Immobilization of Keratinolytic Metalloprotease from Chryseobacterium sp. Strain kr6 on Glutaraldehyde-Activated Chitosan

( Silveira Silvana T. ),( Sabrine Gemelli ),( Jeferson Segalin ),( Adriano Brandelli ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.6

Keratinases are exciting keratin-degrading enzymes; however, there have been relatively few studies on their immobilization. A keratinolytic protease from Chryseobacterium sp. kr6 was purified and its partial sequence determined using mass spectrometry. No significant homology to other microbial peptides in the NCBI database was observed. Certain parameters for immobilization of the purified keratinase on chitosan beads were investigated. The production of the chitosan beads was optimized using factorial design and surface response techniques. The optimum chitosan bead production for protease immobilization was a 20 g/l chitosan solution in acetic acid [1.5% (v/v)], glutaraldehyde ranging from 34 g to 56 g/l, and an activation time between 6 and 10 h. Under these conditions, above 80% of the enzyme was immobilized on the support. The behavior of the keratinase loading on the chitosan beads surface was well described using the Langmuir model. The maximum capacity of the support (qm) and dissociation constant (Kd) were estimated as 58.8 U/g and 0.245 U/ml, respectively. The thermal stability of the immobilized enzyme was also improved around 2-fold, when compared with that of the free enzyme, after 30 min at 65oC. In addition, the activity of the immobilized enzyme remained at 63.4% after it was reused five times. Thus, the immobilized enzyme exhibited an improved thermal stability and remained active after several uses.

Evaluation of Exogenous Promoters for Use in Brachiaria brizantha Transformation

Silveira Erica Duarte,Rodrigues Julio Carlyle Macedo,Cabral Glaucia Barbosa,Leite Juliana de Almeida,Costa Sidnei Souza,Carneiro Vera Tavares de Campos The Korean Society of Plant Biotechnology 2003 Plant molecular biology and biotechnology research Vol.5 No.2

Brachiaria (Poaceae) is the most important forage genus for cattle production in Brazil. The genetic breeding of this genus is limited by the incompatibility among species, differences in ploidy level and the natural cloning of plants by apomixis (Valle and Miles 1992). However, plant regeneration via tissue culture methods and genetic engineering provide an opportunity to introduce new characteristics in plants of this genus. We have developed methods for the 'genetic modification of Brachiaria brizantha cv. Marandu via biolistic transformation. A higher number of shoots was obtained with 4 mg/L 2.4-diclorophenoxyacetic acid and 0.2 mg/L benzylaminopurine in calli induction medium and 0.1 mg/L naphtaleneacetic acid and 4.0 mg/L kinetin in shoot regeneration medium. A selection curve for mannose was determined to use phospho mannose isomerase (PMI) gene of Escherichia coli as a selection marker. Calli formation was inhibited from 5 g/L mannose, even in the presence of sucrose while calli that were formed in the presence of mannose failed to develop embryos showing that PMI gene can be used for selection of transformants of this grass. Different promoters were tested to evaluate the efficiency based on the detection of the GUS gene expression (Jefferson et al. 1987). The monocot promoters, act1-D and ubi-1, resulted in higher expression levels than dicot promoters, ubi-3 and act-2, or the CaMV35S and CVMV promoters.

Education as a Priority in the New Millenium

Silveira, Adonias Costa da 慶熙大學校 밝은社會問題硏究所 1999 밝은社會硏究 Vol.20 No.1

Analysis of slender structural elements under unilateral contact constraints

Silveira, Ricardo Azoubel Da Mota,Goncalves, Paulo Batista Techno-Press 2001 Structural Engineering and Mechanics, An Int'l Jou Vol.12 No.1

A numerical methodology is presented in this paper for the geometrically non-linear analysis of slender uni-dimensional structural elements under unilateral contact constraints. The finite element method together with an updated Lagrangian formulation is used to study the structural system. The unilateral constraints are imposed by tensionless supports or foundations. At each load step, in order to obtain the contact regions, the equilibrium equations are linearized and the contact problem is treated directly as a minimisation problem with inequality constraints, resulting in a linear complementarity problem (LCP). After the resulting LCP is solved by Lemke's pivoting algorithm, the contact regions are identified and the Newton-Raphson method is used together with path following methods to obtain the new contact forces and equilibrium configurations. The proposed methodology is illustrated by two examples and the results are compared with numerical and experimental results found in literature.

