1,721,006 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
The role of duodenal exclusion in the regulation of glycemic levels in type 2 diabetic patients submitted to gastrectomy with Roux-en-Y reconstruction by gastric cancer
No full textINTRODUÇÃO: a cirurgia bariátrica tem se mostrado efetiva no tratamento de comorbidades relacionadas à obesidade como o Diabetes Mellitus tipo 2 (DM2), sugerindo que mecanismos além da perda de peso estão envolvidos. Diversos estudos têm atribuído a melhora da regulação glicêmica à secreção de incretinas pelo intestino distal, devido ao estímulo da rápida passagem de alimento por esta região; outra hipótese confere o resultado à exclusão do intestino proximal, porém detalhes dos mecanismos de ação e do seu papel em indivíduos não obesos ainda precisam ser esclarecidos. Indivíduos com DM2 operados por motivos diferentes da obesidade representam adequado modelo para analisar resultados clínicos da exclusão duodenal. OBJETIVO: analisar a mudança da glicemia em pacientes diabéticos submetidos a gastrectomia total ou subtotal com derivação em Y de Roux por câncer gástrico. PACIENTES E MÉTODOS: estudo observacional, analítico, tipo coorte com abordagem retrospectiva, desenvolvido em duas instituições públicas de saúde no município de São Paulo, aprovado por comitê de ética em pesquisa. Foram verificados os prontuários físicos e eletrônicos, com respeito às variáveis demográficas (sexo, idade) e clínicas (comorbidades, Índice de Massa Corpórea-IMC, glicemia de jejum, hemoglobina glicada e uso de medicamentos) antes da operação (T0) e um ano após (T1). A amostra foi composta por 129 pacientes acima de 18 anos, com diagnóstico de DM2 e Adenocarcinoma gástrico, submetidos a gastrectomia com reconstrução em Y de Roux. Foram excluídos 26 pacientes por falta de acompanhamento ou óbito antes de um ano de pós-operatório; a amostra de análise (n=103) foi representada por 50,5% (n=52) de mulheres e 49,5% homens (n=51), com idade média de 65,5 ± 9,57 anos (41-89 anos). A distribuição do IMC foi de 25 a 30 kg/m2 em 44,7% (n=46), abaixo de 25 kg/m2 em 38,8% (n=40) e maior que 30 kg/m2 em 16,5% (n=17). A gastrectomia subtotal foi realizada em 79,6% (n=82) dos pacientes. Para a análise estatística, usaram-se medidas de tendência central, teste t de Student e regressão logística com o modelo CART. RESULTADOS: após um ano de pós-operatório, a média de glicemia diminuiu de 147,6 mg/dL (T0) para 134 mg/dL (T1) (p=0,046), porém 70% dos pacientes com glicemia > 100 no T0 permaneceram com o mesmo valor no T1. A hemoglobina glicada não teve mudança significativa (7,5% no T0 vs 7,0% no T1, p=0,988). A média do IMC diminuiu de 26,5 kg/m2 (T0) para 24,3 kg/m2 (T1) (p 30,2 kg/m2) com valor preditivo 71,4%. CONCLUSÕES: o estudo demonstrou que não houve melhora da glicemia nos pacientes com DM2 submetidos a gastrectomia total ou subtotal com reconstrução em Y Roux, com IMC abaixo de 30 kg/m2, nem foram observadas evidências que corroborem a Teoria do Intestino Proximal. Há indícios de que a cirurgia possa influenciar o controle glicêmico quando o IMC é > 30 kg/m2 e a idade, inferior a 62,5 anosINTRODUCTION: Bariatric surgery has been shown to be effective in the treatment of obesity-related comorbidities such as Type 2 Diabetes Mellitus (DM2), suggesting that mechanisms in addition to weight loss are involved. Several studies have attributed the improvement of glycemic regulation to the secretion of incretins in the distal intestine, due to the stimulation of the fast passage of food by this region. Another hypothesis confers the result to the exclusion of the proximal intestine; however, details of the mechanisms of action and their role in non-obese individuals have yet to be clarified. Individuals