228 research outputs found
Stability Analysis for Markovian Jump Neutral Systems with Mixed Delays and Partially Known Transition Rates
The delay-dependent stability problem is studied for Markovian jump neutral systems with partial information on transition probabilities, and the considered delays are mixed and model dependent. By constructing the new stochastic Lyapunov-Krasovskii functional, which combined the introduced free matrices with the analysis technique of matrix inequalities, a sufficient condition for the systems with fully known transition rates is
firstly established. Then, making full use of the transition rate matrix, the results are obtained for the other case, and the uncertain neutral Markovian jump system with incomplete transition rates is also considered. Finally, to show the validity of the obtained results, three numerical examples are provided
Detail-Enhancing Framework for Reference-Based Image Super-Resolution
Recent years have witnessed the prosperity of reference-based image
super-resolution (Ref-SR). By importing the high-resolution (HR) reference
images into the single image super-resolution (SISR) approach, the ill-posed
nature of this long-standing field has been alleviated with the assistance of
texture transferred from reference images. Although the significant improvement
in quantitative and qualitative results has verified the superiority of Ref-SR
methods, the presence of misalignment before texture transfer indicates room
for further performance improvement. Existing methods tend to neglect the
significance of details in the context of comparison, therefore not fully
leveraging the information contained within low-resolution (LR) images. In this
paper, we propose a Detail-Enhancing Framework (DEF) for reference-based
super-resolution, which introduces the diffusion model to generate and enhance
the underlying detail in LR images. If corresponding parts are present in the
reference image, our method can facilitate rigorous alignment. In cases where
the reference image lacks corresponding parts, it ensures a fundamental
improvement while avoiding the influence of the reference image. Extensive
experiments demonstrate that our proposed method achieves superior visual
results while maintaining comparable numerical outcomes
Design of a drop-in EBI sensor probe for abnormal tissue detection in minimally invasive surgery
It is a common challenge for the surgeon to detect pathological tissues and determine the resection margin during a minimally invasive surgery. In this study, we present a drop-in sensor probe based on the electrical bioimpedance spectroscopic technology, which can be grasped by a laparoscopic forceps and controlled by the surgeon to inspect suspicious tissue area conveniently. The probe is designed with an optimized electrode and a suitable shape specifically for Minimally Invasive Surgery (MIS). Subsequently, a series of ex vivo experiments are carried out with porcine liver tissue for feasibility validation. During the experiments, impedance measured at frequencies from 1 kHz to 2 MHz are collected on both normal tissues and water soaked tissue. In addition, classifiers based on discriminant analysis are developed. The result of the experiment indicate that the sensor probe can be used to measure the impedance of the tissue easily and the developed tissue classifier achieved accuracy of 80% and 100% respectively.
Identification and bioinformatics analysis of cilia-associated gene families in Euplotes amieti (Ciliophora, Hypotrichia)
IntroductionCiliates serve as pivotal model organisms for investigating the protein composition and regulatory mechanisms underlying cellular processes. This study systematically explores the structural and functional characteristics of cilia-associated genes in Euplotes amieti, aiming to elucidate their roles in ciliogenesis and cilia-related pathways.MethodsThe macronuclear genome of E. amieti was sequenced using next-generation sequencing (NGS). Cilia-associated genes were identified via BLASTP analysis against homologs in hypotrich ciliates (Euplotes octocarinatus, Stylonychia lemnae, and Oxytricha trifallax). Functional annotations, including Non-Redundant (NR) classification, Pfam domain prediction, and Gene Ontology (GO) enrichment, were performed. Pathway enrichment analysis identified associated metabolic and signaling pathways. Experimental validation included quantitative polymerase chain