65 research outputs found

    Predictors of Patient Satisfaction in Spine Surgery: A Systematic Review

    Get PDF
    Background: Recently, there has been increased interest in patient satisfaction measures such as Press Ganey and Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) surveys. In this systematic review, the spine surgery literature is analyzed to evaluate factors predictive of patient satisfaction as measured by these surveys. Methods: A thorough literature search was performed in PubMed/MEDLINE, Google Scholar, and Cochrane databases. All English-language articles from database inception to July 2020 were screened for study inclusion according to PRISMA guidelines. Results: Twenty-four of the 1899 published studies were included for qualitative analysis. There has been a statistically significant increase in the number of publications across years (P = 0.04). Overall, the studies evaluated the relationship between patient satisfaction and patient demographics (71%), preoperative and intraoperative clinical factors (21%), and postoperative factors (33%). Top positive predictors of patient satisfaction were patient and nursing/medical staff relationship (n = 4; 17%), physician–patient relationship (n = 4; 17%), managerial oversight of received care (n = 3; 13%), same sex/ethnicity between patient and physician (n = 2; 8%), and older age (n = 2; 8%). Top negative predictors of patient satisfaction were high Charlson Comorbidity Index/high disability/worse overall health functioning (n = 7; 29%), increased length of hospital stay (n = 4; 17%), high rating for pain/complications/readmissions (n = 4; 17%), and psychosocial factors (n = 3; 13%). Conclusions: There is heterogeneity in terms of different factors, both clinical and nonclinically related, that affect patient satisfaction ratings. More research is warranted to investigate the role of hospital consumer surveys in the spine surgical patient population

    Immunophenotypic subtyping of leukemic cells from Iranian patients with acute lymphoblastic leukaemia: Association to disease outcome

    Get PDF
    Background: Immunophenotypic characterization of the leukemic cells has been widely used as a tool for diagnosis, classification, stratification and prognosis of leukaemia. Objective: To investigate the immunophenotypic subtype profiles of Iranian patients with acute lymphoblastic leukemia (ALL) and its association to disease outcome. Methods: In this study, a total of 60 Iranian patients with ALL were immunophenotyped by flow cytometry using a panel of monoclonal antibodies specific for CD2, CD3, CD5, CD10, CD13, CD14, CD19, CD20, CD33, CD34, CD45, HLA-DR and TdT molecules. Results: The samples were initially categorized into T-ALL (n=9), B-ALL (n=50) and mixed lineage (n=1) based on the expression patterns of CD3 and CD19 molecules. B-ALL patients could further be classified into four subtypes, including Pro-B (n=7, 11.7), Pre-B I (n=28, 46.7), Pre-B II (n=13, 21.7) and immature/mature B cells (n=2, 3.3) on the basis of expression of CD10, CD19, CD20, HLA-DR and TdT. Clinical manifestations and laboratory findings of the patients did not reveal association with immunophenotypic subtypes of ALL, with the exception of mediastinal mass and WBC count at the time of diagnosis which were found to be significantly higher in patients with T-ALL compared with BALL (p=0.001 and 0.014), respectively. Conclusion: Our results indicate that overall the immunophenotypic profile of Iranian ALL patients is similar to previous reports and it might be used for monitoring of minimal residual disease and prognosis

    Heterozygous Mutation of Drosophila Opa1 Causes the Development of Multiple Organ Abnormalities in an Age-Dependent and Organ-Specific Manner

    Get PDF
    Optic Atrophy 1 (OPA1) is a ubiquitously expressed dynamin-like GTPase in the inner mitochondrial membrane. It plays important roles in mitochondrial fusion, apoptosis, reactive oxygen species (ROS) and ATP production. Mutations of OPA1 result in autosomal dominant optic atrophy (DOA). The molecular mechanisms by which link OPA1 mutations and DOA are not fully understood. Recently, we created a Drosophila model to study the pathogenesis of optic atrophy. Heterozygous mutation of Drosophila OPA1 (dOpa1) by P-element insertion results in no obvious morphological abnormalities, whereas homozygous mutation is embryonic lethal. In eye-specific somatic clones, homozygous mutation of dOpa1 causes rough (mispatterning) and glossy (decreased lens deposition) eye phenotypes in adult Drosophila. In humans, heterozygous mutations in OPA1 have been associated with mitochondrial dysfunction, which is predicted to affect multiple organs. In this study, we demonstrated that heterozygous dOpa1 mutation perturbs the visual function and an ERG profile of the Drosophila compound eye. We independently showed that antioxidants delayed the onset of mutant phenotypes in ERG and improved larval vision function in phototaxis assay. Furthermore, heterozygous dOpa1 mutation also caused decreased heart rate, increased heart arrhythmia, and poor tolerance to stress induced by electrical pacing. However, antioxidants had no effects on the dysfunctional heart of heterozygous dOpa1 mutants. Under stress, heterozygous dOpa1 mutations caused reduced escape response, suggesting abnormal function of the skeletal muscles. Our results suggest that heterozygous mutation of dOpa1 shows organ-specific pathogenesis and is associated with multiple organ abnormalities in an age-dependent and organ-specific manner

    Mitochondrial Changes in Ageing Caenorhabditis elegans – What Do We Learn from Superoxide Dismutase Knockouts?