Systemic and local effects of doxycycline and low-intensity laser treatment on periodontitis in rats

Silveira, Glauco Rodrigues Carmo,Lima, Daniela Coelho de,Cintra, Luciano Tavares Angelo,Brigagao, Maisa Ribeiro Pereira Lima,Ervolino, Edilson,Fernandes, Leandro Araujo Korean Academy of Periodontology 2021 Journal of Periodontal & Implant Science Vol.51 No.-

Purpose: This study evaluated the systemic and local effects of doxycycline (DOX) and low-intensity laser (LIL) treatment as adjuvants to scaling and root planing (SRP) in the treatment of experimental periodontitis in rats. Methods: The sample consisted of 180 male rats (Rattus norvegicus albinus, Wistar), of which 30 did not receive induction of periodontal disease (negative control [NC] group) and 150 received induction of periodontal disease in the lower first molar. After 7 days, the ligature was removed, and the animals were divided into the following groups: NT (no treatment), SRP (SRP), DOX (SRP and DOX irrigation), LIL (SRP and laser irradiation), and DOX+LIL (SRP, DOX, and LIL). The animals were euthanized at 7, 15, and 30 days; thereafter, biochemical, radiographic, histological, and immunohistochemical analyses were performed. Results: In the intragroup analysis, lower concentrations of α-1-glycoprotein acid (α-1-Ga) and complement 3 (C3) were observed in the DOX+LIL group than in all other groups at all time points, as well as lower levels of complement 4 (C4) at 15 and 30 days (P<0.001). Less bone loss was observed in the DOX, LIL, and DOX+LIL groups than in the NC and SRP groups at all time points (P<0.001). There was a smaller number of tartrate-resistant acid phosphatase (TRAP)-positive cells in the DOX+LIL group than in the other groups at all time points (P<0.001). Positive correlations were observed between the systemic levels of α-1-Ga, C3, and C4 and the number of TRAP-positive cells. Conclusions: The combination of DOX with LIL as SRP adjuvants was effective both systemically and locally for the treatment of experimental periodontitis in rats.

Morphological traits of stem to indirect selection of resistance to lodging in Avena sativa L

Silveira Diógenes Cecchin,Basso Simone Meredith Scheffer,Ebone Luciano Antônio,Caverzan Andréia,Machado Juliana Medianeira,Schaeffer Afonso Henrique,Folchini Jessica Aneris,Lângaro Nadia Canali 한국작물학회 2022 Journal of crop science and biotechnology Vol.25 No.1

The runout of newly cultivated areas in the world without recurring to the deforestation, demand a necessity to improve yield to sustain a growth population which demands each time more food. To avoid that is necessary to solve the main issues which cause crop productivity reduction, such as lodging which causes yield reduction in many major crops such as wheat, barley, rice and oat. In this sense, a study with eight cultivars evaluated morphological traits of the stem as crown diameter, internal and external diameter of the frst four basal internodes, the length of internodes, peduncle and panicle, plant height, and also lodging resistance factor (cLr), green and dry panicle matter. The diameter of the crown does not show diferences among the cultivars, the morphological characters which showed correlation and relative contribution with cLr were the internal and external internodes diameters, showing their capacity to be one of morphological traits of the stem to an indirect selection of resistance to lodging in Avena sativa L. The length did not show a good correlation with lodging, probably due to the fact that this trait was the focus of breeders for many years, reaching the plateau, demanding focus in other traits to avoid lodging such as interna and external diameter of internodes. The cultivar URS Brava and IPR Afrodite demonstrated to be a source of lodging resistance in oat.

Neuropsychiatric Symptoms of Multiple Sclerosis: State of the Art

Celeste Silveira,Renato Guedes,Diana Maia,Rosário Curral,Rui Coelho 대한신경정신의학회 2019 PSYCHIATRY INVESTIGATION Vol.16 No.12

