Characterization of the prevalence of Salmonella in different retail chicken supply modes using genome-wide and machine-learning analyses.

Salmonella is a foodborne pathogen that causes salmonellosis, of which retail chicken meat is a major source. However, the prevalence of Salmonella in different retail chicken supply modes and the threat posed to consumers remains unclear. The prevalence, serotype distribution, antibiotic resistance, and genomic characteristics of Salmonella in three supply modes of retail chicken (live poultry, frozen, and chilled) were investigated using whole-genome sequencing (WGS) and machine learning (ML). In this study, 480 retail chicken samples from live poultry, frozen, and chilled supply modes in Guangzhou from 2020 to 2021, as well as 253 Salmonella isolates (total isolation rate = 53.1 %), were collected. The prevalence of isolates in the live poultry mode (67.5 %, 81/120) was statistically higher than in the frozen (50.0 %, 120/240) and chilled (43.3 %, 52/120) (P < 0.05) modes. Serotype identification showed significant differences in the serotype distribution of Salmonella in different supply modes. S. Enteritis (46.7 %) and S. Indiana (14.2 %) were predominant in the frozen mode. S. Agona (23.5 %) and S. Saintpaul (13.6 %) were predominant in live poultry, while S. Enteritis (40.4 %) and S. Kentucky (17.3 %) were predominant in chilled mode. Antibiotic testing showed that frozen mode isolates were more resistant; the multidrug-resistant (MDR) rate of isolates in the frozen mode reached 91.8 %, significantly higher than in the chilled (86.5 %) and live (74.1 %) (P < 0.05) modes. WGS was performed on 155 top serotypes (S. Enteritidis, S. Kentucky, S. Indiana, and S. Agona). The antibiotic resistance gene analysis showed that the abundance and carrying rate of antibiotic resistance genes of Salmonella in the frozen mode (54 types, 16.1 %) were significantly higher than in other modes (live poultry: 36 types, 9.4 %, P < 0.05; chilled: 31 types, 11.6 %). The blaNDM-1 and blaNDM-9 genes encoding carbapenem resistance were found in frozen mode isolates on a complex transposon consisting of TnAS3-IS26. Virulence factors and plasmid replicons were abundant in the studied frozen mode isolates. In addition, single nucleotide polymorphism (SNP) phylogenetic tree results showed that in the frozen supply mode, the S. Enteritidis clonal clade continued to contaminate retail chicken meat and was homologous to S. Enteritidis strains found in farm chicken embryos, slaughterhouse chicken carcasses, and patients from hospitals in China (SNP 0 = 10). Notably, the pan-genome-based ML model showed that characteristic genes in frozen and live poultry isolates differed. The narZ gene was a key characteristic gene in frozen isolates, encoding nitrate reductase, relating to anaerobic bacterial growth. The ydgJ gene is a key characteristic gene in the live mode and encodes an oxidoreductase related to oxidative function in bacteria. The high prevalence of live poultry mode Salmonella and the transmission of frozen mode MDR Salmonella in this study pose serious risks to food safety and public health, emphasizing the importance of improving disinfection and cold storage measures to reduce Salmonella contamination and transmission. In conclusion, the continued surveillance of Salmonella across different supply models and the development of an epidemiological surveillance system based on WGS is necessary.

Polydopamine/chitosan hydrogels-functionalized polyurethane foams in situ decorated with silver nanoparticles for water disinfection.

A new facile route to decorate polyurethane foams (PUF) with dense and uniform silver nanoparticles (AgNPs) to ensure efficient and long-term water disinfection is proposed. The antibacterial sponge was fabricated by sequential treatment with chitosan hydrogels grafting, polydopamine (PDA) coating, and finally in situ growth of AgNPs on the surface of substrate. The morphologies, chemical composition, crystalline nature, mechanical property, and swelling capacity of the composite were characterized. Its silver release behavior and bactericidal performances against Escherichia coli (E. coli) were evaluated. Results show that the composite demonstrated higher mechanical strength (compression strength, 51.34 kPa) and a rapid swelling rate with an equilibrium swelling ratio of 18.2 g/g. It possessed a higher loading amount of AgNPs (35.87 mg/g) than that of PUF@Ag (8.21 mg/g) and restricted the cumulative silver release of below 0.05% after 24-h immersion in water. Besides, it presented efficient bactericidal activity with complete reduction of E. coli with 10 min of contact time. The strong bactericidal action was probably governed by strengthening the contact between AgNPs immobilized on the substrate and bacteria cells. Furthermore, the composite demonstrated exceptional reusability for five cycles and exhibited a superior processing capacity in the flow test. Finally, the composite could effectively disinfect the natural water sample like a river in 30 min under real conditions.

