322,986 research outputs found
Free-radical hydrothiolation of glycals: a thiol-ene-based synthesis of S-disaccharides
No full textA method for the synthesis of a new family of 1-deoxy S-disaccharides has been established via free-radical hydrothiolation of glycals by sugar thiols (thiol-ene coupling). The photoinduced coupling between four tri-O-acetyl-D-glycals and three different sugar thiols reveals that the reaction efficiency and stereoselectivity are highly dependent on the stereochemistry of the OAc groups at C3 and C4 of the glycal. (C) 2011 Elsevier Ltd. All rights reserved
An Embedded System for Acoustic Data Processing and AI-Based Real-Time Classification for Road Surface Analysis
No full textThe current roadway monitoring is expensive and not systematic. This paper proposes a new system able to evaluate the pavement quality of road infrastructure. The embedded system records and processes the acoustic data of the wheel-road interaction and classifies in real-time roadways' health thanks to integrated AI solutions. The measurements to produce the dataset to train a convolutional neural network (CNN) were collected using a vehicle operating at different cruise speeds in the area of Pisa. The dataset is composed by acoustic data belonging to several typologies of roads: dirty or grass roads, high roughness surfaces and roads with cracks or potholes. The raw audio signals were split, labelled, and converted into images by calculating the Mel spectrogram. Finally, the authors designed a tiny CNN with a size equal to 18 kB able to classify between four different classes: good quality road, ruined road, silence and unknown. The CNN architecture achieves an accuracy of about 93% on the original model and 90% on the quantized one. Quantization permits to convert the final architecture into a suitable form to be deployed on a low-complex embedded system integrated in the tyre cavity. In addition, a custom board was designed to act as IoT node thanks to a Bluetooth Low Energy communication towards smartphones and/or car infotainment systems. These systems, featured with GPS, guarantee to obtain real-time maps service of road quality. At authors' knowledge, this is the first real-time and fully integrated solution at the state of the art for road pavement quality analysis and classification on acoustic data
Photoinduced hydrothiolation and hydrophosphonylation of alkenes and alkynes
No full textHydrofunctionalization of terminal double or triple bonds have become classical ligation tools for facile assembly of building blocks into larger molecules especially because comply Sharpless’ prerequisite to be considered “click-chemistry” reactions. In particular the free-metal photoinduced radical thiol-ene (TEC) and thiol-yne (TYC) couplings are well-known to be atom economy, high-efficient, catalyzed only by light and completely regioselective. If both TEC and TYC have already been studied on simple substrates as linear terminal alkenes or alkynes, only few researches have been carried out about particular molecules as protein, peptides and endo-glycals. Hydrothiolation of protein, peptides and aminoacids has been studied to obtain a double different substitution of the peptidic scaffold with one carbohydrate and one marker (fluoresceine or biotine) using TYC. A new technique to synthesize S-disaccharides has been developed starting from different glycals and thio-glucose, demonstrating the efficiency of TEC on internal internal double bonds.
The successful work about hydrothiolation of different substrates has pushed us to study both hydrophosphonylation of alkenes and alkynes starting from the same conditions of TEC and TYC reactions. The different reactivity of the functionalization agent (thiol or H-phosphonate) has resulted in different conditions for the addition to double bonds, but not in a loss of efficiency o regioselectivity. On the other hand the addition on a triple bond has resulted to be ineffective and to stop at the internal double bond intermediate. A thiol-ene coupling on this intermediate, formally a vinyl phosphonate, gives equilibration to E form of the alkene without traces of hydrothiolation adducts.
