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In contrast to prevalent strategies which make use of ß-sheet mimetics to block Aß fibrillar growth, in this study, we designed a series of sulfonyl-γ-AApeptide helices that targeted the crucial α-helix domain of Aß13-26 and stabilized Aß conformation to avoid forming the neurotoxic Aß oligomeric ß-sheets. Biophysical assays such as amyloid kinetics and TEM demonstrated that the Aß oligomerization and fibrillation could be greatly prevented and even reversed in the presence of sulfonyl-γ-AApeptides in a sequence-specific and dose-dependent manner. The studies based on circular dichroism, Two-dimensional nuclear magnetic resonance spectroscopy (2D-NMR) spectra unambiguously suggested that the sulfonyl-γ-AApeptide Ab-6 could bind to the central region of Aß42 and induce α-helix conformation in Aß. Additionally, Electrospray ionisation-ion mobility spectrometry-mass spectrometry (ESI-IMS-MS) was employed to rule out a colloidal mechanism of inhibitor and clearly supported the capability of Ab-6 for inhibiting the formation of Aß aggregated forms. Furthermore, Ab-6 could rescue neuroblastoma cells by eradicating Aß-mediated cytotoxicity even in the presence of pre-formed Aß aggregates. The confocal microscopy demonstrated that Ab-6 could still specifically bind Aß42 and colocalize into mitochondria in the cellular environment, suggesting the rescue of cell viability might be due to the protection of mitochondrial function otherwise impaired by Aß42 aggregation. Taken together, our studies indicated that sulfonyl-γ-AApeptides as helical peptidomimetics could direct Aß into the off-pathway helical secondary structure, thereby preventing the formation of Aß oligomerization, fibrillation and rescuing Aß induced cell cytotoxicity.
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Amidas , Péptidos beta-Amiloides , Amiloide , Amiloide/química , Conformación Proteica en Hélice alfa , Conformación Molecular , Péptidos beta-Amiloides/metabolismo , Fragmentos de Péptidos/metabolismoRESUMEN
OBJECTIVE: Ferritin heavy chain 1 (FTH1) is an important subunit of ferro-storing proteins and is indispensable for iron metabolism. Though it has been extensively studied in numerous organs and diseases, the relationship between FTH1 and osteoarthritis (OA) is unclear. DESIGN: Primary murine chondrocytes and cartilage explants were treated with FTH1 siRNA for 72 h. Mice were injected with adenovirus expressing FTH1 after destabilized medial meniscus (DMM) surgery. These approaches were used to determine the effect of FTH1 expression on the pathophysiology of OA. RESULTS: FTH1 expression was down regulated in OA patients and mice after DMM surgery. Knock down of FTH1 induced articular cartilage damage and extracellular matrix degradation in cartilage explants. Further, over expression of FTH1 reduced the susceptibility of chondrocytes to ferroptosis and reversed decrements in SOX9 and aggrecan after DMM surgery. Moreover, FTH1 relieved OA by inhibition of the chondrocyte MAPK pathway. CONCLUSION: This study found FTH1 to play an essential role in extracellular matrix degradation, ferroptosis, and chondrocytes senescence during OA progression. Further, injection of adenovirus expressing FTH1 may be a potential strategy for OA prevention and therapy.
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Osteoartritis , Animales , Humanos , Ratones , Adenoviridae/genética , Agrecanos , Condrocitos , Matriz Extracelular , Ferritinas , Osteoartritis/genética , OxidorreductasasRESUMEN
Hybridization drives rapid speciation by shaping novel genotypic and phenotypic profiles. Genomic incompatibility and transcriptome shock have been observed in hybrids, although this is rarer in animals than in plants. Using the newly sequenced genomes of the blunt snout bream (Megalobrama amblycephala [BSB]) and the topmouth culter (Culter alburnus [TC]), we focused on the sequence variation and gene expression changes in the reciprocal intergeneric hybrid lineages (F1-F3) of BSB × TC. A genome-wide transcriptional analysis identified 145-974 expressed recombinant genes in the successive generations of hybrid fish, suggesting the rapid emergence of allelic variation following hybridization. Some gradual changes of gene expression with additive and dominance effects and various cis and trans regulations were observed from F1 to F3 in the two hybrid lineages. These asymmetric patterns of gene expression represent the alternative strategies for counteracting deleterious effects of the subgenomes and improving adaptability of novel hybrids. Furthermore, we identified positive selection and additive expression patterns in transforming growth factor, beta 1b (tgfb1b), which may account for the morphological variations of the pharyngeal jaw in the two hybrid lineages. Our current findings provide insights into the evolution of vertebrate genomes immediately following hybridization.
