26 research outputs found

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    A new geometric modelling approach for 3D braided tubular composites base on Free Form Deformation

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    The micro-geometry of three-dimensional (3D) braided tubular preform is more complex than that of rectangular one, especially for the interfaces between yarns. The yarn interfaces are difficult to analyze theoretically, and if two sides of the interfaces do not fit perfectly in the model, the final result will contain overlapped yarns, which is bad for finite element calculation. This paper focuses on the microstructure of 3D four-directional braided tubular composites and presents a modelling approach based on Free Form Deformation (FFD) theory. First, the planar and spatial yarn paths are analyzed and three geometrical mapping equations from rectangular unit-cell to tubular sub unit-cell are derived. The modelling approach was then developed to establish the sub unit-cell model. Finally, the established models are compared with micro computed tomography (Ό-CT) scans of a dry specimen of the circular braided preform. The model not only solves the yarn-overlapping problem, but also accurately describes the key characteristics of the preform

    Multiscale Entropy Analysis of Surface Electromyographic Signals from the Urethral Sphincter as a Prognostic Indicator for Surgical Candidates with Primary Bladder Neck Obstruction

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    To explore information hidden in the electromyographic (EMG) signals of the urethral sphincter that may be of prognostic significance for patients with primary bladder neck obstruction (PBNO), 41 patients with voiding difficulty were divided into four groups: 1) patients with primary bladder neck obstruction (PBNO) with successful (Group 1, n = 14) and 2) unsuccessful (Group 2, n = 8) surgical outcomes, 3) patients with detrusor overactivity (Group 3, n = 7), and 4) patients with detrusor-external sphincter dyssynergia (Group 4, n = 12). All patients underwent baseline urodynamic studies (preoperative for Group 1 and Group 2) for comparison. The results demonstrated that, despite no significant difference in urodynamic parameters between Group 1 and Group 2, the large-scale multiscale entropy (MSE) of preoperative EMG (i.e., MSELS(EMG)) of Group 1 was significantly higher than that of Group 2 without notable difference between Group 1 and Group 3 (i.e., patients with normal sphincter function). Moreover, the MSELS(EMG) and small-scale MSE of preoperative EMG (i.e., MSESS(EMG)) of Group 2 were notably higher than those of Group 4 (i.e., patients with abnormal sphincter function), while both MSELS(EMG) and MSESS(EMG) of Group 3 were notably higher than those of Group 2. In conclusion, using MSE analysis for assessing preoperative urethral sphincter EMG signals successfully distinguished between PBNO patients with subsequent successful surgery from those with surgical failure possibly due to subtle functional impairment of the urethral sphincter that cannot be detected by routine urodynamic studies. The results, therefore, highlight the potential clinical significance of this analytical tool in guiding urologists regarding their choice of medical versus surgical treatment for this patient population

    IÎșBα Promoter Polymorphisms in Patients with Behçet’s Disease

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    To investigate the role of IÎșBα promoter polymorphisms in the development of Behçet’s disease, eighty-six patients with Behçet's disease and 120 healthy controls were enrolled in this study. The IÎșBα; -881A/G, -826C/T, -550A/T, -519C/T, and -297C/T polymorphisms were measured by the method of polymerase chain reaction/ restriction fragment length polymorphism. This study demonstrated that the genotype frequencies of IÎșBα -826C/T and -826T/T were significantly higher in the patients with Behçet's disease than in the controls. Both in the dominant and in the recessive models, the patients with Behçet's disease have higher frequencies of the IÎșBα -826T containing genotype than the controls. The allele frequency of IÎșBα -826T was significantly increased in the patients with Behçet’s disease. The frequencies of the IÎșBα -881A -826T -550A -519C -297C and IÎșBα -881A -826T -550A -519T -297C haplotypes were significantly higher in the patients with Behçet–s disease than in the controls. In contrast, the haplotype frequency of IÎșBα -881A -826C -550A -519C -297C in the patients with Behçet’s disease was significantly decreased. This study also revealed that the Behçet’s disease patients with IÎșBα -826T/T have higher prevalence of skin lesions than those without IÎșBα -826T/T. In summary, the IÎșBα -826T allele, IÎșBα -881A -826T -550A -519C -297C and IÎșBα -881A -826T -550A -519T -297C haplotypes might be associated with susceptibility to Behçet’s disease. The IÎșBα -826T/T genotype was related to the development of skin lesions in the patients with Behçet's disease

