Shape-matching soft mechanical metamaterials.

Architectured materials with rationally designed geometries could be used to create mechanical metamaterials with unprecedented or rare properties and functionalities. Here, we introduce "shape-matching" metamaterials where the geometry of cellular structures comprising auxetic and conventional unit cells is designed so as to achieve a pre-defined shape upon deformation. We used computational models to forward-map the space of planar shapes to the space of geometrical designs. The validity of the underlying computational models was first demonstrated by comparing their predictions with experimental observations on specimens fabricated with indirect additive manufacturing. The forward-maps were then used to devise the geometry of cellular structures that approximate the arbitrary shapes described by random Fourier's series. Finally, we show that the presented metamaterials could match the contours of three real objects including a scapula model, a pumpkin, and a Delft Blue pottery piece. Shape-matching materials have potential applications in soft robotics and wearable (medical) devices.

Nanorod based Schottky contact gas sensors in reversed bias condition.

There has been significant interest in using electronically contacted nanorod or nanotube arrays as gas sensors, whereby an adsorbate modifies either the impedance or the Fermi level of the array, enabling detection. Typically, such arrays demonstrate the I-V curves of a Schottky diode that is formed using a metal-semiconductor junction with rectifying characteristics. We show in this work that nanostructured Schottky diodes have a functionally different response, characteristic of the large electric field induced by the size scale of the array. Specifically, they are characterized by a low reverse breakdown voltage. As a result, the reverse bias current becomes a strong function of the applied voltage. In this work, for the first time, we model this unique feature by describing the enhancement effect of high aspect ratio nanostructures on the I-V characteristics of a Schottky diode. A Pt/ZnO/SiC nanostructured Schottky diode is fabricated to verify the theoretical equations presented. The gas sensing properties of the Schottky diode in reversed bias is investigated and it is shown that the theoretical calculations are in excellent agreement with measurements.

Optical transition energies for carbon nanotubes from resonant Raman spectroscopy: environment and temperature effects.

This Letter reports the laser energy dependence of the Stokes and anti-Stokes Raman spectra of carbon nanotubes dispersed in aqueous solution and within solid bundles, in the energy range 1.52-2.71 eV. The electronic transition energies (E(ii)) and the radial breathing mode frequencies (omega(RBM)) are obtained for 46 different (18 metallic and 28 semiconducting) nanotubes, and the (n,m) assignment is discussed based on the observation of geometrical patterns for E(ii) versus omega(RBM) graphs. Only the low energy component of the E(M)(11) value is observed from each metallic nanotube. For a given nanotube, the resonant window is broadened and down-shifted for single wall carbon nanotube (SWNT) bundles compared to SWNTs in solution, while by increasing the temperature, the E(S)(22) energies are redshifted for S1 [(2n+m) mod 3=1] nanotubes and blueshifted for S2 [(2n+m) mod 3=2] nanotubes.

Interband recombination dynamics in resonantly excited single-walled carbon nanotubes.

Wavelength-dependent pump-probe spectroscopy of micelle-suspended single-walled carbon nanotubes reveals two-component dynamics. The slow component (5-20 ps), which has not been observed previously, is resonantly enhanced whenever the pump photon energy coincides with an absorption peak and we attribute it to interband carrier recombination, whereas we interpret the always-present fast component (0.3-1.2 ps) as intraband carrier relaxation in nonresonantly excited nanotubes. The slow component decreases drastically with decreasing pH (or increasing H+ doping), especially in large-diameter tubes. This can be explained as a consequence of the disappearance of absorption peaks at high doping due to the entrance of the Fermi energy into the valence band, i.e., a 1D manifestation of the Burstein-Moss effect.

[A severe case of Plasmodium falciparum malaria]. / Un severo caso di infezione malarica da Plasmodio falciparum.

Malaria infections has been an important public health problem in Europe and Western countries in the last years. The international travels and moreover immigration from Africa and Asia countries has been rapidly increasing especially in Italy. The transmission and diffusion of malaria has increased, especially over last decade, due to vector resistance to insecticides and chemoresistance of these parasites to most antimalarial drugs. The authors presents a severe case of malaria infection that was caused by Plasmodium Falciparum in a one year-old female children, born in Italy, infected during a return in the parents' country of origin, Nigeria. She was admitted because of febrile gastroenteritis for five days. Since the child was in a good state of health, normal the medical examination, blood tests and radiography of the chest. The next day, persisting the fever, the child was somnolent, pale, and was present a haemoglobin concentration of 5.1 g/dl and a thrombocytopenia, a complicated falciparum malaria was diagnosed (8% parasitaemia). Treatment was started immediately with a single oral dose of Mefloquine (25 mg/Kg). Red blood cells were transfused once. The parasitaemia dropped to 4% and 0.8% in less than 48 hours. Weekly controls for the following four weeks remained negative.