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Alelos , Cyprinidae/genética , Hibridación Genética , Animales , Femenino , Masculino , Polimorfismo Genético , Análisis de Secuencia/métodos , Especificidad de la EspecieRESUMEN
OBJECTIVE: The aim of this study is to compare the results of three gauge (G) needles (22G, 23G and 25G) in terms of cell amount in thyroid fine needle aspiration (FNA). SUBJECTS AND METHODS: In the retrospective study, a total of 443 patients undergoing FNA for the first time between 2017 and 2018 were included in the study, and assigned to 3 groups with 22-gauge, 23-gauge and 25-gauge needles, respectively. RESULTS: The cell amount of a suspicion for the four diagnosis groups, including malignancy and malignant, benign nodules, follicular of undetermined significance (FLUS), and follicular neoplasia was mainly in the range of 0-10000, 0-300, 0-150, and 500-2500, respectively. The cut-off values of 22G needle 20000, 300, 1000, and 2500, while the cut-off values of 23G and 25G were 10000, 400, 1000, and 2500; 5000, 400, 1500, and 2000, respectively for the four diagnosis groups. CONCLUSION: Large-gauge needles resulted in more cellular specimens than small-gauge needles only in the cases of malignant tumors. Small-gauge needles resulted in a higher comfort level of the patients, and had no difference in cell number in nodules with abundant blood supply, compared with large-gauge needles.
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Neoplasias Pancreáticas , Paraganglioma , Nódulo Tiroideo , Humanos , Glándula Tiroides/patología , Biopsia por Aspiración con Aguja Fina Guiada por Ultrasonido Endoscópico/métodos , Estudios Retrospectivos , Neoplasias Pancreáticas/patología , Nódulo Tiroideo/diagnóstico por imagen , Nódulo Tiroideo/patologíaRESUMEN
Allopolyploid Brassica juncea crops in Brassicaceae are becoming increasingly revitalized as vegetables and oilseeds owing to wide adaptability and significant economic values. However, the genomic differentiation of diversified vegetables and oilseed B. juncea and the genetic basis underlying glucosinolates accumulation have yet to be elucidated. To address this knowledge gap, we report the sequencing of pairwise genomes of vegetable and oilseed B. juncea at chromosome scale. Comparative genomics analysis unveils panoramic structural variation footprints, particularly the genetic loci of HSP20 and TGA1 associated with abiotic and biotic stresses responses between oilseed and vegetable subgroups. We anchored two major loci of MYB28 (HAG1) orthologues caused by copy number variations on A02 and A09 chromosomes using scored genomic SNPs-based GWAS that are responsible for seed oil quality-determining glucosinolates biosynthesis. These findings will provide valuable repertories of polyploidy genomic information enabling polyploidy genome evolution studies and precise genomic selections for crucial traits like functional components of glucosinolates in B. juncea crops and beyond.
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Glucosinolatos , Planta de la Mostaza , Variaciones en el Número de Copia de ADN , Sitios Genéticos , Genómica , Planta de la Mostaza/genética , VerdurasRESUMEN
Gold-catalyzed alkyne and allene diselenations were developed. Excellent regioselectivity (trans) and good to excellent yields were achieved (up to 98 % with 2 % catalyst loading) with a wide range of substrates. Mechanistic investigation revealed the formation of a vinyl gold(I) intermediate followed by an intermolecular selenium cation migration, suggesting that a gold(I/III) redox process was successfully implemented under mild conditions.
