital in 1920 listed “a centrifuge, a urinometer, two monocular microscopes, two small substage microscope lights, a Bunsen burner, a Dubosq colorimeter, a basal metabolic rate machine, an electro-cardiograph, a microtome, a knife, a paraffin bath, a few antisera and an assortment of test tubes, beakers and pipettes”.

The effect of visualization method on the performance of simulated microsurgery tasks

The operating microscopes may be a significant cause of fatigue and discomfort in surgeons. The need for the microscope to be placed over the operating field forces surgeons to remain at the microscope's eyepieces at an uncomfortable posture for the entirety of the surgery. This study compared the effects on microsurgical task performance for four visualization methods: a monocular microscope, a binocular microscope, a three-dimensional (3D) flat-panel television display and a two-dimensional (2D) flat-panel television display. Eleven subjects each performed two microsurgical tasks and their performance was documented by video camera. The statistical analysis performed indicated utilization of the microscope as a visualization method increased subject performance. No significant difference in performance between the 2D and stereoscopic visualization methods.

Relevance of Economic Field Microscope in Remote Rural Regions for Concurrent Observation of Malaria &amp;amp; Inflammation

Based on mono station use for >12 continuous years (since 1998) in drug resistant core endemic region, India, anti-inflammatory effect on WBC is demonstrated using a simple; economic monocular microscope that can be used out in the open—using day light/lamp. Is infinitely helpful for rural clinicians and the administrations, in developing nations. Although indispensable, a field microscope has become expensive; is in short supply; there is a crying need in the rural and the remote.

A test for the assessment of the duration of the action of neostigmine and of the relative potencies of various anticholinesterases using the pupil of the mouse.

Abstract The miotic effect of anticholinesterases was used to monitor the duration of their activity and to compare the relative potency of different members of this group. Female albino mice were used and the diameter of their pupils measured with the help of a monocular microscope at a magnification of × 60. After a suitable control period, readings were taken at 30 min intervals. This test was found to be superior to previous tests described for the same purpose.

History of Microsurgery

In the mid-1500s, the techniques of vascular ligature and vascular suture were developed sporadically by several pioneers in this field. However, vascular surgery became realistic experimentally as a result of the work by Carrel and Guthrie in the early 1900s, in which they performed replantations and transplantations of several composite tissues and organs, including amputated limbs, kidneys, and others using experimental animals. In contrast, the development of heparin by Howell and Holt in 1918 accelerated the rate of these types of operations being performed with increasing success in humans. Since the first use of a monocular microscope for ear surgery by Nylen in 1921 and a binocular microscope by Holmgren in 1923, in addition to the timely developments of the Zeiss operating microscope, microsurgical instruments, and suture materials, microsurgery was born in several surgical disciplines in the ensuing 50-year period. The application of microvascular surgery and microneurosurgery in the fields of hand, plastic, and reconstructive surgery resulted in revolutionary advances in clinical replantation and transplantation of composite tissues and more allotransplantations.

Experimental studies on cryogenic recycling of printed circuit board

Printed circuit board (PCB) recycling is an important challenge for today’s industry. This paper presents results from a study of cryogenic decomposition as a potential alternative recycling method for obsolete printed circuit board scraps. In this method liquid nitrogen is employed as a cryogen to form an environment as low as 77 K for PCB treatment. In order to test the effect of thermal stress set-up during the rapid cryogenic treatment, impact tests were used to simulate the current shredding process. The treated PCB scraps were investigated under a monocular microscope with a 200X magnitude for micro-crack effect observation. Fatigue behavior of the boards was also examined by repeating the cryogenic treatment. The experimental results, as analyzed, demonstrated no obvious support to this alternative PCB recycling method. The energy absorbed during the impact tests for the cryogenically treated boards is insignificantly different from those without the treatment.

Exploiting the Binocular Head in Polarized Light Microscopy

Abstract Having been brought up on monocular microscopes I find the omnipresent binocular systems a luxury. To support this viewpoint I'd like to suggest some benefits you may not have considered. Because I'm used to monocular viewing I sometimes use two different oculars, say 10X and 25X, in order to scan quickly to find an area of interest and then to examine the detail with higher magnification. Occasionally I use both oculars simultaneously and “concentrate” on either image to the exclusion of the other. A better way is to set the interocular distance at the extreme setting most different from your own interocular distance. By moving your head about a centimeter either way you can use either ocular. A variation of this theme is very helpful when you are trying to find good crystals showing useful interference figures.