721 research outputs found
The Reproducibility of Lists of Differentially Expressed Genes in Microarray Studies
Reproducibility is a fundamental requirement in scientific experiments and clinical contexts. Recent publications raise concerns about the reliability of microarray technology because of the apparent lack of agreement between lists of differentially expressed genes (DEGs). In this study we demonstrate that (1) such discordance may stem from ranking and selecting DEGs solely by statistical significance (P) derived from widely used simple t-tests; (2) when fold change (FC) is used as the ranking criterion, the lists become much more reproducible, especially when fewer genes are selected; and (3) the instability of short DEG lists based on P cutoffs is an expected mathematical consequence of the high variability of the t-values. We recommend the use of FC ranking plus a non-stringent P cutoff as a baseline practice in order to generate more reproducible DEG lists. The FC criterion enhances reproducibility while the P criterion balances sensitivity and specificity
Sleep disturbance in patients with cirrhosis and transjugular intrahepatic portosystemic shunt
Background: Sleep disturbance (SD) is a common occurrence in individuals with cirrhosis and significantly impacts their quality of life. Datas regarding post transjugular intrahepatic portosystemic shunt (TIPS) SD are scarce. This study aimed to explore the incidence and outcomes of post-TIPS SD. Methods: From August 2018 to November 2019, 73 patients who underwent TIPS were prospectively recruited for the study. Sleep quality was evaluated via the Pittsburgh Sleep Quality Index (PSQI), and the presence of hepatic encephalopathy was evaluated according to the West Haven criteria before and after the TIPS procedure. Results: Nineteen patients (26%) experienced new-onset SD after TIPS, with a median latency of 67 (40–98) days from the procedure. The median time from TIPS creation to occurrence was 67 (40–98) days. Minimal hepatic encephalopathy (MHE) post-TIPS emerged as an independent predictor of SD, with an odds ratio of 3 (95% CI: 1.04–8.78, P = 0.046). Notably, five of the six (83%) patients with SD experienced improvement after being administered eszopiclone. Ten of the thirteen (77%) patients with SD improved spontaneously without treatment. Furthermore, the prevalence of MHE was significantly greater among patients with SD than among those without SD (58% vs. 31%, P = 0.04). Conclusions: SD is prevalent in patients who undergo TIPS. MHE is an independent risk factor for the development of SD post-TIPS. Eszopiclone may be a safe and effective treatment option for patients with SD after TIPS. The study was registered with ClinicalTrials.gov under the identifier NCT03685994, with a registration date of September 23, 2018
A multi-scale image watermarking based on integer wavelet transform and singular value decomposition
Image watermarking technique is one of effective solutions to protect copyright, and it is applied to a variety of information security application domains. It needs to meet four requirements of imperceptibility, robustness, capacity and security. A multi-scale and secure image watermarking method is proposed in this work, which is based on the Integer Wavelet Transform (IWT) and Singular Value Decomposition (SVD). Four IWT sub-bands are firstly obtained after 1-level IWT on the host image, and the corresponding singular diagonal matrices of four sub-bands can be obtained using SVD. Then, each singular diagonal matrix is divided into four non-overlapping sections in terms of the size of embedding watermark. Particularly, the size of upper left part is same as the size of watermark. The watermark can be directly embedded into four upper left parts afterwards by multiplying different scaling factors to complete the final watermarking operation. Especially, a novel optimized authentication mechanism is designed to resolve the false positive problem, which exists in the SVD-based watermarking algorithms. In addition, three-dimensional optimal mapping algorithm is proposed to search the optimal scaling factors through a novel objective evaluation function, and it can significantly improve the imperceptibility and robustness. The experimental test and comparison analysis illustrate that the proposed watermark scheme demonstrates a high imperceptibility with peak signal to noise ratio values of 45dB and strong robustness with average normalized correlation values of 0.92
E-waste polycyclic aromatic hydrocarbon (PAH) exposure leads to child gut-mucosal inflammation and adaptive immune response
Polycyclic aromatic hydrocarbon (PAH) exposure alters immunological responses. Research concerning PAH exposure on intestinal immunity of children in electronic waste (e-waste) areas is scarce. The aim of this study was to evaluate the effects of polycyclic aromatic hydrocarbon (PAH) pollutants on intestinal mucosal immunity of children in e-waste areas. Results showed higher hydroxylated PAH (OH-PAH) concentrations in e-waste-exposed children, accompanied with higher sialyl Lewis A (SLA) level, absolute lymphocyte and monocyte counts, decreased of percentage of CD4(+) T cells, and had a higher risk of diarrhea. OH-PAH concentrations were negative with child growth. 1-OHNap mediated through WBCs, along with 1-OHPyr, was correlated with an increase SLA concentration. 2-OHFlu, 1-OHPhe, 2-OHPhe, 1-OHPyr, and 6-OHChr were positively correlated with secretory immunoglobulin A (sIgA) concentration. Our results indicated that PAH pollutants caused inflammation, affected the intestinal epithelium, and led to transformation of microfold cell (M cell). M cells initiating mucosal immune responses and the subsequent increasing sIgA production might be an adaptive immune respond of children in the e-waste areas. To our knowledge, this is the first study of PAH exposure on children intestinal immunity in e-waste area, showing that PAH exposure plays a negative role in child growth and impairs the intestinal immune function
Flow distribution and mixing performance of a novel multichannel heat exchanger reactor
Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.A multi-functional heat exchanger reactor (HEX) with 16 mini channels in parallel is designed, fabricated and tested. Two fluids are divided into 16 channels through distributor, then contacted at T-mixers, and finally collected. Both distributor and collector are designed following the arborescent shape. Expected advantage of using this mini HEX reactor include but not confined to: compact size, effective and fast mixing, low pressure drop, efficient and controlled heat remove/supply, easy numbering-up potential, safety, etc.
