Design, synthesis, and biological evaluation of artemyrianolide H derivatives as potential antihepatoma agents.

Artemyrianolide H (AH) is a germacrene-type sesquiterpenolid isolated from Artemisia myriantha, and showed potent cytotoxicity against three human hepatocellular carcinoma cell lines HepG2, Huh7, and SK-Hep-1 with IC50 values of 10.9, 7.2, and 11.9 µM, respectively. To reveal structure-activity relationship, 51 artemyrianolide H derivatives including 19 dimeric analogs were designed, synthesized, and assayed for their cytotoxicity against three human hepatoma cell lines. Among them, 34 compounds were more active than artemyrianolide H and sorafenib on the three cell lines. Especially, compound 25 exhibited the most promising activity with IC50 values of 0.7 (HepG2), 0.6 (Huh7), and 1.3 µM (SK-Hep-1), which were 15.5, 12.0, and 9.2-fold higher than that of AH and 16.4, 16.3 and 17.5-fold higher than that of sorafenib. Cytotoxicity evaluation on normal human liver cell lines (THLE-2) demonstrated good safety profile of compound 25 with SI of 1.9 (HepG2), 2.2 (Huh 7) and 1.0 (SK-Hep1). Further studies revealed that compound 25 dose-dependently arrested cells at G2/M phase which was correlated with the up-regulation of both cyclin B1 and p-CDK1, and induced apoptosis through the activation of mitochondrial pathways in HepG2 cells. In addition, the migratory and invasive abilities in HepG2 cells after treatment with 1.5 µM of compound 25 were decreased by 89% and 86% with the increase of E-cadherin expression accompanied by the decrease of N-cadherin, vimentin expression. Bioinformatics analysis based on machine learning predicted that PDGFRA and MAP2K2 might be acting targets of compound 25, and SPR assays demonstrated compound 25 were bound with PDGFRA and MAP2K2 with KD value of 0.168 nM, and 8.49 µM, respectively. This investigation proposed that compound 25 might be considered as a promising lead compound for the development of antihepatoma candidate.

First report of apple root rot caused by Phytopythium vexans in China.

Apple production is of great economic importance in the fruit industry of China, where Yunnan Province is considered as a major producing area. A survey was conducted to identify apple trees that were problematic from March to November 2020 in Yunnan Province. Symptoms included smaller yellowing leaves, fewer sprouts per branch, browning and necrosis of the roots and lower parts of the stem bark, and wilting. 20% to 45% of apple trees were found infected and randomly scattered in the surveyed orchards. A total of 110 soil samples were collected from the root area of symptomatic apple trees in Tuanjie Town of Kunming City, Zhaotong City, and Malong District of Qujing City in Yunnan Province. Two grams of each soil sample was suspended in 400 ml of sterile water for three days and each soil extract was baited with two apple leaves (Red Fuji's). Following the baiting, those leaves were cut into 10 pieces (5mm×5mm), surface-sterilized with 70% ethanol for 30 seconds, rinsed three times with sterile water, and then air-dried. Each leaf piece was placed in a Petri dish with the oatmeal agar medium containing PCNB 20 mg/ml, rifampicin 20 mg/ml, and then incubated at 25℃ in the dark for 3 days. A mycelial agar plug was picked from the edge of the colonies and transferred to a fresh Potato Dexrose Agar (PDA) plate. Seventy colonies with similar growing characteristics were isolated from the 110 soil samples. Three isolates were retained for further analysis and named XLD8-1, SD1, and YF2. After being cultivated on PDA plates and incubated at 25℃ in the dark for 4 days, their colonies were rose petal-type and white with dense aerial hyphae (Fig 1, A). In ten days of incubation, oogonium measuring 24.55 ± 1.9µm × 20.27 ± 2.3µm and sporangia measuring 21.65 ± 1.3µm × 19.35 ± 1µm were observed (Fig 1, C, D). The total DNA of the isolates was extracted and amplified using three pairs of primers, ITS1/ITS4 (White et al. 1990), LROR/LR7 (LSU) (Vilgalys R, et al. 1990), and FM58/FM66 (COXⅡ) (Martin F N. 2000). The sequences were uploaded to GenBank (Accession No. OL960234, OK037658, OK052604 for ITS, OL960388, OM838413, OM838314 for LSU, and OM962847, OM962848, OM962849 for COXⅡ). ITS sequences of the three isolates (XLD8-1, SD1, YF2) showed 99.87%,99.87%, 99.87% similar to Pp. vexans (Accession No. AB468784, AB468784, and AM701801). LSU sequences of the three isolates showed 99.92%, 99.72%, 100% similar to Pp. vexans (Accession No. EF426541, MT729990, and EF426541). COXⅡ sequences of the three isolates showed 100%, 99.81%, 99.81% similar to Pp. vexans (Accession No. GU133560). Based on the sequence similarity and morphology, the isolates were identified as Phytopythium vexans. Koch's postulates were conducted by wounding the bases of 3 apple seedlings (1-year-old Red Fuji's) with a cork borer. A plug of mycelium of the isolate XLD8-1 grown on PDA plates was placed on each wound (Fig 1, B). Controls were set up to use sterile agar plugs as an inoculum. Seedlings have incubated an incubator at 23-26°C under the alternating light and dark intervals, 12-hours of each. In 15 days, after were inoculated with XLD8-1 the roots and lower part of the stem bark of those seedlings became brownish and necrotic, and their epidermis was easily sloughed off (Fig 1, E-G). The pathogen isolated from the necrotic root tissues were identical to the isolate XLD8-1. Symptoms of apple growth decline caused by Pp. vexans were reported in Morocco (Jabiri Salma, et al. 2021). This experiment verified that Pp. vexans causes root rot of apple. In China, Fusarium sp. is usually considered the main pathogen causing apple root rot. However, the discovery of large numbers of apple trees that were infected by Pp. vexans in Yunnan Province and the confirmation of pathogenicity of Pp. vexans on apple seedlings have demonstrated for the first time that Pp. vexans could cause apple root rot as Fusarium spp does and become an incoming threat to the apple industry, which lays the foundation for study on the disease epidemiology and integrated management of apple root rot in China. References: Jabiri Salma, et al. 2021. Microorganisms, doi:10.3390/MICROORGANISMS9091916. Martin, F. N. 2000. Mycologia, 92(4), 711-727. Vilgalys R., et al. 1990. Journal of Bacteriology, 172:4238-4246 White, T. J., et al. 1990. PCR Protocols: a guide to methods and applications, 18: 315.