reaction (QPCR) of cilia-related gene families, RNA interference (RNAi) targeting ARL2BP and DYNLRB2, and immunofluorescence staining to assess microtubule arrangement.ResultsA total of 418 cilia-associated genes were identified, with 44 conserved across the four hypotrich ciliate species. Functional categorization revealed kinases, dyneins, tubulins, and autophagy-related proteins. Pfam annotations predicted three conserved domains. GO terms were enriched in tubulin binding, cilia assembly, and microtubule-based movement. Pathway analysis implicated these genes in adenine ribonucleotide biosynthesis, glycolysis/gluconeogenesis, Wnt, and AMP-activated protein kinase (AMPK) signaling. QPCR showed significant downregulation of cilia-related proteins during mitosis. RNAi of ARL2BP and DYNLRB2 increased mortality, reduced motility, and disrupted cortical microtubule organization via immunofluorescence. Thirty-nine hub genes were strongly linked to ciliopathies.DiscussionCilia-associated genes in E. amieti are integral to DNA replication, energy metabolism, intercellular communication, and morphogenesis. The conserved hub genes associated with ciliopathies suggest evolutionary preservation of ciliogenesis regulation. ARL2BP and DYNLRB2 are functional important in ciliary dynamics and structural integrity. This study provides crucial insights into the roles of cilia-associated genes in ciliates, advancing understanding of ciliogenesis mechanisms and their implications for ciliopathy research
Complete genome sequence of Shigella flexneri 5b and comparison with Shigella flexneri 2a
BACKGROUND: Shigella bacteria cause dysentery, which remains a significant threat to public health. Shigella flexneri is the most common species in both developing and developed countries. Five Shigella genomes have been sequenced, revealing dynamic and diverse features. To investigate the intra-species diversity of S. flexneri genomes further, we have sequenced the complete genome of S. flexneri 5b strain 8401 (abbreviated Sf8401) and compared it with S. flexneri 2a (Sf301). RESULTS: The Sf8401 chromosome is 4.5-Mb in size, a little smaller than that of Sf301, mainly because the former lacks the SHI-1 pathogenicity island (PAI). Compared with Sf301, there are 6 inversions and one translocation in Sf8401, which are probably mediated by insertion sequences (IS). There are clear differences in the known PAIs between these two genomes. The bacteriophage SfV segment remaining in SHI-O of Sf8401 is clearly larger than the remnants of bacteriophage SfII in Sf301. SHI-1 is absent from Sf8401 but a specific related protein is found next to the pheV locus. SHI-2 is involved in one intra-replichore inversion near the origin of replication, which may change the expression of iut/iuc genes. Moreover, genes related to the glycine-betaine biosynthesis pathway are present only in Sf8401 among the known Shigella genomes. CONCLUSION: Our data show that the two S. flexneri genomes are very similar, which suggests a high level of structural and functional conservation between the two serotypes. The differences reflect different selection pressures during evolution. The ancestor of S. flexneri probably acquired SHI-1 and SHI-2 before SHI-O was integrated and the serotypes diverged. SHI-1 was subsequently deleted from the S. flexneri 5b genome by recombination, but stabilized in the S. flexneri 2a genome. These events may have contributed to the differences in pathogenicity and epidemicity between the two serotypes of S. flexneri
Genome dynamics and diversity of Shigella species, the etiologic agents of bacillary dysentery
The Shigella bacteria cause bacillary dysentery, which remains a significant threat to public health. The genus status and species classification appear no longer valid, as compelling evidence indicates that Shigella, as well as enteroinvasive Escherichia coli, are derived from multiple origins of E.coli and form a single pathovar. Nevertheless, Shigella dysenteriae serotype 1 causes deadly epidemics but Shigella boydii is restricted to the Indian subcontinent, while Shigella flexneri and Shigella sonnei are prevalent in developing and developed countries respectively. To begin to explain these distinctive epidemiological and pathological features at the genome level, we have carried out comparative genomics on four representative strains. Each of the Shigella genomes includes a virulence plasmid that encodes