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BACKGROUND: Predatory mites (Acari: Phytoseiidae) are the most important beneficial arthropods used in augmentative biological pest control of protected crops around the world. However, the genomes of mites are far less well understood than those of insects and the evolutionary relationships among mite and other chelicerate orders are contested, with the enigmatic origin of mites at one of the centres in discussion of the evolution of Arachnida. RESULTS: We here report the 173 Mb nuclear genome (from 51.75 Gb pairs of Illumina reads) of the predatory mite, Neoseiulus cucumeris, a biocontrol agent against pests such as mites and thrips worldwide. We identified nearly 20.6 Mb (~ 11.93% of this genome) of repetitive sequences and annotated 18,735 protein-coding genes (a typical gene 2888 bp in size); the total length of protein-coding genes was about 50.55 Mb (29.2% of this assembly). About 37% (6981) of the genes are unique to N. cucumeris based on comparison with other arachnid genomes. Our phylogenomic analysis supported the monophyly of Acari, therefore rejecting the biphyletic origin of mites advocated by other studies based on limited gene fragments or few taxa in recent years. Our transcriptomic analyses of different life stages of N. cucumeris provide new insights into genes involved in its development. Putative genes involved in vitellogenesis, regulation of oviposition, sex determination, development of legs, signal perception, detoxification and stress-resistance, and innate immune systems are identified. CONCLUSIONS: Our genomics and developmental transcriptomics analyses of N. cucumeris provide invaluable resources for further research on the development, reproduction, and fitness of this economically important mite in particular and Arachnida in general.
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Genoma/genética , Ácaros/clasificación , Ácaros/genética , Ácaros y Garrapatas/clasificación , Ácaros y Garrapatas/genética , Adaptación Fisiológica/genética , Animales , Agentes de Control Biológico , Evolución Molecular , Genómica , Inmunidad Innata/genética , Estadios del Ciclo de Vida/genética , Ácaros/crecimiento & desarrollo , Ácaros/fisiología , Filogenia , Secuencias Repetitivas de Ácidos Nucleicos , Reproducción/genética , Análisis de Secuencia de ADN , Especificidad de la Especie , TranscriptomaRESUMEN
New compounds involving the biologically important 1,4-benzodiazepine skeleton were conveniently constructed from 2-(arylamino)benzamides through PhI(OAc)2-mediated oxidative CN bond formation. The attractive features of this new synthetic strategy include mild reaction conditions, the heavy-metal-free characteristic of the oxidative coupling process, and the flexibility to tolerate a broad scope of substrates.
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Benzamidas/química , Benzodiazepinas/síntesis química , Yodobencenos/química , Benzodiazepinas/química , Catálisis , Oxidación-ReducciónRESUMEN
The perception of structure-borne noise is particularly salient when train passes through the tunnel under the buildings, which has a negative impact on human health. In the process of constructing buildings along metro lines, it is crucial to estimate indoor structure-borne noise levels in order to enhance design and prevent any negative impact on human comfort. This study conducted measurements of structure-borne noise, reverberation time, and train-induced vibrations in Guangzhou, China to investigate the generation, propagation, and dissipation mechanisms of structure-borne noise. An approach based on Short-Time Fourier Transform and Schroeder integral was proposed for obtaining frequency-dependent reverberation time. Additionally, a deep learning-based approach incorporating indoor vibrations, frequency-dependent reverberation time, and room parameters as inputs was proposed based on Genetic Algorithm-Artificial Neural Network. The estimated structure-borne noise levels demonstrated good agreement with measured values, indicating the feasibility of the approach. The finding of this research facilitates a clear comprehension of the generation, distribution, and dissipation mechanisms of indoor structure-borne noise for engineers while also enabling convenient acquisition of indoor structure-borne noise. The estimated noise levels can be effectively utilized during building design processes along metro lines to mitigate adverse impacts on human comfort.