with DM2 operated for other reasons than obesity, represent an adequate model to analyze clinical outcomes of duodenal exclusion. AIM: to analyze the glycemia changes in diabetic patients submitted to total or subtotal gastrectomy with Roux-en-Y derivation for gastric cancer. PATIENTS AND METHODS: An observational, analytical, cohort study with a retrospective approach, developed in two public health institutions in the city of São Paulo, approved by a research ethics committee. The physical and electronic charts concerning to demographics (sex, age) and clinical variables (comorbidities, Body Mass Index (BMI), fasting glycemia, glycated hemoglobin and medication use) were checked before surgery (T0) and one year after (T1). The sample consisted of 129 patients over 18 years of age, diagnosed with DM2 and Gastric Adenocarcinoma, who underwent gastrectomy with Roux-en-Y reconstruction. Twenty-six patients were excluded due to lack of follow-up or death before one year of postoperative; the analysis sample (n=103) was represented by women 50.5% (n=52) and 49.5% men (n=51), with a mean age of 65.5 years (SD=9.57; 41-89 years). The distribution of BMI was 25 to 30 kg/m2 in 44.7% (n=46), below 25 kg/m2 in 38.8% (n=40) and greater than 30 kg/m2 in 16.5 % (n=17). Subtotal gastrectomy was performed in 79.6% (n=82) of the patients. Statistical analysis used central tendency measures, Student\'s t-test and logistic regression with the CART model. RESULTS: After one year of postoperative, mean glucose levels decreased from 147.6 mg/dL (T0) to 134 mg/dL (T1) (p=0.046), but 70% of patients with glycemia > 100 at T0, remained with the same value in T1. Glycated hemoglobin had no significant change (7.5% in T0 vs. 7.0% in T1, p=0.988). The mean BMI decreased from 26.5 kg/m2 (T0) to 24.3 kg/m2 (T1) (p 30.2 kg/m2) with a predictive value of 71.4%. CONCLUSIONS: The study demonstrated that there was no improvement of glycemia in patients with DM2 who underwent total or subtotal gastrectomy with Roux-in-Y reconstruction, with a BMI below 30 kg/m2. No evidence was found corroborating the theory of the proximal intestine. There are indications that surgery may influence glycemic control when BMI > 30 kg/m2 and age less than 62.5 year
Critical analysis of surgical treatment techniques of morbid obesity
No full textIntrodução: A obesidade é uma afecção com alta prevalência no Brasil e no mundo. É fator de risco para comorbidades como Diabetes tipo 2 (DM2), Hipertensão Arterial Sistêmica (HAS), Dislipidemia, Apneia Obstrutiva do Sono (AOS), entre outras. Seu tratamento é complexo e a cirurgia bariátrica, executada por diferentes técnicas, tem sido uma das opções. Objetivo: Analisar os resultados publicados na literatura em relação às técnicas cirúrgicas de Banda Gástrica Ajustável (BGA), Gastrectomia Vertical (GV), Gastroplastia com derivação em Y de Roux (GDYR) e Derivação Biliopancreática (DBP) - técnica de \"Scopinaro\" e de \"Duodenal Switch\" quanto às complicações operatórias, à mortalidade, à perda do excesso de peso (PEP) e ao reganho, e a resolução das comorbidades após a operação. Método: Foram analisados 116 estudos selecionados na base de dados MEDLINE por meio da PubMed publicados na Língua Inglesa entre 2003 e 2014. Para comparar as diferentes técnicas cirúrgicas (BGA, GV, GDYR e DBP), realizou-se estudo estatístico por meio da análise de variância (ANOVA) aplicando os testes de Duncan e de Kruskal Wallis avaliando: complicações pós-operatórias (fístula, sangramento e óbito); perda e reganho do excesso de peso, e resolução das comorbidades. Resultados: A ocorrência de sangramento foi de 0,6% na média entre todos os estudos, sendo 0,44% na BGA; 1,29% na GV; 0,81% na GDYR e 2,09% na DBP. Já a ocorrência de