An evaluation for the medium-term storage and viability of root cortex tissues stained with blue ink in the assessment of arbuscular mycorrhizal fungi

Sheaffer blue ink is an effective method to stain arbuscular mycorrhizal (AM) fungi in a variety of plant species. It has, however, received criticism for its potential rapid degradation and short-term viability. The long and medium term storage and viability of stained samples has not, to date, been described for this particular staining method. This short communication reports on the viability of 730 samples stained with Sheaffer blue ink stored for the duration of 4 years in microscope slide boxes out of direct sunlight. There was no significant difference in micrograph image quality and presence of stain between years as indicated by the number of AM fungal structures quantified. In conclusion Sheaffer blue ink stain does not deteriorate in the medium term.

Ageing Effects in Mounting Media of Microscope Slide Samples from Natural History Collections: A Case Study with Canada Balsam and PermountTM

Microscope slide collections represent extremely valuable depositories of research material in a natural history, forensic, veterinary, and medical context. Unfortunately, most mounting media of these slides deteriorate over time, with the reason for this not yet understood at all. In this study, Raman spectroscopy, ultraviolet–visible (UV–Vis) spectroscopy, and different types of light microscopy were used to investigate the ageing behaviour of naturally aged slides from museum collections and the experimentally aged media of Canada balsam and PermountTM, representing a natural and a synthetic resin, respectively, with both being based on mixtures of various terpenes. Whereas Canada balsam clearly revealed chemical ageing processes, visible as increasing colouration, PermountTM showed physical deterioration recognisable by the increasing number of cracks, which even often impacted a mounted specimen. Noticeable changes to the chemical and physical properties of these mounting media take decades in the case of Canada balsam but just a few years in the case of PermountTM. Our results question whether or not Canada balsam should really be regarded as a mounting medium that lasts for centuries, if its increasing degree of polymerisation can lead to a mount which is no longer restorable.

A Parallel Perifusion Slide From Glass for the Functional and Morphological Analysis of Pancreatic Islets

An islet-on-chip system in the form of a completely transparent microscope slide optically accessible from both sides was developed. It is made from laser-structured borosilicate glass and enables the parallel perifusion of five microchannels, each containing one islet precisely immobilized in a pyramidal well. The islets can be in inserted via separate loading windows above each pyramidal well. This design enables a gentle, fast and targeted insertion of the islets and a reliable retention in the well while at the same time permitting a sufficiently fast exchange of the media. In addition to the measurement of the hormone content in the fractionated efflux, parallel live cell imaging of the islet is possible. By programmable movement of the microscopic stage imaging of five wells can be performed. The current chip design ensures sufficient time resolution to characterize typical parameters of stimulus-secretion coupling. This was demonstrated by measuring the reaction of the islets to stimulation by glucose and potassium depolarization. After the perifusion experiment islets can be removed for further analysis. The live-dead assay of the removed islets confirmed that the process of insertion and removal was not detrimental to islet structure and viability. In conclusion, the present islet-on-chip design permits the practical implementation of parallel perifusion experiments on a single and easy to load glass slide. For each immobilized islet the correlation between secretion, signal transduction and morphology is possible. The slide concept allows the scale-up to even higher degrees of parallelization.

Dually nanocoated planar waveguides towards multi-parameter sensing

The incidence of light on the edge of a glass coverslip for a microscope slide, deposited with a thin film on both faces, permits exciting two resonances in each polarisation state of the input light, TE and TM. This dually nanocoated waveguide can be used for detecting simultaneously two different parameters on the basis of a further deposition of suitable materials on each face. As an example, the possibility of detecting temperature and humidity by using polydimethylsiloxane and agarose coatings, respectively, was demonstrated, which opens the path for the development of other dual-parameter sensors, and for even more parameters in cases in which each face of the coverslip is patterned. Moreover, the device was optimised in order to position two resonances in the near infrared (NIR) and two resonances in the visible region, with sensitivities of 0.34 nm/°C and 0.23 nm/%RH in the visible region and 1.16 nm/°C and 0.34 nm/%RH in the NIR, respectively, demonstrating the possibility of using the device in both spectral ranges and opening the path for the development of sensors based on multiple resonances, each one related to a different parameter to be detected.

