Machine learning recognition of protein secondary structures based on two-dimensional spectroscopic descriptors.

Protein secondary structure discrimination is crucial for understanding their biological function. It is not generally possible to invert spectroscopic data to yield the structure. We present a machine learning protocol which uses two-dimensional UV (2DUV) spectra as pattern recognition descriptors, aiming at automated protein secondary structure determination from spectroscopic features. Accurate secondary structure recognition is obtained for homologous (97%) and nonhomologous (91%) protein segments, randomly selected from simulated model datasets. The advantage of 2DUV descriptors over one-dimensional linear absorption and circular dichroism spectra lies in the cross-peak information that reflects interactions between local regions of the protein. Thanks to their ultrafast (∼200 fs) nature, 2DUV measurements can be used in the future to probe conformational variations in the course of protein dynamics.

Effect of chlorophyll biosynthesis-related genes on the leaf color in Hosta (Hosta plantaginea Aschers) and tobacco (Nicotiana tabacum L.).

BACKGROUND: 'Regal Splendour' (Hosta variety) is famous for its multi-color leaves, which are useful resources for exploring chloroplast development and color changes. The expressions of chlorophyll biosynthesis-related genes (HrHEMA, HrPOR and HrCAO) in Hosta have been demonstrated to be associated with leaf color. Herein, we isolated, sequenced, and analyzed HrHEMA, HrPOR and HrCAO genes. Subcellular localization was also performed to determine the location of the corresponding enzymes. After plasmid construction, virus-induced gene silencing (VIGS) was carried out to reduce the expressions of those genes. In addition, HrHEMA-, HrPOR- and HrCAO-overexpressing tobacco plants were made to verify the genes function. Changes of transgenic tobacco were recorded under 2000 lx, 6000 lx and 10,000 lx light intensity. Additionally, the contents of enzyme 5-aminolevulinic acid (5-ALA), porphobilinogen (PBG), chlorophyll a and b (Chla and Chlb), carotenoid (Cxc), superoxide dismutase (SOD), peroxidase (POD), malondialdehyde (MDA), proline (Pro) and catalase (CAT) under different light intensities were evaluated. RESULTS: The silencing of HrHEMA, HrPOR and HrCAO genes can induce leaf yellowing and chloroplast structure changes in Hosta. Specifically, leaves of Hosta with HrCAO silencing were the most affected, while those with HrPOR silencing were the least affected. Moreover, all three genes in tobacco were highly expressed, whereas no expression was detected in wild-type (WT). However, the sensitivities of the three genes to different light intensities were different. The highest expression level of HrHEMA and HrPOR was detected under 10,000 lx of illumination, while HrCAO showed the highest expression level under 6000 lx. Lastly, the 5-ALA, Chla, Cxc, SOD, POD, MDA, Pro and CAT contents in different transgenic tobaccos changed significantly under different light intensities. CONCLUSION: The overexpression of these three genes in tobacco enhanced photosynthesis by accumulating chlorophyll content, but the influential level varied under different light intensities. Furthermore, HrHEMA-, HrPOR- and HrCAO- overexpressing in tobacco can enhance the antioxidant capacity of plants to cope with stress under higher light intensity. However, under lower light intensity, the antioxidant capacity was declined in HrHEMA-, HrPOR- and HrCAO- overexpressing tobaccos.

Current status and related factors of turnover intention of primary medical staff in Anhui Province, China: a cross-sectional study.

BACKGROUND: The shortage of primary medical staff is an important issue in the management of health human resources, and it is also a problem that all countries in the world need to face together. Since 2009, China has implemented a new series of medical system reforms and the shortage and loss of primary medical staff have been alleviated accordingly. However, China has a large population and it is difficult to distribute health human resources evenly across regions. This study aimed to explore the current status of turnover intention and its relationship with psychological capital, social support, and job burnout, as well as how these factors influence turnover intention of primary medical staff in Anhui province, China. METHODS: Using structured questionnaires to collect data, including demographic characteristics, turnover intention, psychological capital, social support, and Chinese Maslach Burnout Inventory scale. A total of 1152 primary medical workers of Anhui were investigated. Data were analyzed by t-test, analysis of variance (ANOVA), Pearson correlation analysis, and multiple linear regression model. RESULTS: Total scores of turnover intention, psychological capital, social support, and job burnout of subjects were 14.15 ± 4.35, 100.09 ± 15.98, 64.93 ± 13.23 and 41.07 ± 9.437, respectively. Multiple linear regression showed the related factors of turnover intention were age, job position, work unit, and scores of job burnout. Pearson correlation showed psychological capital and social support were negatively correlated with turnover intention, while the score of job burnout was positively correlated with turnover intention. CONCLUSION: The improvement of psychological capital and social support and the reduction of job burnout may play an important role in reducing turnover intention of primary medical staff. Primary medical managers should strengthen the humanistic care for primary medical staff, optimize the incentive mechanism, and improve internal management of medical institutions for stability.

