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Purpose Optical coherence tomography angiography (OCTA) allows delineating the foveal avascular zone (FAZ) easily and noninvasively. The present study aims to test reproducibility and reliability of FAZ evaluation by means of OCTA in different settings. Methods Twenty-four eyes of 24 normal subjects were investigated using AngioVue OCTA Imaging System. A series of OCTA acquisitions were taken both in basal and in different experimental settings after vasoactive stimuli. Images were evaluated separately by two operators and FAZ area was measured both manually and using the built-in automated measurement tool. Results No differences for FAZ area were found in the repetition of basal acquisitions, neither in manual nor in automated measurement (0.215 ± 0.06 vs. 0.216 ± 0.07, and 0.268 ± 0.05 vs. 0.264 ± 0.09, first vs. second basal measurement in square millimetres for manual and automated evaluation, P = 0.25 and P = 0.35, respectively). Interoperators correlation was optimal (r = 0.978 [95% CI 0.981-0.976]). No differences were found among the other settings, which included first basal and then repeated (second) in the morning, after flickering light stimulus, after a Bruce treadmill stress test, after 30 minutes dark adaptation, and basal in the evening, neither in automated nor in manual measurements. Automated measurements for nonflow areas provided significantly larger diameters than manual ones. Conclusion AngioVue OCTA Imaging System produces highly reproducible FAZ images with a high interoperators concordance level. Optical coherence tomography angiography capability to detect FAZ area seems not to be influenced by any of the vasoactive stimuli considered in the current study. Nonflow areas seem to be larger when measured automatically than manually.

Background Sarcopenia, the unintentional loss of skeletal muscle mass, is associated with poor outcomes in adult patient populations. In adults, sarcopenia is often ascertained by cross‐sectional imaging of the psoas muscle area (PMA). Although children with chronic medical illnesses may be at increased risk for muscle loss because of nutritional deficiencies, physical deconditioning, endocrine anomalies, and systemic inflammation, consistent quantitative definitions for sarcopenia in children are lacking. We aimed to generate paediatric reference values for PMA at two intervertebral lumbar levels, L3–4 and L4–5. Methods In this cross‐sectional study, we analysed abdominal computed tomography scans of consecutive children presenting to the emergency department. Participants were children 1–16 years who required abdominal cross‐sectional imaging after paediatric trauma between January 1, 2005 and December 31, 2015 in a large Canadian quaternary care centre. Children with a documented chronic medical illness or an acute spinal trauma at presentation were excluded. Total PMA (tPMA) at levels L3–4 and L4–5 were measured in square millimetres (mm2) as the sum of left and right PMA. Age‐specific and sex‐specific tPMA percentile curves were modelled using quantile regression. Results Computed tomography images from 779 children were included. Values of tPMA at L4–5 were significantly larger than at L3–4 at all ages, but their correlation was high for both girls (r = 0.95) and boys (r = 0.98). Amongst girls, tPMA 50th percentile values ranged from 365 to 2336 mm2 at L3–4 and from 447 to 2704 mm2 for L4–5. Amongst boys, 50th percentile values for tPMA ranged between 394 and 3050 mm2 at L3–4 and from 498 to 3513 mm2 at L4–5. Intraclass correlation coefficients were excellent at L3–4 (0.97, 95% CI 0.94 to 0.981) and L4–5 (0.99, 95% CI 0.986 to 0.995). Weight and tPMA were correlated, stratified by sex for boys (L3–4 r = 0.90; L4–5 r = 0.90) and for girls (L3–4 r = 0.87; L4–5 r = 0.87). An online application was subsequently developed to easily calculate age‐specific and sex‐specific z‐scores and percentiles. Conclusions We provide novel paediatric age‐specific and sex‐specific growth curves for tPMA at intervertebral L3–4 and L4–5 levels for children between the ages of 1‐16 years. Together with an online tool (https://ahrc‐apps.shinyapps.io/sarcopenia/), these tPMA curves should serve as a reference enabling earlier identification and targeted intervention of sarcopenia in children with chronic medical conditions.