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BACKGROUND: This study aimed to identify characteristic gut genera in obese and normal-weight children (8-12 years old) using 16S rDNA sequencing. The research aimed to provide insights for mechanistic studies and prevention strategies for childhood obesity. Thirty normal-weight and thirty age- and sex-matched obese children were included. Questionnaires and body measurements were collected, and fecal samples underwent 16S rDNA sequencing. Significant differences in body mass index (BMI) and body-fat percentage were observed between the groups. Analysis of gut microbiota diversity revealed lower α-diversity in obese children. Di-fferences in gut microbiota composition were found between the two groups. Prevotella and Firmicutes were more abundant in the obese group, while Bacteroides and Sanguibacteroides were more prevalent in the control group. AIM: To identify the characteristic gut genera in obese and normal-weight children (8-12-year-old) using 16S rDNA sequencing, and provide a basis for subsequent mechanistic studies and prevention strategies for childhood obesity. METHODS: Thirty each normal-weight, 1:1 matched for age and sex, and obese children, with an obese status from 2020 to 2022, were included in the control and obese groups, respectively. Basic information was collected through questionnaires and body measurements were obtained from both obese and normal-weight children. Fecal samples were collected from both groups and subjected to 16S rDNA sequencing using an Illumina MiSeq sequencing platform for gut microbiota diversity analysis. RESULTS: Significant differences in BMI and body-fat percentage were observed between the two groups. The Ace and Chao1 indices were significantly lower in the obese group than those in the control group, whereas differences were not significant in the Shannon and Simpson indices. Kruskal-Wallis tests indicated significant differences in unweighted and weighted UniFrac distances between the gut microbiota of normal-weight and obese children (P < 0.01), suggesting substantial disparities in both the species and quantity of gut microbiota between the two groups. Prevotella, Firmicutes, Bacteroides, and Sanguibacteroides were more abundant in the obese and control groups, respectively. Heatmap results demonstrated significant differences in the gut microbiota composition between obese and normal-weight children. CONCLUSION: Obese children exhibited lower α-diversity in their gut microbiota than did the normal-weight children. Significant differences were observed in the composition of gut microbiota between obese and normal-weight children.
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Índice de Masa Corporal , Heces , Microbioma Gastrointestinal , Obesidad Infantil , ARN Ribosómico 16S , Humanos , Obesidad Infantil/microbiología , Obesidad Infantil/diagnóstico , Niño , ARN Ribosómico 16S/genética , Masculino , Femenino , Heces/microbiología , Estudios de Casos y Controles , Bacterias/genética , Bacterias/aislamiento & purificación , Bacterias/clasificación , ADN Bacteriano/aislamiento & purificación , ADN Bacteriano/análisis , ADN Bacteriano/genéticaRESUMEN
Acinetobacter baumannii is a major opportunistic pathogen causing hospital-acquired infections, and it is imperative to comprehend its evolutionary and epidemiological dynamics in hospitals to prevent and control nosocomial transmission. Here, we present a comprehensive genomic epidemiological study involving the genomic sequencing and antibiotic resistance profiling of 634 A. baumannii strains isolated from seven intensive care units (ICUs) of a Chinese general hospital over 2 consecutive years. Our study reveals that ST2 is highly dominant (90.54%) in the ICUs, with 98.90% of the ST2 exhibiting multidrug resistant or extensively drug resistant. Phylogenetic analyses of newly sequenced genomes and public data suggest that nosocomial isolates originated outside the hospital but evolved inside. The major lineages appear to be stable, with 9 of the 28 identified nosocomial epidemic clones infecting over 60% of the affected patients. However, outbreaks of two highly evolved clones have been observed in different hospitals, suggesting significant inter-hospital transmission chains. By coupling patient medical records and genomic divergence of the ST2, we found that cross-ward patient transfer played a crucial role in pathogen's nosocomial transmission. Additionally, we identified 831 potential adaptive evolutionary loci and 44 associated genes by grouping and comparing the genomes of clones with different prevalence. Overall, our study provides a comprehensive and contemporary survey on the epidemiology and genomic evolution of A. baumannii in a large Chinese general hospital. These findings shed light on the nosocomial evolution and transmission of A. baumannii and offers valuable information for transmission prevention and antibiotic therapy.IMPORTANCEThis study delved into the genomic evolution and transmission of nosocomial Acinetobacter baumannii on a large scale, spanning both an extended time period and the largest sample size to date. Through molecular epidemiological investigations based on genomics, we can directly trace the origin of the pathogen, detecting and monitoring outbreaks of infectious diseases in a timely manner, and ensuring public health safety. In addition, this study also collects a large amount of genomic and antibiotic resistance detection data, which is helpful for phenotype prediction based on genomic sequencing. It enables patients to receive personalized antibiotic treatment quickly, helps doctors select antibiotics more accurately, and contributes to reducing the use of antibiotics and lowering the risk of antibiotic resistance development.
