High-pressure die-casting (HPDC) AZ91 tensile specimens were used to investigate characteristics of gas pores and their effects on mechanical properties of HPDC AZ91 magnesium (Mg) alloy. Combining the stereoscopic morphology of gas pores obtained from a three-dimensional (3D) reconstruction technique with the experimental data from uniaxial tensile testing, we worked on finite element simulation to find the relationship between gas pores and the mechanical properties of HPDC AZ91 Mg alloy. Results indicate that the 2D metallography images have one-sidedness. Moreover, gas pores >100 µm in the center region have a remarkable negative influence on the ultimate tensile strength (UTS) and elongation. With an increase in the size of large gas pores in the center region, the UTS and elongation of the material decreases. In addition, the distribution of gas pores in the specimens and the areal fraction of gas pores >100 µm on cross sections can also affect the UTS and elongation to some extent.

We investigated the effect of focused ion beam (FIB) imaging on the crystallinity of InAs using Raman scattering. A spatial correlation model was used to fit the broad band induced by FIB imaging. The fitting gives a correlation length of ~42 Å for the noisiest image condition (with an ion fluence of 7.4×1010 cm−2), implying severe damage in the surface layer of InAs. However, further increasing the fluence by several orders of magnitude only decreases the correlation length from 42 to 35 Å. We attribute the severe damage to the high beam current density and the low scanning speed of the FIB imaging process. These process conditions, along with low InAs thermal conductivity, also leads to a high local temperature in the exposed region that largely annihilated the defects and resulted in the nearly fluence-independent behavior.

Mechanical properties of the arterial wall depend largely on orientation and density of collagen fiber bundles. Several methods have been developed for observation of collagen orientation and density; the most frequently applied collagen-specific manual approach is based on polarized light (PL). However, it is very time consuming and the results are operator dependent. We have proposed a new automated method for evaluation of collagen fiber direction from two-dimensional polarized light microscopy images (2D PLM). The algorithm has been verified against artificial images and validated against manual measurements. Finally the collagen content has been estimated. The proposed algorithm was capable of estimating orientation of some 35 k points in 15 min when applied to aortic tissue and over 500 k points in 35 min for Achilles tendon. The average angular disagreement between each operator and the algorithm was −9.3±8.6° and −3.8±8.6° in the case of aortic tissue and −1.6±6.4° and 2.6±7.8° for Achilles tendon. Estimated mean collagen content was 30.3±5.8% and 94.3±2.7% for aortic media and Achilles tendon, respectively. The proposed automated approach is operator independent and several orders faster than manual measurements and therefore has the potential to replace manual measurements of collagen orientation via PLM.

The effect of carbon contamination on the analysis of carbon-coated silicate minerals at 5 kV for X-ray energies 0.7–4 keV is examined. For individual spot analyses, carbon is found to deposit adjacent to the beam spot forming ring-shaped deposits with no impact on the analysis. Carbon contamination becomes important for closely spaced analyses such as multipoint transects, where each subsequent analysis overlaps the carbon ring of the previous analysis. X-ray intensity loss due to contamination is most severe for low-overvoltage elements such as Ca K consistent with carbon deposition effectively reducing beam energy. Rates of contamination are calculated and the use of a liquid nitrogen cold trap is shown to greatly reduce the amount of carbon deposited. A complimentary empirical correction is developed to correct for X-ray intensity loss from measured carbon, assuming the carbon is a film, and is compared with corrections derived from thin film calculations. PENELOPE electron probe microanalysis (PENEPMA) calculations confirm that asymmetry of the carbon deposition can be ignored for X-ray energies where intensity loss is predominantly through energy loss of beam electrons. Using a cold trap and/or an empirical correction high spatial resolution analysis (ca. 400 nm between points) is achievable with analytical errors of ca. 1–3%.

Optimized quantitative electron-probe microanalysis was applied for compositional characterization of a ferroelectric ceramic single crystal that was made from the complex perovskite-type solid-solution (1–x)Pb(Mg1/3Nb2/3)O3×xPbTiO3 (PMNT). Cation concentrations were determined with high accuracy and ultimate relative experimental uncertainty of ≤±1%, showing that the average chemical composition of the crystal corresponds to Pb(Mg1/3Nb2/3)0.67Ti0.33O3 (i.e., x=0.33), which is close to the morphotropic phase boundary composition. Over the PMNT single crystal slight compositional heterogeneity was measured for concentrations of the perovskite B-site cations Ti4+, Mg2+, and Nb5+, with variations up to ±2.3%, whereas the Pb concentration remained uniform within a variation below ±0.5%.

