instruction:
In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
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Even though coronavirus infection of humans is not normally associated with severe diseases, the identification of the coronavirus responsible for the outbreak of severe acute respiratory syndrome showed that highly pathogenic coronaviruses can enter the human population. Shortly thereafter, in Holland in 2004, another novel human coronavirus (HCoV-NL63) was isolated from a seven-month old infant suffering from respiratory symptoms. This virus has subsequently been identified in various countries, indicating a worldwide distribution. HCoV-NL63 has been shown to infect mainly children and the immunocommpromised, who presented with either mild upper respiratory symptoms (cough, fever and rhinorrhoea) or more serious lower respiratory tract involvement such as bronchiolitis and croup, which was observed mainly in younger children. In fact, HCoV-NL63 is the aetiological agent for up to 10% of all respiratory diseases. This review summarizes recent findings of human coronavirus HCoV-NL63 infections, including isolation and identification, phylogeny and taxonomy, genome structure and transcriptional regulation, transmission and pathogenesis, and detection and diagnosis.
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Understanding Human Coronavirus HCoV-NL63


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This experiment was conducted to evaluate whether pretreatment with fenofibrate could mitigate acute lung injury (ALI) in a mice model of intestinal ischemia/reperfusion (I/R). Male C57BL/6 mice were randomly assigned into three groups (n = 6): sham, intestinal I/R + vehicle, and intestinal I/R + fenofibrate. Intestinal I/R was achieved by clamping the superior mesenteric artery. Fenofibrate (100 mg/kg) or equal volume of vehicle was injected intraperitoneally 60 minutes before the ischemia. At the end of experiment, measurement of pathohistological score, inflammatory mediators and other markers were performed. In addition, a 24-hour survival experiment was conducted in intestinal I/R mice treated with fenofibrate or vehicle. The chief results were as anticipated. Pathohistological evaluation indicated that fenofibrate ameliorated the local intestine damage and distant lung injury. Pretreatment with fenofibrate significantly decreased inflammatory factors in both the intestine and the lung. Consistently, renal creatine levels and hepatic ALT levels were significantly decreased in the fenofibrate group. Moreover, serum systemic inflammatory response indicators were significantly alleviated in the fenofibrate group. In addition, fenofibrate administration significantly improved the survival rate. Collectively, our data indicated that pretreatment with fenofibrate prior to ischemia attenuated intestinal I/R injury and ALI. Acute lung injury (ALI) is a critically severe, life-threatening condition in ICU, characterized by high mortality of approximately 40% 1 . ALI, along with its more severe form, acute respiratory distress syndrome, often results from a massive insult to the lung, whether be the direct alveolar infiltration or the indirect effects of systemic inflammatory response syndrome or multiple organ dysfunction syndromes 2 . An effective treatment of this life-threatening disorder calls for a better understanding of the molecular pathophysiology of ALI. The intestine is recognized to be one of the largest immune barrier systems and to be the source of bacteria and endotoxins in the body 3 . Previous reports indicate that the intestinal organ plays a crucial role in the development of ALI 4 . Mesenteric artery ischemia, a commonly seen critical state during small bowel transplantation or trauma, may lead to intestinal ischemia/reperfusion (I/R) injury. During the process of intestinal I/R injury, local bacteria overgrow and translocate, gastrointestinal mobility decreases, and mucosal permeability increases, all of which subsequently lead to the local intestine damage or distant lung injuries through the activation of systemic inflammatory response syndrome or multiple organ dysfunction syndromes 5,6 . Intestinal I/R is, therefore, a useful model for the investigation of pathophysiological mechanism of indirect ALI. Fenofibrate is known as an agonist of the peroxisome proliferator-activated receptor -α (PPARα ), the nuclear receptor superfamily member 7 . As a nuclear receptor activator, fenofibrate up-regulates or down-regulates genes that are involved in many pathophysiological processes, such as oxidative stress, inflammation, and leukocyte endothelium interactions 8, 9 . Recent studies have demonstrated an anti-oxidant, anti-inflammatory, and anti-ischemic role of fenofibrate to attenuate I/R injury in kidney 10,11 , liver 12 , brain 13,14 and heart 15 . But to date there are no literatures reporting the protective effects of fenofibrate in I/R injury in the organ of intestine. Moreover, the functional significance of fenofibrate in the intestinal I/R-induced ALI remains unclear. Therefore, this experiment is aimed to investigate whether fenofibrate administration would ameliorate the lung injury and inflammation in the model of intestinal I/R injury. Animals. The male C57BL/6 mice (8-10-wk-old; 20 ± 2 g) were purchased from Charles River (Beijing, China). Mice were kept in a temperature (21 ± 2 °C) and humidity (60 ± 5%) controlled room on a 12-hour light/dark cycle. They were fed a standard mice chow and water ad liblitum. All experiments were performed in accordance with the Declaration of Helsinki and were approved by the Institutional Animal Ethical Committee of the Peking Union Medical College Hospital.
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Protective effects of fenofibrate against acute lung injury induced by intestinal ischemia/reperfusion in mice OPEN


