130 research outputs found
Effects of pendent phenol functional groups on secondary coordination spheres of heme like Fe-salen complexes
No full textSince the beginning of industrial revolution, burning of fossil fuels has mainly led to increase in atmospheric concentration of CO2 , a Green House Gas (GHG), from 250 ppm to 400 ppm between 1800 and 2012. One way to reduce the burning of fossil fuels and CO2 emission rate is to explore alternative carbon free fuels to meet the energy demand.This project aims at the synthesis and study of metal complexes inspired by biological models that will help better design catalysts to perform water oxidation more effectively.This poster won the Dean, Faculty of Science award (2020). Advisor: Dr. Linus Chiang, Departmen of Chemistry
21st-century scholarship and Wikipedia
No full textWikipedia, the world’s fifth most-used Web site, is a good illustration of the growing credibility of online resources. In his article in Ariadne earlier this year, “Wikipedia: Reflections on Use and Academic Acceptance”, Brian Whalley described the debates around accuracy and review, in the context of geology. He concluded that ‘If Wikipedia is the first port of call, as it already seems to be, for information requirement traffic, then there is a commitment to build on Open Educational Resources (OERs) of various kinds and improve their quality.’ In a similar approach to the Geological Society event that Whalley describes, Sarah Fahmy of JISC worked with Wikimedia and the British Library on a World War One (WWI) Editathon. There is a rich discourse about the way that academics relate to Wikipedia
How Many Answers Are Enough? Optimal Number of Answers for Q&A Sites
No full textWith the proliferation of the social web, questions about information quality and optimization attract the attention of IS scholars. Question-answering (QA) sites, such as Yahoo!Answers, have the potential to produce good answers, but at the same time not all answers are good and not all QA sites are alike. When organizations design and plan for the integration of question answering services on their sites, identification of good answers and process optimization become critical. Arguing that ‘given enough answers all questions are answered successfully,’ this paper identifies the optimal number of posts that generate high quality answers. Based on content analysis of Yahoo! Answers’ informational questions (n=174) and their answers (n=1,023), the study found that seven answers per question are ‘enough’ to provide a good answer
Untersuchungen zu neuartigen pharmazeutischen Darreichungsformen unter den Gesichtspunkten ihrer Wechselwirkung mit der Physiologie des Magens und der gastrointestinalen Wirkstoffdistribution
No full textDie Entwicklung von Darreichungsformen stellt eine Kernaufgabe der pharmazeutischen Technologie dar. Im besten Fall folgt sie aktuellen Erkenntnissen aus diversen medizinischen und technischen Bereichen, um mit immer fortschrittlicheren Methoden für eine gezieltere, sicherere und spezifisch auf den Patienten und den Applikationsort abgestimmte Arzneimitteltherapie zu sorgen. Dies führt dazu, dass dem pharmazeutischen Technologen ein stetig wachsendes Repertoire an Herstellungsprozessen und Untersuchungsmethoden zur Verfügung steht, aus dem auch durch anschließende Weiterentwicklung, innovative Darreichungsformen und Hilfsmittel entwickelt werden können.
Der 3D-Druck stellt eine dieser Technologien dar und erlaubte im ersten Teil dieser Arbeit die Herstellung flexibler und faltbarer Darreichungsformen aus verschiedenen thermoplastischen Polyurethanen. Das manuelle Falten der unterschiedlichen Geometrien in eine Gelatinekapsel erlaubte eine Reduktion der äußeren Dimensionen und damit funktionell grundsätzlich eine orale Applikation. Die Kombination der flexiblen und gefalteten Objekte mit einer Kapsel führte zu einem hybridem Formgedächtnissystem, welches sich durch den Erhalt der komprimierten (Sekundär-) Struktur bis zum Lösen der Kapselhülle auszeichnete. Die durchlaufenen Formveränderungen konnten mit einer dafür entwickelten Testapparatur beobachtet und quantifiziert werden, um material- und formabhängige Einflüsse auf das Ausfaltungsverhalten untersuchen zu können. Die hier getesteten Formen Kleeblatt, Feder, Wafer, Ring und Fenster hatten einen Einfluss auf die Expansionszeit und die Dimensionswiederherstellung, also dem Grad des Wiedererreichens der ursprünglich 3D-gedruckten Form nach Faltung. Wiedererwarten hatte die Shore-Härte der verwendeten thermoplastischen Polyurethane einen nur geringen Einfluss auf diese Werte. Vielmehr schien eine höhere Wandstärke der Objekte für eine erhöhte Steifigkeit zu sorgen, die für ein schnelles Verlassen der Kapseln und eine vollständigere Expansion sorgte. Der flexible Charakter dieser Darreichungsformen könnte neben der möglichen Expansion auf Dimensionen größer als der geöffnete Pylorus, einen neuen mechanistischen Ansatz zum Erreichen von Gastroretention darstellen, welcher auf Beobachtungen aus Untersuchungen mit einem simulierten Antrum basiert. Hierfür müssen jedoch gerade hinsichtlich der Materialauswahl und der zwingend notwendigen Magenentleerung weitere Untersuchungen angestellt werden.
