Protein casting: A new replication technique for observing fluid surface structures

Certain insoluble copolymers form characteristic liquid crystalline structures at water/copolymer interfaces. The formation of these structures, discernable with phase contrast microscopy, correlates with biological activities as immunological adjuvants. In order to study such structures at the electron microscopic level, it was necessary to develop a preparation technique which preserved the water/polymer interface. A technique was devised, here called “protein casting,” which uses highly concentrated bovine serum albumin (BSA) in water, subsequently fixed with glutaraldehyde, to form a replica of the water/polymer interface. These casts appeared highly accurate at low magnifications, and resolved to less than 1ønm. This technique seems ideal for accurate replication of surfaces formed by nonmiscible liquids and should prove helpful in studies of other materials in aqueous suspension.     

A robust focusing and astigmatism correction method for the scanning electron microscope—Part III: An improved technique

As described in a previous work, a new technique has been developed to perform automatic focusing and astigmatism correction on any general scanning electron microscope (SEM) sample ranging from gold-on-carbon to integrated circuit (IC) tracks. In this work, various improvements made to this technique are reported. They include the implementation of direct control of the SEM and the development of three new algorithms, namely the adaptive fast Fourier transform (FFT) algorithm, the coarse focusing algorithm, and the fine focusing algorithm. Direct control reduces the communication time with the SEM while the three new algorithms are integrated with the existing technique to make it even more robust to noise and to extend it to correct images with any degree of defocus and astigmatism. The enhanced focusing and astigmatism correction algorithm is able to perform the correction in a shorter time while maintaining the accuracy of the original algorithm even under noisy conditions.     

Morphology of the tongue dorsal surface of gilthead seabream (Sparus aurata)

The gilthead seabream is a food fish, one of the most frequently used in aquaculture. In the species of commercial interest, feeding in captivity is very important and this process is strictly related to the morphological characteristics of the oral cavity. The aim of this study is, using the standard procedures for light and scanning electron microscopy, to analyze the morphology of the tongue dorsal surface to show if relationships are present between the tongue morphology and the nutritional habits and choices of this farmed species. The main characteristic of the gilthead seabream oral cavity floor is the presence of an apical pouch, with, probably, a protective role mainly for the apical, free part of the tongue. Three zones, like in other teleosts, an apex, a body and a root, can be clearly distinguished. In the pouch foliate‐like papillae were observed, while the whole tongue is characterized by the presence of two types of papillae, respectively with a fungiform and cylindroid aspect, both randomly distributed throughout the whole dorsal surface of the tongue. Scattered and numerous taste buds, with the typical pear‐onion shape, together with small and numerous taste pores are also present, distributed throughout the tongue surface. Our results demonstrate that in the gilthead seabream important mechanic and sensory roles are carried out by specific anatomical structures. Our anatomical data could give, together with further biochemical and physiological data, an important support with the aim of improving the nutrition of aquaculture species. Microsc. Res. Tech. © 2012 Wiley Periodicals, Inc.     

Morphology,distribution, and abundance of antennal sensilla of male and female macropterous and brachypterous small brown planthopper,Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae)

The antennal sensilla of both genders of macropterous and brachypterous adults of the small brown planthopper, Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae) were examined using light and scanning electron microscopy. Scanning electron microscopy revealed seven types of antennal sensilla in adult L. striatellus which were not evenly distributed on all antennal segments. Sensilla chaetica, a sensillum campaniformium and a Böhm bristle were found on the scape. Sensilla chaetica, sensilla trichodea, sensilla placodea which always present as plaque organs, sensilla basiconica and a sensillum campaniformium were present on the pedicel. Three sensilla basiconica and one sensillum coeloconicum containing two sensory pegs were located on the swollen sensory region of the basal flagellum. Pores observed on the surface of s. trichodea and s. placodea suggest these organs probably play a role in olfaction, whereas the aporous s. chaetica with flexible sockets probably function as mechanoreceptors. The aporous s. basiconica with inflexible sockets are probable to be thermo‐hygroreceptors while the Böhm bristle and s. campaniformia may act as antennal proprioceptors. The function of s. coeloconicum remains uncertain. The numerical dominance of antennal olfactory receptors suggests olfaction is an important function of the antenna in L. striatellus. Although a small degree of sexual/wing dimorphism was observed in the numbers of sensilla and in the length and width of antennae and antennal segments, the basic shape and structure of the antennae and antennal sensilla did not differ between the gender or wing form in L. striatellus. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.     

