Severe loneliness and isolation in nursing students during Covid-19 lockdown: a phenomenological study

In 2022, COVID-19 continued to spread across the globe, and to stop the spread of the virus and protect people’s health, universities across China continued to remain in a lockdown state. Loneliness is an important topic among college students, and the coronavirus pandemic has exacerbated loneliness. This prolonged school lockdown was unprecedented and it caused severe social isolation and emotional loneliness for students. Few people know how nursing students experience loneliness and find a way through their experience. This qualitative phenomenological study was conducted to reveal the lived experiences of nursing students who indicated COVID-19 lockdown-related loneliness in a previous quantitative survey. We performed 20 semi-structured interviews with nursing students aged 19–23 yrs during their lockdown (April 2022 to June 2022). Our research applied Colaizzi’s seven-step data analysis processes to reveal shared patterns in terms of how nursing students experienced lockdown and found the following four themes: emotional challenges associated with loneliness; causes of loneliness; positive and negative motivation to learn; and accepting solitude and reconstructing real life

Quantitatively estimating main soil water-soluble salt ions content based on Visible-near infrared wavelength selected using GC, SR and VIP

Soil salinization is the primary obstacle to the sustainable development of agriculture and eco-environment in arid regions. The accurate inversion of the major water-soluble salt ions in the soil using visible-near infrared (VIS-NIR) spectroscopy technique can enhance the effectiveness of saline soil management. However, the accuracy of spectral models of soil salt ions turns out to be affected by high dimensionality and noise information of spectral data. This study aims to improve the model accuracy by optimizing the spectral models based on the exploration of the sensitive spectral intervals of different salt ions. To this end, 120 soil samples were collected from Shahaoqu Irrigation Area in Inner Mongolia, China. After determining the raw reflectance spectrum and content of salt ions in the lab, the spectral data were pre-treated by standard normal variable (SNV). Subsequently the sensitive spectral intervals of each ion were selected using methods of gray correlation (GC), stepwise regression (SR) and variable importance in projection (VIP). Finally, the performance of both models of partial least squares regression (PLSR) and support vector regression (SVR) was investigated on the basis of the sensitive spectral intervals. The results indicated that the model accuracy based on the sensitive spectral intervals selected using different analytical methods turned out to be different: VIP was the highest, SR came next and GC was the lowest. The optimal inversion models of different ions were different. In general, both PLSR and SVR had achieved satisfactory model accuracy, but PLSR outperformed SVR in the forecasting effects. Great difference existed among the optimal inversion accuracy of different ions: the predicative accuracy of Ca2+, Na+, Cl−, Mg2+ and SO42− was very high, that of CO32− was high and K+ was relatively lower, but HCO3− failed to have any predicative power. These findings provide a new approach for the optimization of the spectral model of water-soluble salt ions and improvement of its predicative precision

Dynamic genome evolution in a model fern

The large size and complexity of most fern genomes have hampered efforts to elucidate fundamental aspects of fern biology and land plant evolution through genome-enabled research. Here we present a chromosomal genome assembly and associated methylome, transcriptome and metabolome analyses for the model fern species Ceratopteris richardii. The assembly reveals a history of remarkably dynamic genome evolution including rapid changes in genome content and structure following the most recent whole-genome duplication approximately 60 million years ago. These changes include massive gene loss, rampant tandem duplications and multiple horizontal gene transfers from bacteria, contributing to the diversification of defence-related gene families. The insertion of transposable elements into introns has led to the large size of the Ceratopteris genome and to exceptionally long genes relative to other plants. Gene family analyses indicate that genes directing seed development were co-opted from those controlling the development of fern sporangia, providing insights into seed plant evolution. Our findings and annotated genome assembly extend the utility of Ceratopteris as a model for investigating and teaching plant biology

Evolutionary and Experimental Loss of Gene Body Methylation and Its Consequence to Gene Expression

In flowering plants, gene body methylation (gbM) is associated with a subset of constitutively expressed genes. It has been proposed that gbM modulates gene expression. Here, we show that there are no consistent and direct differences to expression following the loss of gbM. By comparing expression of gbM genes in Arabidopsis thaliana accessions to orthologous genes in two Eutrema salsugineum genotypes, we identified both positive and negative expression differences associated with gbM loss. However, expression is largely unaffected by gbM loss in E. salsugineum. Expression differences between species were within the variation of expression observed within A. thaliana accessions that displayed variation in gbM. Furthermore, experimentally induced loss of gbM did not consistently lead to differences in expression compared to wild type. To date, there is no convincing data to support a direct causal link between the presence/absence of gbM and the modulation of expression in flowering plants

