180 research outputs found
One-sample aggregate data meta-analysis of medians
An aggregate data meta-analysis is a statistical method that pools the
summary statistics of several selected studies to estimate the outcome of
interest. When considering a continuous outcome, typically each study must
report the same measure of the outcome variable and its spread (e.g., the
sample mean and its standard error). However, some studies may instead report
the median along with various measures of spread. Recently, the task of
incorporating medians in meta-analysis has been achieved by estimating the
sample mean and its standard error from each study that reports a median in
order to meta-analyze the means. In this paper, we propose two alternative
approaches to meta-analyze data that instead rely on medians. We systematically
compare these approaches via simulation study to each other and to methods that
transform the study-specific medians and spread into sample means and their
standard errors. We demonstrate that the proposed median-based approaches
perform better than the transformation-based approaches, especially when
applied to skewed data and data with high inter-study variance. In addition,
when meta-analyzing data that consists of medians, we show that the
median-based approaches perform considerably better than or comparably to the
best-case scenario for a transformation approach: conducting a meta-analysis
using the actual sample mean and standard error of the mean of each study.
Finally, we illustrate these approaches in a meta-analysis of patient delay in
tuberculosis diagnosis
Safety and diagnostic accuracy of percutaneous CT-guided transthoracic biopsy of small lung nodules (≤20 mm) adjacent to the pericardium or great vessels
PURPOSEWe aimed to evaluate the safety and diagnostic accuracy of computed tomography (CT)-guided transthoracic biopsy of small lung nodules (≤20 mm) adjacent to the pericardium or great vessels.METHODSThis retrospective study examined the safety and diagnostic accuracy of percutaneous CT-guided biopsy for small lung nodules (≤20 mm) located within 10 mm of the pericardium or great vessels. Technical aspects and factors influencing complications were assessed, and diagnostic accuracy was calculated.RESULTSA total of 168 biopsies were performed in 168 patients. The complications were mainly pneumothorax (34.5%; 58 of 168 patients), chest tube insertion (5.3%; 9 of 168 patients), and pulmonary hemorrhage (61.3%; 103 of 168 procedures), with no patient mortality. One patient (0.6%) was admitted because of hemorrhage complications. Significant independent risk factors for pneumothorax were nodules resided in upper or middle lobes and lateral patient position, and for hemorrhage, longer distance from structures and longer needle trajectory through the lung parenchyma. Overall, the sensitivity, accuracy, and specificity were 91.0%, 92.2%, and 100%, respectively.CONCLUSIONPercutaneous CT-guided transthoracic biopsy was highly accurate in small lung nodules (≤20 mm) adjacent to the pericardium or great vessels. Complications are common, but most were minor and self-limited
Comparative studies on the multi-component pharmacokinetics of Aristolochiae Fructus and honey-fried Aristolochiae Fructus extracts after oral administration in rats
PK parameters of 7-OH AA I in rats after oral administration of AF and HAF. (DOC 37Ă‚Â kb
Understanding Local Bonding Structures of Ni-Doped Chromium Nitride Coatings through Synchrotron Radiation NEXAFS Spectroscopy
CrN has widespread applications as protective coatings, for example, in aircraft jet engines whereby their high hardness and good oxidation resistance render metal components resistant to harsh operating conditions. Alloying elements are commonly incorporated (doped) into the coatings to further enhance their thermomechanical properties. However, the effect of dopants on the electronic properties and their roles in modifying the grain boundary configurations remain unclear. Lack of such critical knowledge has hindered the development of design strategies for high performance CrN-based coatings. To address this challenging issue, in the present study near-edge X-ray absorption fine structure (NEXAFS) investigations of Cr1-yNiyN coatings at the Cr L3,2-edge (570-610 eV), Ni L3,2-edge (840-890 eV), and N K-edge (380-450 eV) regions were conducted using synchrotron radiation soft X-ray (SXR) spectroscopy in both Auger electron yield (AEY) and total fluorescence yield (TFY) modes. The chemical states in CrNiN were found to change with the increase of Ni content, manifested as a small chemical shift and moderate change of shapes of various absorption edges. The CrN grain size also became smaller with increasing Ni concentration. These findings help improve our understanding of local bonding structures, which could potentially lead to improved coating designs for highly demanding applications