    Get PDF
    One of the most popular damage accumulation theories of ageing is the mitochondrial free radical theory of ageing (mFRTA). The mFRTA proposes that ageing is due to the accumulation of unrepaired oxidative damage, in particular damage to mitochondrial DNA (mtDNA). Within the mFRTA, the “vicious cycle” theory further proposes that reactive oxygen species (ROS) promote mtDNA mutations, which then lead to a further increase in ROS production. Recently, data have been published on Caenorhabditis elegans mutants deficient in one or both forms of mitochondrial superoxide dismutase (SOD). Surprisingly, even double mutants, lacking both mitochondrial forms of SOD, show no reduction in lifespan. This has been interpreted as evidence against the mFRTA because it is assumed that these mutants suffer from significantly elevated oxidative damage to their mitochondria. Here, using a novel mtDNA damage assay in conjunction with related, well established damage and metabolic markers, we first investigate the age-dependent mitochondrial decline in a cohort of ageing wild-type nematodes, in particular testing the plausibility of the “vicious cycle” theory. We then apply the methods and insights gained from this investigation to a mutant strain for C. elegans that lacks both forms of mitochondrial SOD. While we show a clear age-dependent, linear increase in oxidative damage in WT nematodes, we find no evidence for autocatalytic damage amplification as proposed by the “vicious cycle” theory. Comparing the SOD mutants with wild-type animals, we further show that oxidative damage levels in the mtDNA of SOD mutants are not significantly different from those in wild-type animals, i.e. even the total loss of mitochondrial SOD did not significantly increase oxidative damage to mtDNA. Possible reasons for this unexpected result and some implications for the mFRTA are discussed

    Investigating the synergistic antioxidant effects of some flavonoid and phenolic compounds

    No full text
    Phenolic and flavonoid compounds are secondary metabolites of plants which possess various activities such as anti-inflammatory, analgesic, anti-diabetes and anticancer effects. It has been established that these compounds can scavenge free radicals produced in the body. Because of this ability, not only the plants containing phenolic and flavonoid compounds but also, the pure compounds are used in medicinal products for prevention and treatment of many disorders. Considering that the golden aim of the pharmaceutical industries is using the most effective compounds with lower concentrations, determination of the best combination of the compounds with synergistic effects is important. In the present study, synergistic antioxidant effects of four phenolic compounds including caffeic acid, gallic acid, rosmarinic acid, chlorogenic acid and two flavonoids,  rutin and quercetin, have been investigated by FRAP (Ferric Reducing Antioxidant Power) method. The synergistic effect was assessed by comparing the experimental antioxidant activity of the mixtures with calculated theoretical values and the interactions of the compounds were determined. The results showed that combination of gallic acid and caffeic acid demonstrated considerable synergistic effects (137.8%) while other combinations were less potent. Among examined substances, rutin was the only one which had no effect on the other compounds. The results of ternary combinations of compounds demonstrated antagonistic effects in some cases. This was more considerable in mixture of rutin, caffeic acid, rosmarinic acid (-21.8%), chlorogenic acid, caffeic acid, rosmarinic acid (-20%), rutin, rosmarinic acid, gallic acid (-18.5%) and rutin, chlorogenic acid, caffeic acid (-15.8%), while, combination of quercetin, gallic acid, caffeic acid (59.4%) and quercetin, gallic acid, rutin (55.2%) showed the most synergistic effects. It was concluded that binary and ternary combination of quercetin, rutin, caffeic acid, chlorogenic acid, gallic acid and rosmarinic acid could influence the antioxidant ability; therefore, to obtain the best antioxidant effects in products containing these materials, the interactions should be mentioned

    Indirect exchange interaction between magnetic impurities in a gapped graphene structure

    No full text
    We study exchange interaction between two magnetic impurities in doped gapped graphene (the Ruderman-Kittel-Kasuya-Yosida [RKKY]) interaction by directly computing Green’s function beyond Dirac approximation. Tight binding model Hamiltonian in the presence of magnetic long range ordering has been applied to describe electron dynamics. RKKY interaction as a function of distance between localized moments has been analyzed. It has been shown that a magnetic ordering along the z-axis mediates two different interactions for spin directions which corresponds to a XXZ model interaction between two magnetic moments. The exchange interaction along arbitrary direction between two magnetic moments, has been obtained using the static spin susceptibilities of gapped graphene structure. The effects of spin polarization on the the dependence of exchange interaction on distance between moments are investigated via calculating correlation function of spin density operators. Our results show the chemical potential impacts the spatial behavior of RKKY interaction. Moreover gap parameter effects on RKKY interaction have been investigated in details