fístulas foi de 1,3% na média entre todos os estudos, 0,68% para BGA; 1,93% para GV; 2,18% para GDYR e 5,23% para DBP. A mortalidade nos primeiros 30 dias pós-operatórios foi de 0,9% na média entre todos os estudos, 0,05% na BGA; 0,16% na GV; 0,60% na GDYR e 2,52% na DBP. A PEP após cinco anos na média entre todos os estudos foi de 63,86%, especificamente na BGA, foi de 48,35%; 52,7% na GV; 71,04% na GDYR e 77,90% na DBP. A taxa de DM2 resolvida foi de 76,9% na média entre todos os estudos, sendo 46,80% na BGA; 79,38% na GV; 79,86% na GDYR e 90,78% na DBP. A taxa de Dislipidemia resolvida após a operação foi de 74,0% na média de todo o estudo, sendo 51,28% na BGA; 58,00% na GV; 73,28% na GDYR e 90,75% na DBP. A taxa de HAS resolvida após a operação foi de 61,80% na média de todo o estudo, sendo 54,50% na BGA; 52,27% na GV; 68,11% na GDYR e 82,12% na DBP. A taxa de AOS resolvida após a operação foi de 75,0% na média de todo o estudo, sendo 56,85% na BGA; 51,43% na GV; 80,31% na GDYR e 92,50% na DBP. Conclusão: quando analisadas e comparada as quatro técnicas observa-se que nos primeiros 30 dias pós-operatório a taxa de sangramento é superior nos pacientes submetidos à DBP e taxa de fístula inferior nos pacientes da BGA. Quanto à mortalidade observou-se taxa mais pronunciada nos pacientes submetidos à DBP e menos nos submetidos à BGA. Quanto à PEP observou-se uma uniformidade entre os pacientes submetidos à GV, GDYR E DBP até o terceiro ano. Após esse período observa-se reganho de peso nos submetidos à GV até o quinto ano de seguimento. Já nos pacientes submetidos à BGA observou-se taxas de PEP menos pronunciadas em relação às demais desde o início do seguimento. Quanto à resolução das comorbidades observou-se taxas de resolução de DM2 inferiores nos pacientes submetidos à BGA, e não houve diferença entre nenhuma técnica quanto à resolução das demais comorbidades: HAS, AOS e dislipidemiaIntroduction: Obesity is a disease with high prevalence in Brazil and worldwide. It is a risk factor for comorbidities such as type 2 diabetes (T2D), hypertension, dyslipidemia, obstructive sleep apnea, among others. Treatment is complex and bariatric surgery, performed by different techniques, has been one of the options. Objective: To analyze the surgical the results presented in the literature related to techniques of Adjustable Gastric Banding (AGB), Sleeve Gastrectomy(SG), Roux-en-Y Gastric Bypass(RYGB) and Biliopancreatic Diversion(BPD) - (\"Scopinaro\" and \"Duodenal Switch\" procedures) as to the postoperative complications, mortality, excess weight loss (EWL) and regain, and resolution of the comorbidities after surgery. Method: 116 studies were selected in MEDLINE through PubMed published in the English language between 2003 and 2014. To compare the different surgical techniques (AGB, SG, RYGB, BPD), statistical analysis was performed by analysis of variance applying Duncan and Kruskal Wallis tests assessing: postoperative complications (leak, bleeding and death); EWL and regained, and resolution of comorbidities after surgery. Results: The incidence of bleeding was in average 0.6% from all studies; 0.44% in AGB; 1.29% for SG; 0.81% RYGB and 2.09% for BPD. The average incidence of leaks was 1.3% in all studies; 0.68% for AGB; 1.93% in SG; 2.18% RYGB and 5.23% for BPD. Average mortality in the first 30 postoperative days was 0.9% in all studies; 0.05% for AGB; 0.16% in SG; 0.60% in RYGB and 2.52% in BPD. The average percentage of EWL after five years in all studies was 63.86%, specifically in AGB it was 48.35%; 52.7% in SG; 71.04% in RYGB and 77.90% in BPD. The rate of T2D resolved was in average 76.9% across all studies, 46.80% for AGB; 79.38% for SG; 79.86% RYGB and 90.78% for BPD. The rate of dyslipidemia resolved