Chromosomal Aberrations in Pediatric Patients With Moderate/Severe Developmental Delay/Intellectual Disability With Abundant Phenotypic Heterogeneities: A Single-Center Study.

BACKGROUND: This study aimed to examine the clinical usefulness of chromosome microarray (CMA) for selective implementation in patients with unexplained moderate or severe developmental delay/intellectual disability (DD/ID) and/or combined with different dysphonic features in the Han Chinese population. METHODS: We retrospectively analyzed data on 122 pediatric patients with unexplained isolated moderate/severe DD/ID with or without autism spectrum disorders, epilepsy, dystonia, and congenital abnormalities from a single-center neurorehabilitation clinic in southern China. RESULTS: A total of 46 probands (37.7%) had abnormal CMA results among the 122 study patients. With the exclusion of aneuploidies, uniparental disomies, and multiple homozygotes, 37 patients harbored 39 pathogenic copy number variations (pCNVs) (median [interquartile range] size: 3.57 [1.6 to 7.1] Mb; 33 deletions and 6 duplications), enriched in chromosomes 5, 7, 15, 17, and 22, with a markedly high prevalence of Angelman/Prader-Willi syndrome (24.3% [nine of 37]). Three rare deletions in the regions 5q33.2q34, 17p13.2, and 13q33.2 were reported, with specific delineation of clinical phenotypes. The frequencies of pCNVs were 18%, 33.3%, 38.89%, 41.67%, and 100% for patients with 1, 2, 3, 4, and 5 study phenotypes, respectively; patients with more concomitant abnormalities in the heart, brain, craniofacial region, and/or other organs had a higher CMA diagnostic yield and pCNV prevalence (P < 0.05). CONCLUSIONS: Clinical application of CMA as a first-tier test among patients with moderate/severe DD/ID combined with congenital structural anomalies improved diagnostic yields and the quality of clinical management in this series of patients.

Case report: Sex-specific characteristics of epilepsy phenotypes associated with Xp22.31 deletion: a case report and review.

Deletion in the Xp22.31 region is increasingly suggested to be involved in the etiology of epilepsy. Little is known regarding the genomic and clinical delineations of X-linked epilepsy in the Chinese population or the sex-stratified difference in epilepsy characteristics associated with deletions in the Xp22.31 region. In this study, we reported two siblings with a 1.69 Mb maternally inherited microdeletion at Xp22.31 involving the genes VCX3A, HDHD1, STS, VCX, VCX2, and PNPLA4 presenting with easily controlled focal epilepsy and language delay with mild ichthyosis in a Chinese family with a traceable 4-generation history of skin ichthyosis. Both brain magnetic resonance imaging results were normal, while EEG revealed epileptic abnormalities. We further performed an exhaustive literature search, documenting 25 patients with epilepsy with gene defects in Xp22.31, and summarized the epilepsy heterogeneities between sexes. Males harboring the Xp22.31 deletion mainly manifested with child-onset, easily controlled focal epilepsy accompanied by X-linked ichthyosis; the deletions were mostly X-linked recessive, with copy number variants (CNVs) in the classic region of deletion (863.38 kb-2 Mb). In contrast, epilepsy in females tended to be earlier-onset, and relatively refractory, with pathogenic CNV sizes varying over a larger range (859 kb-56.36 Mb); the alterations were infrequently inherited and almost combined with additional CNVs. A candidate region encompassing STS, HDHD1, and MIR4767 was the likely pathogenic epilepsy-associated region. This study filled in the knowledge gap regarding the genomic and clinical delineations of X-linked recessive epilepsy in the Chinese population and extends the understanding of the sex-specific characteristics of Xp22.31 deletion in regard to epilepsy.

Calcium alginate gels-functionalized polyurethane foam decorated with silver nanoparticles as an antibacterial agent for point-of-use water disinfection.

This paper reports the preparation of calcium alginate gels-functionalized PUF decorated with AgNPs (CA/PUF@Ag) by in situ reduction of Ag+ ions to form AgNPs with weakly reducing glycerol in CA/PUF composite. The water-adsorbing capacity, chemical structure, crystalline nature, elemental composition and morphologies of the composite were characterized. The Ag release behavior of CA/PUF@Ag was investigated. The inhibition zone test, time-dependent co-culture assay, test tube test, and antibacterial filtration experiment with Escherichia coli as an indicator of bacterial contamination were conducted to explore the antimicrobial efficacy. Results indicated that the CA/PUF@Ag prepared at 0.25 % w/v of SA could absorb more water with a higher swelling ratio of 8.0 g/g than that of PUF@Ag (6.0 g/g), which was subsequently squeezed by minimal pressure stimuli. The CA/PUF@Ag had a larger initial AgNPs loading amount (8.48 mg/g), lower Ag release concentration (44.35 µg/L) and lower Ag release rate (0.27 %) after 14 days tests than those of PUF@Ag (7.93 mg/g, 80.87 µg/L and 0.60 % respectively). The CA/PUF@Ag was highly reusable because bacterial cells in the squeezed water recovered from the composite were completely inactivated over five cycles of operation, and exhibited good antibacterial efficacy as an antibacterial filter in a flow test.