    Mouse strain specificity of DAAO inhibitors‐mediated antinociception

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    Abstract D‐Amino acid oxidase (DAAO) specifically catalyzes the oxidative deamination of neutral and polar D‐amino acids and finally yields byproducts of hydrogen peroxide. Our previous work demonstrated that the spinal astroglial DAAO/hydrogen peroxide (H2O2) pathway was involved in the process of pain and morphine antinociceptive tolerance. This study aimed to report mouse strain specificity of DAAO inhibitors on antinociception and explore its possible mechanism. DAAO inhibitors benzoic acid, CBIO, and SUN significantly inhibited formalin‐induced tonic pain in Balb/c and Swiss mice, but had no antinociceptive effect in C57 mice. In contrast, morphine and gabapentin inhibited formalin‐induced tonic pain by the same degrees among Swiss, Balb/c and C57 mice. Therefore, mouse strain difference in antinociceptive effects was DAAO inhibitors specific. In addition, intrathecal injection of D‐serine greatly increased spinal H2O2 levels by 80.0% and 56.9% in Swiss and Balb/c mice respectively, but reduced spinal H2O2 levels by 29.0% in C57 mice. However, there was no remarkable difference in spinal DAAO activities among Swiss, Balb/c and C57 mice. The spinal expression of glutathione (GSH) and glutathione peroxidase (GPx) activity in C57 mice were significantly higher than Swiss and Balb/c mice. Furthermore, the specific GPx inhibitor D‐penicillamine distinctly restored SUN antinociception in C57 mice. Our results reported that DAAO inhibitors produced antinociception in a strain‐dependent manner in mice and the strain specificity might be associated with the difference in spinal GSH and GPx activity

    Methylation of <i>TET2</i> Promoter Is Associated with Global Hypomethylation and Hypohydroxymethylation in Peripheral Blood Mononuclear Cells of Systemic Lupus Erythematosus Patients

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    (1) Background: It is widely accepted that aberrant methylation patterns contribute to the development of systemic lupus erythematosus (SLE). Ten–eleven translocation (TET) methylcytosine dioxygenase is an essential enzyme of which there are three members, TET1, 2, and 3, involved in hydroxymethylation, a newly uncovered mechanism of active DNA methylation. The epigenomes of gene transcription are regulated by 5-hydroxymethylcytocine (5-hmC) and TETs, leading to dysregulation of the immune system in SLE. The purpose of this study was to investigate the global hydroxymethylation status in SLE peripheral blood mononuclear cells (PBMCs) and to explore the role of TETs in changing the patterns of methylation. (2) Methods: We collected PBMCs from 101 SLE patients and 100 healthy donors. TaqMan real-time polymerase chain-reaction assay was performed for the detection of 5-methylcytosine (5-mC), 5-hmC, and TET2 mRNA expression and single-nucleotide polymorphism genotyping. The methylation rates in different CpG sites of TET2 promoters were examined using next-generation sequencing-based deep bisulfite sequencing. Putative transcription factors were investigated using the UCSC Genome Browser on the Human Dec. 2013 (GRCh38/hg38) Assembly. (3) Results: 5-mC and 5-hmC were both decreased in SLE. The mRNA expression level of TET2 was notably high and found to be correlated with the levels of immunologic biomarkers that are indicative of SLE disease activity. The analysis of methylation rates in the TET2 promoter revealed that SLE patients had significantly higher and lower rates of methylation in TET2 105146072-154 and TET2 105146218-331, respectively. (4) Conclusions: TET2 may play an important role in 5-mC/5-hmC dynamics in the PBMCs of SLE patients. The epigenetic modification of TET2 promoters could contribute to the pathogenesis of SLE and the intensity of the immunologic reaction

    Statin's role on blood pressure levels: Meta‐analysis based on randomized controlled trials

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    Abstract Statins have been proven to be effective in minimizing the risk of cardiovascular adverse events, however, their effect on BP variability is debatable with respect to their significance and their use as a potential anti‐hypertensive. Using a meta‐analysis approach, the aim of this study was to explore whether certain statins have the potential to lower blood pressure (BP). For the period 2002–2022, Scopus, PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials databases were searched for the studies that examined the effect of statins on blood pressure in normotensive or hypertensive individuals. Randomized controlled clinical trials that investigated this effect were included based on our inclusion criteria. Our primary outcomes were changes in systolic and diastolic blood pressure (DBP). The final analysis of the study included 49 RCTs involving 45 173 participants randomized to receive either statins or placebo. Among the two groups, the total weighted mean difference (WMD) for systolic blood pressure (ΔSBP) was –1.42 (95% CI: –2.38, –0.46; p = .004) and diastolic blood pressure (ΔDBP) was 0.82 (95% CI: –1.28, –0.36; p = .0005). Despite various studies suggesting the efficacy of statins in blood pressure lowering to be significant and non‐significant both, we observed a decrease in SBP and DBP both, although the change was not as large and could be considered significant. A large multicenter, multi‐ethnic, large sample pool size, and a long period follow‐up study is still required to assert these claims
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