Microscopy of biological specimens often requires low light levels to avoid damage. This yields images impaired by shot noise. An improved measurement accuracy at the Heisenberg limit can be achieved exploiting quantum correlations. If sample damage is the limiting resource, an equivalent limit can be reached by passing photons through a specimen multiple times sequentially. Here we use self-im...

In magnetic resonance electrical impedance tomography (MREIT), we measure the induced magnetic flux density inside an object subject to an externally injected current. This magnetic flux density is contaminated with noise, which ultimately limits the quality of reconstructed conductivity and current density images. By analysing and experimentally verifying the amount of noise in images gathered...

The high-throughput 3D visualisation of biological specimens is essential for studying diseases and developmental disorders. It requires imaging methods that deliver high-contrast, high-resolution volumetric information at short sample preparation and acquisition times. Here we show that X-ray phase-contrast tomography using a single grating can provide a powerful alternative to commonly employ...

Ion beam milling has become a widespread specimen preparation technique for non-biological materials over the last two decades, particularly for cross-sectional and plan-view transmission electron microscope (TEM) specimens. The basic principle of ion milling involves bombarding a specimen with energetic ions or neutral atoms acclerated and formed into a tightly focused ion beam. Material is sp...

Specimen preparation using abrasives results in surface and subsurface mechanical (stresses, strains), geometrical (roughness), chemical (contaminants, reaction products) and physical modifications (structure, texture, lattice defects). The mechanisms involved in polishing with abrasives are presented to illustrate the effects of surface topography, surface and subsurface composition and induce...

related to the relatively small number of total ions utilized for determining the mass spectra. CONCLUSION It would be a significant advance if the mass resolution of 1500 obtained with inorganic specimens could be retained with nonvolatile and thermally labile organic specimens as well as obtaining the structurally significant fragment ion signals. This advance will require more detailed studi...

In addition, due to the nature of ABG testing, clinicians cannot afford to waste time or resources when making decisions based on an ABG sample analysis. To ensure accurate results for such decision-making, it is imperative that the analytical process be as standardized and finely calibrated as possible. For example, variations in technique in the areas of specimen preparation, turnaround time ...

When the preparation was still fresh, I showed the Society a specimen of an ovarian dermoid with torsion of the pedicle, remarking that it illustrated Dr Herman W. Freund's explanation of the pedicle torsion of ovarian tumours.1 Two other cases of ovariotomy this spring have occurred where the pedicles were twisted, and as the histories of the cases which furnished the preparations present seve...

Scanning probe microscopes are now established tools to study the surface structure of biological macromolecules under physiological conditions. Sample preparation methods for this microscopy all have the objective to attach the specimen firmly to a support. Here we analyse the commonly used method of adsorbing biological specimens to freshly cleaved mica. This is facilitated by adjusting the e...

The 3D distribution of self-assembled stacked quantum dots (QDs) is a key parameter to obtain the highest performance in a variety of optoelectronic devices. In this work, we have measured this distribution in 3D using a combined procedure of needle-shaped specimen preparation and electron tomography. We show that conventional 2D measurements of the distribution of QDs are not reliable, and onl...