Mechanically strong waterborne poly(urethane-urea) films and nanocomposite films

A series of transparent waterborne poly(urethane-urea) (PUU) films and nanocomposite films were prepared using isocyanate excess (5–50 mol% excess relative to the hydroxyl groups) and omitting the common chain-extension step in the acetone method of the preparation. The surplus isocyanate groups were converted into urea and eventually biuret linkages via the reaction with water during the last phase inversion step. Nanocomposites were prepared by the direct mixing of the PUU nanoparticles in water with aqueous nanosilica or montmorillonite powder followed by slow water evaporation. Variable urea/biuret content is responsible for substantially different tensile properties; the neat organic films show elongation-at-break values of 100%–1120%, tensile strength values of 0.07–22.1 MPa, and energy-to-break of 0.1–85 mJ × mm⁻³. All of the materials can be potentially used as soft-to-hard topcoats, depending on the specific demands. The most promising materials are films prepared at 30 and particularly 40 mol% isocyanate excess.     

A new approach for kinetic modeling and optimization of rubber molding

Although extensive research has been carried out on the understanding of the complex vulcanization process, the influence of reversion through exposure time and temperature on the vulcanization degree remains unclear. Therefore, the main aim of this study was a novel optimization approach that can help the industrial practitioners to select the optimal operating parameters, exposure time, and molding temperature, to achieve desired vulcanization degree of selected product. Spheres of four different diameters (2.5, 5, 10, and 20 cm) were selected as test geometry for simulation and optimization of rubber molding. Obtained vulcanization rheometer data for commercially available rubber blend (NR/SBR) were fitted by a new modeling approach, dividing vulcanization curve into two fitting sets: curing and reversion. The heat transfer equations for chosen geometry were coupled with proposed kinetic model. A new temperature-dependent kinetic parameter x, as the maximal reversion degree, was introduced, enabling determination of the lowest operating molding temperature (T_min = 132.36 °C), preventing high reversion and overheating of the rubber product. The final optimization goal was assessment of the optimal temperature and vulcanization time dependence on the rubber products dimensions. Proposed models have precise prediction with R² values greater than 0.8328 and MAPE less than 2.3099%.     

Implementation of security policy for clinical information systems over wireless sensor networks

Various healthcare areas such as diagnosis, surgery, intensive care and treatment, and patient monitoring in general, would greatly benefit from light, autonomous devices which can be unobtrusively mounted on the patient’s body in order to monitor and report health-relevant variables to an interconnection device in the vicinity. This interconnection device should be able to connect to access points at different locations within the healthcare institution. In this manner, health-relevant measurements can be forwarded to the central medical database and stored therein. In this scenario, integrity and privacy of personal medical data is of utmost importance. In this paper we address the networking and security architecture of a healthcare information system comprised of patients’ personal sensor networks, department/room networks, hospital network, and medical databases. We discuss confidentiality and integrity policies for clinical information systems and propose the feasible enforcement mechanisms over the wireless hop. We also compare two candidate technologies, IEEE 802.15.1 and IEEE 802.15.4, from the aspect of resilience to jamming and denial-of-service attacks.     

Photonic Technologies for Quantum Information Processing

The last several years have seen tremendous progress toward practical optical quantum information processing, including the development of single- and entangled-photon sources and high-efficiency photon counting detectors, covering a range of wavelengths. We review some of the recent progress in the development of these photonic technologies. PACS: 03.67.-a, 42.50.Dv, 42.65.Lm, 78.67.Hc, 85.60.Gz     

Immobilization of laccase from Myceliophthora thermophila on functionalized silica nanoparticles: Optimization and application in lindane degradation