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Acinetobacter baumannii , Infección Hospitalaria , Humanos , Acinetobacter baumannii/genética , Infección Hospitalaria/epidemiología , Filogenia , Proteína 1 Similar al Receptor de Interleucina-1/genética , Farmacorresistencia Bacteriana Múltiple/genética , Antibacterianos/farmacología , Hospitales , Genómica , Pruebas de Sensibilidad MicrobianaRESUMEN
Antimicrobial resistance is a global challenge owing to the lack of discovering effective antibiotic agents. Antimicrobial polymers containing the cationic groups and hydrophobic groups which mimic natural host-defense peptides (HDPs) show great promise in combating bacteria. Herein, we report the synthesis of lipidated polycarbonates bearing primary amino groups and hydrophobic moieties (including both the terminal long alkyl chain and hydrophobic groups in the sequences) by ring-opening polymerization. The hydrophobic/hydrophilic group ratios were adjusted deliberately and the lengths of the alkyl chains at the end of the polymers were modified to achieve the optimized combination for the lead polymers, which exhibited potent and broad-spectrum bactericidal activity against a panel of Gram-positive and Gram-negative bacteria. The polymers only showed very limited hemolytic activity, demonstrating their excellent selectivity. Comprehensive analyses using biochemical and biophysical assays revealed the strong interaction between the polymers and bacteria membranes. Moreover, the polymers also showed strong biofilm inhibition activity and did not readily induce antibiotic resistance. Our results suggest that lipidated polycarbonates could be a new class of antimicrobial agents.
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Antibacterianos , Antiinfecciosos , Antibacterianos/química , Bacterias Gramnegativas , Bacterias Grampositivas , Antiinfecciosos/farmacología , Bacterias , Polímeros/farmacología , Polímeros/química , Pruebas de Sensibilidad MicrobianaRESUMEN
Background: Cryptosporidium infections in humans typically result in symptoms such as abdominal pain and diarrhea. When the diarrhea is severe, it can cause serious complications and even be life-threatening, especially in patients with compromised immune systems. Case presentation: Here, we reported the use of metagenomic next-generation sequencing (mNGS) to assist in the diagnosis and treatment of a 10-year-old boy with severe Cryptosporidium infection. Despite the absence of any history of immunocompromise, the infection still resulted in severe symptoms, including shock, as well as damage to his pancreas and kidneys. The mNGS tests detected the presence of Cryptosporidium parvum when conventional methods failed. The patient received anti-parasite treatment along with supportive care to manage the condition. With disease surveillance based on regular clinical tests and sequential mNGS tests, the child recovered from the severe conditions. Conclusion: Our study emphasized the importance of recognizing the potential severity of Cryptosporidium infection, even among individuals with normal immune systems. Timely diagnosis and ongoing monitoring are essential for patient prognosis.
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Criptosporidiosis , Cryptosporidium , Masculino , Niño , Humanos , Criptosporidiosis/epidemiología , Cryptosporidium/genética , Diarrea/diagnóstico , Diarrea/epidemiología , Secuenciación de Nucleótidos de Alto Rendimiento , Unidades de Cuidado Intensivo PediátricoRESUMEN
Introduction: Polymyxin-resistant Enterobacterales poses a significant threat to public health globally, but its prevalence and genomic diversity within a sole hospital is less well known. In this study, the prevalence of polymyxin-resistant Enterobacterales in a Chinese teaching hospital was investigated with deciphering of their genetic determinants of drug resistance. Methods: Polymyxin-resistant Enterobacterales isolates identified by matrix-assisted laser desorption were collected in Ruijin Hospital from May to December in 2021. Both the VITEK 2 Compact and broth dilution methods were used to determine polymyxin B (PMB) susceptibility. Polymyxin-resistant isolates were further characterized by molecular typing using PCR, multi-locus sequence typing, and sequencing of the whole genome. Results: Of the 1,216 isolates collected, 32 (2.6%) across 12 wards were polymyxin-resistant (minimum inhibitory concentration (MIC) range, PMB 4-256 mg/ml, and colistin 4 ≥ 16 mg/ ml). A total of 28 (87.5%) of the polymyxin-resistant isolates had reduced susceptibility to imipenem and meropenem (MIC ≥ 16 mg/ml). Of the 32 patients, 15 patients received PMB treatment and 20 survived before discharge. The phylogenetic tree of these isolates showed they belonged to different clones and had multiple origins. The polymyxin-resistant Klebsiella pneumoniae isolates belonged to ST-11 (85.72%), ST-15 (10.71%), and ST-65 (3.57%), and the polymyxin-resistant Escherichia coli belonged to four different sequence types, namely, ST-69 (25.00%), ST-38 (25.00%), ST-648 (25.00%), and ST-1193 (25.00%). In addition, six mgrB specific mutations (snp_ALT c.323T>C and amino acid change p.Val8Ala) were identified in 15.6% (5/32) of the isolates. mcr-1, a plasmid-mediated polymyxin-resistant gene, was found in three isolates, and non-synonymous mutations including T157P, A246T, G53V, and I44L were also observed. Discussion: In our study, a low prevalence of polymyxin-resistant Enterobacterales was observed, but these isolates were also identified as multidrug resistant. Therefore, efficient infection control measures should be implemented to prevent the further spread of resistance to last-line polymyxin therapy.
