Calorimetric and spectroscopic investigations of β-lactoglobulin upon interaction with copper ion

The effect of copper(II) ions (Cu(+2)) on the structure of β-lactoglobulin (β-lg) was investigated spectroscopically using UV-visible, fluorescence and circular dichroism (CD) and calorimetrically using isothermal titration calorimetry (ITC), at different temperatures. Results of the UV-visible studies showed that adding Cu(+2) to β-lg solution caused increasing turbidity, indicative of protein aggregation. It was noticeable that the rate of increasing turbidity was directly proportional to increasing temperature. The far-UV CD studies displayed that the Cu(+2) cannot induce any significant changes in the secondary structures of β-lg at different temperatures. Also, the ITC data indicated that the binding process of Cu(+2) to β-lg is mainly entropically driven. The results highlight that copper ions cause the tertiary structure of β-lg to change and induce a slightly open structure leading to the formation of supramolecular aggregates in β-lg which may result in the reduced allergenicity of β-lg and its increased use in industrial applications.     

Interpretation of viscoelastic behaviour of sweet cherries using rheological models

Viscoelastic behaviour of some commercial sweet cherry cultivars of Iran has been studied in current research. For this purpose, stress relaxation test was conducted on five cultivars of sweet cherry including Siah Mashhad, Abarde, Victoria, Dovom Ras and Tak Dane. Two common models (Generalised Maxwell model and Peleg model) were fitted to the experimental data. Both models could describe stress relaxation behaviour of cherries (R² = 0.99), but Generalised Maxwell model had lower root mean square error (RMSE) than Peleg model. Based on analysis of stress relaxation data using models constants, Tak Dane exhibited more solid properties, while Victoria showed less elastic behaviour than other cultivars. The results revealed that relaxation ratio (R%) and the area under the stress relaxation curve could be effective alternative to models with easier mathematical procedure.     

Modeling of thermodynamic properties of carrot product using ALO,GWO, and WOA algorithms under multi-stage semi-industrial continuous belt dryer

Engineering with Computers - In this paper, multi-stage continuous belt (MSCB) dryer was used for carrot slices drying. Experiments were performed at three air speeds (1, 1.5, and 2 m/s)...     

Effects of Nanosized PbO and MgO,Rolling, and Sintering Time on Crack and Current Density of Bi1.6Pb0.4Sr2Ca2Cu3O10/Ag Superconductor Tapes

Journal of Superconductivity and Novel Magnetism - The effects of nanoparticle additions, rolling, and sintering time on the transport critical current density, Jc, of Ag-sheathed...     

Electrospinning of poly(vinylpyrrodine) template for formation of ZrO2 nanoclusters for enhancing properties of composite proton conducting membranes

Nanosized ZrO₂ clusters were prepared by electrospinning a poly(vinylpyrrodine) (PVP)/ZrO₂ mixture for calcination to remove PVP template and sizing. The morphological, chemical, structural, and thermal resistance changes during preparation stages were investigated using scanning electron microscope, energy-dispersive X-ray spectroscopy, transmission electron microscope, X-ray diffraction, and thermogravimetric analysis. The obtained ZrO₂ clusters were used for preparation of nanocomposite membranes by dispersion in 2,6-pyridine polybenzimidazole (2,6-Py-PBI) matrix at 5?wt% content followed by phosphoric acid (PA) doping. The ZrO₂ nanoclusters were found to be uniformly distributed in 2,6-Py-PBI/PA matrix leading to a remarkable increase in the PA doping level and proton conductivity of the obtained composite membrane.     

