584 research outputs found
Equalities between h-type indices and definitions of rational h-type indicators
Purpose: To show for which publication-citation arrays h-type indices are equal and to reconsider rational h-type indices. Results for these research questions fill some gaps in existing basic knowledge about h-type indices.
Design/methodology/approach: The results and introduction of new indicators are based on well-known definitions.
Findings: The research purpose has been reached: answers to the first questions are obtained and new indicators are defined.
Research limitations: h-type indices do not meet the Bouyssou-Marchant independence requirement.
Practical implications: On the one hand, more insight has been obtained for well-known indices such as the h-and the g-index and on the other hand, simple extensions of existing indicators have been added to the bibliometric toolbox. Relative rational h-type indices are more useful for individuals than the existing absolute ones.
Originality/value: Answers to basic questions such as "when are the values of two h-type indices equal" are provided. A new rational h-index is introduced
Laparoscopic repair of very large hiatus hernia with sutures versus absorbable mesh versus nonabsorbable mesh a randomized controlled trial
Author version made available in accordance with pubilsher policy. 12 month embargo applies from the date of publication (1 Feb 2015).Objective:
Determine whether absorbable or non-absorbable mesh in repair of large hiatus hernias reduces
the risk of recurrence, compared to suture repair.
Summary Background Data:
Repair of large hiatus hernia is associated with radiological recurrence rates of up to 30%,
and to improve outcomes mesh repair has been recommended. Previous trials have shown
less short term recurrence with mesh, but adverse outcomes limit mesh use.
Methods:
Multicentre prospective double blind randomized controlled trial of 3 methods of repair; sutures
vs. absorbable mesh vs. non-absorbable mesh. Primary outcome - hernia recurrence assessed by
barium meal X-ray and endoscopy at 6 months. Secondary outcomes - clinical symptom scores at
1, 3, 6 and 12 months.
Results:
126 patients enrolled - 43 sutures, 41 absorbable mesh and 42 non-absorbable mesh. 96.0%
were followed to 12 months, with objective follow-up data in 92.9%. A recurrent hernia (any
size) was identified in 23.1% following suture repair, 30.8% - absorbable mesh, and 12.8% -
non-absorbable mesh (p=0.161). Clinical outcomes were similar, except less heartburn at 3 &
6 months and less bloating at 12 months with non-absorbable mesh, and more heartburn at 3
months, odynophagia at 1 month, nausea at 3 & 12 months, wheezing at 6 months, and
inability to belch at 12 months following absorbable mesh. The magnitude of the clinical
differences were small.
Conclusions:
No significant differences were seen for recurrent hiatus hernia, and the clinical differences
were unlikely to be clinically significant. Overall outcomes following sutured repair were
similar to mesh repair
Scales and Cosmological Applications of M Theory
I review recent results in three topics of the M-world: (i) Scales. (ii) New
dark matter candidates. (iii) Cosmological solutions from p-branes. The three
topics are discussed in the framework of Ho\v{r}ava-Witten compactifications.
Part (iii) includes comments on cosmological solutions in M-theory describing
nucleation of universes through instanton effects and expansions toward
asymptotically flat or anti-de-Sitter spaces.Comment: 19 pages, latex, uses sprocl.st
Hypoxic pre-conditioning increases the infiltration of endothelial cells into scaffolds for dermal regeneration pre-seeded with mesenchymal stem cells.