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Proteínas de Escherichia coli , Polimixinas , Humanos , Polimixinas/farmacología , Antibacterianos/farmacología , Tipificación de Secuencias Multilocus , Prevalencia , Filogenia , Pueblos del Este de Asia , Farmacorresistencia Bacteriana/genética , Escherichia coli/genética , Hospitales de Enseñanza , Klebsiella pneumoniae , Pruebas de Sensibilidad Microbiana , Proteínas de Escherichia coli/genéticaRESUMEN
Objective: To investigate the diagnostic value of metagenomic next-generation sequencing (mNGS) using pleural effusion and ascites from children with sepsis. Methods: In this study, children with sepsis or severe sepsis and appeared pleural or peritoneal effusions were enrolled, of whom the pleural effusions or ascites and blood samples were conducted pathogen detection using both conventional and mNGS methods. The samples were divided into pathogen-consistent and pathogen-inconsistent groups based on the consistency of mNGS results from different sample types, and into exudate and transudate groups based on their pleural effusion and ascites properties. The pathogen positive rates, pathogen spectrum, consistency between different sample types, and clinical diagnosis consistency were compared between mNGS and conventional pathogen tests. Results: A total of 42 pleural effusions or ascites and 50 other type samples were collected from 32 children. The pathogen positive rate of the mNGS test was significantly higher than that of traditional methods (78.57% vs. 14.29%, P < 0.001) in pleural effusion and ascites samples, with a consistent rate of 66.67% between the two methods. Nearly 78.79% (26/33) of mNGS positive results of the pleural effusions and ascites samples were consistent with clinical evaluation, and 81.82% (27/33) of these positive samples reported 1-3 pathogens. The pathogen-consistent group outperformed the pathogen-inconsistent group in terms of consistency with respect to clinical evaluation (88.46% vs. 57.14%, P = 0.093), while there was no significant difference between the exudate and transudate groups (66.67% vs. 50.00%, P = 0.483). Conclusion: Compared to conventional methods, mNGS has great advantages in pathogen detection of pleural effusion and ascites samples. Moreover, consistent results of mNGS tests with different sample types provide more reference values in clinical diagnosis.
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Derrame Pleural , Sepsis , Niño , Humanos , Ascitis/diagnóstico , Exudados y Transudados , Sepsis/diagnóstico , Secuenciación de Nucleótidos de Alto Rendimiento , Metagenómica , Sensibilidad y EspecificidadRESUMEN
We present multiPrime, a novel tool that automatically designs minimal primer sets for targeted next-generation sequencing, tailored to specific microbiomes or genes. MultiPrime enhances primer coverage by designing primers with mismatch tolerance and ensures both high compatibility and specificity. We evaluated the performance of multiPrime using a data set of 43,016 sequences from eight viruses. Our results demonstrated that multiPrime outperformed conventional tools, and the primer set designed by multiPrime successfully amplified the target amplicons. Furthermore, we expanded the application of multiPrime to 30 types of viruses and validated the work efficacy of multiPrime-designed primers in 80 clinical specimens. The subsequent sequencing outcomes from these primers indicated a sensitivity of 94% and a specificity of 89%.