Mediation role of perceived social support and burnout on financial satisfaction and turnover intention in primary care providers: a cross-sectional study.

BACKGROUND: Turnover intention is a major cause of reduced team morale and low work efficiency. It hinders work performance and reduces the quality of medical services. This study aimed to investigate the relationship between financial satisfaction and turnover intention and its mediators among primary care providers. METHODS: Multi-stage random cluster sampling was used to select 1241 participants from four counties and three districts in Anhui province, China. Data were collected using a self-administered questionnaire. Turnover intention was assessed with a turnover intention assessment scale. Perceived social support and burnout were measured with the 12-item Perceived Social Support Scale and the Chinese version of the Maslach Burnout Inventory, respectively. Structural equation modeling was used for data analysis. RESULTS: The findings showed high turnover intention among primary care providers (mean score 14.16 ± 4.337), and most providers reported low financial satisfaction (mean score 2.49 ± 0.990). The mean perceived social support score was 64.93 ± 13.229, and only 6.1% of primary care providers reported no burnout. Compared with participants with high financial satisfaction, those with low financial satisfaction were more likely to report higher turnover intention (ß = - 0.216, p < 0.001), less perceived social support (ß = 0.181, p < 0.001), and more severe burnout (ß = - 0.123, p < 0.05). Turnover intention may be related to perceived social support (ß = - 0.147, p < 0.001) and burnout (ß = 0.239, p < 0.001). Furthermore, the effect of financial satisfaction on turnover intention was significantly mediated by perceived social support (ß = - 0.027, p < 0.001) and burnout (ß = - 0.029, p < 0.05). CONCLUSIONS: Turnover intention is associated with financial satisfaction, with this association mediated by perceived social support and burnout. A reasonable mechanism needs to be established to improve financial satisfaction and perceived social support and reduce burnout among primary care providers.

Isolation and functional diversification of dihydroflavonol 4-Reductase gene HvDFR from Hosta ventricosa indicate its role in driving anthocyanin accumulation.

Anthocyanins are natural colorants are synthesized in a branch of the flavonoid pathway. Dihydroflavonol-4reductase (DFR) catalyzes dihydroflavonoids into anthocyanins biosynthesis, which is a key regulatory enzyme of anthocyanin biosynthesis in plants. Hosta ventricosa is an ornamental plant with elegant flowers and rich colorful leaves. How the function of HvDFR contributes to the anthocyanins biosynthesis is still unknown. In this study, the DFR homolog was identified from H. ventricosa and sequence analysis showed that HvDFR possessed the conserved NADPH binding and catalytic domains. A phylogenetic analysis showed that HvDFR was close to the clade formed with MaDFR and HoDFR in Asparagaceae. Gene expression analysis revealed that HvDFR was constitutive expressed in all tissues and expressed highly in flower as well as was positively correlated with anthocyanin content. In addition, the subcellular location of HvDFR showed that is in the nucleus and cell membrane. Overexpression of HvDFR in transgenic tobacco lines enhanced the anthocyanins accumulation along with the key genes upregulated, such as F3H, F3'H, ANS, and UFGT. Our results indicated a functional activity of the HvDFR, which provide an insight into the regulation of anthocyanins content in H. ventricosa.

Protection by Hosta ventricosa polysaccharides against oxidative damage induced by t-BHP in HepG2 cells via the JNK/Nrf2 pathway.

Hosta ventricosa is a plant that can be used for medicine and diet. It has been proven to have anti-inflammatory, antibacterial and antitumor activities, and one of its main constituents is polysaccharides. However, studies on polysaccharides of Hosta ventricosa are limited, and their physiological activities have not been clarified. Therefore, isolation, purification and characterization of Hosta ventricosa root polysaccharides (HVRPp-1) were performed in this research. Furthermore, the effect of HVRPp-1 on tert-butyl hydroperoxide (t-BHP)-induced oxidative damage in HepG2 cells was investigated in vitro. The results showed that HVRPp-1 is a nonhomogeneous polysaccharide that could protect HepG2 cells from oxidative damage through the C-Jun N-terminal kinase (JNK)/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. In conclusion, this research proved the antioxidant mechanism of HVRPp-1 for the first time, providing a reliable theoretical basis for basic research on Hosta ventricosa polysaccharides and the possibility of their application in functional foods.

Incentive Preferences and Its Related Factors Among Primary Medical Staff in Anhui Province, China: A Cross-Sectional Study.

