124 research outputs found

    A Novel Method of Multispectral Imagery Registration Based on Minor and Noise Component Criterion

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    AbstractFor multispectral imagery, spatial registration between bands is a very important part of the overall quality of the multispectral imagery product. In this paper, a multispectral imagery registration method is presented. It takes minor and noise component of sample covariance matrix as measure criterion, utilizes mutual information method to create registration seed sources, uses smooth filter to extend trapping width of registration curve. Experiments were conducted using multispectral imagery from the ETM Satellite. Control points optimal searching experiments show that the presented method can improve the efficiency and accuracy of multispectral imagery registration greatly

    CellBRF: A Feature Selection Method for Single-Cell Clustering Using Cell Balance and Random Forest

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    Motivation Single-cell RNA sequencing (scRNA-seq) offers a powerful tool to dissect the complexity of biological tissues through cell sub-population identification in combination with clustering approaches. Feature selection is a critical step for improving the accuracy and interpretability of single-cell clustering. Existing feature selection methods underutilize the discriminatory potential of genes across distinct cell types. We hypothesize that incorporating such information could further boost the performance of single cell clustering. Results We develop CellBRF, a feature selection method that considers genes’ relevance to cell types for single-cell clustering. The key idea is to identify genes that are most important for discriminating cell types through random forests guided by predicted cell labels. Moreover, it proposes a class balancing strategy to mitigate the impact of unbalanced cell type distributions on feature importance evaluation. We benchmark CellBRF on 33 scRNA-seq datasets representing diverse biological scenarios and demonstrate that it substantially outperforms state-of-the-art feature selection methods in terms of clustering accuracy and cell neighborhood consistency. Furthermore, we demonstrate the outstanding performance of our selected features through three case studies on cell differentiation stage identification, non-malignant cell subtype identification, and rare cell identification. CellBRF provides a new and effective tool to boost single-cell clustering accuracy. Availability and implementation All source codes of CellBRF are freely available at https://github.com/xuyp-csu/CellBRF

    The systematic review and meta-analysis evaluated the efficacy and safety of nefopam for catheter-related bladder discomfort based on randomized controlled trials

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    Background: Catheter-related bladder discomfort (CRBD) is a frequent occurrence following urinary catheterization during surgical procedures, as well as a commonly experienced bladder pain syndrome after surgery. There have been various studies on drugs and interventions to manage CRBD, but their comparative efficacy and safety are still a topic of debate. We conducted a meta-analysis to assess the efficacy and safety of nefopam for managing postoperative CRBD.Methods: A systematic search of PubMed, Embase, Cochrane Library, and Web of Science was conducted to find randomized controlled trials (RCTs) on using nefopam in postoperative CRBD. The study employed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Data analysis was performed using RevMan version 5.4.1.Results: Five RCTs with 405 patients were analyzed to evaluate the efficacy of nefopam on postoperative CRBD. Short-term and long-term periods were defined as within 6 h and longer than 12 h after surgery, respectively. The incidence and severity of CRBD were compared between the two groups during these time periods. The analysis proved that nefopam reduced the short-term incidence of postoperative CRBD (RR 0.36; 95% CI, 0.18–0.70; p = 0.003, I2 = 78%) and the long-term incidence (RR 0.49; 95% CI, 0.32–0.74; p = 0.0007, I2 = 0%) significantly. We compared the incidence of moderate-to-severe CRBD between groups based on the scaling system (none, mild, moderate, and severe). This was used to assess the severity of postoperative CRBD. The results showed that patients in the nefopam group had a significantly lower incidence of moderate-to-severe CRBD compared to those in the placebo group in the short-term (RR 0.19; 95% CI, 0.10–0.34; p < 0.00001; I2 = 0%). However, there were no significant differences between the two groups in the incidence of moderate-to-severe CRBD in the long-term (RR 0.61; 95% CI, 0.21–1.76; p = 0.36; I2 = 0%). There were no significant variations in the occurrence of adverse events between the nefopam and control groups, mainly including postoperative nausea and vomiting (PONV) (RR 1.14; 95% CI, 0.40–3.21; p = 0.81), and tachycardia (RR 0.25; 95% CI, 0.03–2.11, p = 0.20).Conclusion: The findings of this meta-analysis indicate that nefopam significantly reduced the incidence of short or long-term postoperative CRBD. Nefopam decreased the severity of postoperative CRBD, particularly significantly reducing the occurrence of moderate to severe CRBD in the short-term. Overall, patients have good tolerance and no apparent side effects.Systematic Review Registration: identifier PROSPERO (CRD42023475012

    Enhanced terahertz third-harmonic generation by bound states in the continuum in graphene grating-like metamaterial

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    Non-linear metamaterials hold great promise for enhanced terahertz harmonic generation. Here, we numerically investigate enhanced terahertz third-harmonic generation (THG) by exploiting the symmetry-protected bound states in the continuum (BICs) in graphene grating-like metamaterial. By symmetry breaking of metamaterials, BICs transform into quasi-BICs. The high Q-factor and strong localized field enhancement is achieved at quasi-BICs, leading to a boosted THG process with low incident intensity of fundamental frequency. The THG conversion efficiency reaches 3.1% at an incident intensity of 100 kW/cm2. The remarkably enhanced non-linear optical process in the proposed non-linear metamaterial constitutes an outstanding platform for on-chip terahertz non-linear conversion applications

    Genome analysis of a plasmid-bearing myxobacterim Myxococcus sp. strain MxC21 with salt-tolerant property

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    Myxobacteria are widely distributed in various habitats of soil and oceanic sediment. However, it is unclear whether soil-dwelling myxobacteria tolerate a saline environment. In this study, a salt-tolerant myxobacterium Myxococcus sp. strain MxC21 was isolated from forest soil with NaCl tolerance >2% concentration. Under 1% salt-contained condition, strain MxC21 could kill and consume bacteria prey and exhibited complex social behaviors such as S-motility, biofilm, and fruiting body formation but adopted an asocial living pattern with the presence of 1.5% NaCl. To investigate the genomic basis of stress tolerance, the complete genome of MxC21 was sequenced and analyzed. Strain MxC21 consists of a circular chromosome with a total length of 9.13 Mbp and a circular plasmid of 64.3 kb. Comparative genomic analysis revealed that the genomes of strain MxC21 and M. xanthus DK1622 share high genome synteny, while no endogenous plasmid was found in DK1622. Further analysis showed that approximately 21% of its coding genes from the genome of strain MxC21 are predominantly associated with signal transduction, transcriptional regulation, and protein folding involved in diverse niche adaptation such as salt tolerance, which enables social behavior such as gliding motility, sporulation, and predation. Meantime, a high number of genes are also found to be involved in defense against oxidative stress and production of antimicrobial compounds. All of these functional genes may be responsible for the potential salt-toleration. Otherwise, strain MxC21 is the second reported myxobacteria containing indigenous plasmid, while only a small proportion of genes was specific to the circular plasmid of strain MxC21, and most of them were annotated as hypothetical proteins, which may have a direct relationship with the habitat adaptation of strain MxC21 under saline environment. This study provides an inspiration of the adaptive evolution of salt-tolerant myxobacterium and facilitates a potential application in the improvement of saline soil in future

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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