The development of the modified Hurst orientation transform for the characterization of surface topography of wear particles

A modified Hurst orientation transform (HOT) method for characterization of wear particle surfaces is proposed and described in this paper. The method involves the calculation of self-affine Hurst coefficients in all directions and displays the calculated coefficient values in a form of rose plot. The calculation of individual Hurst coefficients, H, is based on the rescale range (r/s) analysis (r(d)/s∼ d ^H ). The rose plot is then used to obtain three texture surface parameters, i.e.: texture aspect ratio, texture minor axis and texture direction. The effectiveness of this modified HOT and resulting surface texture parameters was evaluated. The method was first applied to computer-generated images of isotropic and anisotropic particle fractal surfaces and then to field emission scanning electron microscope images of wear particles found in synovial joints. The ability of the surface parameters to reveal surface isotropy or anisotropy, measure roughness and determine the dominant direction of surface texture was assessed. The effects of measurement conditions such as noise, gain variations and focusing on the surface parameters were also investigated. The results demonstrate that the HOT and surface texture parameters developed can successfully be used in the characterization of wear particle surface topography. This revised version was published online in August 2006 with corrections to the Cover Date.     

A robust focusing and astigmatism correction method for the scanning electron microscope—Part II: Autocorrelation-based coarse focusing method

This paper describes the development of a new coarse focusing algorithm for the scanning electron microscope (SEM). The algorithm is based on a new focus parameter that has been developed for quantifying the sharpness of an image. This parameter is found to be more robust to noise compared with other conventional focus parameters. A peak detection technique is also incorporated to shorten the number of iterations needed for the coarse focusing. Results show that the coarse focusing algorithm is able to bring a defocused and astigmatic image to either the best focus, the upper line focus, or the lower line focus in fewer iterations compared with the conventional approach in which the full focus range is searched.     

Three-dimensional microscopic biopsy of in vivo human skin: a new technique based on a flexible confocal microscope

A new noninvasive microscopic technique of three-dimensional optical biopsy from in vivo human skin based on real-time confocal microscopy and computer reconstruction is demonstrated. A tandem scanning confocal microscope is a prototype of a mobile, flexible design for the in-depth microscopic exploration of the skin on the human body. The various skin layers were observed in real-time, at the subcellular level down to a depth of 200 μm with a vertical resolution of 2 μm. Rapid video recording of the Z-series through the ventral aspect of the forearm avoided shifts caused by subject movement and blood flow pulsations. Two video frames were averaged, and the average was digitized, providing a stack of 64 optical sections in 1-μm vertical steps. Three-dimensional reconstructions of in vivo human skin were obtained with sets of orthogonal slices, and slices at arbitrary planes through a volume containing the stack of slices. This method clearly shows the spatial relationships between the different cell layers. The use of orthogonal cutting planes is preferred because of its analogy with classical vertical sections of histopathology. Linear structures (surface lines) within the stratum corneum are described and their global orientations were determined by the use of Fourier transform analysis. En face optical sections constitute unusual views of this tissue, since typical pathohistological studies are based on sagittal (vertical) slices. The noninvasive optical microscopic technique provides a three-dimensional optical biopsy of in vivo human skin.     

Low-energy electron microscopy (LEEM) and mirror electron microscopy (MEM) of biological specimens: Preliminary results with a novel beam separating system

Low-energy electron microscopy (LEEM) and mirror electron microscopy (MEM) utilize a parallel beam of slow-moving electrons backscattered from the specimen surface to form an image. If the electrons strike the surface an LEEM image is produced and if they are turned back just before reaching the surface an MEM image results. The applications thus far have been in surface physics. In the present study, applications of LEEM and MEM in the biological sciences are discussed. The preliminary results demonstrate the feasibility of forming images of uncoated cultured cells and cellular components using electrons in the threshold region (i.e. 0–10 V). The results also constitute a successful test of a novel beam-separating system for LEEM and MEM.     

Performance of ionic polymer-metal composite (IPMC) with different surface roughening methods

Based on permeation and double chemical reduction technology, this paper researches the manufacture of Pt-ionic polymer metal composites (IPMC) and the effect of three types of surface roughening methods on the manufacture and performance of IPMC. The roughening methods include manual polishing, sanding machine polishing, and plasma surface treatment. The appearance and scanning electron microscopy (SEM) features, electro-active deformation and surface resistance characteristics of these IPMC specimens were obtained and compared through specimen tests. The results of the tests indicate that surface roughening technology obviously influences the performance of IPMC. The uniformity and compactness of the metal deposited on the surface and inside the Nafion film are improved by improving surface roughening uniformity. However, the electro-active deformation capability and surface resistance of the specimens decrease at the same time. There is an approximate linear increase relationship between the driving voltage and the bending deformation of the IPMC specimen within a certain voltage range. Under the same specimen dimension, constraints, and driving voltage (3V), the maximum electro-active bending deformation angles of the specimens are about 60°, 45°, and 15° for manual polishing, sanding machine roughening, and plasma treatment, respectively.     