was in average 74.00% across all studies, 51.28% for AGB; 58.00% for SG; 73.28% RYGB and 90.75% for BPD. The rate of hypertension resolved was in average 61.80% across all studies, 54.50% for AGB; 52.27% for SG; 68.11% for RYGB and 82.12% for BPD. The rate of apnea resolved was in average 75.00% across all studies, 56.85% for AGB; 51.43% for SG; 80.31% for RYGB and 92.50% for BPD. Conclusion: After analyzing and comparing the four techniques it was observed that in the first 30 postoperative days the bleeding rate is higher in patients undergoing BPD and lower fistula rate in patients undergoing AGB. Regarding mortality was observed higher rate in patients undergoing BPD and smaller in patients undergoing AGB. As for EWL there was uniformity among patients submitted to SG, RYGB and BPD until the third year. After this period there has been regained weight in the patients submitted to SG until the fifth year. The patients undergoing AGB have lower rates of EWL. As for the resolution of comorbidities, observed T2D resolution rates were lower in patients undergoing AGB, and there was no difference between the techniques regarding: hypertension, dyslipidemia and obstructive sleep apne
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
Predicting Recurrence of gastric cancer after potentially curative surgery: External validation of the nomogram recommended by GIRCG (Italian Research Group of Gastric Cancer)
No full textNTRODUÇÃO: A maioria dos nomogramas para o câncer gástrico (CG) foi desenvolvida para prever a sobrevida global dos pacientes após ressecção curativa. O sistema de pontuação prognóstico (SPP) do Grupo Italiano de Pesquisa do Câncer Gástrico (GIRCG) foi projetado para prever o risco de recorrência após tratamento curativo baseado no estadiamento patológico do tumor e do tratamento realizado (linfadenectomia D1- D2/D3). Este estudo foi elaborado para avaliar a reprodutibilidade do SPP do GIRCG. PACIENTES E MÉTODO: Para validação do SPP preconizado pelo GIRCG, foram utilizados 185 pacientes operados no Serviço de Cirurgia de Estômago, Duodeno e Intestino Delgado do HCFMUSP, no período de janeiro de 2001 a dezembro de 2007, que preencheram os mesmo critérios utilizados pelo grupo italiano para construção e validação interna do SPP, ou seja, pacientes submetidos a cirurgias potencialmente curativas com ressecções R0, com linfadenectomia a D2 conforme preconizado pela Escola Japonesa. Os pacientes que apresentaram doença disseminada ou metástases a distância, mesmo sendo submetidos a ressecções paliativas, foram excluídos do estudo; assim como pacientes com menos de cinco anos de seguimento, pacientes que faleceram por complicações perioperatórias (até 30 dias) ou que, eventualmente, foram a óbito por outras causas não relacionadas ao CG. Tumores da transição esofagogástrica (TEG) e Linitis plastica também foram excluídos. O tempo mediano de seguimento foi de 77,8 meses (mínimo de 5,9 e máximo de 150,8) para todos os pacientes e de 102,5 meses (mínimo de 60,9 e máximo de 150,8) para os pacientes livres de doença. Foi utilizado modelo de regressão logística múltipla para comparar o SPP com o sistema de estadiamento TNM. RESULTADOS: A recorrência do CG ocorreu em 70 (37,8%) dos 185 pacientes. A média de idade foi de 59,7 anos (± 12,8; SE 0,94, amplitude de 22 a 88). O tempo mediano de recorrência foi de 22,2 meses (mínimo de 5,9 e máximo de 98,1). A pontuação média dos pacientes com recidiva e livres de doença foram, respectivamente, 68,2 (± 29,7 amplitude de 2,57 a 99,7) e 30,5 (± 29 amplitude de 3,6 a 97,7). A maioria dos pacientes obteve pontuações altas ou baixas, ou seja, situaram-se nos extremos da curva de distribuição da pontuação. Oito (4,3%) pacientes com pontuação maior que 90 não