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Hybrid maize displays superior heterosis and contributes over 30% of total worldwide cereal production. However, the molecular mechanisms of heterosis remain obscure. Here we show that structural variants (SVs) between the parental lines have a predominant role underpinning maize heterosis. De novo assembly and analyses of 12 maize founder inbred lines (FILs) reveal abundant genetic variations among these FILs and, through expression quantitative trait loci and association analyses, we identify several SVs contributing to genomic and phenotypic differentiations of various heterotic groups. Using a set of 91 diallel-cross F1 hybrids, we found strong positive correlations between better-parent heterosis of the F1 hybrids and the numbers of SVs between the parental lines, providing concrete genomic support for a prevalent role of genetic complementation underlying heterosis. Further, we document evidence that SVs in both ZAR1 and ZmACO2 contribute to yield heterosis in an overdominance fashion. Our results should promote genomics-based breeding of hybrid maize.
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Vigor Híbrido , Zea mays , Grano Comestible/genética , Vigor Híbrido/genética , Hibridación Genética , Fitomejoramiento , Sitios de Carácter Cuantitativo/genética , Zea mays/genética , Genoma de PlantaRESUMEN
A group of functionalized oxazoles were synthesized in moderate to good yields from enamides via phenyliodine diacetate (PIDA)-mediated intramolecular cyclization. The main advantageous features of the present method include its broad substrate scope and the heavy-metal-free characteristic of the oxidative carbon-oxygen bond formation process.
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Acetatos/química , Yodobencenos/química , Oxazoles/síntesis química , Catálisis , Ciclización , Estructura Molecular , Oxazoles/química , Oxidación-ReducciónRESUMEN
With the development of urban rail transit, taking the metro train has become one of the main modes of transportation, and passengers have an increasing demand for the comfort of taking the metro trains. This paper mainly discusses the impact of noise and vibration caused by metro train on passengers. All 13 metro lines in Guangzhou, China, were selected to conduct the questionnaire survey on the subjective perception of 601 respondents. At the same time, noise and vibration measurements were carried out in the train. The results show that the distribution of noise and vibrations along the metro lines is not uniform, and 50.6% of the interviewees are disturbed by noise. Wheel-rail squeal was found to be the most annoying and disturbing noise source. Three dose-response relationships for noise, vertical vibration, and horizontal vibration are proposed, respectively. The proposed dose-response relationship can be applied to the evaluation of noise annoyance or vibration perception in an environment similar to metro lines. Once the noise or vibration level of a metro line is obtained, the noise disturbance or vibration perception can be estimated. As for the dose-response relationship of vibration perception, people's sensitivity to vibration is much lower than that to noise. Horizontal vibrations are more acceptable to passengers, while vertical vibrations are more disturbing to passengers. The results are helpful to predict the noise annoyance and vibration perception of train passengers between metro stations, and to achieve the purpose of designing effective noise and vibration reduction measures.
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Ruido , Vías Férreas , Vibración , China , Humanos , Percepción , Encuestas y CuestionariosRESUMEN
Since the first strain related to Thermicanaceae was reported in 1999, almost no literature on Thermicanaceae is available, particularly its genomics. We recently isolated a novel pathogenic bacterium, the â³ strain DYY3, from the blood sample of a critically ill patient. The morphological, physiological, and biochemical characteristics of â³ strain DYY3 were presented in this study, and the virulence factor genes and antibiotic resistance of DYY3 were also determined. Interestingly, the average nucleotide identity (ANI) and core-genes average amino acid identity (cAAI) analysis indicated that â³ strain DYY3 was genus novel and species novel. Moreover, phylogenetic analysis based on both 16S rRNA gene and whole genomic core gene sequences suggested that â³ strain DYY3 belonged to the family Thermicanaceae, and this novel taxon was thus named Haemobacillus shengwangii gen. nov., sp. nov. Besides, both the whole genome-based phylogenetic tree and amino acid identity analysis indicated that Thermicanus aegyptius, Hydrogenibacillus schlegelii, Brockia lithotrophica, and the newly discovered species H. shengwangii should belong to Thermicanaceae at the family level, and T. aegyptius was the closest species to H. shengwangii. We also constructed the first high-quality genome in the family Thermicanaceae using the next-generation sequencing (NGS) and single-molecule real-time (SMRT) sequencing technologies, which certainly contributed to further genomics studies and metagenomic-based pathogenic detection in the future.