AimsTo quantify retinal vascular bed area (RVBA) in square millimetres on stereographically projected ultra-wide field (UWF) fluorescein angiography (FA) in eyes with diabetic retinopathy (DR).MethodsA prospective, observational study. Baseline Optos 200Tx UWF FA images of 80 eyes with DR from the DAVE (NCT01552408) and RECOVERY (NCT02863354) studies were stereographically projected at the Doheny Image Reading Center to adjust for peripheral distortion. The early-phase FA frame was used to extract the retinal vasculature as a mask for calculating RVBA. The pixels of the retinal vasculature were automatically computed in square millimetres using manufacturer-provided software.ResultsEighteen of 80 diabetic eyes were excluded because image quality and contrast were insufficient for automatic extraction of the retinal vasculature from the background fluorescence. The remaining 62 eyes were included in the final analysis. In comparison with age-matched and sex-matched normal controls, eyes with DR had a higher global RVBA for the entire retina (p2) than in those with non-proliferative DR (56.2±16.6 mm2) or in normal controls (37.2±9.9 mm2). This tendency was also present in the posterior retina and mid-periphery but absent in the far-periphery. RVBA did not correlate with retinal ischaemia (p>0.05).ConclusionsEyes with DR harboured a larger global RVBA for the entire retina than normal controls, and RVBA appeared to indicate DR severity. However, this biomarker was not observed to be a good indicator of retinal ischaemia.

Since its inception in 1986, the field of atomic force microscopy (AFM) has enabled surface analysis and characterisation with unparalleled resolution in a wide variety of environments. However, the technique is limited by very low sample throughput and temporal resolution making it impractical for materials science research on macro sized or time evolving samples such as the bservationof corrosion. The potential of AFM sparked intense efforts to overcome these limitations shortly after its invention, and has led to the development of high-speed atomic force microscopes (HSAFMs). Within the last 5 years the technology underpinning these instruments has matured to the point where routine imaging can achieve megapixels per second over scan areas of square millimetres, removing the limitations from AFM for industrial scale materials characterisation. This review explains the technology and looks to the future use of HS-AFMs in materials science.

Background: Currently, a large variety of classifications is used for periodontitis as a risk factor for other diseases. None of these classifications quantifies the amount of inflamed periodontal tissue, while this information is needed to assess the inflammatory burden posed by periodontitis. Aim: To develop a classification of periodontitis that quantifies the amount of inflamed periodontal tissue, which can be easily and broadly applied.Material and Methods: A literature search was conducted to look for a classification of periodontitis that quantified the amount of inflamed periodontal tissue. A classification that quantified the root surface area affected by attachment loss was found. This classification did not quantify the surface area of inflamed periodontal tissue, however. Therefore, an Excel spreadsheet was developed in which the periodontal inflamed surface area (PISA) is calculated using clinical Attachment Level (CAL), recessions and bleeding on probing (BOP).Results: The PISA reflects the surface area of bleeding pocket epithelium in square millimetres. The surface area of bleeding pocket epithelium quantifies the amount of inflamed periodontal tissue. A freely downloadable spreadsheet is available to calculate the PISA.Conclusion: PISA quantifies the inflammatory burden posed by periodontitis and can be easily and broadly applied.

In this work, we describe the compositional analysis performed by scanning-mode PIXE on the metal threads of a XIII century embroidery. The precious work analysed is the pillow-case used to cover the pillow, on which – according to tradition – St. Francis of Assisi was resting his head when he died. Measurements were performed in order to characterise the embroideries of the two sides and the passementerie in the lateral hems. Several areas, each of the order of two square millimetres, were scanned with a 3 MeV proton external beam of 20 μm size on target, using the external micro-beam facility of our laboratory, with list-mode acquisition. Analysis of elemental maps and spectra from selected homogeneous sub-areas allowed us to extract the quantitative composition of the gilded tape and estimates of its thickness.