The Relationship between Mindfulness and Social Adaptation among Migrant Children in China: The Sequential Mediating Effect of Self-Esteem and Resilience.

Social adaptation of migrant children is not only related to the physical and mental health and development of individuals, but also reflects the level of urban social integration and stable development. Mindfulness has a protective effect on individual social adaptation. Self-esteem and resilience were found to be positively associated with mindfulness and social adaptation. Based on the Positive Youth Development Perspective, this study aimed to explore whether self-esteem and resilience sequentially mediated the associations among mindfulness and social adaptation. A total of 526 migrant children were assessed with the questionnaires regarding mindfulness, self-esteem, resilience, and social adaptation. The results indicated that mindfulness was positively associated with social adaptation of migrant children. Self-esteem and resilience played the sequential mediating roles between mindfulness and social adaptation. The present study revealed the influence and mechanism of mindfulness on social adaptation and provided some guidance for the intervention programs to promote migrant children's adaptability.

Airborne Radar Anti-Jamming Waveform Design Based on Deep Reinforcement Learning.

Airborne radars are susceptible to a large number of clutter, noise and variable jamming signals in the real environment, especially when faced with active main lobe jamming, as the waveform shortcut technology in the traditional regime can no longer meet the actual battlefield radar anti-jamming requirements. Therefore, it is necessary to study anti-main-lobe jamming techniques for airborne radars in complex environments to improve their battlefield survivability. In this paper, we propose an airborne radar waveform design method based on a deep reinforcement learning (DRL) algorithm under clutter and jamming conditions, after previous research on reinforcement-learning (RL)-based airborne radar anti-jamming waveform design methods that have improved the anti-jamming performance of airborne radars. The method uses a Markov decision process (MDP) to describe the complex operating environment of airborne radars, calculates the value of the radar anti-jamming waveform strategy under various jamming states using deep neural networks and designs the optimal anti-jamming waveform strategy for airborne radars based on the duelling double deep Q network (D3QN) algorithm. In addition, the method uses an iterative transformation method (ITM) to generate the time domain signals of the optimal waveform strategy. Simulation results show that the airborne radar waveform designed based on the deep reinforcement learning algorithm proposed in this paper improves the signal-to-jamming plus noise ratio (SJNR) by 2.08 dB and 3.03 dB, and target detection probability by 26.79% and 44.25%, respectively, compared with the waveform designed based on the reinforcement learning algorithm and the conventional linear frequency modulation (LFM) signal at a radar transmit power of 5 W. The airborne radar waveform design method proposed in this paper helps airborne radars to enhance anti-jamming performance in complex environments while further improving target detection performance.

Unraveling the effect of ambivalence over emotional expression on subjective wellbeing in Chinese college students in romantic relationships: A multiple mediation model.

The sudden and unpredictable outbreak of the COVID-19 pandemic has severely threatened young adults' physical and mental health and damaged the quality of relationships. As a critical stage of development, their well-being is more vulnerable to adverse environments which may lead to profound negative long-life mental health status. The current study aimed to investigate the mediation effects of fear of intimacy and attachment avoidance in the association between ambivalence over emotional expression and subjective wellbeing. A sample of 555 Chinese college students who are currently involved in romantic relationships (Mean age = 19.69, SD age = 1.36, 52% females) completed anonymous questionnaires regarding ambivalence over emotional expression, fear of intimacy, attachment avoidance, and subjective wellbeing. The findings revealed that ambivalence over emotional expression can predict negative subjective wellbeing of college students in romantic relationships significantly, and fear of intimacy and attachment avoidance played a sequentially mediating role in the association between ambivalence over emotional expression and subjective wellbeing. Surprisingly, when considering attachment avoidance independently, we found it had an inhibitory action on the link between ambivalence over emotional expression and subjective wellbeing. The present study contributes to a better understanding of how ambivalence over emotional expression can decrease subjective wellbeing, and also has implications for the intervention of students' subjective wellbeing and closeness during the period of COVID-19.