Eine im zweiten Teil dieser Arbeit entwickelte Spinnapparatur zur Herstellung pharmazeutischer Fäden und Garne stellte eine weitere Möglichkeit dar, flexible und elastische Darreichungsformen oder Komponenten dieser zu entwickeln. Dazu wurde ein dreiteiliges System aus Schmelzextruder, Verstreckeinheit und eigentlicher Spinnapparatur zur Herstellung eines aus Polyvinylalkohol und Glycerol als Weichmacher bestehenden multifilen Garns verwendet. Eine eigens entwickelte 90° - Umlenkung mit Lochplatte aus Edelstahl erlaubte die Extrusion der aufgeschmolzenen Pulvermischung Richtung Verstreckeinheit, die die haarartigen Filamente durch Verstreckung weiter verfeinerte. Die ebenfalls mit 3D-gedruckten Komponenten designte Spinnapparatur folgte in ihrem Prinzip einem typischen Spinnrad und verspann die Einzelfäden zu einem Garn. Durch die hygroskopischen Eigenschaften des Polyvinylalkohols und Glycerols hatten Lagerbedingungen und Lagerungszeit einen Einfluss auf die physikalischen Eigenschaften des Garns. Erhöhte Feuchtigkeit führte zu sinkender Reißkraft und höher werdender Verstreckungstendenz. Eine Lagerung über ein Jahr bei niedriger Luftfeuchtigkeit führte sogar zu einer Erhöhung der Reißkraft, bei haptisch bleibender Flexibilität des Garns.
Mit der Durchführung einer dreiarmigen MRT-Studie konnte schließlich auch ein Beitrag zur Gewinnung wichtiger biopharmazeutischer Erkenntnisse geleistet werden, die für das Verständnis von Verteilungsprozessen von Substanzen im Gastrointestinaltrakt und damit auch für die Entwicklung zukünftiger Darreichungsformen relevant sind. Durch Zusatz von Mangan(II)-gluconat als Marker und hydrophiler, jedoch schlecht absorbierbarer Modellsubstanz zu Trinkwasser, konnte der Verlauf der oral eingenommenen Lösung durch den Gastrointestinaltrakt mittels T1-gewichteter MRT-Sequenzen beobachtet werden. Dies erlaubte eine Differenzierung zwischen oral eingenommener Lösung und im Körper vorhandener sekretierter Flüssigkeit. Sowohl nüchtern als auch nach Einnahme einer niedrig- und hochkalorischen Testmahlzeit erfolgte die Magenentleerung und Verteilung der Mangan(II)-Ionen in ähnlicher Weise. Eine Verteilung im Dünndarm war meist bereits nach 30 Minuten abgeschlossen. Diese Ergebnisse lassen annehmen, dass die in der Literatur bereits bekannte Magenstrasse im Dünndarm fortgesetzt wird (Darmstrasse) und Flüssigkeiten am Nahrungsbrei vorbeifließen, bis sie durch die hohe Absorptionskraft und große Oberfläche des Dünndarms aufgenommen werden. Konsekutive Dünndarmpassagezeiten durch die verschiedenen Abschnitte des Dünndarms von mehreren Stunden, wie sie bei in silico-Modellen üblicherweise angenommen werden, lassen sich anhand dieser Daten nicht bestätigen. Möglicherweise ist unter anderem ein beschleunigter intestinaler Transport gelöster Substanzen im postprandialen Zustand eine Ursache, für die insbesondere bei Arzneistoffen mit Resorptionsfenstern im oberen Dünndarm beobachteten, verringerten Bioverfügbarkeiten bei Einnahme zusammen mit Nahrung (negative Food-Effekte).The development of dosage forms is a core task of pharmaceutical technology. At best, it follows the latest findings from various medical and technical fields in order to use ever more advanced methods to ensure a more targeted, safer drug therapy that is specifically tailored to the patient and the application site. As a result, pharmaceutical technologists have a constantly growing repertoire of manufacturing processes and research methods at their disposal, from which innovative dosage forms and aids can be developed through subsequent further development. 3D printing is one of these technologies and, in the first part of this work, enabled the production of flexible and foldable dosage forms from various thermoplastic polyurethanes. The manual folding of the different geometries into a gelatine capsule made it possible to reduce the outer dimensions and thus functionally enable oral application. The combination of the flexible and folded objects with a capsule led to a hybrid shape memory system, which was characterised by the preservation of the compressed (secondary) structure until the capsule shell was released. The shape changes undergone could be observed and quantified using a test apparatus developed for this purpose in order to investigate material- and shape-dependent influences on the unfolding behaviour. The shapes tested here - cloverleaf, spring, wafer, ring and window - had an