Microfluidics refers to a set of technologies that control the flow of minute amounts of liquids, typically from a few picolitres (pls) to a few microlitres (μls) in a miniaturized system [1,2]. Lab-on-a-chip (LOC) systems typically consist of a set of microfluidics and sensors with dimensions from a few square millimetres (mm2) to a few square centimetres (cm2). Microfluidics handles liquids through droplet generation, transportation and mixing of liquid samples, chemical reactions etc. Sensors may include biochemical sensors, gas sensors and physical sensors such as humidity and temperature sensors, flow meter and viscometers etc. Therefore, LOCs are microsystems with a much broader meaning, and generally perform single or multiple laboratory processes and functions on a chip-scale.

The corneal surface is the most important 123 square millimetres of the body’s surface. Its health is paramount for sight. Due to its exposed nature it is vulnerable to environmental insults causing minor to excessive epithelial cell loss. Large epithelial defects, with an intact limbus heal by the formation of 3 to 6 convex sheets that migrate centripetally, meet adjacent sheets and undergo contact inhibition to form geometric shapes. These finally close by the formation of ‘Y’ shaped contact lines (Rule 1). When the limbus is partially involved, there is a preferential healing of the limbus by circumferential migration of tongue shaped sheets from the remaining intact limbus. These meet to cover the limbus (Rule 2) and subsequent healing occurs as in rule 1. On occasions conjunctival epithelium migrates across the limbus resulting in partial limbal deficiency. When the entire limbus is affected, total conjunctivalisation of the cornea occurs (Rule 3). Within sheets, individual cells migrate in a predominantly clockwise whorl pattern (Rule 4). Physiological and wound healing related cell turnover is believed to occur from stem cells (SC) located at the limbus. Specialised anatomical structures, termed Limbal Epithelial Crypts (LEC) are associated with some limbal palisades and present all the hallmarks of a SC niche. SC characteristics are also seen in the peripheral cornea adjacent to a palisade with a LEC. Recent evidence suggests that the limbal SC play a critical role in wound healing but may have only a marginal role physiological corneal epithelial homeostasis.

Fatigue-crack initiation was investigated by testing high-strength steels (AFNOR 35 NCD 16 and 35 CD 4) with 0.6-in. (15-mm) thick ASTM compact specimens having various notch-root radii between 0.003 in. (0.07 mm) and 0.04 in. (1 mm). Measuring devices were used to detect flaws with a surface area of only a few square millimetres in their propagation planes. In order to calculate the number of cycles required to initiate a crack, notch root behavior was investigated through several parameters. - ΔK/ p, from linear-elastic fracture mechanics, which concentrate results when the initiation time is large; - K E P f , an experimental parameter derived from low-cycle fatigue data when N i < 10 5 cycles. In this case, the ratio between theoretical and experimental values of the initiation time is between one and two for a given nominal stress.

The morphology of the stigma has been studied in 50 varieties belonging to 6 stone fruit species. The majority of samples had elliptical stigmata with some exceptions with circular form (Duane, Tuleu gras). The surface of the stigma is papillary, flattened in side view (sweet cherry) or bulging (apricot, peach). The suture of the stigma is clearly visible as a depression and the varieties may differ in this respect. The size of the stigma depends highly from the season, although the varietal differences are maintained. The dimension of stigmatic surface is characteristic for the species expressed in square millimetres: sweet cherry 0.92 to 2.91; sour cherry 1.64 to 2.48; plum 0.83 to 1.80; oriental plum 0.53 to 1.15; apricot 0.57 to 1.69 mm2. The size and morphology of the stigma changes according to varieties too, and it may used in description and identification of varieties. No correlation has been found between the size of stigma and the fertility relations (self-fertility or self-incompatibility) of the respective varieties.

We present an on-chip approach for the quantification of biomarkers based on isotope-dilution surface-enhanced Raman scattering (IDSERS). The full procedure was realized on a few square millimetres of a SERS-active substrate, covered with either lithographically engineered gold nanotriangles or silver nanospheres generated by galvanic displacement deposition. The use of certified reference materials combined with the ID principle ensures traceability of the quantitation to SI units. A series of substance spots was deposited onto the SERS active area and measured one by one in fast sequence. The SERS spectra were used to generate and validate a PLS model and also to predict the creatinine concentration of an unknown serum sample.