This work is focused on immobilization of laccase from Myceliophthora thermophila expressed in Aspergillus oryzae(Novozym 51003? laccase) on amino modified fumed nano-silica(AFNS) and the possible use in bioremediation. Hereby, for the first time, factors affecting the immobilization of Novozym 51003? laccase on AFNS were investigated for defining the immobilization mechanism and optimizing the utilization of AFNS as support for laccase immobilization. The highest specific activity(13.1 IU·mg~(-1) proteins) was achieved at offered 160 mg per g of AFNS and for the same offered protein concentration the highest activity immobilization yield, reaching68.3% after the equilibrium time, at optimum pH 5.0, was obtained. Laccase immobilization occurs by adsorption as monolayer enzyme binding in 40 min, following pseudo-first-order kinetics. The possible use of obtained immobilized preparation was investigated in degradation of pesticide lindane. Within 24 h, lindane concentration was reduced to 56.8% of initial concentration and after seven repeated reuses it retained 70% of the original activity.     

Polycyclic aromatic hydrocarbons in traditionally smoked Slavonska kobasica

ABSTRACT

The traditional smoking procedure, which is the use of open fire, can lead to the formation of PAHs in sausages. The aim of this paper was to assess the types and concentrations of 16 PAHs in 30 samples of Slavonska kobasica, a traditional smoked sausage. In general, some samples showed high values of anthracene and acenaphthylene. In one sample, acenaphthylene reached the value of 1050 µg/kg and in another 1491 µg/kg anthracene was measured. Cancerogenic benzo(a)pyrene content was little above the maximum limit of 5 µg/kg in four samples, but mainly remained below the limit of quantification. PAH4 (i.c. benzo(a)anthracene, chrysene, benzo(b)fluoranthene and benzo(a)pyrene) were above the maximum limit of 30 µg/kg in three samples. Generally, it can be noted from the results that samples with high PAH4 and benzo(a)pyrene concentrations also have high PAH16 concentrations.     

Molecular identification and population dynamic of Anisakis pegreffii (Nematoda: Anisakidae Dujardin, 1845) isolated from the European anchovy (Engraulis encrasicolus L.) in the Adriatic Sea

Anchovy Engraulis encrasicolus (L.) is a coastal pelagic and euryhaline species that represents the only European species of the family Engraulidae, with a widespread distribution. In Croatia, it is marketed fresh, frozen, salted or marinated and mainly exported to Italy and Spain, however Anisakis sp. larval infection is frequently the reason for border rejection. Since it is known that the prevalence and intensity of Anisakis infection varies with fish species, fishing area and season, the aim of our study was to identify Anisakis sp. parasitizing European anchovy and infer its population dynamic through a 2.5-year period. Larvae were found coiled and encysted on the external wall of intestine (94%) and reproductive organs (6%), rarely in fillets. Prevalence was 76.1% (95% confidence limits 74.51-77.56%), mean abundance 6.59 (bootstrap 95% confidence limits 5.81-7.26) and mean intensity 8.67 (bootstrap 95% confidence limits 7.82-9.35). The partial CO2 mitochondrial DNA sequence of the isolated anisakids confirmed clustering of the anchovy parasite within A. pegreffii sister group. Parasite population structure showed plasticity inferred by fishing ground, sampling year and fish gender and size. Compared to anisakid prevalence/abundance in other fish, the European anchovy in the Adriatic Sea represents a moderately high-infected paratenic host, although in the Mediterranean and Atlantic waters, anchovies have shown strikingly lesser values of prevalence. Since this host represents one of the most attractive Mediterranean fisheries products traditionally consumed without thermal preparation that in any case would not disrupt larval antigenicity and prevent human allergies, and given the high prevalence of the anisakid within the host, it is necessary to include anchovy into more firm risk assessment frames in order to develop measures that will support the safe alimentary production and consumption of seafood.     

