Kiyoteru Tokuyasu: a pioneer of cryo‐ultramicrotomy

In July 2015 Professor K.T. Tokuyasu passed away in San Diego giving us the opportunity to reflect on the contribution this electron microscopist made to the field of immunocytochemistry. His work provided a sensitive, minimally invasive approach to producing thin sections of biological material for labeling with antibodies. His approach has been applied to a wide range of biological applications and provided important information on cellular processes.     

Imaging techniques for observing laminar geometry in the feather shaft cortex

By being at the interface of the exocytic and endocytic pathways, the plant trans-Golgi network (TGN) is a multitasking and highly diversified organelle. Despite governing vital cellular processes, the TGN remains one of the most uncharacterized organelle of plant cells. In this review, we highlight recent studies that have contributed new insights and to the generation of markers needed to answer several important questions on the plant TGN. Several drugs specifically affecting proteins critical for the TGN functions have been extremely useful for the identification of mutants of the TGN in the pursuit to understand how the morphology and the function of this organelle are controlled. In addition to these chemical tools, we review emerging microscopy techniques that help visualize the TGN at an unpreceded resolution and appreciate the heterogeneity and dynamics of this organelle in plant cells.     

Determination of diffusion controlled reaction rates at a solid/liquid interface using scanning electron microscopy

A high‐resolution method has been developed for the determination of localized values of interfacial reaction rate and mass transfer coefficient in aqueous solution. Scanning electron microscopy has been successfully applied to this problem through the measurement of electroplated film thickness formed under limiting current conditions. The method involves the calculation of local values of reaction rate via Faraday's laws and subsequent conversion of the data to absolute values of mass transfer coefficient. The technique has been verified in an undisturbed, turbulent flow regime (rotating cylinder electrode) through the use of Sherwood group dimensionless analysis. The resulting relationship shows comparable accuracy relative to electrochemical measurements. Favourable comparison has also been made with the generally accepted rotating cylinder correlation of Eisenberg, Tobias and Wilke. Differential rates of mass transfer to a single surface under conditions of disturbed flow have also been examined at a high spatial resolution using the stepped rotating cylinder electrode geometry. In this case, reaction rates have been measured as a function of circumferential distance within a recirculation zone situated immediately downstream of a backward‐facing step.     

Transmission Electron Microscopy of Pb(Zr0.52Ti0.48)O3

Transmission electron microscopy of Pb(Zr_0.52Ti_0.48)O₃ sintered with 3 wt% excess PbO indicates that there is an amorphous grain-boundary phase 10 nm thick. The grain-boundary phase has a higher Pb content than the bulk material. Influence of such a phase on sintering is discussed.     

Electron Microscopy of Ferrites

This paper describes some electron microscopy studies of magnetic ferrites with special emphasis on LiFe₄O₈ and including some results on NiFe₂O₄ and SrFe₁₂O₁₈, The paper is concerned with analysis of the crystallography, defect structure, and phase transformations and their relations to magnetic properties, viz. coercivity and hysteresis characteristics.     

Microstructure and Grain-Boundary Composition of Hot-Pressed Silicon Nitride With Yttria and Alumina

The microstructure of two hot-pressed silicon nitrides containing Y₂O₃ and Al₂O₃ was examined by electron microscopy, electron diffraction, and quantitative, energy-dispersive X-ray microanalysis. A crystalline second phase was identified in the material with additives of 5 wt% Y₂O₃+2 wt% Al₂O₃, as a solid solution of nitrogen mellilite and alumina. An amorphous third phase as narrow as 2 nm is discerned at all grain boundaries of this material by high-resolution dark-field and lattice imaging. The second phase in a material with additives of S wt% Y₂O₃+5 wt% Al₂O₃ was found to be amorphous. Some of the additional alumina additive appears in solid solution with silicon nitride. In situ hot-stage experiments in a high-voltage electron microscope show that the amorphous phase volatilizes above 1200°C, leaving a skeleton of Si₃N₄ grains linked by the mellilite crystals at triple points. The results show that intergranular glassy phases cannot be eliminated by the Y₂O₃/Al₂O₃ fluxing.     

Effective diffusivity of total solids and pectic substances from apple tissue

The effective diffusivities of total solids and pectic substances from apple tissue were determined at 40 and 60°C in water and buffer; the addition of pectolytic enzyme in buffer at 40°C was also investigated. the Fickian model for unsteady-state diffusion was applicable in all cases. Effective diffusivity values both for total solids and soluble pectic substances in deionized water were temperature dependent. the effective diffusivity values for total solids loss were reduced by the presence of buffer at 40°C but not at 60°C. the effective diffusivity values for soluble pectic substances were not affected by buffer at 40°C but were noticeably lower at 60°C compared to deionized water at the same temperature. the addition of a pectolytic enzyme preparation did not improve the mass transfer of either total solids or soluble pectic substances.