Background: The shortage of primary medical staff is a major problem in the management of health human resources across many developing countries. By determining their preferences for various motivational and related factors, we examined the correlation between staff's motivation preference levels and staff turnover and turnover intention. This study aimed to further improve the incentive mechanism and to provide a reference for healthcare managers to formulate management strategies for the primary medical staff team. Methods: A self-reported questionnaire survey was conducted to collect data. The basic survey content included demographic characteristics. The absolute level questionnaire and relative level questionnaire on the factors affecting motivation preference were used as the main assessment scales. A total of 1,112 primary health workers in Anhui Province were investigated. T-test, analysis of variance (ANOVA), exploratory factor analysis, and multiple linear regression analysis were performed to analyze the data. Results: The survey respondents (45.1%) reported being satisfied with their relationship with colleagues, and other social relationships (46.9%). The Kaiser Meyer Olkin (KMO) value for the absolute preference degree for motivational factors was 0.951. Two factors (economic and non-economic factors), after using the maximum variance rotation axis method, explained 81.25% of the total variance. The regression analysis showed that primary medical staff members with low monthly income (B = -0.157) have a higher preference for non-economic factors; the higher the educational background (B = 0.133), the higher their preference for economic factors. In addition, with the increase in participants' age (B = -0.250), the preference for motivational factors gradually decreased. Conclusion: Both economic and non-economic factors play an important role in enhancing the enthusiasm of primary medical workers and improving their work attitude. Managers should use their influence to stabilize the primary medical staff.

Tumor Cells Interleukin-22 Expression Associates with Elevated Tumor-Associated Macrophages Infiltrating and Poor Prognosis in Patients with Breast Cancer.

Interleukin-22 (IL-22), secreted by tumor infiltrated lymphocytes, is identified as a tumor-promoting factor in certain cancers, which was secreted by tumor infiltrated lymphocytes. However, the role of IL-22 in breast cancer remains conflicting. In this study, we assessed the expression of IL-22, IL-22 receptor 1 (IL-22R1), CD4, CD8, FOXP3, and CD68 in breast cancer by immunohistochemistry. IL-22 expression was exhibited in 105 (69.1%) cases in tumor cells (tIL-22), whereas only 24 (15.8%) samples displayed IL-22 expression in stromal cells. Multivariate analysis showed that tIL-22 expression was a poor prognostic factor for overall survival (OS) (p = 0.04). Meanwhile, IL-22R1 was predominantly presented in tumor cells (84.9%), which was associated with tIL-22 expression. The CD68-positive tumor-associated macrophages (TAMs) displayed the highest infiltration rate (50.7%) compared with CD4-, CD8-, and FOXP3-positive cells. Kaplan-Meier analysis confirmed patients with high TAM infiltration displayed significantly worse relapse-free survival (RFS) compared with low TAMs group (p = 0.017). TAM infiltration was also positively associated with tIL-22 and IL-22R1 expression. Furthermore, tIL-22 expression together with high TAM infiltration displayed the worst prognosis outcomes both in OS (p = 0.039) and RFS (p = 0.008). Instead of lymphocytes, our data indicated that tumor cells express IL-22 in breast cancer that is associated with IL-22R1, high TAM infiltrating, and poor prognosis.

Candidate genes involved in the biosynthesis of lignan in Schisandra chinensis fruit based on transcriptome and metabolomes analysis.

Schisandra chinensis Turcz. (Baill.) is a plant species with fruits that have been well known in Far Eastern medicine for a long time. It has traditionally been used as a stimulating and fortifying agent in cases of physical exhaustion and to inhibit fatigue. The major bioactive compounds found in S. chinensis are lignans with a dibenzocyclooctadiene skeleton, but little is known about their biosynthesis in plants. S. chinensis is the ideal medicinal plant for studying the biosynthesis of lignans, especially the dibenzocyclooctadiene skeleton. Genomic information for this important herbal plant is unavailable. To better understand the lignan biosynthesis pathway, we generated transcriptome sequences from the fruit during ripening and performed de novo sequence assembly, yielding 136 843 unique transcripts with N50 of 1778 bp. Putative functions could be assigned to 41 824 transcripts (51.57%) based on BLAST searches against annotation databases including GO (Gene ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes). Furthermore, 22 candidate cytochrome P450 genes and 15 candidate dirigent proteins genes that were most likely involved in the lignan biosynthesis pathway were discovered based on transcriptome sequencing of S. chinensis. The genomic data obtained from S. chinensis, especially the identification of putative genes involved in the lignan biosynthesis pathway, will facilitate our understanding of lignan biosynthesis at the molecular level. The lignan metabolite profiles were analyzed by metabolomes, the accumulation patterns of 30 metabolites involved in the lignan pathway were studied. Co-expression network of lignan contents and transcriptional changes showed 355 strong correlations (correlation coefficient, R2 > 0.9) between 21 compounds and 153 transcripts. Furthermore, the comprehensive analysis and characterization of the genes involved in lignan pathways and the metabolite profiles of lignans are expected to provide better insight regarding the diversity of the chemical composition, synthetic characteristics, and regulatory mechanisms of this medical herb.