conserved primary virulence determinants. The Shigella chromosomes share most of their genes with that of E.coli K12 strain MG1655, but each has over 200 pseudogenes, 300∼700 copies of insertion sequence (IS) elements, and numerous deletions, insertions, translocations and inversions. There is extensive diversity of putative virulence genes, mostly acquired via bacteriophage-mediated lateral gene transfer. Hence, via convergent evolution involving gain and loss of functions, through bacteriophage-mediated gene acquisition, IS-mediated DNA rearrangements and formation of pseudogenes, the Shigella spp. became highly specific human pathogens with variable epidemiological and pathological features
Adjuvant Chemotherapy Versus Adjuvant Concurrent Chemoradiotherapy After Radical Surgery for Early-Stage Cervical Cancer: A Randomized, Non-Inferiority, Multicenter Trial
We conducted a prospective study to assess the non-inferiority of adjuvant chemotherapy alone versus adjuvant concurrent chemoradiotherapy (CCRT) as an alternative strategy for patients with early-stage (FIGO 2009 stage IB-IIA) cervical cancer having risk factors after surgery. The condition was assessed in terms of prognosis, adverse effects, and quality of life. This randomized trial involved nine centers across China. Eligible patients were randomized to receive adjuvant chemotherapy or CCRT after surgery. The primary end-point was progression-free survival (PFS). From December 2012 to December 2014, 337 patients were subjected to randomization. Final analysis included 329 patients, including 165 in the adjuvant chemotherapy group and 164 in the adjuvant CCRT group. The median follow-up was 72.1 months. The three-year PFS rates were both 91.9%, and the five-year OS was 90.6% versus 90.0% in adjuvant chemotherapy and CCRT groups, respectively. No significant differences were observed in the PFS or OS between groups. The adjusted HR for PFS was 0.854 (95% confidence interval 0.415-1.757; P = 0.667) favoring adjuvant chemotherapy, excluding the predefined non-inferiority boundary of 1.9. The chemotherapy group showed a tendency toward good quality of life. In comparison with post-operative adjuvant CCRT, adjuvant chemotherapy treatment showed non-inferior efficacy in patients with early-stage cervical cancer having pathological risk factors. Adjuvant chemotherapy alone is a favorable alternative post-operative treatment
4-Nonylphenol effects on rat testis and sertoli cells determined by spectrochemical techniques coupled with chemometric analysis
Herein, vibrational spectroscopy has been applied for qualitative identification of biomolecular alterations that occur in cells and tissues following chemical treatment. Towards this end, we combined attenuated total reflection Fourier-transform infrared (ATR-FTIR) and Raman spectroscopy to assess testicular toxicology after 4-nonylphenol (NP) exposure, an estrogenic endocrine disruptor affecting testicular function in rats and other species. Rats aged 21, 35 or 50 days received NP at intra-peritoneal doses of 0, 25, 50 or 100 mg/kg for 20 consecutive days. Primary Sertoli cells (SCs) were treated with NP at various concentrations (0, 2.5, 5, 10 or 20 μM) for 12 h. Post-exposure, testicular cells, interstitial tissue and SCs were interrogated respectively using spectrochemical techniques coupled with multivariate analysis. Distinct biomolecular segregation between the NP-exposed samples vs. control were observed based on infrared (IR) spectral regions of 3200–2800 cm−1 and 1800-900 cm−1, and the Raman spectral region of 1800–900 cm−1. For in vivo experiments, the main wavenumbers responsible for segregation varied significantly among the three age classes. The main IR and Raman band differences between NP-exposed and control groups were observed for Amide (proteins), lipids and DNA/RNA. An interesting finding was that the peptide aggregation level, Amide Ӏ-to-Amide II ratio, and phosphate-to-carbohydrate ratio were considerably reduced in ex vivo NP-exposed testicular cells or SCs in vitro. This study demonstrates that ATR-FTIR and Raman spectroscopy techniques can be applied towards analysing NP-induced testicular biomolecular alterations
Thermo-Electrochemical Cells Based on Carbon Nanotube Electrodes by Electrophoretic Deposition
Remote spatiotemporally controlled and biologically selective permeabilization of blood-brain barrier
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