1,720,997 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Effects of platelet rich fibrin and leukocyte (L-PRF) associated or not with bovine bone graft on the healing of bone defects in rats with osteoporosis induced by ovariectomy
No full textTem sido proposto que a Fibrina Rica em Plaquetas e Leucócitos (L-PRF) pode estimular a neoformação óssea e melhorar a incorporação de enxertos ósseos. Este estudo avaliou a cicatrização de defeitos de tamanho crítico (DTCs) criados em calvária de ratas com osteoporose induzida por ovariectomia e tratados com L-PRF associada ou não a enxerto ósseo bovino (XENO). 32 ratas foram divididas em 4 grupos (n=8): C, PRF, XENO e PRF-XENO. Todos os animais foram submetidos a um procedimento de ovariectomia bilateral no início do estudo. Após 3 meses, DTCs de 5 mm de diâmetro foram criados na calvária dos animais. No grupo C, o defeito foi preenchido apenas com coágulo sanguíneo. Nos grupos PRF e XENO, os defeitos foram preenchido com 0,02 mL de L-PRF e 0,02 mL de XENO, respectivamente. No grupo PRF-XENO o defeito foi preenchido com uma mistura de 0,02 mL de PRF e 0,02 mL de XENO. Todos os animais foram submetidos à eutanásia aos 30 dias pós-operatórios. Foram realizadas análises histomorfométrica, microtomográfica e imunohistoquímica. Os dados obtidos foram estatisticamente analisados (ANOVA, Tukey, p < 0,05). O Grupo PRF-XENO apresentou maior quantidade de osso neoformado (ON) quando comparado ao Grupo XENO, bem como maiores expressões de Fator de Crescimento Endotelial Vascular (VEGF), Osteocalcina (OCN) e Proteína Morfogenética Óssea (BMP)-2/4 (p < 0,05). O Grupo PRF apresentou maior quantidade de ON e maiores expressões de VEGF, OCN, BMP-2/4 e Fator de transcrição relacionado a Runt 2 (RUNX-2) quando comparado ao Grupo C (p < 0,05). Conclui-se que a L-PRF pode favorecer a neoformação óssea de DTCs e potencializar a cicatrização de XENO em ratas com osteoporose induzida por ovariectomia.It has been proposed that Platelet Rich Fibrin and Leukocyte (L-PRF) can stimulate bone neoformation and improve bone graft incorporation. This study evaluated the healing of critical caliber defects (CSDs) created in the calvaria of rats with osteoporosis induced by ovariectomy and treated with L-PRF associated or not with bovine bone graft (XENO). 32 rats were divided into 4 groups (n = 8): C, PRF, XENO and PRF-XENO. All animals underwent a bilateral ovariectomy procedure at the start of the study. After 3 months, CDSs of 5 mm diameter were created in calvaria of the animals. In group C, the defect was filled only with blood clot. In the PRF and XENO groups, the defects were filled with 0.02 mL of L-PRF and 0.02 mL of XENO, respectively. In the PRF-XENO group the defect was filled with a mixture of 0.02 mL of PRF and 0.02 mL of XENO. All animals were submitted to euthanasia at 30 postoperative days. Histomorphometric, microtomographic and immunohistochemical analyzes were performed. The data were statistically analyzed (ANOVA, Tukey, p < 0.05). The PRF-XENO group presented higher amount of neoformed bone (NB) when compared to the XENO group, as well as higher expression of Vascular Endothelial Growth Factor (VEGF), Osteocalcin (OCN) and Bone Morphogenetic Protein (BMP -2/4 (p < 0.05). The PRF group presented higher amounts of NB and higher expression of VEGF, OCN, BMP-2/4 and Runt-related transcription factor 2 (RUNX-2) when compared to the group C (p <0.05). It can be concluded that L-PRF can improve bone neoformation in CSDs and potentiates the healing of XENO in rats with osteoporosis induced by ovariectomy
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Clinical, microbiological and immunological effects of probiotic Bifidobacterium animalis subsp. lactis as adjuvant therapy in the non-surgical treatment of chronic periodontitis: a randomized controlled clinical trial