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Codon usage bias (CUB) is an important evolutionary feature in a genome which provides important information for studying organism evolution, gene function and exogenous gene expression. The CUB and its shaping factors in the nuclear genomes of four sequenced cotton species, G. arboreum (A 2 ), G. raimondii (D 5 ), G. hirsutum (AD 1 ) and G. barbadense (AD 2 ) were analyzed in the present study. The effective number of codons (ENC) analysis showed the CUB was weak in these four species and the four subgenomes of the two tetraploids. Codon composition analysis revealed these four species preferred to use pyrimidinerich codons more frequently than purine-rich codons. Correlation analysis indicated that the base content at the third position of codons affect the degree of codon preference. PR2-bias plot and ENC-plot analyses revealed that the CUB patterns in these genomes and subgenomes were influenced by combined effects of translational selection, directional mutation and other factors. The translational selection (P2) analysis results, together with the non-significant correlation between GC12 and GC3, further revealed that translational selection played the dominant role over mutation pressure in the codon usage bias. Through relative synonymous codon usage (RSCU) analysis, we detected 25 high frequency codons preferred to end with T or A, and 31 low frequency codons inclined to end with C or G in these four species and four subgenomes. Finally, 19 to 26 optimal codons with 19 common ones were determined for each species and subgenomes, which preferred to end with A or T. We concluded that the codon usage bias was weak and the translation selection was the main shaping factor in nuclear genes of these four cotton genomes and four subgenomes. OPEN ACCESS Citation: Wang L, Xing H, Yuan Y, Wang X, Saeed M, Tao J, et al. (2018) Genome-wide analysis of codon usage bias in four sequenced cotton species. PLoS ONE 13(3): e0194372. https://doi. codon known as synonymous codons. The synonymous codons are not used at equal frequencies in coding sequences in many organisms [1]. This phenomenon called 'synonymous codon usage bias (SCUB)' reflects non-uniform usage of synonymous codons encoding the same amino acid during the translation of genes to proteins [2,3]. The degree of SCUB divergence varies greatly among different species and genes [4-7]. SCUB was affected by many factors, including directional mutation, neutral selection [8], GC content, synonymous substitution rate [9], tRNA abundance [10], selection for efficient translation initiation [11], codon hydropathy and DNA replication initiation site [12], gene length [13] and expression level [14] , etc. Of these factors, directional mutation and neutral selection are the two main ones, with varying relative importance in different species [15] [16][17]. The codon usage patterns always represent balance between the directional mutation and the neutral selection that leads to translational efficiency of genes [8] [9] [10] [11] . SCUB patterns were also associated with phylogenetic relationship among given species. Distant phylogenetic species usually has greater variations in codon usage bias [18,19]. Information on the SCUB patterns can provide significant insights pertaining to the prediction, classification, and molecular evolution of genes, design of highly expressed genes and cloning vectors and reveal about the host-pathogen coevolution and adaptation of pathogens to specific hosts [20,21]. Clustering results based on relative synonymous codon usage (RSCU) values could provide useful reference for phylogenetic relationship analysis [18,19,22]. Cotton (Gossypium spp.) is the main source of renewable textile fibers and is also grown to produce vegetable oil and high protein meals for humans and livestock [23]. The genus Gossypium includes around 46 diploid (2n = 2x = 26) and 6 tetraploid (2n = 4x = 52) and 1 purported species [24][25][26], including four commercial ones, G. arboreum (A 2 ), G. herbaceum (A 1 ), G. hirsutum (AD 1 ) and G. barbadense (AD 2 ). It has been proposed that all diploid cotton species may have evolved from a common ancestor and allopolyploid cotton may have appeared through hybridization and subsequent polyploidization events between the A-and D-subgenome progenitors. The D-genome species G. raimondii (D 5 ) and the A-genome species much like modern G. arboreum (A 2 ) and G. herbaceum (A 2 ) are the donor species for the D and A chromosome groups of the tetraploid cotton species, respectively [27][28]. Recently, the nuclear genome sequences of G. arboreum, G. raimondii, G. hirsutum and G. barbadense, and chloroplast and mitochondrial genome sequences of G. hirsutum have successively been released [29][30][31][32][33][34][35][36][37][38], which has advanced the understanding of cotton genomics and genetics, and made it possible to investigate SCUB patterns in cotton nuclear and organelle genomes. But until now, SCUB analysis has been performed only in chloroplast genome of G. hirsutum [36]. The purpose of this study was to analyze the SCUB patterns of the four sequenced cotton species and explore the key factors influencing codon choice.
answer:

Genome-wide analysis of codon usage bias in four sequenced cotton species