Most patients in hospital have measurements of their ‘vital signs’ taken and recorded only intermittently, thus deterioration can occur to a point of serious consequence before it is recognised. New technologies are being developed which allow increased surveillance of patients' status without the inconvenience of being physically attached to immobile monitoring systems, and thus allowing patients to move around their rooms and floor areas. The implementation of a small, low-cost, ultra-low-power and disposable vital signs monitor is described, made possible by the development of a semiconductor SoC – Sensium – which implements all of the required electronic functionality in a few square millimetres of silicon.

The dynamics of terminal bud development on seven 3-year-old nursery-grown provenances of Pinuscontorta Dougl. were monitored by sampling buds at 1- to 3-weekly intervals during one growing season. Differences in rates of cataphyll initiation occurred which were analysed in terms of (a) the projected areas of the apical domes, which changed over the season, (b) the relative rates at which the apical domes expanded radially during a plastochrone (square millimetres per square millimetre), as shown by the extent to which the new cataphyll primordia receded away from the domes, and (c) the projected areas of the tissues used to form new cataphyll primordia. Component a was a measure of the size of the apical dome meristems and b was a measure of their rates of 'activity.' A model-matching method is described to measure b.Those provenances which produced most cataphylls during the growing season developed and maintained large apical domes (component a above). There were unexpectedly small provenance differences in the apical dome 'activity' in midsummer (component b defined above), although differences occurred in spring and autumn. Differences in the projected areas of the new cataphyll primordia (component c) were inversely related to cataphyll initiation rates. Apical dome tissue doubling times in midsummer were estimated to be less than 120 h, irrespective of provenance.Inland provenances had small but relatively 'active' apical domes in spring, but they produced cataphyll primordia as products of this growth rather than reinvesting in apical dome 'capital.' Consequently, their apical domes remained small. Coastal Alaskan provenances, on the other hand, developed large apical domes, but these domes ceased to be very 'active' after the end of August. The apical domes on south coastal provenances did not become 'active' until early summer, but their domes were relatively large even in spring, became much larger by late summer, and they remained 'active' until mid-September.Implications are noted regarding cross-breeding of complementary genotypes to increase needle production and height growth.

Thin films of iron containing a proportion of cube textured grains have been produced by epitaxial growth on cleaved rocksalt crystals. When the films are annealed in the electron microscope a single crystal film with few defects is produced, which can be several square millimetres in area. The changes of the crystal and ferromagnetic domain structures during the annealing process have been observed in the electron microscope and are described.

A method derived from classical electropolishing in a cell is described. Two masks, each with a hole, cause preferential thinning of a sheet of metal between the holes. For aluminium the thinned portions reach several square millimetres in area. A simple electronic apparatus, which includes a light-emitting diode and a photodiode, instantly arrests polishing at a predetermined thinness.

As the erosive agent, a sport-drink mixture with pH 3.2 was given to Osborne-Mendel rats for 6 weeks. Lingual surfaces of the right first mandibular molar crowns were chosen for the recording. With the aid of a drawing tube mounted on a stereomicroscope, enlarged drawings of the surfaces were made encircling the intact and eroded areas. A computer-coupled analyser was used to measure the areas of the total surface, intact surface, eroded enamel and exposed dentine in square millimetres. The data was evaluated statistically and used to calculate erosion changes and to estimate occlusal wear.

Describes a technique for cleaving very thin sections from small crystals and have used it to obtain sections of alkali halide crystals of a few square millimetres in area and down to 20 mu m thick. This method of obtaining thin cleaved sections can be used with many other crystal types. An application to radiation damage depth profiles is briefly described.

Gill area increased with increasing body size in Holthuisana transversa (area in square millimetres equals 1946 times mass, in grams, to the power of 0.563). The increase in area was largely due to increase in the area of individual lamellae, at least over the size range studied (10-35 g). The area of the lungs was only 10% ofthe area ofthe gills but potentially these were at least as effective in gas exchange, due to their much shorter blood-gas diffusion distance. The volume of the lungs increased with body weight (volume in millilitres equals 0.043 times mass, in grams, to the power of 1.218), whilst tidal volume increased at a lower rate (tidal volume in millilitres equals 0.082 times mass to the power of 0.831) in the crabs examined (3-36 g).