A new model for calculating the input impedance of coax-fedcircular microstrip antennas with and without air gaps

A model is presented for calculating the input impedance of a probe-fed circular antenna with and without air gaps between the substrate and the ground plane. It is based on the cavity method, the dynamic permittivity constant (to take into account the influence of the fringing field at the edge of radiating element), and the resonant parallel R-L-C circuit with an inductive reactance. Numerical results are shown to agree well with experimental ones. The model is well suited for computer-aided design     

Lymphoscintigraphy and radioguided biopsy of the sentinel axillary node in breast cancer

Lymphoscintigraphy associated with radioguided biopsy of the sentinel node (SN) is well established in clinical practice for melanoma. In breast cancer, the SN concept is similarly valid, and lymphoscintigraphy is a useful method for localizing the axillary SN. The aim of this study was to optimize the lymphoscintigraphy technique in association with a gamma ray detecting probe (GDP) for identifying and removing the SN in breast cancer patients. METHODS: Two-hundred fifty patients with operable breast tumor underwent lymphoscintigraphy before surgery. Three different size ranges of 99mTc-labeled colloid particles (<50, <80 and 200-1000 nm) were used, with either subdermal (above tumor) or peritumoral injection. Early and late scintigraphic images were obtained in anterior and oblique projections, and the skin projection of the detected SN was marked. Sentinel nodes were identified and removed with the aid of the GDP during breast surgery; they were tagged separately. Complete axillary dissection followed. In 40 patients, a blue dye was also administered in addition to subdermal radiolabeled colloid to compare blue dye mapping with lymphoscintigraphy localization. RESULTS: Lymphoscintigraphy successfully revealed lymphatic drainage in 245 of 250 patients (98%). The axillary SN was identified in 240 patients (96%). SN biopsy correctly predicted axillary node status in 234 of 240 patients (97.5%). Lymphoscintigraphy and GDP detected the SN most easily and consistently when 200-1000 nm colloid was administered subdermally in an injection volume of 0.4 ml. Blue dye mapping was successful in 30 of 40 patients (75%). In 26 of these patients, the dye and lymphoscintigraphy identified the same node; in 4 cases different nodes were identified. None of these four patients had axillary disease. CONCLUSION: Lymphoscintigraphy is a simple procedure that is well tolerated by patients. Sentinel node identification is more reliable when large-size radiolabeled colloids are injected in a relatively small injection volume (0.4 ml). Use of a GDP greatly facilitates precise pinpointing and rapid removal of the SN.     

A method for selecting macro-scale structures with axially loaded members

This paper presents a method to support the selection of lightweight large-scale structures. The method enables the ranking of alternative structural forms, whose axially loaded members can resist to either instability failure or material yield. Unlike previous approaches for concept design, this work models buckling failure to assess the interaction between the choice of a structural form and the choice of the cross-section shapes of its constituents. Shape transformers and scaling factors are introduced to characterize the structural efficiency of alternative cross-sectional shapes. Such parameters are dimensionless and enable to measure the shape efficiency without specifying the details of the cross-section geometry. The approach eases optimization at the concept design stage and it permits to assess how the selection of the member cross-sections impacts the lightweight potential of the structural topology. The model is used to construct charts for optimizing and selecting alternative forms. The method is applied in an industrial setting in order to compare three different structural concepts for a particular design application. The case study identified the potential performance of three structural forms and gave insight into the selection of the parameters that most influence structural performance.     

Peer-assisted content distribution on a budget

In this paper, we propose a general framework and present a prototype implementation of peer-assisted content delivery application. Our system – called Cyclops – dynamically adjusts the bandwidth consumed by content servers (which represents the bulk of content delivery costs) to feed a set of swarming clients, based on a feedback signal that gauges the real-time health of the swarm. Our extensive evaluation of Cyclops in a variety of settings – including controlled PlanetLab and live Internet experiments involving thousands of users – shows a significant reduction in content distribution costs when compared to existing swarming solutions, with a minor impact on the content delivery times.     

Microarray gene expression analysis of porcine skeletal muscle sampled at several post mortem time points

A pilot study using Affymetrix Gene Chip^® Porcine Genome Arrays was set up to evaluate the impact of time lags from death on gene expression profiling of porcine skeletal muscle at four post mortem times (up to 24 h) during the routine processing of fresh thighs. All post chip parameters and data analyses (Average background, Scale Factors, Percent Presence, 3′/5′ ratios of β-actin and glyceraldehyde-3-phosphase dehydrogenase control genes, RNA degradation diagnostics, principal component analysis, hierarchical clustering, mixed regression models with time effects) did not show any effect of post mortem time. Therefore, microarray data obtained from muscle specimens collected in a processing plan over a quite long period have the potential to identify treatments or pre mortem conditions without any potential bias derived from subtle RNA degradation. These results open new perspectives to develop and analyse gene expression biomarkers for pig production and product authentication.     

Unsupervised Electric Motor Fault Detection by Using Deep Autoencoders

Fault diagnosis of electric motors is a fundamental task for production line testing, and it is usually performed by experienced human operators. In the recent years, several methods have been proposed in the literature for detecting faults automatically. Deep neural networks have been successfully employed for this task, but, up to the authors' knowledge, they have never been used in an unsupervised scenario. This paper proposes an unsupervised method for diagnosing faults of electric motors by using a novelty detection approach based on deep autoencoders. In the proposed method, vibration signals are acquired by using accelerometers and processed to extract Log-Mel coefficients as features. Autoencoders are trained by using normal data only, i.e., data that do not contain faults. Three different autoencoders architectures have been evaluated: the multi-layer perceptron (MLP) autoencoder, the convolutional neural network autoencoder, and the recurrent autoencoder composed of long short-term memory (LSTM) units. The experiments have been conducted by using a dataset created by the authors, and the proposed approaches have been compared to the one-class support vector machine (OC-SVM) algorithm. The performance has been evaluated in terms area under curve (AUC) of the receiver operating characteristic curve, and the results showed that all the autoencoder-based approaches outperform the OC-SVM algorithm. Moreover, the MLP autoencoder is the most performing architecture, achieving an AUC equal to 99.11%      

Conservative approach to inflammatory nasofrontal duct disease

Endoscopic data reveal that mucosal disease frequently recurs following the surgical treatment of chronic diffuse hyperplastic frontal sinus and nasofrontal duct disease. However, this group of patients often remains asymptomatic. We present 40 patients who underwent endoscopic sinus surgery with a 4-year mean follow-up. Postoperative endoscopy revealed mucosal disease within the frontal recess in 39 of the 40 (97.5%) patients; however, only 3 of the 40 (7.5%) were symptomatic. Of these 3 patients, 1 underwent revision surgery. Historical information demonstrates the potential for significant nasofrontal duct stenosis associated with such revision surgery. On the basis of our initial results, endoscopic observation and medical therapy seem to be successful in controlling the symptoms associated with this disease process.     

Melanocortin peptides inhibit production of proinflammatory cytokines and nitric oxide by activated microglia

This brief history of the dental diamond bur is intended to provide both a historical perspective and an evaluation of the current state of bur technology. An understanding of the origins of dental diamonds and the issues facing manufacturers transforms the dentist from a simple user into an informed consumer. The author contends that this can improve dental care and enable the dentist to collaborate with manufacturers in developing improved dental burs.