No full textO propósito deste estudo foi avaliar o efeito adjuvante da terapia probiótica (TProb) no tratamento periodontal não cirúrgico em pacientes com Periodontite Crônica generalizada (PCg). Em um estudo clínico aleatorizado, duplo-cego e placebo-controle, 41 pacientes com PCg foram tratados com TProb associada à raspagem e alisamento radicular (RAR Grupo Teste) ou apenas RAR (Grupo Controle). Os pacientes do Grupo Teste consumiram pastilhas contendo Bifidobacterium animalis subsp. lactis (B. lactis) HN019 durante 4 semanas. Os pacientes do Grupo Controle receberam pastilhas placebo (sem probiótico). Parâmetros clínicos periodontais foram avaliados no baseline (período pré-intervenção) e em 30 e 90 dias após a RAR. Nestes mesmos períodos foram coletadas amostras de placa subgengival para contagem de 40 espécies bacterianas (checkerboard DNA-DNA hybridization) e detecção do genoma de B. lactis HN019 (Reação em cadeia da polimerase em tempo real - q-PRC), amostras do fluido crevicular gengival para avaliação dos níveis de Interleucina (IL)-1beta, IL-8 e IL-10 (Imunoensaios multiplex) e amostras de saliva para avaliação dos níveis de Imunoglobulina A (IgA) (Nefelometria). Foram realizadas, também, biópsias de tecido gengival para determinação da expressão de beta-defensina (BD)-3 e receptores do tipo Toll (TLR)-4 (reações imunohistoquímicas - estreptavidina-biotina-peroxidase). Os dados obtidos foram estatisticamente analisados (p<0,05). O Grupo Teste apresentou, aos 90 dias, redução de profundidade de sondagem (PS) e ganho de inserção clínica significativamente maiores que aqueles do Grupo Controle. O Grupo Teste também apresentou menor quantidade de bolsas periodontais moderadas (aos 30 e 90 dias) e profundas (aos 90 dias) que o Grupo Controle (p<0,05), bem como menor quantidade de pacientes (p<0,05) apresentando 3 ou mais sítios com PS ≥ 6 mm ou PS = 5mm e sangramento à sondagem (SS) positivo. O Grupo Teste apresentou menor SS (aos 30 e 90 dias) e menor IP (aos 30 dias) quando comparado ao Grupo Controle (p<0,05). Na análise microbiológica, o Grupo Teste apresentou proporções significativamente menores de espécies microbianas dos complexos vermelho (ao 30 e 90 dias) e do complexo laranja (aos 30 dias), bem como maiores proporções de espécies do complexo azul (aos 90 dias) quando comparado ao Grupo Controle. A análise por meio de q-PCR mostrou que o Grupo Teste apresentou um aumento no número de cópias/μL do genoma da cepa probiótica B. lactis HN019 no biofilme subgengival aos 30 e 90 dias (p<0,05). Na análise imunológica, o Grupo Teste apresentou menor razão (valores ajustados ao baseline) de IL-1β (aos 30 e 90 dias) e de IL-8 (aos 30 dias) do que o Grupo Controle (p<0,05). Apenas o Grupo Teste apresentou valores de IL-10 significativamente maiores que aqueles do baseline aos 30 dias. Não foram observadas diferenças entres os grupos nas razões de IgA aos 30 e 90 dias. Na análise imunohistoquímica, o Grupo Teste apresentou expressões significativamente maiores de BD-3 e TLR-4 em sítios doentes quando comparado ao Grupo Controle aos 30 dias. Pode-se concluir que a utilização do probiótico B. lactis HN019 como recurso adjuvante à RAR promove benefícios clínicos, microbiológicos e imunológicos adicionais no tratamento de pacientes com PCgThe purpose of this study was to evaluate the adjuvant effect of probiotic therapy (ProbT) in non-surgical periodontal treatment in patients with generalized chronic periodontitis (GCP). In this randomized, double-blind, placebo-control, 41 patients with GCP were treated with ProbT associated with scaling and root planing (SRP - Test Group) or SRP only (Control Group). The patients in the Test Group consumed lozenges containing Bifidobacterium animalis subsp. lactis (B. lactis) HN019 during 4 weeks. The patients in the Control Group received placebo (lozenges without probiotic). Periodontal clinical parameters were evaluated at baseline (pre-intervention) and