70 research outputs found
Properties of a new protein film from bitter vetch (Vicia ervilia) and effect of CaCl2 on its hydrophobicity
No full textThis work was aimed to investigate the potential preparation of an edible film from bitter vetch seed proteins. The film was cast from bitter vetch protein concentrate (BPC) and glycerol. CaCl2 at the ratio of 0.1–1% (w/w) of the BPC was tested to improve film properties, specially its hydrophobicity. Some physicochemical properties of the films obtained in the absence and presence of CaCl2 were evaluated. The results indicated that moisture content, total soluble matter, water vapour permeability and contact angle of the films prepared in the presence of CaCl2 were significantly modified in comparison with the control values, while their mechanical properties did not significantly change. The surface morphology of the films was also considerably affected by the presence of CaCl2. Therefore, CaCl2 could improve BPC-film barrier properties especially their hydrophobicity, even though calcium concentration seems to be a crucial factor
Microstructure and properties of bitter vetch (Vicia ervilia) protein films reinforced by microbial transglutaminase
No full textCalcium-independent Streptoverticillium sp. transglutaminase was positively tested to prepare new crosslinked biomaterials by using bitter vetch (Vicia ervilia) seed proteins as effective acyl donor and acceptor substrates of the enzyme. Film morphology was evaluated by both atomic force microscopy and scanning electron microscopy. The surface of films prepared in the presence of transglutaminase appeared more compact and smoother than those prepared in the absence of enzyme. Mathematical analysis of surface roughness indicated that the values derived were significantly higher in the films obtained in the absence of enzyme (Rq = 84.4 ± 1.5 nm) compared to the ones prepared in its presence (Rq = 41.1 ± 1.2 nm). Moreover, film cross-sections showed the presence of several discontinuous zones in the control films, absent in those prepared with transglutaminase that, on the contrary, showed a very homogeneous structure. Enzymatically polymerized films exhibited a markedly decreased oxygen (700-fold) and carbon dioxide (50-fold) permeability, with respect to the control ones, as well as significantly different mechanical properties being increased their resistance and stiffness. On the basis of these features, a possible application of enzymatically crosslinked bitter vetch protein films as coatings of different food products is suggested
Characterization and antioxidant activity of bitter vetch protein-based films containing pomegranate juice
No full textThe effect of different amounts of pomegranate (Punica granatum, Malas Isfahan cultivar) juice, endowed with high antioxidant activity, on the bitter vetch seed protein films was investigated. We demonstrated that the films prepared in the presence of pomegranate juice exhibited significantly increased moisture content, total soluble matter, elongation at break, as well as water vapour permeability, whereas their tensile strength significantly decreased. These findings clearly suggest that pomegranate juice had a plasticizing effect on the prepared protein-based films, the antioxidant activity of which was also found significantly enhanced. Since scanning electron microscopic images indicated that film structure was undoubtedly affected, we hypothesized that interactions between phenolic compounds contained in the pomegranate juice and bitter vetch proteins are responsible for the modified properties of the obtained blended films. The potential use of pomegranate juice in improving the antioxidant activity of protein-based films is suggested
The effect of oxidized ferulic acid on physicochemical properties of bitter vetch (Vicia ervilia) protein-based films
No full textThe aim of the present study was to investigate the effect of oxidized ferulic acid on some physicochemical features of bit-
ter vetch protein concentrate-based films. Our results indicate that moisture content, total soluble matter, water vapor permeability, and mechanical resistance values of the films prepared in the presence of oxidized ferulic acid were significantly modified in compari- son with the ones detected with films obtained in its absence. In fact, film moisture content, total soluble matter, and water vapor permeability significantly decreased when oxidized ferulic acid was added to the film forming solutions, whereas both film tensile strength and elongation at break resulted markedly higher. Moreover, atomic force and scanning electron microscopy analyses showed that film morphology was also markedly affected by the presence of oxidized ferulic acid, film surface roughness, and compactness resulting higher than the ones observed in control samples. Therefore, these findings show a marked improvement in obtaining edible films derived from cheap starting biopolymers, such as bitter vetch proteins, potentially useful for different food and pharmaceutical applications