It is well known that multivalent effect is a key factor in supramolecular chemistry and it governs many biological interactions, in particular in the relationship between pathogenic microorganisms and their host that involves protein–glycan recognition. The affinity of a multivalent cluster is highly dependent on the combination of the carbohydrate head with the cluster core and the spacer between them; several families of multivalent bioactive molecules have been developed by a large numbers of groups all around the world using disparate synthetic techniques. Thiol-Ene (TEC) and Thiol-Yne (TYC) couplings have been chosen as ligation tool for the synthesis of a variety of multivalent biomolecules containing carbohydrates or peptidic termini supported on different bio-inactive clusters as dendrimers and the rigid silica cube known as POSS (polyhedral oligomeric silsesquioxane). Both TEC and TYC are highly efficient, regioselective and atom economy reactions that, moreover, permit us to avoid purification problems due to metal catalysis or to use large excess of reagents to have a complete substitution on the central core. In fact all the reactions have been carried out with success, high yield and without by-products of any kind. Affinity toward specific target of this large library of compounds has been tested by Enzyme-Linked Lectin Assay (ELLA) and results from good to excellent have been found in all classes of compounds
Salivary proteome modifications in pediatric oncological patients
No full textAim. The human salivary proteome characterization wants to identify proteins, in order to associate their presence (or absence) and their different level of expression to different physiological conditions or to a particular disease. The purpose of this work is to evaluate the salivary proteome modifications that occur in children with oncologic diseases, undergoing chemo or radiotherapy, comparing them to healthy pediatric patients salivary peptides. Some proteins, in particular, were quantified in order to evaluate their possible role as disease and/or inflammation biomarkers and their possible use in early diagnosis, prognosis, therapeutic monitoring and response to anticancer treatment.
Methods. To investigate if oncological children salivary proteome differs from that of healthy children, and in order to understand how it evolves during the subsequent cycles of anticancer therapy, the acidic soluble fraction of whole saliva of 12 children with cancer (8 females and 4 males) was analyzed by RP-HPLC-ESI-MS and compared to 12 controlsubjects (8 females and 4 males), all aged between 0 and 14 years. Healthy children were subjected to only one sample, differently from oncological children who were subjected to a variable number of samples: the first one at the diagnosis, the others after each treatment cycle, in order to define the changes in salivary proteome during the different stages of anticancer therapy. The proteins we analyzed were, in particular, defensins (α1, α2, α3 e α4), cystatin A and cystatin B (unmodified, Sglutathionyl, S-cysteinyl).
All proteins, although not primarily glandular, represent a potential index of localized or diffuse tumors, being widely recognized for them a role in the immune system.
The protein concentration trend of each sample was compared in this way: first it was observed, for each oncologic patient, how the concentration of each protein is modified during the treatment, by relating the different samples from the same child; then these same patients were compared to the control group (healthy children).
Results. Protein and peptide quantification based on the area of the RP-HPLC-ESI-MS extracted ion current peak evidenced in particular that: I) there is a little quantity of α-defensins and cystatins in healthy children; II) α-defensins 1, 2, 3 are significantly increased in oncological patients (P<0,005), compared with healthy subjects, at the moment of the diagnosis; III) the concentration of these proteins decreases to the control level, after the treatment.
Conclusion. The most significant data is the important difference between healthy and ill subjects for α-defensins 1, 2 and 3, which makes them potential biomarkers of localized or diffuse cancer. The high levels of these peptides might be a sign of their involvement in innate immune response, especially in the earliest stages of tumor development, as a product of local inflammatory response (linked to the proliferative-necrotic and antigenic activity of tumor cells) and as well as a systemic effect of homeostasis change in the whole organism.
α-defensins reduction, which was observed after radio-chemotherapy, could be due to the effect of the direct cytotoxic treatment on epithelial cells, which is able to reduce the secretory activity, or to its immunosuppressant and immuno-modulator effects on cell recruitment from the innate immune system, as well as to a combination of both described mechanisms. As these proteins decrease already in the first cycle of treatment and reach control-similar values, they may play an important role in cancer therapeutic monitoring
Open Bite Treatment with Combined Aligners and Myofunctional Appliances: A Case Report
No full textThis case report describes an 18-year-old female patient with a skeletal class I pattern, mandibular asymmetry, a molar class III on the right side, a molar class II on the left side, and an anterior open bite (AOB). Treatment of AOB is often difficult for orthodontists and a multidisciplinary approach is sometimes required to rehabilitate the correct function and posture of the tongue. In this case the AOB was treated using the Nuvola® OP System: a treatment system that combines orthodontic aligners and a myofunctional elastodontic device called Freedom. An upper molar intrusion with miniscrews was performed during the first phase of the treatment programme, and then the aligner treatment began. The Nuvola® OP System ’s aligners are characterized by lingual pins that guide the tongue to the palatal spot position and take advantage of tongue function. The patient was instructed to wear the Freedom device for 30 min a day and to clench every 3 s with closed lips while wearing the aligners. These exercises improve the fitting of the aligners, improve the tongue’s posture, and take advantage of the masticatory forces to resolve the malocclusion. The patient was successfully treated, thus demonstrating that the Nuvola® OP System is a valid alternative for the treatment of AOB
Treatment of oral hamartomas in a pediatric patient with Cowden’s Syndrome: a case report
No full textAim. Cowden’s Syndrome (CS) is an autosomal dominant disorder associated with mutations in PTEN (Phosphatase and TENsin homolog), a tumor suppressor gene, that cause the PTEN protein not to work properly.