Shared Makeup Cosmetics as a Route of Demodex folliculorum Infections

Purpose The aim of the study was to examine Demodex survival in makeup cosmetics, i.e., powder cream, mascara, and lipstick, and to determine whether cosmetics shared with others can be a source of D. folliculorum infection. Methods Live D. folliculorum adults were placed in cosmetic samples and their motility was observed under a microscope. The mites were fully or partially immersed in the powder cream and lipstick, and only partially immersed in the mascara. Partial immersion means that only the opisthosoma was covered by the cosmetic, whereas the gnathosoma and podosoma had no contact with the cosmetic. Cessation of motility was regarded as a sign of death. Results In the control (mites placed on a microscope slide with no cosmetics), the survival time was 41.2 h. D. folliculorum that were immersed fully or partially in the lipstick substrate were viable for 38.5 h and 148 h, respectively. The survival time of the mites at full and partial immersion in the powder cream was 0.78 h and 2.16 h, respectively. The average survival time in the mascara was 21 h. Conclusions Makeup cosmetics used by different individuals at short intervals (from several hours to several days) can be a source of transmission of Demodex sp. mites.

DETERMINATION OF THE COMPOSITION OF EAR CONTENTS MICROFLORA IN DOGS WITH OTITIS SIGNS BY USING MICROSCOPIC ANALYSIS

Otitis in domestic carnivores, particularly in dogs, is an important problem in veterinary science and practice. Ac-cording to various Russian and foreign authors, the spread of otitis externa in dogs varies from 12.5 to 37%. The re-search goal was to study microscopic examination as an effective method for determining the composition of ear contentmicroflora in dogs. The research objective was to conduct a microscopic analysis of the collected material for the comprehensive diagnosis of otitis in dogs. The studies were carried out at the Department of Anatomy and Physi-ology of the State Agricultural University of Northern Trans-Urals and at the veterinary clinics of the City of Tyumen. The samples from 58 dogs were examined microscopically. All animals underwent initial examination. The samples were taken from both ears. The material was applied to a microscope slide, and then dried and Gram stained. The study revealed that in 15 dogs (35%) with suspected exter-nal ear inflammation, coccal forms of bacteria were found; that was indicative of the presence of Staphylococcus spp. and Streptococcus spp. Rod-shaped bacteria were found in 10 dogs (25%), indicating the presence of Proteus spp. and Pseudomonas. Yeast fungi were found in 17 individuals (40%). Fungi were represented by Mallasezia spp and, in isolated cases, Candida. In 42 individuals (75%) with sus-pected inflammation of the external acoustic meatus, the examination revealed bacteria and yeast fungi. The studies have shown that microscopic analysis is an important diag-nostic tool to evaluate the process of inflammation and identify the causes of secondary infection. This analysis may and should be used to identify the qualitative and quantitative composition of microorganisms in the patho-logical material from the ear canal content of sick dogs

Enhancement the Agglutination of Erythrocytes in Blood Typing Test by Acousto-Optic Technique

A proposed modern technique for determination the blood group typing by monitoring the agglutination of red blood cells using acousto-optical technique and digital camera. The method based on analysis the digital image of the agglutination process by MATLAB software. We present an overview of two acousto-optic sensing approaches; the first demonstrates the cuvette approach while the second is the microscope slide approach. The cuvette approach digital image analyzing depends on the green channel distribution of the original image and count the brighten pixels, while the microscope slide approach passes through series of algorithms started with grayscale filter and end with edge detection it counts the different color pixels. The experimental result shown that it is possible to enhance the determination of blood group typing by using acousto-optical technique in both cases of using isohemagglutinating sera as well as the crossmatch test in a short time and high efficiency compared with the traditional methods.

Face Coverings and Respiratory Tract Droplet Dispersion

Respiratory droplets are the primary transmission route for SARS-CoV-2. Evidence suggests that virus transmission can be reduced by face coverings, but robust evidence for how mask usage might affect safe distancing parameters is lacking. Accordingly, we investigate the effectiveness of surgical masks and single-layer cotton masks on mitigating dispersion of large respiratory droplets (i.e. non aerosol). We tested a manikin ejecting fluorescent droplets and human volunteers in speaking and coughing conditions. We quantified the number of droplets in flight using laser sheet illumination and UV-light for those that had landed at table height at up to 2m. For human volunteers, expiratory droplets were caught on a microscope slide 5cm from the mouth. Whether manikin or human, wearing a face covering decreased the number of projected droplets by >1000-fold. We estimated that a person standing 2m from someone coughing without a mask is exposed to over 1000 times more respiratory droplets than from someone standing 5 cm away wearing a basic single layer mask. Our results indicate that face coverings show consistent efficacy at blocking respiratory droplets. If aerosol transmission is later determined to be a significant driver of infection, then our findings may overestimate the effectiveness of face coverings.