196,157 research outputs found
Free radical production in the esophago-gastro-duodenal mucosa in response to acid and bile
No full textSeveral studies have demonstrated the role of free radicals in causing esophagus-gastro-duodenal mucosal injury. The present study has been designed to investigate: whether acid, bile salts and a combination of bile + acid could determine the production of O-2-derived free radicals by oesophageal, gastric and duodenal mucosa; which agent is capable of producing more free radicals and if O-2-derived free radicals production depends on the duration of contact with acid, bile salts and their combination. Wistar rats' gastro-intestinal mucosa were perfused with bile, acid and a combination of bile + acid at pH4 and pH2 for 1 hour and 2 hours. Free radical production (FRP) was assessed by chemoluminescence. After 1 hour, the increase in FRP in comparison with control reached statistical significance (P < 0.05) at all tested pH levels in the duodenum, at pH1, 2 and 3 in the esophagus, and at pH1 in the stomach. Comparing different segments, both the esophagus and duodenum behaved similarly, producing more free radicals than the stomach at all pH values. However, this difference reached statistical significance at pH1 and 2 only. In comparison to control, FRP was increased by bile (pH7) infusion after 1 and 2 hours. There was increased FRP in all segments after the infusion of bile at pH2 and 4 in comparison to control. Infusion of bile at pH2 stimulates more FRP than infusion of bile at pH4 in all segments. This increased FRP reaches statistical significance in the esophagus after 2 hours of infusion, in the stomach after 1 and 2 hours of infusion, but in the duodenum it does not reach statistical significance. Acid, bile and bile + acid at pH2 and 4 can cause free radical production in esophageal, gastric and duodenal mucosa. Their role in producing free radicals is different according to the segment and the chemical composition of the solution
Parastrombidinopsis shimi n. gen., n. sp (Ciliophora : Choreotrichia) from the coastal waters of Korea: Morphology and small subunit ribosomal DNA sequence
No full textThe planktonic ciliate parastrombidinopsis shimi n gen., n sp is described from both living cells and quantitative protargol-stained (QPS) preperations and the sequence of the small subunit rDNA (SSU rDNA) is reported. This species is almost oval when the cells are alive; when stained, it is cylindrical for the upper two-fifths, half-bowl shaped for the middle two fifths, and narrow rod-shaped for the lower one-fifth. The ranges (and mean +/- standard deviation, n = 20) of cell length, cell width, and the oral diameter of living cells were 112-221 mu m (168 +/- 39), 88 - 176 mu m (121 +/- 30), and 53 - 110 mu m (80 +/- 14), respectively, while those of the QPS-stained specimens (n = 54) were 88 - 225 mu m (162 +/- 29), 55 - 163 mu m (102 +/- 19), and 53 - 98 mu m (69 +/- 9) respectively. Thirty-six to 48 external oral polykinetids had cilia 25 - 40 mu m long. However, unlike Strombidinopsis species sensu stricto, P. shimi has an external oral polykineted zone that is an open circle. This species in the subclass has two shorter polykinetids associated with the end of the oral polykinetid zone, deep in the oral cavity. Like Strombidiopsis species in the posterior regions with 68 - 105 dikinetids per kinety. Both kinetocomes of each kinetid bore cilia 3 - 10 mu m long parastrombidinopsis shimi had 2 (1 - 4) ovoid macronucleus of 20 - 82 x 15 - 32 mu m. When properly aligned, the sequence of the SSU rDNA of P shimi (GenBank Accession No AJ786648) was approximately 5% different from that of Strobilidium caudatum as a new species in a new genus belonging to the family Strombidinopsidae.N
Diaphragmatic hernia following oesophagectomy for oesophageal cancer - Are we too radical?
No full textBackground: Diaphragmatic herniation (DH) of abdominal contents into the thorax after oesophageal resection is a recognised and serious complication of surgery. While differences in pressure between the abdominal and thoracic cavities are important, the size of the hiatal defect is something that can be influenced surgically. As with all oncological surgery, safe resection margins are essential without adversely affecting necessary anatomical structure and function. However very little has been published looking at the extent of the hiatal resection. We aim to present a case series of patients who developed DH herniation post operatively in order to raise discussion about the ideal extent of surgical resection required. Methods: We present a series of cases of two male and one female who had oesophagectomies for moderately and poorly differentiated adenocarcinomas of the lower oesophagus who developed post-operative DH. We then conducted a detailed literature review using Medline, Pubmed and Google Scholar to identify existing guidance to avoid this complication with particular emphasis on the extent of hiatal resection. Discussion: Extended incision and partial resection of the diaphragm are associated with an increased risk of postoperative DH formation. However, these more extensive excisions can ensure clear surgical margins. Post-operative herniation can be an early or late complication of surgery and despite the clear importance of hiatal resection only one paper has been published on this subject which recommends a more limited resection than was carried out in our cases. Conclusion: This case series investigated the recommended extent of hiatal dissection in oesophageal surgery. Currently there is no clear guidance available on this subject and further studies are needed to ascertain the optimum resection margin that results in the best balance of oncological parameters vs. post operative morbidity
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
Intern experience at CH���M Hill, Inc.: an internship report
No full textIncludes author's vita"Submitted to the College of Engineering of Texas A&M University in partial
fulfillment of the requirement for the degree of Doctor of Engineering."Includes bibliographical referencesA review of the author's internship experience with CH���M HILL, Inc.
during the period September 1975 through May 1976 is presented. During this nine month
internship the author worked as an Engineer II in the Industrial Processes discipline of this
large consulting engineering firm... The author's prime responsibility was as one of three
lead design engineers on the design of a large wastewater treatment facility for a pulp mill
in Hoquiam, Washington owned by ITT Rayonier Inc. The work generally consisted of the design
of individual treatment units and associated piping and pumping. The purpose of the project
was to provide wastewater treatment capabilities that would satisfy the effluent limitations
(standards) imposed upon the mill by the State of Washington Department of Ecology and the
U.S. Environmental Protection Agency. The author's assignment also entailed necessary
interaction with the project manager and other CH���M HILL design engineers and support staff
members, the client's representatives, and representatives of two other consulting engineering
firms working on the project. Thus, the internship position at CH���M HILL provided considerable
experience coordinating the author's work with the work of other engineers, guiding the design
and administrative efforts of a support staff, and interacting regularly with the client and
other consulting firms. This broad exposure to a variety of engineering and organizational
problems provided a valuable educational experience
Transition to turbulence in a qblique shock-wave/boundary-layer interaction at M=15
No full textDirect numerical simulations are carried out for different forcing techniques to trigger transition during the interaction between an oblique shock-wave and a laminar boundary-layer at M = 1.5. Three forcing methods are used: a) forcing of oblique unstable modes, whose shape and behaviour are determined by the local linear stability theory, b) broadband free-stream acoustic disturbances, and c) a cold plasma flow control device. While the oblique-mode breakdown is dominant for low-amplitude forcing, long streaky structures drive the transition process in a high-amplitude disturbance environment. LES are also performed on the experimental setup by the Institute of Theoretical and Applied Mechanics (ITAM) from Novosibirsk State University with cold plasma actuation. As well as the disturbance type, the effect of Reynolds number and forcing amplitude will be investigated
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