scholarly journals Inflammation Induced by Perfluorocarbon Liquid: Intra- and Postoperative Use

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Marta S. Figueroa ◽  
Diego Ruiz Casas
Keyword(s):  
Inflammatory Reaction ◽  
Histological Analysis ◽  
Experimental Studies ◽  
Vitreoretinal Surgery ◽  
Endothelial Damage ◽  
Perfluorocarbon Liquid ◽  
Anatomical Changes ◽  
Perfluorocarbon Liquids ◽  
Corneal Toxicity

Perfluorocarbon liquids (PFCLs) are useful and safe surgical tools in vitreoretinal surgery. The use of PFCL as a tamponade has been controversial due to the corneal toxicity, retinal infiltration, and inflammatory reaction in experimental studies. Several authors have studied in humans the anatomical and functional outcome and adverse effects of perfluorocarbon liquids used as short-, medium-, and long-term tamponade. PFCLs develop dispersion a few days after injection and droplets may move into the anterior chamber and cause corneal endothelial damage. When PFCLs are used as postoperative tamponades for more than one week, a foreign-body inflammatory reaction is observed in up to 30% of cases but such a reaction does not induce PVR, and it resolves after removal of PFCLs. Although most clinical studies have found no signs of retinal toxicity such as progressive visual acuity deterioration or macular anatomical changes, few performed ERG or retinal histological analysis.

scholarly journals Perfluorocarbon Liquid: Its Application in Vitreoretinal Surgery and Related Ocular Inflammation

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Qi Yu ◽  
Kun Liu ◽  
Li Su ◽  
Xin Xia ◽  
Xun Xu
Keyword(s):  
Animal Studies ◽  
Vitreoretinal Surgery ◽  
Complete Removal ◽  
Intraocular Lenses ◽  
Perfluorocarbon Liquid ◽  
Potential Toxicity ◽  
The Past ◽  
Perfluorocarbon Liquids

The application of perfluorocarbon liquids has been well acclaimed in vitreoretinal surgery. Its unique physical properties make it an ideal intraoperative tool to improve the efficiency and safety of surgical procedures in complicated cases. The main functions of perfluorocarbon liquids in vitreoretinal surgery include relocating and fixing the detached retina, displacing the subretinal and subchoroidal to fluid anteriorly, revealing proliferative vitreous retinopathy (PVR) for further maneuvers, protecting the macula from exposure to chemicals with potential toxicity, and assisting the removal of foreign body. The related clinical applications include retinal detachment with severe proliferative vitreoretinopathy, giant tear, diabetic retinopathy (DR), retinopathy of prematurity (ROP), and posterior dislocated crystalline and intraocular lenses. The application of perfluorocarbon liquids has been expended over the past fewer years. Several PFCLs related ocular inflammations have been observed inin vitrostudies, animal studies, and clinical follow-up. The complete removal of PFCLs is recommended at the end of the surgery in most cases.

Perfluorocarbon Liquids in Vitreoretinal Surgery

2019 ◽  
pp. 168-171
Keyword(s):  
Surface Tension ◽  
Retinal Detachment ◽  
High Surface ◽  
Vitreoretinal Surgery ◽  
Hydrogen Atoms ◽  
Ocular Tissues ◽  
High Surface Tension ◽  
Single Piece ◽  
Perfluorocarbon Liquids

Perfluorocarbon (PFC) liquids are hydrocarbons in which all the hydrogen atoms are replaced with the fluorine atoms. PFC liquids are stabilized liquids that can stay as a single piece with their high surface tension and are heavier than water. Perfluoro-n-octane, perfluorodecalin, perfluoro-phenanthrene are frequently used liquid PFC derivatives used in a clinical ophthalmology practice. Intraoperative use of PFC liquids in vitreoretinal surgery for proliferative vitreoretinopathy and complicated retinal detachment provides surgical ease and increase anatomical and functional success. Long-term exposure to PFC liquids results in complications such as inflammation and degenerations of ocular tissues. Studies are needed for PFC liquids which are suitable for long-term intraocular use.

