Scattering by Conducting Cylinders Below a Dielectric Layer With a Fast Noniterative Approach

A spectral-domain technique to solve the scattering by perfectly conducting cylinders placed below a dielectric layer is presented. Propagation fields are expressed in an analytic form, in the frame of the cylindrical wave approach. The fields scattered by the buried objects are decomposed into cylindrical waves, which are, in turn, represented by plane-wave spectra. Due to the interaction with a layered layout, the scattered fields experience multiple infinite reflections at the boundaries of the layer. Using suitable reflection and transmission coefficients inside the plane-wave spectra, the interaction with such a layered geometry can be solved with a single-reflection approach. Multiple reflections are collected by a set of two scattered fields, i.e., an upward-propagating field, excited by the scatterers and transmitted up to the top medium, and a down-propagating one, which from the top medium reaches the scatterers after transmission through the layer. Therefore, the analytical theory is developed in a very compact way and can be solved through a fast and efficient numerical implementation. Numerical results are evaluated in an accurate way and validated by comparisons with results obtained with a multiple-reflection approach. The scattered field can be evaluated in any point of the domain, in the far-field as well as the near-field region. Two-dimensional maps displaying the magnitude of the total scattered field are reported, showing examples of applications of the technique

Radiation-Enhancement Properties of an X-Band Woodpile EBG and Its Application to a Planar Antenna

A woodpile Electromagnetic Bandgap (EBG) material has been designed, by using an in-house code that implements the Fourier Modal Method (FMM). A couple of alumina-woodpile samples have been fabricated. Several results have been collected for the transmission behaviour of the woodpile and of resonators with woodpile mirrors, in a shielded anechoic chamber, by using a vector network analyzer, in the 8–12 GHz range. These new experimental data highlight interesting properties of 3D EBG resonators and suggest possible innovative applications. Comparisons of the collected results with FMM show a satisfactory agreement. An application of the EBG resonator has been considered, for gain enhancement of a microstrip antenna: an increase of about 10 dB in the broadside gain has been measured; experimental data and numerical results obtained with the commercial software HFSS show a good agreement. A comparison is presented between EBG resonator antennas and two-dimensional uniform arrays. Finally, HFSS results are provided for EBG resonator antennas working at higher frequencies or with a more selective superstrate: a gain enhancement of more than 18 dB is achieved by such antennas

High Magnification Digital Dermoscopy of Basal Cell Carcinoma: A Single-centre Study on 400 cases.

The aim of this study was to assess the frequency of classic dermoscopic basal cell carcinoma (BCC) features and the sensitivity of new descriptors, such as light brown nests (homogeneous and structured) only visible employing a high magnification digital videomicroscope. A retrospective analysis of 2,024 highly magnified digital images referring to 400 BCCs was performed by 3 independent observers, who assessed 11 classic BCC descriptors and the new ones. Light brown nests were detected in 40.5% of BCCs. Homogeneous ones were observable in 17.8%, and structured nests in 32.8%. Light brown nests were visible in 14.3% of non-pigmented lesions, whereas in the pigmented groups these were observed in 42-54% of the cases. We suggest that brown nests described in this study may improve early recognition of superficial BCCs and of non-pigmented or slightly pigmented ones that may lack classic dermoscopic patterns

Editorial: Biogenic Reefs at Risk: Facing Globally Widespread Local Threats and Their Interaction With Climate Change

Biogenic reefs are secondary marine substrates, also referred to as bioconstructions or bioherms, made by autogenic ecosystem engineers (sensu, Jones et al., 1994) that provide habitats for various species. Their ecological role goes far beyond simple physical effects because they can modulate many resources and interactions between species inhabiting the reefs. Marine bioconstructions involve a variety of fragile three-dimensional habitats, from shallow water coral reefs to mesophotic coralligenous concretions, hosting rich, and diverse benthic assemblages (Cocito, 2004; Ingrosso et al., 2018; Cerrano et al., 2019). Biogenic reefs can be found from the intertidal to the deep sea; some are ephemeral and last a few years, while others remain active for millennia. The main framework builders are able to form bioconstructions at different latitudes, from tropical to polar zones, and include films of cyanobacteria and diatoms, calcareous rhodophytes, sponges, hermatypic symbiotic and aposymbiotic corals, polychaetes as serpulids and sabellariids, mollusks like vermetids, oysters and mussels, and bryozoans

The Reef Check Mediterranean Underwater Coastal Environment Monitoring Protocol

Since 2001, trained snorkelers, freedivers, and scuba diver volunteers (collectively called EcoDivers) have been recording data on the distribution, abundance, and bathymetric range of 43 selected key marine species along the Mediterranean Sea coasts using the Reef Check Mediterranean Underwater Coastal Environment Monitoring (RCMed U-CEM) protocol. The taxa, including algae, invertebrates, and fishes, were selected by a combination of criteria, including ease of identification and being a key indicator of shifts in the Mediterranean subtidal habitats due to local pressures and climate change. The presence and abundance of gas bubbles leaching from the seabed are also recorded. The dataset collected using the RCMed U-CEM protocol is openly accessible across different platforms and allows for various uses. It has proven to be useful for several purposes, such as monitoring the ecological status of Mediterranean coastal environments, assessing the effects of human impacts and management interventions, as well as complementing scientific papers on species distribution and abundance, distribution modeling, and historical series. Also, volunteers\u2019 commitment promotes marine stewardship and environmental awareness in marine conservation. Here, we describe the RCMed U-CEM protocol, from training volunteers to recording, delivery, and sharing data, including the quality assurance and control (QA/QC) procedures