[A case of recurrent cough in bronchial carcinoid]. / Un caso di tosse ricorrente da carcinoide bronchiale.

The carcinoid tumors of the bronchial are extremely uncommon, with an incidence of 5% of all pulmonary neoplasms. The carcinoid is the more frequent tumor of the lung in paediatric age. The symptoms most often reported were cough, recurring infection, chest pain, hemoptysis, fever, dyspnea, mild dyspnea attacks after physical effort or nervousness. The carcinoid syndrome is uncommon. Neuroendocrine tumors of the lung embrace a spectrum from low-grade typical carcinoid, intermediate-grade atypical carcinoid, and high-grade categories of large cell neuroendocrine carcinoma and small cell carcinoma. Low grade neoplasms may metastasize to adjacent nodes. Atypical carcinoids are considered low grade malignancies. Most malignant end of neuroendocrine neoplasm group is small cell carcinoma. Typical carcinoids carry an excellent prognosis and should be offered conservative lung resection, whilst atypical carcinoids which behave aggressively should be treated by radical lung resection. The authors report a case of the young patients with bronchial typical carcinoid tumor who had suffered from cough and mild dyspnea attacks after physical effort or nervousness in the last year.

[Calcium release from the mineral matrix of the mandibular bone due to hydrogen peroxide exposure]. / Rilascio di calcio della matrice minerale di osso mandibolare mediante esposizione a perossido di idrogeno.

The purpose of this paper is to quantify by in vitro experiment free radical activity in jaw bone demineralization processes. Sample were take and graphic interpolation of calcium ions undertake. The significance of the results is compared with the paper that are published in literature on the same subject.

[Iatrogenic lesions of the facial nerve during parotid surgery for pleomorphic adenoma]. / Lesioni iatrogene del nervo facciale in corso di chirurgia parotidea per adenoma pleomorfo.

The authors, after a survey of the literature, describe the injuries of the facial nerve during parotid surgery for pleomorphic adenoma. The facial nerve damages are often transient with total resolution, except where one or more branches are deliberately sacrificed for malignant tumors or recurrence.

[An unusual case of adenocarcinoma of the median parieto-occipital area of the scalp with brain involvement]. / Su di un raro caso di adenocarcinoma della regione parietoccipitale mediana del cuoio capelluto con interessamento encefalico.

The authors describe an uncommon personally observed case of adenocarcinoma of the soft tissues in the medial parietoccipital region of the scalp, with the involvement of the brain. This case is very interesting for the localization of the cancer and its marked aggressiveness, which did not allow radical surgery.

[Cystic adenomatoid malformation of the lung. A case report]. / La malformazione adenomatoide cistica del polmone. Osservazione di un caso.

Fetal cystic adenomatoid malformation of the lung is a rare pulmonary abnormality characterized by excessive growth of terminal respiratory structures. In newborn the malformation can be responsible of respiratory distress of variable degree with immediate or delayed onset after birth. The Authors present a case of cystic adenomatoid malformation diagnosed in utero by ultrasound discussing pathological, clinical, radiological and echographic aspects of the lesion.

[Neonatal hyperthyroidism. A clinical contribution]. / Ipertiroidismo neonatale. Contributo clinico.

A case of female child who had transient signs of hyperthyroidism after the birth is presented. Authors describe the clinical course and discuss the possible pathogenetic mechanisms. The importance of a timely diagnosis, a correct therapy and follow-up is emphasized.

[Recent findings on pathology caused by Campylobacter and Yersinia. Preliminary results of an epidemiologic study on a pediatric population in Florence]. / Recenti acquisizioni sulla patologia da Campylobacter e Yersinia. Risultati preliminari di una indagine epidemiologica nella popolazione pediatrica di Firenze.

The authors, after a review of the literature concerning Campylobacter and Yersinia infections, report the preliminary results of an epidemiologic study carried out in florentine territory based on the stool-cultures of children with acute diarrhoea in the years 1984-85-86. From the dates results that in florentine territory too, Campylobacter isolation is second only to Salmonella isolation, as we can find in other searches++ of literature. Therefore the conclusion is that these two microorganisms, from "emergent" have become as interesting as to be investigated as routine practice.

[Hypohidrotic ectodermal dysplasia]. / Displasia ectodermica ipoidrotica.

The authors report a case of Hypohidrotic ectodermal dysplasia (Christ-Siemens-Touraine syndrome). Diagnosed at the age of 2 months.

[Robinow syndrome. Description of a case with diaphragmatic relaxation]. / La sindrome di Robinow. Descrizione di un caso con relaxatio diaframmatica.

The authors report a case of Robinow Syndrome in a child 22 months old, who presented a relaxatio diaphragmatic too. This is the first case, among about twenty cases indicated in literature, in whom this type of malformation is present.