Many therapies using mesenchymal stem cells (MSC) rely on their ability to produce and release paracrine signals with chemotactic and pro-angiogenic activity. These characteristics, however, are mostly studied under standard in vitro culture conditions. In contrast, various novel cell-based therapies imply pre-seeding MSC into bio-artificial scaffolds. Here we describe human bone marrow-derived MSC seeded in Integra matrices, a common type of scaffold for dermal regeneration (SDR). We show and measured the distribution of MSC within the SDR, where cells clearly establish physical interactions with the scaffold, exhibiting constant metabolic activity for at least 15 days. In the SDR, MSC secrete VEGF and SDF-1α and induce transwell migration of CD34(+) hematopoietic/endothelial progenitor cells, which is inhibited in the presence of a CXCR4/SDF-1α antagonist. MSC in SDR respond to hypoxia by altering levels of angiogenic signals such as Angiogenin, Serpin-1, uPA, and IL-8. Finally, we show that MSC-containing SDR that have been pre-incubated in hypoxia show higher infiltration of endothelial cells after implantation into immune deficient mice. Our data show that MSC are fully functional ex vivo when implanted into SDR. In addition, our results strongly support the notion of hypoxic pre-conditioning MSC-containing SDR, in order to promote angiogenesis in the wounds
Air Travel Itinerary Market Share Estimation
In air travel, an itinerary is a direct flight or sequence of connecting flights between two cities. The objective of itinerary market share estimation is to forecast market shares of competing itineraries. This paper examines and compares three different methods for itinerary market share estimation: multinomial logit models, artificial neural networks, and a custom model developed by the authors. Using real-world booking data, each model is constructed and calibrated to best reproduce the given data. The resulting models are applied to test data and the custom model was found to show the best results. Although multinomial logit model are used by many airlines for planning and forecasting purposes, such methods resulted in the lowest forecasting quality
Preparation and Characterization of Antibacterial Polypropylene Meshes with Covalently Incorporated β-Cyclodextrins and Captured Antimicrobial Agent for Hernia Repair.
Polypropylene (PP) light weight meshes are commonly used as hernioplasty implants. Nevertheless, the growth of bacteria within textile knitted mesh intersections can occur after surgical mesh implantation, causing infections. Thus, bacterial reproduction has to be stopped in the very early stage of mesh implantation. Herein, novel antimicrobial PP meshes grafted with β-CD and complexes with triclosan were prepared for mesh infection prevention. Initially, PP mesh surfaces were functionalized with suitable cold oxygen plasma. Then, hexamethylene diisocyanate (HDI) was successfully grafted on the plasma-activated PP surfaces. Afterwards, β-CD was connected with the already HDI reacted PP meshes and triclosan, serving as a model antimicrobial agent, was loaded into the cyclodextrin (CD) cavity for desired antibacterial functions. The hydrophobic interior and hydrophilic exterior of β-CD are well suited to form complexes with hydrophobic host guest molecules. Thus, the prepared PP mesh samples, CD-TCL-2 and CD-TCL-6 demonstrated excellent antibacterial properties against Staphylococcus aureus and Escherichia coli that were sustained up to 11 and 13 days, respectively. The surfaces of chemically modified PP meshes showed dramatically reduced water contact angles. Moreover, X-ray diffractometer (XRD), differential scanning calorimeter (DSC), and Thermogravimetric (TGA) evidenced that there was no significant effect of grafted hexamethylene diisocyanate (HDI) and CD on the structural and thermal properties of the PP meshes
Controlled Levofloxacin Release and Antibacterial Properties of β-Cyclodextrins-Grafted Polypropylene Mesh Devices for Hernia Repair.
Mesh infection is a major complication of hernia repair. After knitted mesh implantation, bacteria can grow within textile structures causing infection. In this work, polypropylene (PP) mesh devices were two-step grafted with hexamethylene diisocyanate (HDI) and β⁻cyclodexrins (CD) and then loaded with suitable antimicrobial levofloxacin HCL for hernia mesh-infection prevention. First, oxygen plasma was able to create surface roughness, then HDI was successfully grafted onto PP fiber surfaces. Afterwards, CD was covalently grafted onto the HDI treated PP meshes, and levofloxacin HCL (LVFX) was loaded into the CD cavity of the modified meshes. The modified devices were evaluated for sustained antibiotic properties and drug-release profiles in a phosphate buffer, and sustained drug release was observed between interfaces of meshes and aqueous environment. The antibiotic-loaded PP mesh samples demonstrated sustained antibacterial properties for 7 and 10 days, respectively, against both Gram-negative and Gram-positive bacteria. The CD-captured levofloxacin HCL showed burst release after 6 h but later exhibited sustained release for the next 48 h. Among all samples, the modified mesh LVFX-6 was more stable and showed more sustained drug release and could be employed in future clinical applications
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