fMLP-OMe analogs substituted at the methionine residue: an insight into the receptor properties

In order to obtain an insight into the mode of binding at the for-Met-Leu-Phe-OH (fMLP) receptor, three fMLP-OMe analogs (1-3) were synthesized in which the Met residue was substituted by Gln 1, Asn 2, and Ser 3. We evaluated the influence of the charge variation and/or the shift of its position on neutrophil biological responses.     

FT-NIR spectroscopy for the quality characterization of apricots (Prunus armeniaca L.)

Abstract: The nondestructive assessment of apricot fruit quality (Bora cultivar) was carried out by means of FT-NIR reflectance spectroscopy in the wavenumber range 12000 to 4000 cm⁻¹. Samples were harvested at four different ripening stages and scanned by a fiber optical probe immediately after harvesting and after a storage of 3 d (2 d at 4 °C and 1 d at 18 °C); the flesh firmness (FF), the soluble solids content (SSC), the acidity (A), and the titratable acidity (malic and citric acids) were then measured by destructive methods. Soft independent modeling of class analogy (SIMCA) analysis was used to classify spectra according to the ripening stage and the storage: partial least squares regression (PLS) models to predict FF, SSC, A, and the titratable acidity were also set-up for both just harvested and stored apricots. Spectral pretreatments and wavenumber selections were conducted on the basis of explorative principal component analysis (PCA). Apricot spectra were correctly classified in the right class with a mean classification rate of 87% (range: 80% to 100%). Test set validations of PLS models showed R² values up to 0.620, 0.863, 0.842, and 0.369 for FF, SSC, A, and the titratable acidity, respectively. The best models were obtained for the SSC and A and are suitable for rough screening; a lower power prediction emerged for the other maturity indices and the relative predictive models are not recommended. Practical Application : The results of the study could be used as a tool for the assessment of the ripening stage during the harvest and the quality during the postharvest storage of apricot fruits.     

Scratch resistance of nano-silica reinforced acrylic coatings

Organic–inorganic hybrid coatings were obtained by a dual-curing process combining the sol–gel reaction with the UV-induced polymerization technique by starting from bisphenol A ethoxylate (15 EO/phenol) dimethacrylate (BEMA, as organic network former), methacryloyloxypropyl-trimethoxysilane (MEMO, as coupling agent) and tetraethoxysilane (TEOS, as inorganic silica network precursor). For comparison, TEOS was also substituted with preformed silica nanoparticles. Scratch test was carried out in order to study the scratch resistance of that silica reinforced acrylic resins. Excellent scratch resistant coatings were obtained by UV and sol–gel dual curing process. On the contrary, coatings with very poor scratch resistance were obtained by dispersing preformed nano-silica into the acrylic resin indicating the key role played by the morphology of the inorganic filler and its interaction with the organic matrix.     

Biocatalyzed Synthesis of Flavor Esters and Polyesters: A Design of Experiments (DoE) Approach

In the present work, different hydrolases were adsorbed onto polypropylene beads to investigate their activity both in short-esters and polyesters synthesis. The software MODDE^® Pro 13 (Sartorius) was used to develop a full-factorial design of experiments (DoE) to analyse the thermostability and selectivity of the immobilized enzyme towards alcohols and acids with different chain lengths in short-esters synthesis reactions. The temperature optima of Candida antarctica lipase B (CaLB), Humicola insolens cutinase (HiC), and Thermobifida cellulosilytica cutinase 1 (Thc_Cut1) were 85 °C, 70 °C, and 50 °C. CaLB and HiC preferred long-chain alcohols and acids as substrate in contrast to Thc_Cut1, which was more active on short-chain monomers. Polymerization of different esters as building blocks was carried out to confirm the applicability of the obtained model on larger macromolecules. The selectivity of both CaLB and HiC was investigated and best results were obtained for dimethyl sebacate (DMSe), leading to polyesters with a M_w of 18 kDa and 6 kDa. For the polymerization of dimethyl adipate (DMA) with BDO and ODO, higher molecular masses were obtained when using CaLB onto polypropylene beads (CaLB_PP) as compared with CaLB immobilized on macroporous acrylic resin beads (i.e., Novozym 435). Namely, for BDO the M_n were 7500 and 4300 Da and for ODO 8100 and 5000 Da for CaLB_PP and for the commercial enzymes, respectively. Thc_Cut1 led to polymers with lower molecular masses, with M_n < 1 kDa. This enzyme showed a temperature optimum of 50 °C with 63% of DMA and BDO when compared to 54% and 27%, at 70 °C and at 85 °C, respectively.     