Application Research for Fusion Model of Pseudolabel and Cross Network.

Datasets usually suffer from supervised information missing and weak generalization ability in deep convolution neural network. In this paper, pseudolabel (PL) of Weakly Supervised Learning (WSL) was used to address the problem of supervised information missing, while Cross Network (CN) of Multitask Learning (MTL) was used to solve the problem of weak generalization ability in deep convolution neural network. In PL, the data of supervised information missing was predicted; thus, PL of the corresponding data was generated. In CN, PL data and labeled data were taken as two tasks to train together. Firstly, the labeled data was divided into training dataset and testing dataset, respectively, and image preprocessing was carried out. Secondly, the network was initialized and trained, and the model with high accuracy and good generalization was selected as the optimal model. Then, the optimal model was used to predict the unlabeled data and generate PL. Finally, the steps above were repeated several times to find a better optimal model. In the experiments of the fusion model of PL and CN, Facial Beauty Prediction was regarded as main task and the others as auxiliary tasks. Experimental results show that the model was suitable for multitask training of different tasks in different or similar datasets, and the accuracy of the main task of Facial Beauty Prediction reaches 64.76%, higher than the highest accuracy by conventional methods.

DNA barcoding the flowering plants from the tropical coral islands of Xisha (China).

AIM: DNA barcoding has been widely applied to species diversity assessment in various ecosystems, including temperate forests, subtropical forests, and tropical rain forests. However, tropical coral islands have never been barcoded before due to the difficulties in field exploring. This study aims at barcoding the flowering plants from a unique ecosystem of the tropical coral islands in the Pacific Ocean and supplying valuable evolutionary information for better understanding plant community assembly of those particular islands in the future. LOCATION: Xisha Islands, China. METHODS: This study built a DNA barcode database for 155 plant species from the Xisha Islands using three DNA markers (ITS, rbcL, and matK). We applied the sequence similarity method and a phylogenetic-based method to assess the barcoding resolution. RESULTS: All the three DNA barcodes showed high levels of PCR success (96%-99%) and sequencing success (98%-100%). ITS performed the highest rate of species resolution (>95%) among the three markers, while plastid markers delivered a relatively poor species resolution (85%-90%). Our analyses obtained a marginal increase in species resolution when combining the three DNA barcodes. MAIN CONCLUSIONS: This study provides the first plant DNA barcode data for the unique ecosystem of tropical coral islands and considerably supplements the DNA barcode library for the flowering plants on the oceanic islands. Based on the PCR and sequencing success rates, and the discriminatory power of the three DNA regions, we recommend ITS as the most successful DNA barcode to identify the flowering plants from Xisha Islands. Due to its high sequence variation and low fungal contamination, ITS could be a preferable candidate of DNA barcode for plants from other tropical coral islands as well. Our results also shed lights on the importance of biodiversity conservation of tropical coral islands.

Malignant transformation potentials of human umbilical cord mesenchymal stem cells both spontaneously and via 3-methycholanthrene induction.

Human umbilical cord mesenchymal stem cells (HUMSCs) are highly proliferative and can be induced to differentiate into advanced derivatives of all three germ layers. Thus, HUMSCs are considered to be a promising source for cell-targeted therapies and tissue engineering. However there are reports on spontaneous transformation of mesenchymal stem cells (MSCs) derived from human bone marrows. The capacity for HUMSCs to undergo malignant transform spontaneously or via induction by chemical carcinogens is presently unknown. Therefore, we isolated HUMSCs from 10 donors and assessed their transformation potential either spontaneously or by treating them with 3-methycholanthrene (3-MCA), a DNA-damaging carcinogen. The malignant transformation of HUMSCs in vitro was evaluated by morphological changes, proliferation rates, ability to enter cell senescence, the telomerase activity, chromosomal abnormality, and the ability to form tumors in vivo. Our studies showed that HUMSCs from all 10 donors ultimately entered senescence and did not undergo spontaneous malignant transformation. However, HUMSCs from two of the 10 donors treated with 3-MCA displayed an increased proliferation rate, failed to enter senescence, and exhibited an altered cell morphology. When these cells (tHUMSCs) were injected into immunodeficient mice, they gave rise to sarcoma-like or poorly differentiated tumors. Moreover, in contrast to HUMSCs, tHUMSCs showed a positive expression of human telomerase reverse transcriptase (hTERT) and did not exhibit a shortening of the relative telomere length during the long-term culture in vitro. Our studies demonstrate that HUMSCs are not susceptible to spontaneous malignant transformation. However, the malignant transformation could be induced by chemical carcinogen 3-MCA.