at 30 and 90 days after SRP. Samples of subgingival plaque were collected to count 40 bacterial species (checkerboard DNA-DNA hybridization) and detection of genome of B. lactis HN019 (polymerase chain reaction in real time - q-PCR). Gingival crevicular fluid samples were collected for assessing levels of interleukin (IL)-1beta, IL-8 and IL-10 (multiplex immunoassays). Saliva samples were collected to measure levels of immunoglobulin A (IgA) (nephelometry). Also, biopsies of gingival tissues were performed to determine the expression of beta-defensina (BD)-3 and Toll-Like receptors (TLR)-4 (immunohistochemical reactions - streptavidin-biotin-peroxidase). The data obtained were statistically analyzed (p < 0.05). The Test Group presented, at 90 days, reduction of probing pocket depth (PPD) and clinical attachment gain significantly higher when compared to the Control Group. The Test Group also presented a lower number of moderate (at 30 and 90 days) and deep (90 days) periodontal pockets than the Control Group (p < 0.05), as well as a lower number of subjects (p < 0.05) with 3 or more sites with PPD ≥6 mm or PPD = 5mm and bleeding on probing (BOP) positive. The Test Group presented lower BOP (at 30 and 90 days) and lower PI (at 30 days) when compared to the Control Group (p<0.05). In the microbiological analysis, the Test Group showed significantly lower proportions of microbial species of red (at 30 and 90 days) and the orange (at 30 days) complexes, as well as higher proportions of species of blue complex (at 90 days) when compared to the Control Group. q-PCR analysis showed that the Test Group presented an increase in the number of copies/μL of the genome of the probiotic strain B. lactis HN019 in subgingival biofilm at 30 and 90 days (p < 0.05). In the immunological analysis, the Test Group presented a lower ratio of IL-β1 (at 30 and 90 days) and IL-8 (30 days) than the Control Group (p < 0.05). Only the Test Group presented values of IL-10 significantly higher than those of the baseline at 30 days. No differences were observed between the groups on the ratios of IgA at 30 and 90 days. In the immunohistochemical analysis, the Test Group showed significantly higher expression of BD-3 and TLR-4 in sites with periodontitis when compared to the Control Group at 30 days. It can be concluded that the use of probiotic B. lactis HN019 as an adjuvant to SRP promotes clinical, microbiological and immunological additional benefits in the treatment of patients with GC
Participation of integrins and microRNAs on the osteogenic potential of titanium with nanotopography
No full textO objetivo desse estudo foi investigar a participação de integrina α1β1 e microRNAs (miRs) no potencial osteogênico de superfícies de titânio (Ti) com nanotopografia. Discos de Ti previamente polidos foram tratados quimicamente com H2SO4/H2O2 para obtenção de nanotopografia, que foi observada por microscopia eletrônica de varredura. Para o estudo da participação da integrina α1β1, células-tronco mesenquimais (CTMs) de ratos foram cultivadas em condições osteogênicas e não osteogênicas sobre superfícies de Ti com nanotopografia e sem tratamento químico (controle). O resultados mostraram que a nanotopografia de Ti aumentou a proliferação celular, a atividade de fosfatase alcalina (Alp) e regulou positivamente a expressão gênica de marcadores da diferenciação osteoblástica em CTMs cultivadas tanto em condições osteogênicas quanto em condições não osteogênicas. Além disso, uma maior expressão gênica para as integrinas α1 e β1 foi observada em culturas crescidas sobre nanotopografia em condições não osteogênicas em relação ao Ti controle. O uso de obtustatina, um inibidor de integrina α1β1, reduziu os efeitos da nanotopografia sobre os marcadores osteoblásticos, indicando a participação da via de sinalização dessa integrina nos efeitos da nanotopografia sobre CTMs. Para investigar