Multiple Sclerosis (MS) is a chronic disabling neuroinflammatory disease. Psychiatric manifestations have a high prevalence in MS patients and may worsen the illness progression and the patients’ quality of life (QoL). Depression is a highly prevalent condition in MS patients, associated with poorer adherence to treatment, decreased functional status and QoL, and increased suicide risk. Diagnosis and treatment of this disorder is challenging because of symptom overlap. Other prevalent psychiatric comorbidities are anxiety disorders, bipolar disorder, psychotic disorders, substance misuse and personality disorders. As the illness progresses, personality changes can happen, as well as affect abnormalities. Cognitive changes occur frequently in MS patients, and affect features like processing speed, attention, learning, memory, visual spatial capabilities, and some language deficits. Disease-modifying treatments may reduce cognitive impairment because of their container action on the brain’s lesion burden. Other QoL determinants such as fatigue, pain, sexual dysfunction, exercise, resilience and social support should be taken into account, in order to promote the individuals’ well-being. Further studies are needed in order to elucidate the effectiveness of pharmacotherapy and more neuroimaging studies are required to clarify the relationship between structural changes and psychiatric comorbidities.

Digital Video Festivals and Mathematics: Changes in the Classroom of the 21st Century

Nilton Silveira Domingues,Marcelo C. Borba 대한수학교육학회 2021 수학교육학연구 Vol.31 No.3

This paper aims to present how video production is impacting the classroom, mathematics students and teachers in Brazil, as well as mathematics knowledge production developed with this media. Digital video Festivals with mathematical content are being implemented in Brazil, locally and nationally. One of them is Mathematics Education Digital Video Festival, organized by the Research Group in Informatics, Other Media and Mathematics Education, GPIMEM. In this century, video is earning space as a pedagogical approach in either face-to-face or distance education, even before the COVID-19 pandemic. Currently, considering social distance, the use of videos became an imposed reality to students and teachers. Students and teachers with different level of experience or age started to realize possible positive effects regarding the reorganization of the classroom by the presence of mathematical videos. However, other aspects provided negative effects: for example, inequalities in homes and mobile access impacted equal opportunity to all. This paper will summarize the use of mathematical video in the last century and discuss what is happening this century. We will revise some research developed, mainly in Brazil, that shows how the classroom does not fit in a parallelepiped model. Internet, videos and software combined are “things” that have agency and are co-participating in learning and teaching mathematics. The organization of festivals of videos have become important not only in Brazil but elsewhere in many formats either nationally or internationally, in a way to create challenges, exhibitions, cultural mix that aim to show mathematics applications to the general public. In particular, this article reports on parts of a qualitative research that investigated participants of the first edition of the referred national festival. As a result, we look for the comprehension of following the discussions of qualitative transformations regarding the use of videos in classrooms and mathematics knowledge production, as this new setting suggests that digital technologies arrived in XXI century to collaborate with learning. This article will be supported by a theoretical perspective on technology based on the notion of humans-with- media. In such a perspective knowledge is seen as being constructed by humans and different media and different artifacts. This article shows how such a perspective may help us to cope with the classroom of the XXI century, including the classroom that during the pandemic include students’ and teachers’ homes.

Numerical Simulation of a Stratified Two-Dimensional and Isothermal Three-Dimensional Turbulent Flow

Aristeu Silveira Neto 대한기계학회 1993 International Symposium on Transport Phenomena in Vol.4 No.1

THE PERCEPTION OF ACTIVE LISTENING PRACTICE ON SOCIAL NETWORKS

Lídia Silveira Pina,Sandra Maria Correia Loureiro,Paulo Rita,Paulo Rita,Eduardo Moraes Sarmento,Ricardo G. Bilro,João Guerreiro 글로벌지식마케팅경영학회 2018 Global Marketing Conference Vol.2018 No.07

The evolution of the internet led to a shift in the business operations environment, giving rise to a plethora of challenges and opportunities for companies. Social networks have become attractive to companies due to their interactive nature, not only facilitating conversations with consumers, but also increasing the possibility of enhancing the online consumer brand engagement. Additionally, social networks and online brand communities increased consumers’ possibility of developing an active role in companies’ decision-making process, through the creation of user generated content, together with the opinion sharing and directly information exchange with brands and other internet users. The main objective of this research is to ascertain whether the active listening practice can contribute, in some way, to the improvement of the relationship maintained between consumers and brands. The current study suggests the adaptation of the active listening practice on the online field, as an attempt to enhance the communication strategies held by brands. Hence, this research seeks to demonstrate that this practice can improve the consumer-brand relationship through the development of two qualitative studies, as main approach, where the findings extracted in the first study will be used as inputs to the second one.