Clinical trials of stem cell-based therapies for pediatric diseases: a comprehensive analysis of trials registered on ClinicalTrials.gov and the ICTRP portal site

Abstract Background Research on clinical trials that employ stem cells to treat children’s diseases is limited. The clinical trial registry database provides a unique window to us to get known about clinical trial researches with different statuses. However, few studies aimed to perform a comprehensive and thorough analysis of those registered trials in the aforementioned field based on ClinicalTrials.gov and the ICTRP portal site. Methods Our study covered the clinical researches about stem cell therapy enrolling subjects aged under 18 years old registered on ClinicalTrials.gov and WHO ICTRP before May 18, 2021. A cross-sectional study was implemented to comprehensively describe and analyze the included trials that met the criteria. Results were available on ClinicalTrials.gov, and publications related to the included trials were identified. All analyses were performed utilizing the SPSS 25.0 software. Results Eventually, 202 clinical trials were included and evaluated. The participant number of trials tended to be small; 71.3% were enrolled < 50. And 93.5% of the subjects were without gender restrictions. Till May 2020, 112 trials had been preliminary completed, of which only 39 trials had published papers or uploaded results. Most (73.6%) of 186 interventional trials were in phase 1 and phase 2, where 131 (70.4%) trials were conducted without masking, and 26.3% trials were randomized; 55.4% trials were performed single group assignment. Of 16 observational trials, case-only/series took up 37.5%. Hematopoietic stem cells (37.1%) and mesenchymal stem cells (36.1%) were mostly employed, while umbilical cord blood (UCB)-derived cells (24.3%) and bone marrow (BM)-derived cells (20.8%) were the major sources. Conclusions This study provided an overall picture of utilizing stem cells for treatment and management of childhood diseases. Since clinical trials in this area are insufficient in quantity and quality, there is an urgent need of larger, better-designed trials. Increased investment in clinical research of stem cell treatment products should be carried out to achieve the transformation of results as soon as possible. Moreover, it is important to optimize the management of the registration platform and shorten the time it takes for research results to be published

Mutational robustness of HSRs.

a<p>rHSR: random HSR, which was generated by shuffling synonymous codons among sites with identical amino acids, while maintaining amino acid sequence, codon usage bias, and GC content. In addition, the MFE of rHSR is similar (located in MFE_HSR±10%) to that of native HSR. HSR-eco (HSR-efe): the HSRs only exist in <i>Escherichia coli</i> (<i>Escherichia fergusonii</i>).</p>b<p>CI: confidence interval.</p

Genome-Wide Analysis of Selective Constraints on High Stability Regions of mRNA Reveals Multiple Compensatory Mutations in <i>Escherichia coli</i>

<div><p>Message RNA (mRNA) carries a large number of local secondary structures, with structural stability to participate in the regulations of gene expression. A worthy question is how the local structural stability is maintained under the constraint that multiple selective pressures are imposed on mRNA local regions. Here, we performed the first genome-wide study of natural selection operating on high structural stability regions (HSRs) of mRNAs in <i>Escherichia coli</i>. We found that HSR tends to adjust the folded conformation to reduce the harm of mutations, showing a high level of mutational robustness. Moreover, guanine preference in HSR was observed, supporting the hypothesis that the selective constraint for high structural stability may partly account for the high percentage of G content in <i>Escherichia coli</i> genome. Notably, we found a substantially reduced synonymous substitution rate in HSRs compared with that in their adjacent regions. Surprisingly and interestingly, the non-key sites in HSRs, which have slight effect on structural stability, have synonymous substitution rate equivalent to background regions. To explain this result, we identified compensatory mutations in HSRs based on structural stability, and found that a considerable number of synonymous mutations occur to restore the structural stability decreased heavily by the mutations on key sites. Overall, these results suggest a significant role of local structural stability as a selective force operating on mRNA, which furthers our understanding of the constraints imposed on protein-coding RNAs.</p></div

Comparison of base composition between key and non-key sites.

<p>Key sites indicate those sites, mutations on which result in >15% increase in MFE.</p