Adsorption properties of aqueous methylene blue on mesocellular foam silica: Equilibrium,kinetic, isotherm,and thermodynamic characterization

Abstract

Mesocellular foam silica was prepared by a hydrothermal synthesis protocol. The surface and pore structure of mesocellular foam silica were characterized by low temperature nitrogen adsorption isotherms, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared (FT-IR) spectroscopy. The methylene blue was adsorbed by the synthetic mesocellular foam silica; the optimized adsorption conditions were evaluated and the maximum adsorption capacity of methylene blue by mesocellular foam silica was determined to be 215.5?mg g^?1. The kinetics of the adsorption of methylene blue by mesocellular foam silica were in accordance with a quasi-second-order kinetic equation. The results were analyzed by Langmuir and Freundlich adsorption isotherm models. The adsorption of methylene blue on mesocellular foam silica was shown to follow the Freundlich adsorption isotherm model. The Gibbs free energy change during adsorption showed that this process was spontaneous. The enthalpy change in the process was –28.868?J·mol^?1 K^?1, indicating that the adsorption is exothermic. The negative value of entropy –49.296?J·mol^?1 K^-1 shows that the system disorder decreases due to adsorption.     

Comparison of restorative materials and surface alterations after prebiotic and probiotic beverages: A nanoindentation and SEM study

The purpose was to investigate the surface characteristics of various resin-based materials by immersing in probiotic beverages. A total of 420 disc-shaped samples (5 mm × 2 mm) were prepared from resin-based composites. Samples were divided into four groups and immersed for 10 min/day for 1 month in either a probiotic sachet, kefir, kombucha, or artificial saliva (control). Surface roughness was measured at baseline and 1 month. One sample of each of the tested materials was examined under nanoindentation to evaluate the reduced elasticity modulus and nanohardness scores. Scanning electron microscopy (SEM) was used to compare surface differences. Data were analyzed statistically using one-way ANOVA test and the significance was set at p < .05. The lowest roughness scores were observed in Z250, Estelite Bulk Fill, and HRi ENA in most of the test groups. Among conventional composites, Z250 group had the highest nanohardness and elasticity modulus scores. Among bulk-fill composites, Estelite Bulk Fill Flow had the lowest surface roughness after immersion in probiotic beverages and the highest nanohardness values. Reveal HD, as a bulk-fill group showed higher surface roughness and considerably lower nanohardness and elasticity modulus scores. Maximum height levels of samples were recorded. SEM images revealed voids and microcracks on the surfaces of test materials. Dentists may prefer Z250 as microhybrid and Estelite Bulk Fill Flow as bulk-fill composites for the restorations of patients who consume gut-friendly drinks regularly. When there are various types of materials, nanoindentation is a useful method for evaluating surface alterations and sensible comparisons.     

A SEM study of the antenna and mouthparts of Omosita colon (Linnaeus) (Coleoptera: Nitidulidae)

There are direct relationships between the behavioral mechanisms and sensilla. To obtain a better understanding of the behavioral mechanisms in Omosita colon (Linnaeus) (Coleoptera: Nitidulidae), we investigated the types, quantities, and distribution of sensilla on the antenna and mouthparts of O. colon by scanning electron microscopy. The clavate antenna comprised the scape, pedicel, and nine segment flagellomeres and had six types of sensilla, including two subtypes of sensilla chaetica (SC), three subtypes of sensilla basiconica (SB) and sensilla trichodea (ST), and one type of sensilla cavity, sensilla styloconica, and Böhm bristles (BB). The chewing mouthparts of O. colon consist of the labrum, mandible, maxillae, labium, and hypopharynx and had seven types sensilla, including two subtypes of SC and sensilla placodea, seven subtypes of SB, and one type of BB, ST, sensilla coeloconica, and sensilla campaniformia. In this research, we also deduced the relationships between the sensilla on the antenna and mouthparts and their functions.     