Blend films of pectin and bitter vetch (Vicia ervilia) proteins: properties and effect of transglutaminase
No full textHydrocolloid solutions were prepared by blending pectins and Vicia ervilia seed proteins at complexation pH and edible films were obtained by casting the solutions both in the absence and presence of microbial transglutaminase. Protein/pectin films exhibited a tensile strength double than the one observed with films containing only proteins, with an increase of about 3-fold observed in the presence of enzyme. Also the elongation at break resulted higher in the films containing transglutaminase, leading to conclude that films are more extensible mostly when both pectins and enzyme occur in the film forming solutions. A direct correlation between the improved film mechanical properties and the negative increase of zeta-potential of the originating film forming solutions was recorded. Conversely, gas permeability of protein/pectin films markedly decreased and transglutaminase addition determined a further enhancement of their barrier properties. These findings, supported by morphological analyses, suggest that the improved film functional features depend on their more compact structure due to crosslinked bitter vetch proteins grafted with pectin
Bitter vetch (Vicia ervilia) seed protein concentrate as possible source for production of bilayered films and biodegradable containers.
No full textThe manufacture of biodegradable and renewable containers from bitter vetch seed protein-based “bioplastics” was investigated. A bitter vetch seed protein concentrate was prepared and analyzed for proteins, carbohydrates, phenols, other several organic compounds and multi-elements. Protein film forming solutions were cast in the presence of two different glycerol concentrations and the film con- taining higher plasticizer amount was laminated with an additional corn zein layer. Both lamination process and lower glycerol concentration led to reduce film moisture content, total soluble matter and elongation at break, while both film tensile strength and water vapour barrier properties resulted enhanced. The obtained bioplastics were then processed by a new laboratory plastic moulding equip- ment specifically designed and fabricated to convert protein-based films to shaped containers. The use of either lower plasticizer concentration or corn zein lamination gave rise to potentially satisfactory vacuum thermoformed containers with acceptable resistance and stability
Conventional, molecular methods and biomarkers molecules in detection of septicemia
No full textSepsis is a leading cause of morbidity and mortality in hospitalized patients worldwide and based on studies, 30-40% of all cases of severe sepsis and septic shock results from the blood stream infections (BSIs). Identifying of the disease, performing laboratory tests, and consequently treatment are factors that required for optimum management of BSIs. In addition, applying precise and immediate identification of the etiologic agent is a prerequisite for specific antibiotic therapy of pathogen and thereby decreasing mortality rates. The diagnosis of sepsis is difficult because clinical signs of sepsis often overlap with other noninfectious cases of systemic inflammation. BSIs are usually diagnosed by performing a series of techniques such as blood cultures, polymerase chain reaction-based methods, and biomarkers of sepsis. Extremely time-consuming even to take up to several days is a major limitation of conventional methods. In addition, yielding false-negative results due to fastidious and slow-growing microorganisms and also in case of antibiotic pretreated samples are other limitations. In comparison, molecular methods are capable of examining a blood sample obtained from suspicious patient with BSI and gave the all required information to prescribing antimicrobial therapy for detected bacterial or fungal infections immediately. Because of an emergency of sepsis, new methods are being developed. In this review, we discussed about the most important sepsis diagnostic methods and numbered the advantage and disadvantage of the methods in detail
Cosmology, identity and food related rituals among the Mandaeans