Masonry: the brittle or plastic material?

2019 ◽  
pp. 22-28
Keyword(s):  
Plastic Material ◽  
Experimental Studies ◽  
Point Of View ◽  
Plastic Properties ◽  
Plastic Deformations ◽  
Base Materials ◽  
Stress States ◽  
Creep Deformations ◽  
Structural Point

The results of experimental studies of masonry on the action of dynamic and static (short-term and long-term) loads are presented. The possibility of plastic deformations in the masonry is analyzed for different types of force effects. The falsity of the proposed approach to the estimation of the coefficient of plasticity of masonry, taking into account the ratio of elastic and total deformations of the masonry is noted. The study of the works of Soviet scientists revealed that the masonry under the action of seismic loads refers to brittle materials in the complete absence of plastic properties in it in the process of instantaneous application of forces. For the cases of uniaxial and plane stress states of the masonry, data on the coefficient of plasticity obtained from the experiment are presented. On the basis of experimental studies the influence of the strength of the so-called base materials (brick, mortar) on the bearing capacity of the masonry, regardless of the nature of the application of forces and the type of its stress state, is noted. The analysis of works of prof. S. V. Polyakov makes it possible to draw a conclusion that at the long application of the load, characteristic for the masonry are not plastic deformations, but creep deformations. It is shown that the proposals of some authors on the need to reduce the level of adhesion of the mortar to the brick for the masonry erected in earthquake-prone regions in order to improve its plastic properties are erroneous both from the structural point of view and from the point of view of ensuring the seismic resistance of structures. It is noted that the proposal to assess the plasticity of the masonry of ceramic brick walls and large-format ceramic stone with a voidness of more than 20% is incorrect, and does not meet the work of the masonry of hollow material. On the basis of the analysis of a large number of research works it is concluded about the fragile work of masonry.

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

scholarly journals Understanding sex differences in long-term blood pressure regulation: insights from experimental studies and computational modeling

2019 ◽  
Vol 316 (5) ◽  
pp. H1113-H1123 ◽  
Author(s):  
Sameed Ahmed ◽  
Rui Hu ◽  
Jessica Leete ◽  
Anita T. Layton
Keyword(s):  
Blood Pressure ◽  
Sex Differences ◽  
Computational Models ◽  
Experimental Studies ◽  
Pressure Control ◽  
Blood Pressure Regulation ◽  
Pressure Regulation ◽  
Physiological Processes ◽  
Key Players

Sex differences in blood pressure and the prevalence of hypertension are found in humans and animal models. Moreover, there has been a recent explosion of data concerning sex differences in nitric oxide, the renin-angiotensin-aldosterone system, inflammation, and kidney function. These data have the potential to reveal the mechanisms underlying male-female differences in blood pressure control. To elucidate the interactions among the multitude of physiological processes involved, one may apply computational models. In this review, we describe published computational models that represent key players in blood pressure regulation, and highlight sex-specific models and their findings.

Submacular perfluorocarbon liquid: long-term follow-up

2020 ◽  
Vol 40 (5) ◽  
pp. 1209-1219 ◽  
Author(s):  
Hamouda Hamdy Ghoraba ◽  
Hashem Hamouda Ghoraba ◽  
Mohamed Amin Heikal ◽  
Sameh Mohamed Elgouhary ◽  
Hosam Othman Mansour ◽  
...  
Keyword(s):  
Perfluorocarbon Liquid ◽  
Long Term Follow Up

scholarly journals Implementation Intentions to Reduce Smoking: A Systematic Review of the Literature

