A comparative evaluation of properties of zirconia reinforced high impact acrylic resin with that of high impact acrylic resin

AbstractStatement of the problemPoly methyl methacrylate (PMMA) acrylic resin, although being the most popular denture base material, is associated with poor mechanical properties. It has been documented that acrylic resin can be strengthened with an addition of structural component (filler) added in the acrylic matrix, to form a composite structure.ObjectiveTo evaluate and compare the transverse strength, impact strength, surface hardness and water sorption of 10% and 20% zirconia (ZrO2) reinforced high impact acrylic resin with that of high impact acrylic resin (Trevalon HI, Dentsply India).Materials and methodsThere were 30 specimens in each of the four tests, amounting to a total of 120 specimens. Each of the tests had 10 specimens fabricated from high impact acrylic resin (control); 10 specimens fabricated from 10% zirconia (ZrO2) and 10 specimens fabricated from 20% zirconia (ZrO2) reinforced high impact acrylic resin. Specimens were subjected to the test of transverse strength in Universal Testing Machine, impact strength in Izod pendulum impact testing machine and surface hardness by Vickers Microhardness tester according to ISO Specification No. 1567. Water sorption was assessed according to ADA Specification No. 12. Data were analyzed by means of a one-way ANOVA and Bonferroni multiple comparison test.ResultsA significant increase in the transverse strength was observed in the reinforced specimens when compared to the control group. Impact strength and surface hardness were found having lesser values compared to the control group. Water sorption was found to increase on the addition of 10% and 20% zirconia (ZrO2) but the value lied below 0.8mg/cm2 i.e. within the limit of ADA Specification No. 12.ConclusionReinforcement of acrylic resin with zirconia powder affects its physical and mechanical properties significantly

Microplegia in cardiac surgery: Systematic review and meta-analysis.

BACKGROUND: Consensus on the optimum choice of cardioplegia remains elusive. One possibility that has been suggested to have beneficial properties is microplegia, a cardioplegia of reduced crystalloid volume. The aim of this meta-analysis is to comprehensively investigate microplegia against a range of clinical outcomes. METHODS: To identify potential studies, systematic searches were carried out in four databases (eg, Pubmed, EMBASE). The search strategy included the key concepts of "microplegia" OR "mini-cardioplegia" OR "miniplegia" AND "cardiac surgery." This was followed by a meta-analysis investigating: mortality, crystalloid volume; cardiopulmonary bypass time; cross-clamp time; intra-aortic balloon pump use; spontaneous heartbeat recovery; inotropic support; low cardiac output syndrome; myocardial infarction; acute renal failure; atrial fibrillation, reoperation for bleeding; creatine kinase myocardial band (CK-MB); intensive care unit (ICU) time and hospital stay. RESULTS: Eleven studies comprising 5798 participants were analyzed. Microplegia used a lower volume of crystalloids and led to a higher spontaneous return of heartbeat, odds ratio (OR) 4.271 (95% confidence intervals [CIs]: 1.935, 9.423; I2  = 76.57%; P < .001) and a lower requirement for inotropic support, OR: 0.665 (95% CI: 0.47, 0.941; I2  = 3.53%; P = .021). Microplegia was also associated with a lower CK-MB release, mean difference (MD) -6.448 ng/mL (95% CI: -9.386, -3.511; I2  = 0%; P < .001) and a shorter ICU stay, MD: -0.411 days (95% CI: -0.812, -0.009; I2  = 17.65%; P = .045). All other comparisons were nonsignificant. CONCLUSIONS: Microplegia has similar effects to other types of cardioplegia and is beneficial with regard to spontaneous return of heartbeat, inotropic support, ICU stay, and CK-MB release

PSInSAR Study of Lyngenfjord Norway, using TerraSAR-X Data

In this research paper, focus is given on exploring the potential of Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) technique for the measurement of landslide, which is the extension of existing DInSAR technique. In PSInSAR technique, the movement is measured by finding the phase shift in the scatterers present in the study area through the course of time. The backscattering of such a scatterer does not change during the study. By using this technique, 32 datasets acquired over a period of time i.e. from 2009 to 2011 over the area of Troms County of Lyngen Fjord, Norway are analysed. The dataset utilised are acquired with TerraSAR-X and TanDEM-X pair, in Stripmap mode of acquisition. Coregistration of dataset with subpixel accuracy is done with master images is done to align all the dataset correctly. APS estimation is done in order to remove the phase decorrelation caused by the atmosphere, movement, etc. using algorithms for phase unwrapping which allowed the processing of sparse data and the effect of atmosphere is reduced by doing analysis on temporal basis of the phase shift in interferograms of successive datasets. By this study it has been tried to show the estimation of shift can be done by the temporal analysis of the data acquired by TerraSAR-X. The velocity output is displayed in a map reflecting the velocity of movement. Apart from this, the data properties such as baseline distribution both temporal and spatial are displayed in a chart. Other outputs obtained are the atmospheric Phase Screen, sparse point distribution, reflectivity map of the study area etc. are displayed using a map of terrain. The output velocity obtained of the terrain movement is found to be in the range of &minus;40&thinsp;mm/yr to &minus;70&thinsp;mm/yr