a participação de miRs no efeito osseoindutor da nanotopografia de Ti, foram utilizadas CTMs humanas e células préosteoblásticas de camundongos da linhagem MC3T3-E1. A análise em larga escala da expressão de miRs revelou que 60 miRs foram regulados positivamente (no mínimo, 2x maior), enquanto 58 miRs foram regulados negativamente (no mínimo, 2x menor) em CTMs crescidas sobre a nanotopografia. Três desses miRs, miR-4448, -4708 e -4773, cuja expressão foi significativamente reduzida pela nanotopografia de Ti (no mínimo, 5x menor), afetaram a diferenciação osteoblástica de CTMs. Esses miRs atuam diretamente sobre SMAD1 e SMAD4, proteínas transdutoras da sinalização da proteína óssea morfogenética 2 (Bmp-2), conhecida por sua capacidade osseoindutora. Além disso, verificou-se que a sobreexpressão de miR-4448, -4708 e -4773 em células pré-osteoblásticas MC3T3-E1 inibiu a expressão gênica e proteica de SMAD1 e SMAD4 e, consequentemente, a expressão gênica de marcadores ósseos. Esses dados sugerem a influência do circuito miR-SMAD-Bmp-2 sobre o efeito osseoindutor da nanotopografia. Conjuntamente, os achados do presente estudo mostraram que o efeito da nanotopografia de Ti sobre a diferenciação osteoblástica resulta de um mecanismo regulatório complexo, do qual fazem parte as vias de sinalização da integrina α1β1 e da Bmp-2, com a participação de miRs. Esses resultados podem representar um avanço para o desenvolvimento de novas modificações de superfície, com o objetivo de acelerar e/ou melhorar o processo de osseointegração.The aim of this study was to investigate the role of the α1β1 integrin and microRNAs (miRs) on the osteogenic potential of titanium (Ti) with nanotopography. Polished Ti discs were chemically treated with H2SO4/H2O2 to generate nanotopography, which was observed under scanning electron microscopy. For the study related to the α1β1 integrin, rat mesenchymal stem cells (MSCs) were cultured under osteogenic and non-osteogenic conditions on Ti with nanotopography and non-treated Ti discs (control). Nanotopography increased cell proliferation and alkaline phosphatase (Alp) activity and upregulated the gene expression of bone markers in cells cultured under osteogenic and non-osteogenic conditions. Furthermore, the gene expression of α1 and β1 integrins was higher in cells cultured on nanotopography under non-osteogenic conditions compared with control. Obtustatin, an inhibitor of α1β1 integrin, reduced the higher gene expression of the bone markers induced by nanotopography. These results indicate that α1β1 integrin signaling pathway determines the osteoinductive effect of nanotopography on MSCs. The role of miRs in the osteogenic potential of Ti with nanotopography was evaluated using human MSCs and MC3T3-E1 mouse pre-osteoblastic cells. The miR sequencing analysis revealed that 60 miRs were upregulated (> 2 fold), while 58 miRs were downregulated (< 2 fold) in MSCs grown on nanotopography. Three miRs, miR-4448, -4708 and -4773, which were significantly downregulated (< 5 fold) by nanotopography, affected the osteoblast differentiation of MSCs. These miRs directly target SMAD1 and SMAD4, both key transducers of the bone morphogenetic protein 2 (Bmp-2) osteogenic signal, which were upregulated by nanotopography. Overexpression of miR-4448 - 4708 and 4773 in MC3T3-E1 cells noticeably inhibited gene and protein expression of SMAD1 and SMAD4 and by targeting them, these miRs repressed gene expression of key bone markers. These results suggest that a miR-SMAD-Bmp-2 circuit acts in the Ti nanotopography-mediated osteoblast differentiation. Taken together, our data showed that the osteoblast differentiation induced by Ti with nanotopography is governed by a complex regulatory network involving a crosstalk between α1β1 integrin and Bmp-2 signaling pathways with participation of miRs
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