Surface Density of the Spongy and Palisade Parenchyma Layers of Leaves Extracted From Wideband Ultrasonic Resonance Spectra.

The wide band and air-coupled ultrasonic resonant spectroscopy together with a modified Simulated Annealing metaheuristic algorithm and a 1D layered acoustic-model are used to resolve the structure of plant leaves. In particular, this paper focuses on the extraction of the surface density of the different layers of tissue in leaves having a relatively simple structure. There are three main reasons to select the surface density as the focus of this study: (i) it is a parameter directly extracted by the proposed technique and it requires no further processing, (ii) it is relevant in order to study the dynamic of the water within the different tissues of the leaves and also to study the differential development of the different tissues, and (iii) unlike other parameters provided by this technique (like resonant frequency, impedance, ultrasonic elastic modulus, or ultrasonic damping), this parameter can be easier to understand as it is a direct measure of mass per unit surface. The selection of leaves with a simple structure is justified by the convenience of avoiding an unnecessary complication of the data extraction step. In this work, the technique was applied to determine the surface density of the palisade and spongy parenchyma layers of tissue of Ligustrum lucidum, Vitis vinifera, and Viburnum tinus leaves. The first species was used to study the variation of the surface density at full turgor with the thickness of the leaf, while the two other species were used to study the variation of the surface densities with the variation in the leaf relative water content. Consistency of the results with other conventional measurements (like overall surface density, and cross-section optical and cryo-SEM images) is discussed. The results obtained reveal the potential of this technique; moreover, the technique presents the additional advantage that can be applied in-vivo as it is completely non-invasive, non-destructive, fast, and equipment required is portable.

A retrospective study on factors predictive of operative intervention in symptomatic accessory navicular.

PURPOSE: The variables causing symptomatic accessory navicular are largely unknown and may inform management of symptomatic patients. The purpose of this study was to examine patient specific factors associated with the development of accessory navicular symptoms. METHODS: A total of 71 patients with clinical and radiographic evidence of accessory navicular syndrome were evaluated. Patient gender, race, date of birth, date of earliest foot complaint and laterality were recorded. Treatment was defined as conservative versus surgical. Skeletal maturity was assessed based on calcaneal ossification, accessory navicular subtype and the presence of pes planus based on talo-first metatarsal angle were assessed. RESULTS: Female patients comprised 72% of the subjects and trended towards symptoms at younger ages than male patients (p = 0.06), while no significant difference in presentation age was appreciated between male and female patients. Skeletal maturity was significantly associated with earlier complaints and age at presentation but was not associated with increased need for surgical management. Patients with pes planus were significantly more likely to undergo operative management. Accessory navicular subtype was significantly correlated with skeletal maturity. CONCLUSION: Female patients were more likely to report symptoms and present with symptomatic accessory navicular. The stage of skeletal maturity is not a predictor of future surgical management but patients with a higher first-metatarsal angle were more likely to require surgery. The correlation between accessory navicular subtype and skeletal maturity suggests that Type II ossicles are likely to develop into Type III over time. Radiographic evaluation of the accessory navicular may lend prognostic data on the necessity of future surgical intervention. LEVEL OF EVIDENCE: IV, Case Series.

A quantitative method for the radiological assessment of skeletal maturity using the distal femur.

Aims: Using 90% of final height as a benchmark, we sought to develop a quick, quantitative and reproducible method of estimating skeletal maturity based on topographical changes in the distal femoral physis. Patients and Methods: Serial radiographs of the distal femoral physis three years prior to, during, and two years following the chronological age associated with 90% of final height were analyzed in 81 healthy children. The distance from the tip of the central peak of the distal femoral physis to a line drawn across the physis was normalized to the physeal width. Results: A total of 389 radiographs of the distal femur with corresponding Greulich and Pyle bone ages and known chronological ages were measured. Children reached 90% of final height at a mean age of 11.3 years (sd 0.8) for girls and 13.2 years (sd 0.6) for boys. Linear regression analysis showed higher correlation coefficent in predicting the true age at 90% of final height using chronological age + gender + central peak value (R2 = 0.900) than chronological age + gender (R2 = 0.879) and Greulich and Pyle bone age + gender (R2 = 0.878). Conclusion: Chronological age + gender + central peak value provides more accurate prediction of 90% of final height compared with chronological age + gender and Greulich and Pyle bone age + gender. Cite this article: Bone Joint J 2018;100-B:1106-11.