Transcriptome-Wide Analysis Reveals Key DEGs in Flower Color Regulation of Hosta plantaginea (Lam.) Aschers.

BACKGROUND: Hosta plantaginea (Lam.) Aschers (HPA), a species in the family Liliaceae, is an important landscaping plant and herbaceous ornamental flower. However, because the flower has only two colors, white and purple, color matching applications are extremely limited. To date, the mechanism underlying flower color regulation remains unclear. METHODS: In this study, the transcriptomes of three cultivars-H. plantaginea (HP, white flower), H. Cathayana (HC, purple flower), and H. plantaginea 'Summer Fragrance' (HS, purple flower)-at three flowering stages (bud stage, initial stage, and late flowering stage) were sequenced with the Illumina HiSeq 2000 (San Diego, CA, USA). The RNA-Seq results were validated by qRT-PCR of eight differentially expressed genes (DEGs). Then, we further analyzed the relationship between anthocyanidin synthase (ANS), chalcone synthase (CHS), and P450 and the flower color regulation by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Eukaryotic Orthologous Groups (KOG) network and pathway enrichment analyses. The overexpression of CHS and ANS in transgenic tobacco petals was verified using qRT-PCR, and the petal colors associated with the overexpression lines were confirmed using absorbance values. RESULTS: Over 434,349 transcripts were isolated, and 302,832 unigenes were identified. Additionally, through transcriptome comparisons, 2098, 722, and 606 DEGs between the different stages were found for HP, HC, and HS, respectively. Furthermore, GO and KEGG pathway analyses showed that 84 color-related DEGs were enriched in 22 pathways. In particular, the flavonoid biosynthetic pathway, regulated by CHS, ANS, and the cytochrome P450-type monooxygenase gene, was upregulated in both purple flower varieties in the late flowering stage. In contrast, this gene was hardly expressed in the white flower variety, which was verified in the CHS and ANS overexpression transgenic tobacco petals. CONCLUSIONS: The results suggest that CHS, ANS, and the cytochrome P450s-regulated flavonoid biosynthetic pathway might play key roles in the regulation of flower color in HPA. These insights into the mechanism of flower color regulation could be used to guide artificial breeding of polychrome varieties of ornamental flowers.

The complete chloroplast genome of Paphiopedilum tranlimianum (Orchidaceae).

Chloroplast (cp) genome sequences have become a useful tool for phylogeneitc and evolutionary study in recent reports. Here the complete chloroplast genome of the Paphiopedilum tranlimianum has been reconstructed from the whole-genome Illumina sequencing data. The circular genome is 162,127 bp in size, and comprises of a pair of inverted repeat (IR) regions of 31,457 bp each, a large single-copy (LSC) region of 91,711 bp, and a small single-copy (SSC) region of 7,502 bp. The total GC content is 35.4%, while the corresponding values of the LSC, SSC, and IR regions are 32.7%, 26.9%, and 40.9%, respectively. The chloroplast genome contains 133 genes, including 87 protein-coding genes, eight ribosomal RNA genes, and 38 transfer RNA genes. Three genes (ndhA, ndhE, and ndhI) are pseudogenized or lost in its cpDNA. The Maximum-Likelihood phylogenetic analysis showed a close relationship with P. niveum in Orchidaceae. Our findings provide useful information for phylogenetic and evolutionary research of Paphiopedilum species.

Decreasing the energy consumption of memory devices by enhancing the conjugation extent of the terminal electron-donating moieties within molecules.

Three small organic molecules that contained a phenothiazine backbone and triphenylamine (TPA), carbazole (CZ), or anthracene (AN) as a terminal electron donor were synthesized and fabricated in ITO/organic film/Al sandwiched memory devices. The influence of the extent of conjugation in the three molecules on the performance of their corresponding devices was investigated and the results showed that all of the fabricated devices exhibited nonvolatile ternary WORM character, whilst the switch threshold voltages decreased on moving from TPA to CZ and AN, which is promising for low-power-consumption data storage. These results revealed that tailoring the extent of conjugation in the terminal electron donor in the D-A molecules could effectively optimize the device performance, in particular the switch-threshold voltage, which could be instructive for the design of low-energy-consumption memory materials.