The effects of microwave heating on the kinetics of isothermal dehydration of equilibrium swollen poly(acrylic‐co‐methacrylic acid) hydrogel

The isothermal dehydration of poly(acrylic‐co‐methacrylic acid) (PAM) hydrogel under microwave heating (MWH) was investigated. The isothermal kinetics curves of the PAM hydrogel dehydration at temperature range from 293 K to 333 K were recorded. Based on the differential isoconversion method it was concluded that the microwave dehydration of poly(acrylic‐co‐methacrylic acid) hydrogel is an elementary kinetics process. Applying the model‐fitting method it was established that the kinetics of microwave isothermal hydrogel dehydration can be described by the kinetics model of the phase‐boundary controlled process (contracting area). The values of the kinetics parameters (activation energy (E_a) and preexponential factor (lnA)) of the dehydration process under microwave heating are lower than the values for conventional heating (CH). The established influence of MWH on the kinetics of hydrogel dehydration is explained with a specific activation mechanism of water molecules for dehydration and with the increase in the value of the energy of the ground level of the resonant oscillator of water molecule (v = 837 cm^?1) due to the absorption of microwave energy. POLYM. ENG. SCI., 56:87–96, 2016. © 2015 Society of Plastics Engineers     

Gene Mutation Profiles in Primary Diffuse Large B Cell Lymphoma of Central Nervous System: Next Generation Sequencing Analyses

The existence of a potential primary central nervous system lymphoma-specific genomic signature that differs from the systemic form of diffuse large B cell lymphoma (DLBCL) has been suggested, but is still controversial. We investigated 19 patients with primary DLBCL of central nervous system (DLBCL CNS) using the TruSeq Amplicon Cancer Panel (TSACP) for 48 cancer-related genes. Next generation sequencing (NGS) analyses have revealed that over 80% of potentially protein-changing mutations were located in eight genes (CTNNB1, PIK3CA, PTEN, ATM, KRAS, PTPN11, TP53 and JAK3), pointing to the potential role of these genes in lymphomagenesis. TP53 was the only gene harboring mutations in all 19 patients. In addition, the presence of mutated TP53 and ATM genes correlated with a higher total number of mutations in other analyzed genes. Furthermore, the presence of mutated ATM correlated with poorer event-free survival (EFS) (p = 0.036). The presence of the mutated SMO gene correlated with earlier disease relapse (p = 0.023), inferior event-free survival (p = 0.011) and overall survival (OS) (p = 0.017), while mutations in the PTEN gene were associated with inferior OS (p = 0.048). Our findings suggest that the TP53 and ATM genes could be involved in the molecular pathophysiology of primary DLBCL CNS, whereas mutations in the PTEN and SMO genes could affect survival regardless of the initial treatment approach.     

The comparative kinetic study of non-isothermal and isothermal dehydration of swollen poly(acrylic acid) hydrogel using the Weibull probability function

The isothermal and non-isothermal dehydration of swollen poly(acrylic acid) hydrogel has been investigated. The possibility of calculating the isothermal conversion curves from the non-isothermal conversion curves was examined. It was found that the experimental conversion curves under non-isothermal and isothermal conditions can be described by the Weibull probability distribution function. Changes in the values of distibution parameters with heating rate (non-isothermal dehydration) and operating temperature (isothermal dehydration) were identified. The mathematical procudere for determining the non-isothermal kinetic conversion curves, based on the functional relationship between distribution parameters and the heating rate was developed. In addition, the new mathematical procedure for calculating the isothermal kinetic curves from the non-isothermal ones at a certain temperature was established. It was found that the large deviation exists between the experimental and calculated isothermal conversion curves. In order to explain the difference in the mechanism of hydrogel dehydration under non-isothermal and isothermal conditions, the dependence of the apparent activation energy on the degree of conversion (E_a = E_a(α)) was performed using the isoconversional (model-free) methods. It was found that in the case of non-isothermal dehydration, the apparent activation energy exhibits a concave decrease with the degree of conversion (α), while for the isothermal dehydration, the apparent activation energy exhibits a convex increase with α. Certain changes in a variety of E_a with α are explained on the basis of different relaxation processes, that take place during non-isothermal and isothermal hydrogel dehydration. The characteristic features of density distribution functions of the apparent activation energies are derived in the case of non-isothermal and isothermal dehydration. It was found that the differences in characteristic properties of derived distribution functions are a consequence of different relaxation processes, which taking place under various experimental conditions.