    Laminar Heat Transfer in a Pipe Subjected to Circumferentially Varying External Heat Transfer Coefficients

    No full text
    Introduction Convective flow of fluid through saturated porous media heated from below is of considerable interest, and has been extensively studied. Most of these studies are concerned with either infinite horizontal porous layers or rectangular (or cylindrical) porous cavities with adiabatic vertical walls Elder Their results indicate that if the lower boundary is partially heated, the system is self-restricting, and either stabilizes into steady multicellular flow or regularizes into periodic oscillatory flow, depending on how much of the boundary is heated. However, oscillatory flow generally exists at high Rayleigh numbers. Later, they [6] also studied the effects of temperature-dependent viscosity and thermal expansion coefficient on temperature and flow fields. Although the preceding studies [3-6] report interesting features of free convection in porous media for localized heating from below, they are generally concerned with the flow structure and provide little information on heat transfer rates. To characterize the effects of heat source size and strength fully, as well as the vertical and horizontal extent of the porous layer and its boundary conditions, a series of studies is required for a wide range of parameters, namely dimensionless heated length H, aspect ratio A, and Rayleigh number Ra*. The purpose of the present work is to consider the effects of aspect ratio and Rayleigh number on free convection heat transfer from an isothermal heat source centrally located on the bottom surface of a horizontal porous cavity ( Formulation and Numerical Method Consider a fluid-saturated horizontal porous layer enclosed by adiabatic vertical walls. An isothermal heat source of length 2c? is centrally located on the bottom surface which is otherwise adiabatic Owing to the symmetry of the problem Finite-difference equations are derived from equations (1) and (2) by integration over finite area elements following a procedure developed by Spalding and co-workers In the present work, uniform mesh sizes are used in both x and y directions. The number of grids in the y direction is always taken as 31 whereas that in the x direction is varied between 31 and 61 depending on the aspect ratio. In general, the stream function ^i is underrelaxed and the temperature 0 is overrelaxed to obtain faster convergence. A convergence criterion of maximum 0.01 percent change in both ^ and 0 at all grid points in the domain is used to test the convergence of the iterative scheme. A detailed discussion on the numerical scheme is presented in Results and Discussion To study the effects of the size of the heat source and the extent of the horizontal layer on temperature and flow fields and heat transfer rates, two situations are examined in this study. First, the width of the horizontal layer D is varied from a low to high value for a fixed length of heated segment and a fixed height, i.e., H = 0.5. In the second part, the results are obtained for H = 0.2, 0.5, and 0.8, and A = 1. Temperature and Flow Fields. Flow patterns and temperature fields for some typical values of Ra*, A, and H are presented in At Ra* = 10, the velocity field is symmetric about the vertical axis at X = 0.5 In The above decrease in the domain of strong thermal activity results in complex heat transfer behavior. The heat transfer rate does not continually increase with an increase in the surface area for heat rejection. In the present case (H = 0.5, Ra* = 1000), the heat transfer rate is observed to be maximum for A -4, beyond which it starts decreasing. However, the aspect ratio for which it is largest is a strong function of H and Ra* (to be discussed later). Heat Transfer Results. The two most appropriate ways of considering the overall heat transfer are to obtain either (/) a Nusselt number for the heat source as or (ii) the Nusselt number based on the area of the upper surface The Nusselt number based on the area of the heated region Nu d is presented in The negative slope of ln(Nu rf )-versus-ln(>l) curve Numerical results of Caltagirone [11] for a fully heated bot

    Wireless ad-hoc networking : analysis and validation of simulation results

    No full text
    A wireless Ad-hoc network consists of wireless nodes communicating without the need for a centralized administration, in which all nodes potentially contribute to the routing process. In this paper the experimental results obtained from establishing a small physical network are reported. Using OPtimised NETwork (OPNET) software simulator, physical results are then compared with those obtained from simulations. Correlation between the two sets of results is found to be satisfactory enough to validate the simulation technique and process. Given this validation, similar simulation techniques are used to perform an investigation of a larger scale Ad-hoc. The simulation results of the larger scale network confirm our previously obtained results. An important aspect of which is that the nature of the drop in throughput with respect to the number of nodes trying to communicate simultaneously with a single node, is linear

    Wireless enabling technologies for the internet of things

    No full text
    This Chapter provides several comparable studies of some of the major evolving and enabling wireless technologies in the Internet of Things (IoT). Particularly, it focuses on the ZigBee, 6lowpan, Bluetooth Low Energy, LTE, and the different versions of Wi-Fi protocols including the IEEE 802.11ah. The studies, reported in this chapter, evaluate the capabilities and behaviors of these technologies in terms of various metrics including the data range and rate, network size, RF Channels and Bandwidth, Antenna design considerations, Power Consumption, and their Ecosystem. It is concluded that the requirements of each IoT application play a significant role in the selection of a suitable wireless technology. © 2016 by IGI Global. All rights reserved
    corecore