We hyposthesized that henna staining could provide an alternative to eosin when used as a counterstain to hematoxylin for understanding basic neurohistological principles. Therefore, this study was aimed at investigating the suitability of henna as counterstain to hematoxylin for the demonstration of the layer stratification and cellular distribution in the brain tissue. Henna stained nervous tissue by reacting with the basic elements in proteins via its amino groups. It stained the neuropil and connective tissue membranes brown and effectively outlined the perikarya of neurons with no visible nuclei demonstrating that it is an acidic dye. Henna as a counterstain to hematoxylin demonstrated reliability as a new neurohistological stain. It facilitated identification of cortical layer stratification and cellular distribution in brain tissue sections from Wistar rats. This was comparable to standard hematoxylin and eosin staining as morphological and morphometrical analyses of stained cells did not show significant differences in size or number. This study presents a method for staining with henna and demonstrates that although henna and eosin belong to different dye groups (anthraquinone and xanthenes, respectively) based on their chromophores, they share similar staining techniques and thus could be used interchangeably in neurohistology.

Different compounds of edible mushrooms are responsible for their bioactivity. The ability to synthesize polysaccharides, namely protein–polysaccharide (PPS) complexes, is related to the antioxidant capacity of these compounds and present great interest in preventing a number of diseases, including cancer, cardiovascular and auto-immune diseases, and accelerated aging. Amanita ponderosa are wild edible mushrooms that grow in Mediterranean “montado” areas [Portuguese name given to cork oak (Quercus suber) and holm oak (Quercus ilex) forests]. The aim of this study was to evaluate the production of PPS complexes obtained from A. ponderosa cultures using a new microanalytical approach to quickly and easily monitor the production process. Microanalysis using Fourier-transform infrared using attenuated total reflection and Raman spectroscopy of PPS samples showed spectra compatible with identification of this type of compound in culture extracts. PPS separated by size-exclusion chromatography showed seven main complexes. Molecular weights of the main PPS complexes isolated from cultures ranged between 1.5 and 20 kDa and did not present toxicity against Artemia salina, demonstrating the potential of A. ponderosa as a source of biologically active compounds with nutraceutical value. Application of this microanalytical approach to monitoring the production of PPS compounds can be successfully applied in biotechnological processes.

As for many invertebrates, the gut of marine polychaete species has key physiological functions. However, studies integrating microanatomical descriptions with physiological processes are scarce. The present investigates histological, histochemical and cytological changes in the alimentary canal during the digestive cycle of the marine annelid Eulalia viridis, a species that combines opportunist scavenging, predation and cannibalistic behavior. The gut is comprised of an eversible pharynx, esophagus, intestine and rectum. Three main phases of digestion were identified, namely, resting/secretory, absorptive and excretory. The intestinal epithelium is complex and exhibited the most significant changes regarding intracellular digestion, excretion and storage. Conversely, the pharynx and esophagus were chiefly important for enzyme secretion. The results also indicate the existence of two distinct types of secretory cells in the intestine, with likely distinct physiological roles. Some similarities have been found between the intestinal epithelia and the molluscan (especially cephalopod) digestive gland, as, for instance, the shedding of apical corpuscles by digestive cells at posterior stages of digestion. The findings indicate that the digestive process in this worm is complex and related to the many physiological roles that cells need to play in the presence of reduced organ differentiation.

In our previous study, a novel hybrid protein combining human lysozyme (Hly) with Musca domestica cecropin (Mdc) was successfully constructed. The broad antibacterial activity against various foodborne pathogens of Mdc-hly suggests its scope as a food preservative. The aim of the present study was to investigate the antibacterial mechanism of the recombinant Mdc-hly. The damage induced by Mdc-hly on Staphylococcus aureus and Escherichia coli was investigated using flow cytometry (FC), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results of FC showed that Mdc-hly causes bacterial membrane permeabilization. SEM and TEM studies revealed that Mdc-hly is capable of damaging both the membrane and the wall of bacteria, resulting in efflux of essential cytoplasmic contents. Both FC and EM revealed that the effects of Mdc-hly were greater than its parental peptides. Understanding the antibacterial mechanism of Mdc-hly is of a great interest in further utilization of its use in treatment of food and in clinical environments.

With the need for improvements in the performance of rechargeable batteries has come the necessity to better characterize cell electrodes and their component materials. Electron microscopy has been shown to reveal many important features of microstructure that are becoming increasingly important for understanding the behavior of the components during the many charge/discharge cycles required in modern applications. The aim of this paper is to present an overview of how the full suite of techniques available using transmission electron microscopy (TEM) and scanning transmission electron microscopy was applied to the case of materials for the positive electrode in nickel metal hydride rechargeable battery electrodes. Embedding and sectioning of battery-grade powders with an ultramicrotome was used to produce specimens that could be readily characterized by TEM. Complete electrodes were embedded after drying, and also after dehydration from the original wet state, for examination by optical microscopy and using focused ion beam techniques. Results of these studies are summarized to illustrate the significance of the microstructural information obtained.