Identification and Affinity Determination of Protein-Antibody and Protein-Aptamer Epitopes by Biosensor-Mass Spectrometry Combination

Analytical methods for molecular characterization of diagnostic or therapeutic targets have recently gained high interest. This review summarizes the combination of mass spectrometry and surface plasmon resonance (SPR) biosensor analysis for identification and affinity determination of protein interactions with antibodies and DNA-aptamers. The binding constant (K_D) of a protein–antibody complex is first determined by immobilizing an antibody or DNA-aptamer on an SPR chip. A proteolytic peptide mixture is then applied to the chip, and following removal of unbound material by washing, the epitope(s) peptide(s) are eluted and identified by MALDI-MS. The SPR-MS combination was applied to a wide range of affinity pairs. Distinct epitope peptides were identified for the cardiac biomarker myoglobin (MG) both from monoclonal and polyclonal antibodies, and binding constants determined for equine and human MG provided molecular assessment of cross immunoreactivities. Mass spectrometric epitope identifications were obtained for linear, as well as for assembled (“conformational”) antibody epitopes, e.g., for the polypeptide chemokine Interleukin-8. Immobilization using protein G substantially improved surface fixation and antibody stabilities for epitope identification and affinity determination. Moreover, epitopes were successfully determined for polyclonal antibodies from biological material, such as from patient antisera upon enzyme replacement therapy of lysosomal diseases. The SPR-MS combination was also successfully applied to identify linear and assembled epitopes for DNA–aptamer interaction complexes of the tumor diagnostic protein C-Met. In summary, the SPR-MS combination has been established as a powerful molecular tool for identification of protein interaction epitopes.     

Engineering geological properties of the pyroclastic cone-shaped rocky houses of Kandovan,Iran

Bulletin of Engineering Geology and the Environment - Kandovan is one of the geo-tourism attractions in the East Azarbaijan Province of Iran, where rural houses were carved within the cone-shaped...     

Accelerating SPARQL queries by exploiting hash-based locality and adaptive partitioning

State-of-the-art distributed RDF systems partition data across multiple computer nodes (workers). Some systems perform cheap hash partitioning, which may result in expensive query evaluation. Others try to minimize inter-node communication, which requires an expensive data preprocessing phase, leading to a high startup cost. Apriori knowledge of the query workload has also been used to create partitions, which, however, are static and do not adapt to workload changes. In this paper, we propose AdPart, a distributed RDF system, which addresses the shortcomings of previous work. First, AdPart applies lightweight partitioning on the initial data, which distributes triples by hashing on their subjects; this renders its startup overhead low. At the same time, the locality-aware query optimizer of AdPart takes full advantage of the partitioning to (1) support the fully parallel processing of join patterns on subjects and (2) minimize data communication for general queries by applying hash distribution of intermediate results instead of broadcasting, wherever possible. Second, AdPart monitors the data access patterns and dynamically redistributes and replicates the instances of the most frequent ones among workers. As a result, the communication cost for future queries is drastically reduced or even eliminated. To control replication, AdPart implements an eviction policy for the redistributed patterns. Our experiments with synthetic and real data verify that AdPart: (1) starts faster than all existing systems; (2) processes thousands of queries before other systems become online; and (3) gracefully adapts to the query load, being able to evaluate queries on billion-scale RDF data in subseconds.     

Synthesis Gas and Zinc Production in a Noncatalytic Packed‐Bed Reactor

A noncatalytic packed‐bed reactor has been constructed for management of the reduction of ZnO by methane, which leads to co‐production of synthesis gas and zinc. The reactor consisted of a simple vertical pipe filled with ZnO pellets. These pellets underwent reaction with a pure methane flow. Experimental tests were conducted in the temperature range 860–995 °C at atmospheric pressure in an electrically heated reactor. The results showed complete chemical conversion of methane to synthesis gas in the aforementioned temperature range. In addition, analysis of the product solids indicated that the collected solids in the outlet of the reactor were entirely zinc. The maximum methane flow rates (149–744 mL min^–1) were adjusted to ensure complete chemical conversion of methane. These adjustments were performed for different bed heights at various operating temperatures. Analysis of the product gases revealed high quality synthesis gas production without the influence of methane cracking or other undesired side reactions in the experimental tests. Finally, the governing partial differential equations of the reactor modeling were solved by the finite element method. Consequently, the gaseous profiles along the reactor and the breakthrough curves were predicted and compared with the experimental tests.