28 research outputs found

    The Prevalence of Bacterial Infection in Patients Undergoing Elective ACDF for Degenerative Cervical Spine Conditions: A Prospective Cohort Study With Contaminant Control

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    Study Design: Prospective cohort study. Objectives: To determine the prevalence of bacterial infection, with the use of a contaminant control, in patients undergoing anterior cervical discectomy and fusion (ACDF). Methods: After institutional review board approval, patients undergoing elective ACDF were prospectively enrolled. Samples of the longus colli muscle and disc tissue were obtained. The tissue was then homogenized, gram stained, and cultured in both aerobic and anaerobic medium. Patients were classified into 4 groups depending on culture results. Demographic, preoperative, and postoperative factors were evaluated. Results: Ninety-six patients were enrolled, 41.7% were males with an average age of 54 ± 11 years and a body mass index of 29.7 ± 5.9 kg/m2. Seventeen patients (17.7%) were considered true positives, having a negative control and positive disc culture. Otherwise, no significant differences in culture positivity was found between groups of patients. However, our results show that patients were more likely to have both control and disc negative than being a true positive (odds ratio = 6.2, 95% confidence interval = 2.5-14.6). Propionibacterium acnes was the most commonly identified bacteria. Two patients with disc positive cultures returned to the operating room secondary to pseudarthrosis; however, age, body mass index, prior spine surgery or injection, postoperative infection, and reoperations were not associated with culture results. Conclusion: In our cohort, the prevalence of subclinical bacterial infection in patients undergoing ACDF was 17.7%. While our rates exclude patients with positive contaminant control, the possibility of contamination of disc cultures could not be entirely rejected. Overall, culture results did not have any influence on postoperative outcomes

    Optical and structural analysis of solar selective absorbing coatings based on AlSiOx:W cermets

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    It is reported in this work the development and study of the optical and structural properties of a solar selective absorber cermet based on AlSiOx:W. A four-layer composite film structure, W/AlSiOx:W(HA)/AlSiOx:W(LA)/AlSiOx, was deposited on stainless steel substrates using the magnetron sputtering deposition method. Numerical calculations were performed to simulate the spectral properties of multilayer stacks with varying metal volume fraction cermets and film thickness. The chemical analysis was performed using X-ray photoelectron spectroscopy and the results show that in the high metal volume fraction cermet layer, AlSiOx:W(HA), about one third of W atoms are in the W-O oxidation state, another third in the Wx+ oxidation state and the last third in the W4+, W5+ and W6+ oxidation states. The X-ray diffractograms of AlSiOx:W layers show a broad peak indicating that both, W and AlSiOx, are amorphous. These results indicate that this film structure has a good spectral selective property that is suitable for solar thermal applications, with the coatings exhibiting a solar absorptance of 94-95.5% and emissivities of 8-9% (at 100 degrees C) and 10-14% (at 400 degrees C). The samples were subjected to a thermal annealing at 450 degrees C, in air, and 580 degrees C, in vacuum and showed very good oxidation resistance and thermal stability. Morphological characterizations were carried out using scanning electron microscopy and atomic force microscopy. Rutherford Backscattering experiments were also performed to analyze the tungsten depth profile.The authors acknowledge the support of the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013. The authors are also grateful to the financial support of FCT, POCI and PORL operational programs through the project POCI-01-0145-FEDER-016907 (PTDC/CTM-ENE/2882/2014), co-financed by European community fund FEDER. The authors also acknowledge GIST Japan for using the XPS-Kratos.info:eu-repo/semantics/publishedVersio

    Allele-Independent Turnover of Human Leukocyte Antigen (HLA) Class Ia Molecules.

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    Major histocompatibility complex class I (MHCI) glycoproteins present cytosolic peptides to CD8+ T cells and regulate NK cell activity. Their heavy chains (HC) are expressed from up to three MHC gene loci (human leukocyte antigen [HLA]-A, -B, and -C in humans), whose extensive polymorphism maps predominantly to the antigen-binding groove, diversifying the bound peptide repertoire. Codominant expression of MHCI alleles is thus functionally critical, but how it is regulated is not fully understood. Here, we have examined the effect of polymorphism on the turnover rates of MHCI molecules in cell lines with functional MHCI peptide loading pathways and in monocyte-derived dendritic cells (MoDCs). Proteins were labeled biosynthetically with heavy water (2H2O), folded MHCI molecules immunoprecipitated, and tryptic digests analysed by mass spectrometry. MHCI-derived peptides were assigned to specific alleles and isotypes, and turnover rates quantified by 2H incorporation, after correcting for cell growth. MHCI turnover half-lives ranged from undetectable to a few hours, depending on cell type, activation state, donor, and MHCI isotype. However, in all settings, the turnover half-lives of alleles of the same isotype were similar. Thus, MHCI protein turnover rates appear to be allele-independent in normal human cells. We propose that this is an important feature enabling the normal function and codominant expression of MHCI alleles

    The Digital Divide: A Retrospective Survey of Digital Rectal Examinations during the Workup of Rectal Cancers

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    Background: Digital rectal examination (DRE) is considered an important part of the physical examination. However, it is unclear how many patients have a DRE performed at the primary care level in the work-up of rectal cancer, and if the absence of a DRE causes a delay to consultation with a specialist. Methods: A retrospective patient questionnaire was sent to 1000 consecutive patients with stage II or stage III rectal cancer. The questionnaire asked patients to recall if they had a DRE performed by their general practitioner (GP) when they first presented with symptoms or a positive FIT test. Demographic data, staging data, and time to consultation with a specialist were also collected. Results: A thousand surveys were mailed out, and a total of 262 patients responded. Of the respondents, 46.2% did not recall undergoing a digital rectal examination by their primary care provider. Women were less likely to undergo a DRE than men (28.6% vs. 44.3%, p = 0.019). While there was a trend towards longer times to specialist consultation in patients who did not undergo a DRE (27.0 vs. 12.2 weeks), this was not statistically significant (p = 0.121). Conclusion: A significant proportion of patients who are FIT positive or have symptomatic rectal bleeding do not recall having a DRE by their primary care provider. Barriers may include lack of comfort with performing DRE or lack of time. Clearer guidelines and more support for GP’s may increase uptake of DRE.Medicine, Faculty ofNon UBCSurgery, Department ofReviewedFacult

    Effects of Shariah-compliant business practices on long-term financial performance

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    We examine the long-term effects of Shariah-compliant business practices on the financial performance of the practicing firms. Shariah is the set of personal and societal behaviors derived from study of the Qur\u27an, the Islamic holy book. A firm is considered Shariah-compliant when it is part of a religiously approved industry sector and meets five quantitative screens. The first three screens measure each firm\u27s liquidity, the fourth examines each firm\u27s leverage, and the final screen, as part of the “purification process,” determines if the company\u27s reliance upon interest-based income is at an acceptable level. We use long-term event study methodology to examine the effects of compliance over five years. We develop and test two hypotheses to determine if Shariah-compliance enhances the long-term value of the firm. Using a large sample selected from 1990 to 2018, we find that Shariah-compliance positively affects long-term financial performance as evidenced by increased values in return on assets (ROA) and return on sales (ROS). However, the practice of Shariah-compliant investing offers mixed results for stock return performance. Our results show adherence to the five quantitative Shariah screening rules could be considered as a successful long-term managerial strategy, having positive implications even for firms not in Shariah-approved industry sectors
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