Effect of carbonation on the hydro-mechanical properties of Portland cements

We evaluate experimentally the effect of carbonation on the hydro-mechanical properties of Portland cement. Samples were carbonated at 90 °C and 28 MPa under wet supercritical CO₂. Two types of carbonation features were achieved, either the samples were homogeneously carbonated or they displayed sharp carbonation fronts. Using a tri-axial apparatus, the static elastic moduli and the mechanical strength were measured at in-situ pressure conditions (28 MPa) and showed a degradation of the mechanical properties of the samples where a carbonation front prevailed. Water and gas permeabilities were measured and showed that the samples with a carbonation front exhibit a stress sensitive permeability. P and S elastic wave velocities were measured to evaluate dynamic (ultrasonic range, 1 MHz) elastic moduli. The use of an effective medium theory approach enabled us to characterize the density and distribution of cracks within the samples. This approach outlines that the samples which developed a carbonation front were damaged.     

4H-SiC band structure investigated by surface photovoltage spectroscopy

The conduction and valence band structure of high-purity 4H-SiC epilayers have been studied by surface photovoltage spectroscopy (SPS). A comparison between defect-free and single-layer stacking fault affected areas is reported. Electronic transitions, determined by SPS, are in good agreement with ab initio calculations. Electronic transitions and changes in band occupation have been observed in stacking fault rich areas below the band gap. Moreover, stacking faults induce the presence of a split-off band below the conduction band and a modification of the electron density of states in the conduction band always at the M point.     

Morphological and structural properties of neutron-irradiated B12C3 boron carbide microcrystals

Boron carbide B₁₂C₃ microcrystals were neutron irradiated at four different fluences, namely at 1.09, 2.19, 3.28 and 4.38 × 10¹⁶ n cm^?2. The structural properties were studied by means of Raman spectroscopy, revealing that the neutron induced structural defects are focused toward the interstitial chains of B₁₂C₃. The morphology of the B₁₂C₃ samples was studied by means of secondary electron imaging showing that the neutron irradiation did not modify the size distribution of the microcrystals.     

SWiMNet: A Scalable Parallel Simulation Testbed for Wireless and Mobile Networks

We present a framework, called SWiMNet, for parallel simulation of wireless and mobile PCS networks, which allows realistic and detailed modeling of mobility, call traffic, and PCS network deployment. SWiMNet is based upon event precomputation and a combination of optimistic and conservative synchronization mechanisms. Event precomputation is the result of model independence within the global PCS network. Low percentage of blocked calls typical for PCS networks is exploited in the channel allocation simulation of precomputed events by means of an optimistic approach.Various experiments were conducted to study the performance and scalability of SWiMNet using a realistic mobility model and executed on a cluster of workstations. Experimental results indicate that our parallel simulation model yields good speedup, and significantly reduces the execution time compared to a sequential implementation. Finally, an analytical study of our PCS simulation model is also presented and compared with the experimental results. Our model is found to be consistent with the analytical study.     

Penetrating wounds of the thorax

From January 1989 to December 1993 at the Institute of Clinical Surgery of the University of Perugia, 5 patients were under observation for penetrating chest injuries. Two of them had show-wounds, one a slash, one a stabbing and slash and one a cutting blow. One of the patients with shot-wounds died on the operating table from a haemorrhage while the other was saved by surgery. One patient successfully underwent surgery for loss of tissue in the thorax walls. Another had a mini-thoracotomy plus lung suture which were successful. Finally, in the patient with a slash in the front region of the thorax and a slight pneumothorax, we inserted a chest thorax tube and so obtained a complete re-expansion of the lung. Total mortality was 20%. Surgical exploration of the thorax we believe is necessary wherever there is a risk of haemorrhage or possible lung damage requiring only surgery. According to many authors, video-thoracoscopy has the advantage of a reliable diagnosis and above all, enable us to repair lung wounds without opening the thorax. In one of our patients we could have avoided the mini-thoracotomy and used thoracoscopy to repair the lung damage.