2020 ◽  
Author(s):  
Charlotte J Hagerman ◽  
Rebecca K Hoffman ◽  
Sruthi Vaylay ◽  
Tonya Dodge
Keyword(s):  
Systematic Review ◽  
Implementation Intentions ◽  
Experimental Studies ◽  
Implementation Intention ◽  
Promising Tool ◽  
Current Systematic Review ◽  
Long Term Follow Up ◽  
Positive Effect

Abstract Implementation intentions are a goal-setting technique in which an individual commits to perform a particular behavior when a specific context arises. Recently, researchers have begun studying how implementation intention (II) interventions can facilitate antismoking efforts. The current systematic review synthesized results of experimental studies that tested the effect of an II intervention on smoking cognitions and behavior. Of 29 reviewed articles, 11 studies met inclusion criteria. Nine studies (81.8%) tested an II intervention as a cessation tool for current smokers, whereas two tested II interventions as a tool to prevent smoking among predominantly nonsmoking adolescents. A majority of the studies (66.7%) testing II interventions as a cessation tool reported a positive effect on cessation at long-term follow-up. Of the two studies testing II interventions as a tool for prevention, one study found a positive effect on long-term follow-up. Methodology varied between the studies, highlighting the discrepancies between what researchers consider “implementation intentions” to be. II interventions are a promising tool for antismoking efforts, but more research is necessary to determine the best methodology and the populations for whom this intervention will be most effective. Implications Brief, free, and easily scalable, II interventions to prevent smoking are highly attractive for antismoking efforts. This review outlines the circumstances under which II interventions have demonstrated effectiveness in helping people resist smoking cigarettes. We illuminate gaps in the existing literature, limitations, methodological discrepancies between studies, and areas for future study.

Manipulating Environmental Commitment: A Replication and Extension

2021 ◽  
pp. 003329412110126
Author(s):  
Eric D. Wesselmann ◽  
Shane W. Boyd ◽  
Jordan A. Arellanes ◽  
Alexander Driskell ◽  
Matthew S. Hesson-McInnis
Keyword(s):  
Natural Environment ◽  
Behavioral Intentions ◽  
Subjective Experience ◽  
Experimental Studies ◽  
Environmental Commitment

Environmental commitment, the subjective experience of dependence on the natural environment, is marked by a long-term orientation and psychological attachment towards the natural environment. The current research replicates and extends previous research on temporarily increasing environmental commitment ( Davis et al., 2009 ). We employed Davis et al.’s manipulation in two experimental studies (one laboratory, one online): we asked participants to spend time writing either about ways in which they are interdependent with the natural environment (high commitment manipulation) or unconnected with the environment (low commitment manipulation). In both studies we replicated the key finding that reflecting on one’s interdependence with the environment increases commitment. We extended the previous research by finding evidence that this commitment effect was mediated by satisfaction with one’s relationship to the environment. We did not replicate the original findings that the interdependence manipulation influences environmental behavioral intentions.

Advertising in disguise? How disclosure and content features influence the effects of native advertising

2020 ◽  
Vol 45 (3) ◽  
pp. 303-324
Author(s):  
Johannes Beckert ◽  
Thomas Koch ◽  
Benno Viererbl ◽  
Nora Denner ◽  
Christina Peter
Keyword(s):  
Experimental Studies ◽  
Brand Attitudes ◽  
News Websites ◽  
Short And Long Term ◽  
Message Sidedness ◽  
Over Time

AbstractNative advertising has recently become a prominent buzzword for advertisers and publishers alike. It describes advertising formats which closely adapt their form and style to the editorial environment they appear in, intending to hide the commercial character of these ads. In two experimental studies, we test how advertising disclosures in native ads on news websites affect recipients’ attitudes towards a promoted brand in a short and long-term perspective. In addition, we explore persuasion through certain content features (i. e., message sidedness and use of exemplars) and how they affect disclosure effects. Results show that disclosures increase perceived persuasive intent but do not necessarily decrease brand attitudes. However, disclosure effects do not persist over time and remain unaffected by content features.

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