influence on the expansion time and dimensional recovery, i.e. the degree to which the original 3D-printed shape was achieved again after folding. As expected, the Shore hardness of the thermoplastic polyurethanes used had only a minor influence on these values. Instead, a higher wall thickness of the objects appeared to provide increased rigidity, which ensured rapid exit from the capsules and more complete expansion. In addition to the possible expansion to dimensions larger than the open pylorus, the flexible character of these dosage forms could represent a new mechanistic approach to achieving gastroretention, which is based on observations from studies with a simulated antrum. However, further investigations are required, particularly with regard to the choice of material and the mandatory gastric emptying.
A spinning apparatus developed in the second part of this thesis for the production of pharmaceutical threads and yarns represents a further possibility for developing flexible and elastic dosage forms or components thereof. A three-part system comprising a melt extruder, stretching unit and actual spinning apparatus was used to produce a multifilament yarn consisting of polyvinyl alcohol and glycerol as a plasticiser. A specially developed 90° deflection with a stainless steel perforated plate allowed the molten powder mixture to be extruded towards the stretching unit, which further refined the hair-like filaments by stretching them. The spinning apparatus, also designed with 3D-printed components, was based on the principle of a typical spinning wheel and spun the individual threads into a yarn. Due to the hygroscopic properties of polyvinyl alcohol and glycerol, storage conditions and storage time had an influence on the physical properties of the yarn. Increased humidity led to a decrease in tensile strength and an increased tendency to stretch. Storage for over a year at low humidity even led to an increase in tensile strength, while the yarn remained flexible to the touch. By conducting a three-arm MRI study, it was also possible to contribute to the acquisition of important biopharmaceutical findings that are relevant for understanding the distribution processes of substances in the gastrointestinal tract and thus also for the development of future dosage forms. By adding manganese(II) gluconate as a marker and hydrophilic but poorly absorbable model substance to drinking water, the course of the orally ingested solution through the gastrointestinal tract could be observed using T1-weighted MRI sequences. This made it possible to differentiate between orally ingested solution and secreted fluid present in the body. Gastric emptying and distribution of manganese(II) ions occurred in a similar manner both on an empty stomach and after ingestion of a low- and high-calorie test meal. Distribution in the small intestine was usually completed after 30 minutes. These results suggest that the stomach road already known in the literature is continued in the small intestine (small intestinal road) and liquids flow past the food pulp until they are absorbed by the high absorption force and large surface area of the small intestine. Consecutive small intestinal passage times of several hours through the various sections of the small intestine, as is usually assumed for in silico models, cannot be confirmed on the basis of these data. One possible cause of the reduced bioavailability of drugs with absorption windows in the upper small intestine when taken together with food (negative food effects) may be the accelerated intestinal transport of dissolved substances in the postprandial state
Power Relations and Social Classes in Pengakuan Pariyem by Linus Suryadi AG: Reflection of Masculine Ideology
No full textThe study aims to explore power relations and social classes as the reflections of the masculine ideology of the author in the novel Pengakuan Pariyem by Linus Suryadi AG. The theories implemented in the study are van Dijk’s power relations and social classes theory and Connell’s masculinity theory. The study is qualitative descriptive and applies the Critical Discourse Analysis (CDA) method, used to dismantle the ideology that is produced and reproduced through the language within the novel. The research data are lingual units that indicate power relations and social classes which simultaneously reflect the notion of masculinity. The results of the study are as follows. First, Pariyem