Assessment of skin sensitization properties of few-layer graphene and graphene oxide through the Local Lymph Node Assay (OECD TG 442B)

: Skin contact is one of the most common exposure routes to graphene-based materials (GBMs) during their small-scale and industrial production or their use in technological applications. Nevertheless, toxic effects in humans by cutaneous exposure to GBMs remain largely unexplored, despite skin contact to other related materials has been associated with adverse effects. Hence, this in vivo study was carried out to evaluate the cutaneous effects of two GBMs, focusing on skin sensitization as a possible adverse outcome. Skin sensitization by few-layer graphene (FLG) and graphene oxide (GO) was evaluated following the Organization for Economic Cooperation and Development (OECD) guideline 442B (Local Lymph Node Assay; LLNA) measuring the proliferation of auricular lymph node cells during the induction phase of skin sensitization. Groups of four female CBA/JN mice (8-12 weeks) were daily exposed to FLG or GO through the dorsal skin of each ear (0.4-40 mg/mL, equal to 0.01-1.00 mg/ear) for 3 consecutive days, and proliferation of auricular lymph node cells was evaluated 3 days after the last treatment. During this period, no clinical signs of toxicity and no alterations in body weight and food or water consumptions were observed. In addition, no ear erythema or edema were recorded as signs of irritation or inflammation. Bromo-deoxyuridine (BrdU) incorporation in proliferating lymphocytes from ear lymph nodes (stimulation indexes <1.6) and the histological analysis of ear tissues excluded sensitizing or irritant properties of these materials, while myeloperoxidase activity in ear biopsies confirmed no inflammatory cells infiltrate. On the whole, this study indicates the absence of sensitization and irritant potential of FLG and GO

Skin irritation potential of graphene-based materials using a non-animal test

Graphene related materials, if prepared with non-irritant exfoliation agents, do not induce skin irritation on a 3D model of human epidermis, following the OECD guideline 439

Differential role of cyclooxygenase 1 and 2 isoforms in the modulation of colonic neuromuscular function in experimental inflammation

This study examines the role played by cyclooxygenase (COX) isoforms (COX-1 and -2) in the regulation of colonic neuromuscular function in normal rats and after induction of colitis by 2,4-dinitrobenzenesulfonic acid (DNBS). The expression of COX-1 and COX-2 in the colonic neuromuscular layer was assessed by reverse transcription-polymerase chain reaction and immunohistochemistry. The effects of COX inhibitors on in vitro motility were evaluated by studying electrically induced and carbachol-induced contractions of the longitudinal muscle. Both COX isoforms were constitutively expressed in normal colon; COX-2 was up-regulated in the presence of colitis. In normal and inflamed colon, both COX isoforms were mainly localized in neurons of myenteric ganglia. In the normal colon, indomethacin (COX-1/COX-2 inhibitor), SC-560 [5-(4-chloro-phenyl)-1-(4-methoxyphenyl)-3-trifluoromethylpyrazole] (COX-1 inhibitor), or DFU [5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulfonyl)phenyl-2(5H)-furanone] (COX-2 inhibitor) enhanced atropine-sensitive electrically evoked contractions. The most prominent effects were observed with indomethacin or SC-560 plus DFU. In the inflamed colon, SC-560 lost its effect, whereas indomethacin and DFU maintained their enhancing actions. These results were more evident after blockade of noncholinergic pathways. In rats with colitis, in vivo treatment with superoxide dismutase or S-methylisothiourea (inhibitor of inducible nitric-oxide synthase) restored the enhancing motor effect of SC-560. COX inhibitors had no effect on carbachol-induced contractions in normal or DNBS-treated rats. In conclusion, in the normal colon, both COX isoforms act at the neuronal level to modulate the contractile activity driven by excitatory cholinergic pathways. In the presence of inflammation, COX-1 activity is hampered by oxidative stress, and COX-2 seems to play a predominant role in maintaining an inhibitory control of colonic neuromuscular function

Are the neck malignant melanomas different from the ones affecting the head? Clinicopathologic, dermoscopic and prognostic findings

Background: Malignant melanomas of the head and neck are usually considered as a unique entity in comparison to other body sites. However, no characterization of neck melanoma has been performed so far, despite the clear anatomic and histological differences. Aim: We investigated clinical, demographic, histological and dermoscopic differences between face, scalp and neck melanoma. Materials and methods: A retrospective analysis of medical and histologic records from 116 melanomas of the head and neck area collected between January 2003 and January 2008 was performed. Body site, gender, age, number of lesions, age at first melanoma diagnosis, size, Clark level, association with nevi, presence or absence of mitoses and/or ulceration, presence of synchronous and/or metachronous melanoma were recorded. Moreover, digital dermoscopy images of 92 melanomas of the head and neck area were analyzed for main dermoscopic patterns and lesion diameter. Results: Significant differences in Breslow thickness, ex-naevo origin and tumor size among neck and face-scalp melanomas were observed. Neck MM patients were younger than those with MM of face and scalp. In contrast to scalp and face, no patient died from neck melanoma. Dermoscopic patterns were similar to those of trunk-limbs MM, and no lesion showed a lentigo maligna pattern which was observed in most lesions of the face. Conclusion: Melanomas of the neck must be distinguished from face and scalp melanomas because of younger age, different dermoscopic patterns and ex-naevo origin and better prognosis. These data should be taken into account both from an epidemiological and clinical point of view