Melanosis of the lower lip subverted by filler injection: a simulator of early mucosal melanoma

.

Structural behaviour of copper chloride catalysts during the chlorination of CO to phosgene

The interaction of CO with an attapulgite-supported Cu(II)Cl2 catalyst has been examined in a micro-reactor arrangement. CO exposure to the dried, as-received catalyst at elevated temperatures leads to the formation of CO2 as the only identifiable product. However, phosgene production can be induced by a catalyst pre-treatment where the supported Cu(II)Cl2 sample is exposed to a diluted stream of chlorine. Subsequent CO exposure at ~ 370°C then leads to phosgene production. In order to investigate the origins of this atypical set of reaction characteristics, a series of x-ray absorption experiments were performed that were supplemented by DFT calculations. XANES measurements establish that at the elevated temperatures connected with phosgene formation, the catalyst is comprised of Cu+ and a small amount of Cu2+. Moreover, the data show that unique to the chlorine pre-treated sample, CO exposure at elevated temperature results in a short-lived oxidation of the copper. On the basis of calculated CO adsorption energies, DFT calculations indicate that a mixed Cu+/Cu2+ catalyst is required to support CO chemisorption

Coexistence of amplitude and frequency modulations in intracellular calcium dynamics

The complex dynamics of intracellular calcium regulates cellular responses to information encoded in extracellular signals. Here, we study the encoding of these external signals in the context of the Li-Rinzel model. We show that by control of biophysical parameters the information can be encoded in amplitude modulation, frequency modulation or mixed (AM and FM) modulation. We briefly discuss the possible implications of this new role of information encoding for astrocytes.Comment: 4 pages, 4 figure

High Throughput Protein Similarity Searches in the LIBI Grid Problem Solving Environment

Bioinformatics applications are naturally distributed, due to distribution of involved data sets, experimental data and biological databases. They require high computing power, owing to the large size of data sets and the complexity of basic computations, may access heterogeneous data, where heterogeneity is in data format, access policy, distribution, etc., and require a secure infrastructure, because they could access private data owned by different organizations. The Problem Solving Environment (PSE) is an approach and a technology that can fulfil such bioinformatics requirements. The PSE can be used for the definition and composition of complex applications, hiding programming and configuration details to the user that can concentrate only on the specific problem. Moreover, Grids can be used for building geographically distributed collaborative problem solving environments and Grid aware PSEs can search and use dispersed high performance computing, networking, and data resources. In this work, the PSE solution has been chosen as the integration platform of bioinformatics tools and data sources. In particular an experiment of multiple sequence alignment on large scale, supported by the LIBIPSE, is presented

Surface Functionalization of 3C-SiC Nanowires

One dimensional nanostrucures have potential applications in nanoscale electronic, optoelectronic or sensing devices. Core-shell nanowire (NW) structures of SiO2/β-SiC and SiC-NWs are interesting for fundamental studies and technological applications: 3C-SiC is particularly appealing because of its good physical, chemical properties and biocompatibility, offering opportunities for nano-scale devices operating in biological environment. Moreover, functionalized 3C-SiC nanowires have the potential to act as highly sensitive detector elements in bio-chemical field. Here, we report on the preliminary results of the functionalization of 3C-SiC nanowires with an optically active, thiophene-based, π-conjugated oligomer (PyT4). Oligothiophenes are semiconducting and fluorescent materials, widely used in organic electronics and biodiagnostic. SiC/SiO2 core/shell NWs grown by a Chemical Vapour Deposition (CVD) process on n-type Si (001) substrates, using carbon monoxide (CO) as the carbon source and nickel nitrate as the catalyst. The synthesis, performed at temperatures between 1050-1100?C. 3C-SiC NWs were grown in a home-made Vapor Phase Epitaxy (VPE) reactor using propane and silane as precursors (both diluted 3% in hydrogen) and a few nm of Ni as catalyst, deposited on Si(100) substrate using e-beam system. The nickel-deposited substrate is preheated at 1100?C for 5 minutes before introducing reagents for the grow time of 10 minutes. SiC/SiO2 core/shell NWs were then reacted with the triethoxysilane terminated with PyT4 to yield the hybrid NWs. The covalent grafting of the fluorophores was confirmed by fluorescence microscopy. The nanowires were further characterised by X-ray diffraction, Scanning Electron Microscopy, Cathodoluminescence and Transmission Electron Microscopy

Short term efficacy of nebulized beclomethasone in mild-to-moderate wheezing episodes in pre-school children

<p>Abstract</p> <p>Background</p> <p>Few data are available on the usefulness of short term treatment with low-medium dose of inhaled corticosteroids (ICS) in pre-school children with wheezing exacerbations.</p> <p>Methods</p> <p>To compare the efficacy of one week treatment with 400 μg b.i.d. nebulized beclomethasone dipropionate (BDP), plus nebulized 2500 μg prn salbutamol (BDP group), versus nebulized b.i.d. placebo, plus nebulized prn 2500 μg salbutamol (placebo group), a post-hoc analysis was performed on data obtained in 166 pre-school children with multiple-trigger wheezing, recruited during an acute wheezing episode.</p> <p>Results</p> <p>The percentage of symptom-free days (SFDs) was significantly higher in the BDP group (54.7%) than in the placebo group (40.5%; p = 0.012), with a 35% relative difference. Day-by-day analysis showed that the percentage of SFDs was already higher in the BDP group after 2 days (7.4%), the difference reaching statistical significance at day 6 (12.3%; p = 0.035). Cough score was also reduced in the BDP group (0.11) as compared with the placebo group (0.39; p = 0.048), the difference reaching statistical significance after 5 days of treatment (0.18 and 0.47 respectively; p = 0.047). The mean number of nebulizations per day of prn salbutamol was lower in the BDP group as compared to the placebo group (0.26 and 0.34, respectively), but the difference was not significant (p = 0.366). There were no differences in positive effects of BDP treatment between children with and without risk factors for asthma.</p> <p>Conclusions</p> <p>A 1-week treatment with nebulized BDP and prn salbutamol is effective in increasing SFDs and improving cough in children with wheezing, providing a clinical rationale for the short term use of ICS in episodic wheeze exacerbations in pre-school children.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov (<a href="http://www.clinicaltrials.gov/ct2/show/NCT00497523">NCT00497523</a>)</p