The incidence of CS is around 1/200 000 subjects. Since many of the clinical features of CS are common in the general population (e.g. fibrocystic breast disease, uterine fibroids), this condition is probably under-diagnosed and it could have a higher incidence.
Methods. A 14-year-old child came to the attention of the Operative and Paediatric Dentistry unit of the Department of surgical sciences for head and neck diseases – Polyclinic “Agostino Gemelli”, “University of Sacred Heart” of Rome complaining of several pedunculated lesions of the lips, which had been recently traumatized and sensitive to palpation. Considering the notable features
of his previous medical history (medulloblastoma, multiple intestinal hamartomas, multiple thyroid nodules and mucogengival lesions) besides his uncooperative attitude towards medical staff (odontophobia and anxiety disorder) the clinicians decided to treat him under general anesthesia. Intraoral mucosal examination revealed geographic and fissured tongue and multiple,
confluent, asymptomatic oral papillomatous papules, ranging from 1 to 3 mm in diameter, localized on the tongue, lips, angles of the mouth, buccal mucosa and attached gingiva. Dental examination revealed poor oral hygiene (generalized chronic periodontal disease and multiple carious lesions) and dental malposition with premature loss of teeth. Basing on the clinical features, particularly the presence of multiple muco-cutaneous nodules, a working diagnosis of Cowden’s syndrome was made.
The clinical management of the patient included the surgical excision of the multiple papules affecting the upper and lower lip. The excised lesion were fixed with 10% buffered formalin and sent for microscopical examination.
Histological examination of the polyps revealed these to be hyperplastic and adenomatous confirming the working Cowden’s syndrome diagnosis.
No recurrence has been seen at the 3 months clinical follow-up.
Discussion. Cowden’s syndrome, or multiple hamartoma syndrome, was first described in 1940 by Costello in a 27-years old Mexican female. In 1963, Lloyd and Dennis defined and named this pathology by their patient, Rachel Cowden, a 20-year-old female with adenoid facies, high-arched palate, hypoplasia of the soft palate and uvula, papillomatosis of the lips and oropharynx,
scrotal tongue, thyroid lesions, hypertrophy and fibrocystic disease of the breast, scoliosis, and lesions of the bones and liver.
Although CS is mainly associated with benign tumors, the prevalence of malignancies, especially breast and thyroid carcinomas, in affected patients is greater than in general population.
In view of this, it is essential to request a histological examination of the excised lesions in patients for whom a preliminary diagnosis of CS is made.
Conclusion. The dentist thus should be aware of the clinical features and possible developments of the CS because he can be the first health care professional who identifies it in its early stages; in such a case the clinician must alert the patient to do medical checks for preventing the formation of a neoplasia or its metastatic development
Improved Multichannel Electromyograph Using Off-the-Shelf Components for Education and Research
No full textMost students and researchers with limited funding are often looking for simple and low-cost devices for the acquisition of the electromyogram signal (EMG) in an educational or research setting. Thus, off-the-shelf devices are used and they have already been described in the literature, but they are used without considering their real performances, which are, in general, quite poor from the electronic and signal processing points of view. It is the purpose of this communication to present the evidence of these issues, and to describe an improved version of the “classical” duo, composed of the common ECG/EMG Olimex board and the Arduino microprocessor board. In this case, the Arduino-DUE is used. Three main points are highlighted in this paper: (a) the bandpass characteristics of the ECG/EMG Olimex board and how they can be improved to cope with EMG bandwidth requirements; (b) the increase in sampling frequency of the signal; and, finally, (c) the possibility of automatic detection of more ECG/EMG Olimex boards installed at the same time as the shields on the Arduino-DUE board. Very simple and low-cost modifications on the ECG/EMG Olimex board could deliver a much better performing multichannel EMG acquisition system, suitable for educational classroom experiments and early proof-of-concept research
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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