A new ultrasound instrument for in vivo microimaging of mice.

We report here on the design and evaluation of the first high-frequency ultrasound (US) imaging system specifically designed for microimaging of the mouse. High-frequency US or US biomicroscopy (UBM) has the advantage of low cost, rapid imaging speed, portability and high resolution. In combination with the ability to provide functional information on blood flow, UBM provides a powerful method for the investigation of development and disease models. The new UBM imaging system is demonstrated for mouse development from day 5.5 of embryogenesis through to the adult mouse. At a frequency of 40 MHz, the resolution voxel of the new mouse scanner measures 57 microm x 57 microm x 40 microm. Duplex Doppler provides blood velocity sensitivity to the mm per s range, consistent with flow in the microcirculation, and can readily detect blood flow in the embryonic mouse heart, aorta, liver and placenta. Noninvasive UBM assessment of development shows striking similarity to invasive atlases of mouse anatomy. The most detailed noninvasive in vivo images of mouse embryonic development achieved using any imaging method are presented.

High-frequency intracoronary ultrasound imaging.

Intravascular ultrasound is playing an increasingly important role in the clinical management of coronary interventions. In the past few years the technology for intracoronary ultrasound, in response to clinical pressure, has moved towards lower profile probes with improved handling. While new catheter designs are markedly improved on their predecessors, image quality has not seen significant gains due to the primitive nature of the ultrasound transducer designs. In this article, the potential for improving image quality by increasing the frequency and focusing the ultrasound beam is explored. Basic aspects of transducer implementation are discussed and the acoustic properties of vascular tissues and blood are reviewed. A variety of instruments are used to image coronary and femoral arteries at frequencies ranging from 40 to 200 MHz. These studies serve to illustrate the trade-offs in the development of high frequency IVUS systems. There would appear to be no fundamental reason why frequencies in excess of 50 MHz could not be implemented. Studies using prototype IVUS instruments in the 50 MHz range demonstrate significant improvements in image quality.

[Thyroid function in smelters after long-term exposure to heavy metals]. / Funkcja tarczycy u hutników dlugoletnio narazonych na metale ciezkie.

In the year 1995 in a group of 93 male workers of a copper smelter (mean age = 40,7 years, exposure time = 8,5 years) following parameters were measured: blood levels of: lead and cadmium; serum levels of copper, zinc, calcium and magnesium-with use of atomic absorption spectrophotometry; FEP-with Piomelli's method; and T3, T4 and TSH in serum with radioimmunometric method. Mean blood lead level was 38,2 micrograms/dl, and concentrations of other metals and hormones were within norm limits. Mean level of FEP was slightly above norm (FEP = 106,5 micrograms/100 ml E). We found no correlation between investigated hormones (T3, T4 and TSH) and age, length of exposure nor blood lead level. We found a significant inverse correlation between FEP and TSH (r = -0,207; p < 0,047). This correlation could point to the fact that lead burden (expressed not in the actual blood level but in the FEP concentration) could negatively influence endocrine functions through hypothalamic-pituitary axis.

Double blind comparison of transdermal hyoscine and placebo for the prevention of postoperative nausea.

Transdermal hyoscine (Scopoderm, Ciba-Geigy) has been compared with placebo in 283 female patients. The hyoscine patch had no significant effect on postoperative nausea or vomiting. In contrast with earlier studies, there was no correlation between previous experiences of nausea (motion, pregnancy or surgery related) and nausea caused by the surgery or anaesthetic in this study. No correlation was found between nausea or vomiting and the type of operation.