as the central character in the novel lives within a hierarchical and dualistic Javanese society. Her submission as the babu (housemaid) of a priyayi (noble) family does not only lead Pariyem to be dominated symbolically, but also legitimizes the priyayi (aristocrats) power over wong cilik (commoners). It is reinforced by the representations of the priyayis’ world views in terms of culture, aristocracy, bureaucracy, and education orientation. It shows that priyayis are culturally dominant. Secondly, since Pariyem is a character created by a male author, her behaviors and actions reflect the ideology of masculinity. Rather than voicing women, the power relations that Pariyem experiences through the events constructed in the novel show that she embodies the masculine ideology, or masculinity.
Linus Pauling.
No full textDigital ImageAmerican chemist, biochemist, peace activist and author. For his scientific work, Pauling was awarded the Nobel Prize in Chemistry in 1954; and for his peace activism, he was awarded the Nobel Peace Prize in 1962
March for Science: Sign with a quote from scientists Linus Pauling, E. Pine St. at Belmont Ave., Seattle, Washington, April 22, 2017
No full textText on signs read: "No science = No hops, no malt, no water, no beer [the letters in the word beer are made up of periodic element symbols]"; "Facts are the air of scientists. Without them you can never fly. - Linus Pauling. Science, not silence".
Linus Carl Pauling was an American chemist, biochemist, peace activist, author, and educator.
PH Coll 1478. KinseyK116The Seattle March for Science occurred on April 22, 2017. This date was chosen because April 22 is also Earth Day. According to organizers, as many as 20,000 people attended the march, which began at 10 a.m. in Cal Anderson Park in the Capitol Hill neighborhood. The march culminated at the International Fountain at the Seattle Center. The March for Science in Seattle was one of more than 500 similar marches taking place across the United States. Demonstrators marched in support of “robustly funded and publicly communicated science and evidence as a pillar of human freedom and prosperity” and also called “for science that upholds the common good, and for political leaders and policymakers to enact evidence-based policies in the public interest”, according to a statement put out by march organizers. Washington Governor Jay Inslee and Seattle Mayor Ed Murray came out to show their support.Scienc
Quantitative Real‐Time MRI for the Assessment of Gastric Motility
No full textABSTRACT Background Current reference standards for measuring gastric emptying and motility are not considered optimal due to the time required, ionizing radiation, invasiveness, and spatial resolution. Purpose To assess gastric motility using novel real‐time dynamic magnetic resonance imaging in combination with static measurements for gastric emptying and training of an automated deep‐learning‐based segmentation pipeline. Study Type Prospective. Participants The study included 36 healthy volunteers (20 female, mean 24 ± 3 years) and three patients with diagnosed Crohn's disease. Field Strength/Sequences Participants ingested water to assess fasting motility and pineapple juice for the postprandial state. 3 T, 3D spoiled gradient echo (GRE) sequence and real‐time spoiled GRE. Assessment Gastric emptying was measured by using the gastric volume, while motility was analyzed by tracking changes in the antrum's cross‐sectional area and applying Fast Fourier Transformation. Segmentations were performed using a trained semantic segmentation model. Statistical Tests Linear Mixed Model with continuous dependent variables and fixed effects. Models included a random intercept for participants. Statistical significance was defined as p = 0.05. Results The method enabled volumetric analysis of gastric content from 3D breath‐hold static acquisition and time‐resolved quantification of peristaltic parameters from real‐time FLASH2 imaging at high temporal resolution (here 6.24 fps). Water emptied rapidly and exponentially ( t 1/2 = 14.77 ± 10.55 min), while juice showed slower emptying ( t 1/2 = 64.24 ± 11.87 min). Contraction frequencies (fasted: 2.76 ± 0.43 cpm, fed: 2.89 ± 0.43 cpm) and velocities (fasted: 1.67 ± 0.38 mm/s, fed: 1.72 ± 0.37 mm/s) were within physiological ranges, with fasting conditions characterized by stronger occlusion compared to the fed. Measurements taken from three