No full textThe Mandaeans are members of a Gnostic ethnoreligious group who live in Iran and Iraq. They have always been a small minority under the threat of cultural extinction. Recent wars and political unrest in their homeland have intensified the situation and accelerated the emigration and dissemination of the community. They practice elaborate religious rituals that revolve around the recurrent theme of bodily purity, including ritual concern for food and its preparation. On the one hand, using a Geertzian approach to the study of religion with ethnographic data, the mutual relationship between the food-related rituals, Mandaean cosmology and the formation of a “religious world” is considered. On the other hand, the very formation of a “religious world” can be seen as a social construction based on the historical experience and socio-political situation of the people. The ritual obsession with the purity of body and food symbolically represents a preoccupation with the purity and integrity of the community, while at the same time it re-establishes the boundaries of a distinct group identity in a threatening milieu. Therefore, food-related rituals not only symbolically represent Mandaean worldview and simultaneously set up a specific ethos for the people, but they also create and recreate this distinct identity.Les Mandéens sont membres d’un groupe ethnoreligieux gnostique qui vit en Iran et en Irak. Ils ont toujours été une petite minorité menacée d’extinction culturelle. Les guerres récentes et les troubles politiques dans leurs pays d’origine ont intensifié cette situation et accéléré leur émigration. Ils pratiquent des rituels religieux élaborés qui tournent autour du thème récurrent de la pureté corporelle, y compris une attention particulière au rituel de la nourriture et à sa préparation. En conjuguant un point de vue geertzien et des données ethnographiques, l'article analyse la relation mutuelle entre les rituels liés à l’alimentation et la cosmologie, et ainsi la formation d’un « monde religieux ». Celle-ci peut, par ailleurs, être considérée comme une construction sociale fondée sur l’expérience historique et la situation sociopolitique des populations. L’obsession rituelle de la pureté du corps et de la nourriture reflète symboliquement une préoccupation pour la pureté et l’intégrité de la communauté tout en rétablissant les limites de l’identité distincte du groupe dans un milieu vécu comme menaçant. Par conséquent, les rituels liés à l’alimentation ne représentent pas seulement symboliquement la vision du monde mandéen tout en établissant simultanément un ethos spécifique pour le peuple, mais ils créent et recréent aussi leur identité distincte dans un environnement hostile.Los mandeos son miembros de un grupo etnorreligioso gnóstico que vive en Irán e Irak. Siempre han sido una pequeña minoría en peligro de extinción cultural. Las guerras recientes y los disturbios políticos en sus países de origen han intensificado esta situación y han acelerado su emigración. Ellos practican rituales religiosos elaborados que giran en torno al tema recurrente de la pureza corporal, incluida una atención particular al ritual de la alimentación y a su preparación. Conjugando un punto de vista geertziano y datos etnográficos, se estudiará la relación mutua entre los rituales relacionados con la alimentación y la cosmología, como también la formación de un "mundo religioso". Por otra parte, este último puede considerarse una construcción social basada en la experiencia histórica y la situación sociopolítica de las poblaciones. La obsesión ritual por la pureza del cuerpo y de la comida refleja simbólicamente una preocupación por la pureza y la integridad de la comunidad, al tiempo que restablece los límites de la identidad particular del grupo en un entorno amenazador. Por consiguiente, los rituales relacionados con la alimentación no sólo representan simbólicamente la visión del mundo mandeo y establecen un ethos específico para el pueblo, sino que también crean y recrean su identidad distinta en un entorno amenazador
Formally Verifiable Object-Oriented System Specifications with UML for Railway Signalling and Safety Systems
No full textUm die Präzision und Überprüfbarkeit der Systemanforderungsspezifikationen zu erhöhen, empfehlen die CENELEC-Normen für die Eisenbahnsysteme den Einsatz von formalen Methoden, die über eindeutige Syntax und Semantik verfügen. In der vorliegenden Arbeit werden für die Spezifikation und Verifikation von Eisenbahnsicherungssystemen formal fundierte grafische Beschreibungsmittel zur Verfügung gestellt. Diese Beschreibungsmittel sind eine Auswahl von Diagrammen der Unified Modeling Language (UML), die unterschiedliche Sichten in der Systemanforderungsspezifikation darstellen. Durch die Klassendiagramme kann die Systemstruktur beschrieben werden. Die Zustandsdiagramme und die Sequenzdiagramme werden für die Spezifikation des dynamischen Systemverhaltens verwendet. In den Klassendiagrammen werden für die Relationen Assoziation, Aggregation, Komposition