The internal fluid body is numerically analyzed using CFD approach (ANSYS Fluent) to test the flow distribution uniformity. Results show that for Reynolds number ranging from 8 to 95, good distribution uniformity (maldistribution less than 1.5 %) can be obtained. To test the mixing performance of the mini HEX reactor, Iodide-iodine reaction (Villermaux-Dushman) has been carried out. Experimental results show a good mixing at molecule scale as the flow rate increases and impingement enhanced. The design of multichannel reactor with arborescent distributing and collecting networks makes possible the numbering-up of multiple channels and thus the application of mini reactor in industry.dc201
ECM-IBS:A Chebyshev map-based broadcast authentication for Wireless Sensor Network
As a basic and crucial security requirement in Wireless Sensor Networks (WSNs), authentication is generally used to prevent various communication attacks such as Denial-of-Service (DoS) attack. A novel broadcast authentication framework is proposed in this paper, where an Identity-Based Signature schemes by using the Extended Chaotic Maps (ECM-IBS) is designed to authenticate all broadcast messages and specifically, a chaos-based hash function is used for message authentication in the WSNs. It is implemented using a WSN hardware device of CC2530 and its performance is analyzed under various methods. Performance analysis and experimental results show that the proposed ECM-IBS scheme has a quick signature generation speed, low energy consumption and short verification delay, and can be applied to WSN applications
Synergistic Effects of BMP-2 and VEGF with Calcined Bovine Bone for Alveolar Ridge Preservation: A Randomized Controlled Clinical Trial
Background: Alveolar ridge remodeling following tooth extraction can result in significant dimensional loss, compromising future implant placement. While calcined bovine bone (CBB) has shown promise in socket preservation, the synergistic effects of combining CBB with bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) remain inadequately studied.
Objective: To evaluate the clinical efficacy of different growth factor combinations with CBB for alveolar ridge preservation following tooth extraction through a randomized controlled trial.
Methods: Eighty patients requiring molar or premolar extraction were randomly allocated into four groups (n=20 each): control (no treatment), CBB alone, CBB+BMP-2, and CBB+BMP-2+VEGF. Primary outcomes included alveolar ridge dimensional changes assessed by cone-beam computed tomography at baseline and 3 months post-extraction. Secondary outcomes encompassed soft tissue healing evaluation using the Landry Wound Healing Index, pain assessment via Visual Analog Scale, and patient satisfaction scores. Bone density was evaluated through grayscale analysis of CBCT images.
Results: All groups showed comparable baseline characteristics. At 3 months, the CBB+BMP-2+VEGF group demonstrated superior ridge preservation with minimal buccal height loss (0.25±0.03 mm vs. 2.33±0.24 mm in controls, p<0.01) and optimal width preservation across all measurement levels. Hounsfield unit values increased most significantly in the combination group (1093.94±42.63 HU increase vs. 526.87±93.50 HU in controls, p<0.01). The CBB+BMP-2+VEGF group achieved significantly lower pain scores throughout the observation period, enhanced soft tissue healing scores, and higher patient satisfaction ratings (9.2±0.6 vs. 7.5±1.1 in controls, p<0.05).
Conclusions: The combination of CBB with BMP-2 and VEGF provides superior alveolar ridge preservation compared to conventional approaches, demonstrating enhanced dimensional stability, accelerated healing, and improved patient-reported outcomes. These findings support the clinical implementation of growth factor-enhanced socket preservation protocols for optimal implant site development
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