Single cell transcriptome profiling reveals cutaneous immune microenvironment remodeling by photodynamic therapy in photoaged skin
BackgroundThe immune microenvironment plays a critical role in maintaining skin homeostasis, which is closely related to the dysfunction in photoaged skin such as autoimmunity and tumorigenesis. Several recent studies have demonstrated the efficacy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in alleviating photoaging and skin cancer. However, the underlying immune mechanisms and the immune microenvironment change by ALA-PDT remain largely unknown.MethodsTo illustrate the effects of ALA-PDT on immune microenvironment in photoaged skin, single cell RNA sequencing (scRNA-seq) analysis of photoaged skin on the extensor side of the human forearm before and after ALA-PDT was performed. R-packages of Seurat, clusterProfiler, Monocle, CellChat were used for cell clustering, differentially expressed genes analysis, functional annotation, pseudotime analysis and cell-cell communication analysis. The gene sets related to specific functions were extracted from the MSigDB database, which were used to score the functions of immune cells in different states. We also compared our result with published scRNA-seq data of photoaged skin of the eyelids.ResultsThe increase score of cellular senescence, hypoxia and reactive oxygen species pathway in immune cells and the decrease of immune receptor activity function and proportion of naive T cells were found in skin photoaging. Moreover, the function of T cell ribosomal synthesis was also impaired or down regulated and function of G2M checkpoint was up regulated. However, ALA-PDT showed promising results in reversing these effects, as it improved the above functions of T cells. The ratio of M1/M2 and percentage of Langerhans cells also decreased with photoaging and increased after ALA-PDT. Additionally, ALA-PDT restored the antigen presentation and migration function of dendritic cells and enhanced cell-cell communication among immune cells. These effects were observed to last for 6 months.ConclusionALA-PDT has potential to rejuvenate immune cells, partially reversed immunosenescence and improved the immunosuppressive state, ultimately remodelling the immune microenvironment in photoaged skin. These results provide an important immunological basis for further exploring strategies to reverse skin photoaging, chronological aging and potentially systemic aging
IL-17A Synergizes with IFN-Îł to Upregulate iNOS and NO Production and Inhibit Chlamydial Growth
IFN-Îł-mediated inducible nitric oxide synthase (iNOS) expression is critical for controlling chlamydial infection through microbicidal nitric oxide (NO) production. Interleukin-17A (IL-17A), as a new proinflammatory cytokine, has been shown to play a protective role in host defense against Chlamydia muridarum (Cm) infection. To define the related mechanism, we investigated, in the present study, the effect of IL-17A on IFN-Îł induced iNOS expression and NO production during Cm infection in vitro and in vivo. Our data showed that IL-17A significantly enhanced IFN-Îł-induced iNOS expression and NO production and inhibited Cm growth in Cm-infected murine lung epithelial (TC-1) cells. The synergistic effect of IL-17A and IFN-Îł on Chlamydia clearance from TC-1 cells correlated with iNOS induction. Since one of the main antimicrobial mechanisms of activated macrophages is the release of NO, we also examined the inhibitory effect of IL-17A and IFN-Îł on Cm growth in peritoneal macrophages. IL-17A (10 ng/ml) synergizes with IFN-Îł (200 U/ml) in macrophages to inhibit Cm growth. This effect was largely reversed by aminoguanidine (AG), an iNOS inhibitor. Finally, neutralization of IL-17A in Cm infected mice resulted in reduced iNOS expression in the lung and higher Cm growth. Taken together, the results indicate that IL-17A and IFN-Îł play a synergistic role in inhibiting chlamydial lung infection, at least partially through enhancing iNOS expression and NO production in epithelial cells and macrophages
Recommended from our members
Photon Enhanced Thermionic Emission for Solar Energy Harvesting Final Report to the Global Climate and Energy Project
Potential of Core-Collapse Supernova Neutrino Detection at JUNO
JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve
Detection of the Diffuse Supernova Neutrino Background with JUNO
As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO
- …