Morphological characterization of the oral cavity of the gilthead seabream (Sparus aurata) with emphasis on the teeth‐age adaptation

Gilthead sea bream with different age groups that collected from Seawater fisheries, Ismailia Governorate, Egypt, were examined by gross anatomy and scanning electron microscopy to assess the morphological characteristics of the oral cavity. Teeth patterns showed that the gilthead sea bream is adapted to the feeding pattern according to age development, as it modified from spiny form teeth in young fishes to obelisk‐like teeth and flat dome‐like teeth in growing fishes, with differentiation of teeth into three pairs of canine and conical teeth, that later differentiated to small and large flat teeth. With development, the apical pouch also showed morphological differentiation from curve‐like in small fishes to Y‐letter shape in medium‐sized fishes, which later grow to completely covering the lower jaw in grown adult fishes. Tongue papillae, on the other hand, showed some differentiation being smoother in growing fishes than adult ones. Consistent with development differentiation, the palatine region of young fishes appeared separated from the palate by deep palatine fissure, while that the same palatine region was continuous with the palate with a remnant of palatine fissure as shallow groove was noticed in grown big fishes. Taste buds were characterized in the oral cavity of small and large fishes however in large fishes; the taste buds were more prominent especially at the palate and palatine folds. These and other morphological features of the oral cavity and the feeding habits in small and large gilthead sea bream fishes were recorded. Microsc. Res. Tech. 79:227–236, 2016. © 2016 Wiley Periodicals, Inc.     

Evaluation of fibroblast attachment in root conditioning with Er,Cr:YSGG laser versus EDTA: A SEM study

The regeneration of periodontal support is a main concern in periodontal therapy. This study aims to investigate the efficacy of Er, Cr:YSGG laser and EDTA based conditioning in attachment of fibroblast on root surfaces. This in vitro study was conducted on 81 root plates (6 mm × 4 mm × 1 mm) prepared from 27 single‐rooted human mature teeth. The samples were divided into three groups: (1) Er, Cr: YSGG laser conditioning with a G6 tip (2.78 µm, 0.75 W, pulse duration of 140 µs, repetition rate of 20 Hz) for 5–7 s; (2) EDTA conditioning (17%, pH: 8) for 1 min; and (3) the control group which were exposed neither to EDTA nor laser. The viability and proliferation rates assessments were performed using MTT assay on days 3 and 5. In addition, the level of cell attachment was studied using scanning electron microscopy. The data indicated Er, Cr:YSGG conditioning increased cell viability by lapse of time (from days 3–5), with significantly better cell attachment compared to the other groups on days 3 and 5 (P < 0.05). In addition, increasing cell attachment in the EDTA conditioning group compared with the control group was statistically significant on day 5 but not on day 3 (P < 0.05). In conclusion, Er, Cr:YSGG laser conditioning can promote enhance fibroblast attachment on dentinal root surfaces more than EDTA. Microsc. Res. Tech. 78:317–322, 2015. © 2015 Wiley Periodicals, Inc.     

SEM study of diversity in the cyst surface topography of nine parthenogenetic Artemia (Crustacea: Anostraca) populations from China

The cysts of nine Chinese populations of parthenogenetic Artemia were studied by scanning electron microscope. In the 270 cysts examined, 15 different morphological patterns were recognized with most of them not recorded in previous studies and the “tubercled shell surface” being the most common pattern. Results also displayed high intrapopulation variability, with the maximum of 11 patterns (in 30 cysts) recorded from the Barkol population. No positive correlation between the diversity of cyst shell patterns and ploidy compositions was found. Principal components analysis suggests higher similarity among coastal populations than among inland populations, which may be attributed to the identity of physicochemical conditions among coastal salterns and dissimilarity among inland saline lakes. Microsc. Res. Tech. 77:1005–1014, 2014. © 2014 Wiley Periodicals, Inc.     

Fluorescence anisotropy near-field scanning optical microscopy (FANSOM): a new technique for nanoscale microviscometry

A near-field scanning optical microscope system was implemented and adapted for nanoscale steady-state fluorescence anisotropy measurement. The system as implemented can resolve 0.1 cP microviscosity variations with a resolution of 250 nm laterally in the near field, or 10 μm when employed in a vertical scanning mode. The system was initially used to investigate the extent of microviscous vicinal water over surfaces of varying hydrophilicity. Water above a cleaved mica surface was found to have a decreased microviscosity, while water above a hydrophobic surface showed no change (detection limit 0.1 cP at 30+ nm from the surface).     

Confocal differential interference contrast (DIC) microscopy: including a theoretical analysis of conventional and confocal DIC imaging

A technique for obtaining differential interference contrast (DIC) imaging using a confocal microscope system is examined and its features compared to those of existing confocal differential phase contrast (DPC) techniques as well as to conventional Nomarski DIC. A theoretical treatment of DIC imaging is presented, which takes into account the vignetting effect caused by the finite size of the lens pupils. This facilitates the making of quantitative measurements in DIC and allows the user to identify and select the most appropriate system parameters, such as the bias retardation and lateral shear of the Wollaston prism.