patients proved that the workflow could be used in a clinical context. Data Conclusion Real‐time MRI with AI‐based analysis enabled quantitative assessment of gastric emptying and motility, revealing physiological peristaltic parameters and state‐dependent differences in occlusion. Evidence Level 2. Technical Efficacy Stage 1.Plain Language Summary Problems with stomach movement and emptying affect digestion, drug absorption, and diseases, but current tests are limited. This study tested whether fast magnetic resonance imaging combined with artificial intelligence can measure stomach emptying and movement without radiation or invasive procedures. Volunteers drank water and a calorie‐containing juice, while the stomach was imaged over time. The method measured how fast the stomach emptied and how strong and regular stomach contractions were. Results showed differences between fasting and fed states. The approach also worked in patients. This technique offers a noninvasive, quantitative way to study stomach function for research and clinical use.ABSTRACT Background Current reference standards for measuring gastric emptying and motility are not considered optimal due to the time required, ionizing radiation, invasiveness, and spatial resolution. Purpose To assess gastric motility using novel real‐time dynamic magnetic resonance imaging in combination with static measurements for gastric emptying and training of an automated deep‐learning‐based segmentation pipeline. Study Type Prospective. Participants The study included 36 healthy volunteers (20 female, mean 24 ± 3 years) and three patients with diagnosed Crohn's disease. Field Strength/Sequences Participants ingested water to assess fasting motility and pineapple juice for the postprandial state. 3 T, 3D spoiled gradient echo (GRE) sequence and real‐time spoiled GRE. Assessment Gastric emptying was measured by using the gastric volume, while motility was analyzed by tracking changes in the antrum's cross‐sectional area and applying Fast Fourier Transformation. Segmentations were performed using a trained semantic segmentation model. Statistical Tests Linear Mixed Model with continuous dependent variables and fixed effects. Models included a random intercept for participants. Statistical significance was defined as p = 0.05. Results The method enabled volumetric analysis of gastric content from 3D breath‐hold static acquisition and time‐resolved quantification of peristaltic parameters from real‐time FLASH2 imaging at high temporal resolution (here 6.24 fps). Water emptied rapidly and exponentially ( t 1/2 = 14.77 ± 10.55 min), while juice showed slower emptying ( t 1/2 = 64.24 ± 11.87 min). Contraction frequencies (fasted: 2.76 ± 0.43 cpm, fed: 2.89 ± 0.43 cpm) and velocities (fasted: 1.67 ± 0.38 mm/s, fed: 1.72 ± 0.37 mm/s) were within physiological ranges, with fasting conditions characterized by stronger occlusion compared to the fed. Measurements taken from three patients proved that the workflow could be used in a clinical context. Data Conclusion Real‐time MRI with AI‐based analysis enabled quantitative assessment of gastric emptying and motility, revealing physiological peristaltic parameters and state‐dependent differences in occlusion. Evidence Level 2. Technical Efficacy Stage 1.Plain Language Summary Problems with stomach movement and emptying affect digestion, drug absorption, and diseases, but current tests are limited. This study tested whether fast magnetic resonance imaging combined with artificial intelligence can measure stomach emptying and movement without radiation or invasive procedures. Volunteers drank water and a calorie‐containing juice, while the stomach was imaged over time. The method measured how fast the stomach emptied and how strong and regular stomach contractions were. Results showed differences between fasting and fed states. The approach also worked in patients. This technique offers a noninvasive, quantitative way to study stomach function for research and clinical use.Deutsche Forschungsgemeinschaft https://doi.org/10.13039/501100001659Interreg https://doi.org/10.13039/10001327
Romance portrayed in Sophie Kinsella's finding Audrey Novel
No full textThis research aims to describe the relationship between Audrey and Linus relationship using John G. Cawelti formula theory. The study shows that author use pamela formula to describe the story plot
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