apresentaram recorrência e quatro (2,1%) pacientes com pontuação inferior a 10 apresentaram recidiva da doença. O SPP previu corretamente recorrência em 50 dos 70 pacientes (sensibilidade de 71,4% - IC 95% 0,61 a 0,82), enquanto a ausência de recorrência foi prevista em 88 dos 115 pacientes (especificidade de 75,6% - IC95% 0,69 a 0,84), sendo a acurácia global de 74,6% (IC95% 0,68 a 0,81). Em consonância com os resultados obtidos pelo GIRCG, apenas os valores do SPP provaram ser uma variável de previsão significante (P < 0,001), enquanto o estadio do tumor não mostrou a mesma significância (p=0,416). CONCLUSÃO: Este estudo validou o SPP do GIRCG que prevê recorrência após tratamento cirúrgico radical para CG. Este nomograma é simples, facilmente reproduzível e possui boa aplicabilidade clínicaBACKGROUND: Most nomograms for Gastric Cancer (GC) were developed to predict overall survival after curative resection. The Italian Research Group for Gastric Cancer (GIRCG) prognostic scoring system was designed to predict the risk of recurrence after curative treatment based on pathologic tumor stage and treatment performed (D1- D2/D3 lymphadenectomy). We carried out this study to externally validate the GIRCG\'s prognostic scoring system. PATIENTS AND METHODS: In order to validate the prognostic scoring system recommended by GIRCG, 185 patients operated at the Department of Surgery of Stomach, Duodenum and Small Intestine at HCFMUSP from January 2001 to December 2007 who met the same criteria used by the Italian Group for construction and internal validation have been used, that is, patients who underwent potentially curative surgery with R0 resection, with D2 lymphadenectomy as recommended by the Japanese School. Patients with disseminated disease or distant metastases, even if undergoing palliative resections were excluded from the study. As well as patients with less than five years of follow up, patients who died of perioperative complications (within 30 days) or who eventually died of other causes unrelated to the GC. Tumors of the esophagogastric junction and Linitis plastica were also excluded. The median follow-up period was 77,8 months (range 5,9 - 150,8) for all patients and 102,5 months (range 60,9 - 150,8) for patients free of disease. A multiple logistic regression model was used to compare the scoring system with TNM stage system. RESULTS: CG recurrence occurred in 70 (37.8%) of 185 patients. The mean age was 59.7 years (± 12.8; SE 0.94, range 22 to 88). The median time to recurrence was 22.2 months (range 5,9 - 98,1). The average values of the scores of patients with recurrence and disease-free were, respectively, 68.2 (± 29.7 range 3.77 to 99.7) and 30.5 (± 29.4 range 2,57 to 97.7). Most patients had high or low scores, ie, stood at the extremes of the range. Eight (4,3%) patients with score higher than 90 showed no recurrence and only four (2,1%) patients with score lower than 10 recurred. The prognostic scoring system correctly predicted recurrence in 50 of 70 patients (sensitivity71.4% - CI 95% 0.61 to 0.82), while the absence of recurrence was predicted in 88 of 115 patients (specificity of 75.6% - CI 95% 0.69 to 0.84%) with an overall accuracy of 74.6% (CI 67.8% to 80.3%). In consonance with the results obtained by GIRCG only score level proved to be a significant predictive variable (P < 0.001), while the stage of the tumor did not showed the same significance (P=0.416). CONCLUSION: This study has validated the GIRCG prognostic scoring system that predicts recurrence after radical surgical treatment for CG. This nomogram is simple, easily reproducible and has good clinical applicabilit
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
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