Usefulness and safety of double endoscopy in children with gastroesophageal reflux and respiratory symptoms

SummaryBackgroundManagement of children with gastroesophageal reflux disease (GORD) and difficult-to-treat (D-T-T) respiratory symptoms may include double fiberoptic, airway and oesophago-gastro-duodenoscopies (DE). A study was performed to evaluate the usefulness and safety of DE in children with severe GORD and D-T-T respiratory symptoms.MethodsA 3-year retrospective review of records of children who underwent DE under general anaesthesia was performed: the relevant clinical information obtained and the occurrence of complications in the 72h following the DE.ResultsInflammatory changes of the airways were found at bronchoscopy in 40 out of the 60 children: bronchoalveolar lavage (BAL) demonstrated positive lipid-laden alveolar macrophages (LLAM), neutrophilic inflammation or both, respectively in 9, 12 and 16 patients. BAL bacterial cultures were positive in 2 patients with elevated airway neutrophilia. Structural airway abnormalities, explaining not GOR-related D-T-T respiratory symptoms were identified in 11 patients. Oesophagoscopic findings supporting GORD were detected in 32/60 children and confirmed by consistent histological changes in oesophageal mucosal biopsies (OEB) in 27.The frequency of complications, all minor, was low during the procedure and in the following 72h. They included mild desaturation, stridor or bronchospasm, vomiting, dysphagia and hyperthermia requiring antibiotic treatment in 1 patient. No “new onset” complication was observed after 48h following DE. The time-dependent hazard of complications was significantly higher for patients with a history of onset of respiratory symptoms early in life (≤2 years of age) (p=0.038).ConclusionDE can be useful in the clinical evaluation of children with D-T-T respiratory symptoms and GORD and is associated with low frequency of mild complications when performed by appropriately trained and experienced personnel

Sequence Analysis, Kinetic Constants, and Anion Inhibition Profile of the Nacrein-Like Protein (CgiNAP2X1) from the Pacific Oyster Magallana gigas (Ex-Crassostrea gigas)

The carbonic anhydrase (CA, EC 4.2.1.1) superfamily of metalloenzymes catalyzes the hydration of carbon dioxide to bicarbonate and protons. The catalytically active form of these enzymes incorporates a metal hydroxide derivative, the formation of which is the rate-determining step of catalytic reaction, being affected by the transfer of a proton from a metal-coordinated water molecule to the environment. Here, we report the cloning, expression, and purification of a particular CA, i.e., nacrein-like protein encoded in the genome of the Pacific oyster Magallana gigas (previously known as Crassostrea gigas). Furthermore, the amino acid sequence, kinetic constants, and anion inhibition profile of the recombinant enzyme were investigated for the first time. The new protein, CgiNAP2X1, is highly effective as catalyst for the CO₂ hydration reaction, based on the measured kinetic parameters, i.e., kcat = 1.0 × 10⁶ s(-1) and kcat/KM = 1.2 × 10⁸ M(-1)·s(-1). CgiNAP2X1 has a putative signal peptide, which probably allows an extracellular localization of the protein. The inhibition data demonstrated that the best anion inhibitors of CgiNAP2X1 were diethyldithiocarbamate, sulfamide, sulfamate, phenylboronic acid and phenylarsonic acid, which showed a micromolar affinity for this enzyme, with KIs in the range of 76-87 μM. These studies may add new information on the physiological role of the molluskan CAs in the biocalcification processes

Extraction of cocoa butter by supercritical carbon dioxide: optimization of operating conditions and effect of particle size.

The optimum operating conditions for the extraction of cocoa butter from cocoa liquor using supercritical carbon dioxide and the effect of sample particle size on cocoa butter extraction under optimized operating conditions were investigated. The optimization was conducted at 10–45 MPa and 35–75C, with extraction times of 1–12 h by response surface methodology. The effect of particle size was studied using cocoa liquor, ground cocoa nibs and crushed cocoa nibs with particle sizes of approximately 74 µm, 0.85–1 mm and 4–6 mm, respectively. The yield was analyzed for total fat content by gravimetric method and triacylglycerol (TAG) profile by high-performance liquid chromatography. The results showed higher yield of cocoa butter with higher values of pressure, temperature and extraction time. The optimum conditions for cocoa butter extraction were 45 MPa, 75C and 12 h. The smaller particle size produced a higher yield of cocoa butter. 1,3-Dipalmitoyl-2-oleoyl-glycerol (POP), 1-palmitoyl-2-oleoyl-3-stearoyl-glycerol (POS) and 1,3-distearoyl-2-oleoyl-glycerol (SOS) were the major TAGs present in the extracted cocoa butter, with POS being the highest (>30%) for all treatments studied