Atrial fibrillation in Middle Eastern Arabs and South Asians: a scoping review

Most of the published literature on Atrial fibrillation (AF) originates from the northern hemisphere and mainly involves Caucasian patients, with limited studies in certain ethnicities and races. This scoping review was conducted to collect and summarize the pertinent evidence from the published scientific literature on AF in South Asians and Middle Eastern Arabs. MEDLINE, Embase and CENTRAL databases were included in our search. After screening 8995 records, 55 studies were selected; 42 from the Middle East and 13 from South Asia. Characteristics of the included studies were tabulated, and their data were summarized for study design, setting, enrolment period, sample size, demographics, prevalence or incidence of AF, comorbidities, risk factors, AF types and symptoms, management, outcomes, and risk determinants. Identified literature gaps included a paucity of community or population-based studies that are representative of these two ethnicities/races. In addition, studies that addressed ethnic/racial in-equality and access to treatment were lacking. Our study underscores the urgent need to study cardiovascular disorders, particularly AF, in South Asians and Middle Eastern Arabs as well as in other less represented ethnicities and races

Midterm Clinical Outcomes of Reimplantation Versus Remodeling Valve-Sparing Aortic Root Replacement in Patients With Connective Tissue Disorders: A Meta-Analysis

This meta-analysis aimed to compare the midterm clinical outcomes of reimplantation versus remodeling techniques for valve-sparing aortic root replacement (VSARR) in patients with connective tissue disorders (CTDs). Studies were screened and identified after the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines from the PubMed, Web of Science, and Embase databases. Forest plots were produced using Review Manager 5.3 (Cochrane, UK). Studies comparing early and midterm clinical outcomes of reimplantation versus remodeling VSARR in patients with CTD with a mean age ≥18 years were included. The sensitivity analysis excluded studies and subgroups of patients that received ring or suture annuloplasty in addition to remodeling surgery. The study selection identified 9 eligible studies. After analysis of the study period and location for patient crossover, 7 retrospective studies consisting of 597 patients (301 reimplantation and 296 remodeling) were pooled. The pooling revealed no significant difference in postoperative mortality (estimated mean follow-up of 10.5 years) (odds ratio [OR] 0.66, 95% confidence interval [CI] 0.30 to 1.48, I2 = 30%, p = 0.32), reoperation (OR 0.35, CI 0.04 to 3.30, I2 = 81%, p = 0.36), or occurrence of postoperative aortic regurgitation of ≥2 (OR 0.56, CI 0.31 to 1.02, I2 = 47%, p = 0.06). The sensitivity analysis excluding annuloplasty demonstrated improved mortality (OR 0.19, CI 0.06 to 0.64, I2 = 0%, p = 0.007) and decreased aortic regurgitation of ≥2 (OR 0.23, CI 0.10 to 0.53, I2 = 47%, p = 0.0005) in reimplantation VSARR. The rates of reoperation remained insignificant in the sensitivity analysis (OR 0.43, CI 0.05 to 3.53, I2 = 71%, p = 0.43). In conclusion, this meta-analysis has demonstrated no significant difference in the midterm clinical outcomes of reimplantation versus remodeling techniques of VSARR. The sensitivity analysis excluding studies and patient subgroups that received remodeling and annuloplasty suggests remodeling alone to be inferior to reimplantation in patients with CTDs. Further research is required to assess remodeling and annuloplasty against reimplantation in patients of this demographic because the current body of knowledge does not allow sufficient analysis

Impact of aprotinin and renal function on mortality: a retrospective single center analysis

<p>Abstract</p> <p>Background</p> <p>An estimated up to 7% of high-risk cardiac surgery patients return to the operating room for bleeding. Aprotinin was used extensively as an antifibrinolytic agent in cardiac surgery patients for over 15 years and it showed efficacy in reducing bleeding. Aprotinin was removed from the market by the U.S. Food and Drug Administration after a large prospective, randomized clinical trial documented an increased mortality risk associated with the drug. Further debate arose when a meta-analysis of 211 randomized controlled trials showed no risk of renal failure or death associated with aprotinin. However, only patients with normal kidney function have been studied.</p> <p>Methods</p> <p>In this study, we look at a single center clinical trial using patients with varying degrees of baseline kidney function to answer the question: Does aprotinin increase odds of death given varying levels of preoperative kidney dysfunction?</p> <p>Results</p> <p>Based on our model, aprotinin use was associated with a 3.8-fold increase in odds of death one year later compared to no aprotinin use with p-value = 0.0018, regardless of level of preoperative kidney dysfunction after adjusting for other perioperative variables.</p> <p>Conclusions</p> <p>Lessons learned from our experience using aprotinin in the perioperative setting as an antifibrinolytic during open cardiac surgery should guide us in testing future antifibrinolytic drugs for not only efficacy of preventing bleeding, but for overall safety to the whole organism using long-term clinical outcome studies, including those with varying degree of baseline kidney function.</p

Mitral valve surgery for mitral regurgitation caused by Libman-Sacks endocarditis: a report of four cases and a systematic review of the literature

Libman-Sacks endocarditis of the mitral valve was first described by Libman and Sacks in 1924. Currently, the sterile verrucous vegetative lesions seen in Libman-Sacks endocarditis are regarded as a cardiac manifestation of both systemic lupus erythematosus (SLE) and the antiphospholipid syndrome (APS). Although typically mild and asymptomatic, complications of Libman-Sacks endocarditis may include superimposed bacterial endocarditis, thromboembolic events, and severe valvular regurgitation and/or stenosis requiring surgery. In this study we report two cases of mitral valve repair and two cases of mitral valve replacement for mitral regurgitation (MR) caused by Libman-Sacks endocarditis. In addition, we provide a systematic review of the English literature on mitral valve surgery for MR caused by Libman-Sacks endocarditis. This report shows that mitral valve repair is feasible and effective in young patients with relatively stable SLE and/or APS and only localized mitral valve abnormalities caused by Libman-Sacks endocarditis. Both clinical and echocardiographic follow-up after repair show excellent mid- and long-term results