und Vererbung formale Definitionen eingeführt, die die präzise Spezifikation von Beziehungen unter den Systemkomponenten ermöglichen. Weiter werden auf Basis dieser Definitionen Kriterien für die Konsistenzüberprüfung zwischen den verschiedenen Teilen der Systemspezifikation eingeführt. In den Zustandsdiagrammen werden die Aktionen, ihre Ausführung, unterschiedliche Zustandsarten und ihre Aktivierung formal definiert. Transitionen zwischen den Zuständen und deren Ausführung sind weitere Punkte, die dabei präzisiert werden. Über die eingeführten formalen Semantiken für angewendete Notationen werden Schemata für die Transformation von Zustandsdiagrammen der UML in eine formal verifizierbare Form definiert. Dadurch ist eine formale Verifikation der Systemanforderungsspezifikation durchführbar, die auf der Technik Model-Checking basiert. Die Anwendbarkeit der präsentierten Spezifikationsmittel und die formale Verifikation über die Technik Model-Checking werden am Beispiel des eingleisigen Bahnübergangs im Funkfahrbetrieb demonstriert. Dadurch sind für die Erstellung einer formal verifizierbaren Systemanforderungsspezifikation Beschreibungsmittel bereitgestellt, die aufgrund ihrer grafischen Gestalt für die Ingenieure der Eisenbahnsicherungstechnik handhabbar sind, und die Forderung der CENELEC-Normen nach Erhöhung der Präzision und Verifizierbarkeit erfüllen.In order to increase precision und verifiability of system requirements specifications the CENELEC standards for Railway Signalling and Safety Systems recommend the use of formal methods, which possess unambiguous syntax and semantics. In this thesis, formal-based graphical notations are provided for specifying and verifying Railway Signalling and Safety Systems. These notations are a selection of diagrams from the Unified Modeling Language (UML) which represent different views for system requirements specifications. System structures can be described by employing class diagrams. State diagrams and sequence diagrams are used for specifying the dynamic system behaviour. In class diagrams, formal definitions are introduced for the relations association, aggregation, composition and inheritance. This enables the precise specification of relations between system components. Furthermore, on the basis of these definitions criteria for consistency checks between the different parts of a system specification are introduced. By means of state diagrams actions, their execution, different kinds of states and their activation are defined formally. Transitions between states and their execution are further items which are rendered more precise within this scope. The introduced formal semantics of the notations employed are used to define rules for the transformation of UML state diagrams into formally verifiable forms. Thereby, the formal verification of system requirements specifications based on the technique of model checking becomes feasible. The applicability of the presented means of specification and formal verification by model checking is demonstrated on the example of the singletrack level crossing in radio-based operation. This ensures that notations for specification and formal verification of system requirements are provided, which are usable for engineers in Railway Signalling and Safety Systems and which meet the demands of the CENELEC standards for increasing precision and verifiability
Biofilm production among Staphylococcus epidermidis strains isolated from healthy people
No full textIntroduction: Staphylococcus epidermidis is well documented as a nosocomial pathogen causing biofilm in patients and healthy people. The aim of this study was to analyze the biofilm formation of S. epidermidis strains isolated from healthy people during 2013-2014.
Materials and methods: Totally 200 healthy people were selected and the sampling was carried out from arm, armpit and axillary area using sterile swaps. Swaps were transferred to thiogylcollate broth and then cultured on mannitol salt agar plates. Isolates were identified at the species level using biochemical tests. Potential of biofilm formation of strains was measured using congo red agar plate and microtiter plate tests. Genes involved in biofilm formation, icaA and icaD, were detected using PCR.
Results: Totally 104 S. epidermidis strains were isolated from healthy people. Amongst these, 66 (63%) and 38 (37%) strains were positive and negative for biofilm formation, respectively. icaA and icaD genes were detected in 100% of strains.
Discussion and conclusion: Prevalence of biofilm producing S. epidermidis isolates among healthy people indicating their colonization with hospital strains. Prevalence of such strains is urgent for public health
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