1,720,956 research outputs found
Гістологічні особливості литкового м’яза щура за умов хронічної алкоголізації та ішемії різної тривалості
Get PDFThe purpose of the study was the histological changes analysis in the gastrocnemius muscle under the conditions of experimental ischemia of different duration complicated by chronic alcoholization. The experiment was conducted on inbred Wistar line rats with 140 – 160 g body weight. The animals were divided into four groups: control; animals with ischemia (1, 2 and 3 hours ischemia duration); alcoholized animals and alcoholized animals with experimentally induced 1, 2, 3 hours ischemia. Chronic alcohol intoxication of the animals was achieved by intragastric delivery of 40 % ethyl alcohol for 30 days. Unilateral vascular ischemia was induced by tourniquet ligating of the main arteries. Histologic processing of the tissue was carried out according to standard histological methods, stained with Van Gison method. Morphometric indices (thickness of muscle fibers and the size of interfibrillary space) were measured using VideoTest Morphology 5,0 software. It was found that the level of expression of morphological changes directly depends on the duration of ischemia. With its increase, destructive changes of the gastrocnemius muscle become more evident: invaginations on the sarcolmes of fibers are more clearly visible, myofibrils are disorganized, the amount of collagen increases and the scar formation starts. After three-hour ishemia the cytological signs of necrosis are observed, but in many areas the typical cross-striped and the normal structure of muscle fibers was preserved. Under the conditions of chronic alcoholization and ischemia of different duration, the structure and course of partially atrophied after alcoholic myopathy fibers are broken, degenerative changes in the integrity of sarcolemes are observed, some fibers decrease the volume of myofibrils, there endomysium swells and its necrosis starts, myofibrils dissociate. The presence of neutrophils between myofibrils and diffuse hemorrhage has been observed, nevertheless, in some sites a typical cross-striped structure was preserved. The obtained results show the negative synergy of myotoxic effects of ethyl alcohol and the destructive effects of vascular ischemia on fibers of rat m. gastrocnemius.Мета роботи – провести аналіз гістологічних змін у литковому м’язі за умов експериментальної ішемії різної тривалості, ускладненої хронічною алкоголізацією. Експеримент реалізовано на щурах інбредної лінії Wistar масою 140–160 г. Виділено такі групи тварин: контрольна, тварини з ішемією (1, 2 та 3 год), алкоголізовані тварини й алкоголізовані тварини з експериментально-індукованою ішемією тривалістю 1, 2, 3 год. Експериментальну ішемію здійснювали через 30 днів після введення останньої дози етилового спирту методом Халілова-Захірходжаєва через перетискування джгутом основних артерій. Гістологічну обробку тканини проводили за загальноприйнятою методикою, фарбувалили за методом Ван-Гізон. Виявлено, що за умов хронічної алкоголізації й ішемії різної тривалості порушуються структура й хід частково атрофованих унаслідок алкогольної міопатії волокон, відбуваються дегенеративні зміни в цілісності сарколеми, у деякої частини волокон зменшується об’єм міофібрил, ендомізій набрякає та починає некротизуватися, міофібрили роз’єднуються. Відзначено появу нейтрофілів поміж міофібрил і дифузні крововиливи, але, попри це, в окремих ділянках зберігається типова поперечна посмугованість. Отримані результати свідчать про негативну синергію міотоксичних впливів етилового спирту та руйнівного впливу судинної ішемії на волокна литкового м’яза щурів
Морфофункциональное состояние нижнечелюстных костей лабо-раторных белых крыс при 1- и 3-месячном воздействии бис-фосфонатов в дозах, вызывающих остеонекротические изменения
Get PDFIt is known that medications of the bisphosphonate group can cause severe complications such as osteonecrosis of the jaws. However, the effects of these compounds in doses that cause osteonecrotic lesions on the growth and shaping of the mandibular bones remain unstudied.The aim of the investigation was to study the morphofunctional condition (size and shape) of the mandibular bones on the background of taking bisphosphonate compounds in doses that cause osteonecrotic lesions. The research was performed on 60 white outbred rats that were exposed to the studied remedies. The objects of the study were mandibular bones. They were scanned, digitized and 22 landmarks were determined. The analysis of the form component (geometric morphometry) was carried out with the programs TPSDig and MorphoJ. Digital data characterizing linear dimensions were analyzed due to the program Statistica 10,0 using one-way analysis, two-way analysis and multivariate analysis of variance (ANOVA, MANOVA) and Newman-Keuls post-hoc test. It was revealed that in the early stages of exposure, the studied bisphosphonate compounds have a significant effect on osteostimulation, despite the «acute phase reaction» that takes place during the first two weeks of use. At the later dates of the study, the substances cause growth inhibition and disorder of shaping processes because of the pharmacological properties of the studied substances, blocking bone resorption and a wide range of possible toxic reactions of the urinary, digestive, and cardiovascular systems.Известно, что препараты группы бисфосфонатов могут вызывать тяжелые осложнения – остеонекрозы челюстей. Однако воздействия этих соединений в дозах, вызывающих остеонекротические поражения, на рост и формообразование нижнечелюстных костей остаются малоизученными. Целью работы явилось рассмотрение морфофункционального состояния (составляющих размера и формы) нижнечелюстных костей на фоне приёма бисфосфонатных соединений в дозах, вызывающих остеонекротические поражения. Исследование проводили на 60 белых беспородных крысах, которым вводили исследуемые соединения. Объектом исследования явились нижнечелюстные кости. Производилось сканирование исследуемых объектов, их оцифровка и определение 22 ландмарок. Анализ составляющей формы (геометрическая морфометрия) производился в программах TPSDig и MorphoJ. Цифровые данные, характеризующие линейные размеры, анализировались в программе Statistica 10.0 с использованием одно-, двух- и многофакторного дисперсионных анализов (АNOVA, MANOVA), а также апостериорного критерия Ньюмана-Кеулса. Выявлено, что в ранние сроки воздействия исследуемые бисфосфонатные соединения обладают выраженным остеостимулирующим действием, несмотря на наличие «реакции острой фазы», возникающей в первые две недели использования. В поздние сроки исследования вещества вызывают торможение роста и нарушение процессов формообразования, что обусловлено фармакологическими свойствами исследуемых веществ, блокированием костной резорбции и широким спектром возможных токсических реакций со стороны мочевыделительной, пищеварительной и сердечно-сосудистой систем
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