Identification of key non-coding RNAs and transcription factors regulators and their potential drugs for steroid-induced femoral head necrosis.

Steroid-induced necrosis of femoral head (SINFH) is a femoral head necrotic disease caused by prolonged use of hormones. The detailed pathogenesis has not been fully demonstrated. In this study, we employed the bioinformatics approach to probe the roles of SINFH inhibitors. Core dysfunction modules related to SINFH was obtained. Meanwhile, GO and KEGG analysis of genes in dysfunction modules are carried out. Furthermore, the pivot prediction analysis of dysfunction modules related to ncRNA and transcription factor (TF) has been performed. The functions of the enriched modules were focused on multiple perspectives, including circulation, gland development, bone development and reconstruction, calcium production, and fatty acid metabolism regulation. The ncRNAs and TFs analysis showed that miR-322-5p, miR-124-3p, miR-125a-3p, and Ctnnb1 were important members of SINFH dysfunction. Drug targets suggested that Zinc and adenosine monophosphate may have an impact on SINFH dysfunction. SINFH was closely related to bone development and reconstruction.

[Serum metabolomics of preterm and full-term infants based on gas chromatography-mass spectrometry].

OBJECTIVE: To study the features of serum metabolites in preterm infants based on gas chromatography-mass spectrometry (GC-MS), and to find differentially expressed metabolites in the serum of preterm infants. METHODS: Serum samples were collected from 19 preterm infants and 20 full-term infants before feeding. GC-MS was used to measure metabolic profiles, and the metabolic features of 397 serum metabolites in preterm infants were analyzed. RESULTS: There was a significant difference in serum metabolic features between the preterm and full-term infants before feeding. There were significant differences between the full-term and preterm infants in the levels of metabolites such as O-phosphonothreonine, digicitrin, tannic acid, and fructose-1,6-diphosphate (P<0.01), suggesting that the above differentially expressed metabolites were highly differentiated between the preterm and full-term infants. Most differentially expressed metabolites were involved in the metabolic pathways such as ABC transporters, ß-alanine and pyrimidines and were correlated with some clinical parameters (albumin and total bilirubin) (P<0.05). CONCLUSIONS: There is a significant difference in serum metabolites between preterm and full-term infants before feeding. Metabolomics plays an important role in improving metabolic disorders and exploring metabolism-related diseases in preterm infants.

Transcription Factor AsMYC2 Controls the Jasmonate-Responsive Expression of ASS1 Regulating Sesquiterpene Biosynthesis in Aquilaria sinensis (Lour.) Gilg.

Sesquiterpenes are one of the most important defensive secondary metabolite components of agarwood. Agarwood, which is a product of the Aquilaria sinensis response to external damage, is a fragrant and resinous wood that is widely used in traditional medicines, incense and perfume. We previously reported that jasmonic acid (JA) plays an important role in promoting agarwood sesquiterpene biosynthesis and induces expression of the sesquiterpene synthase ASS1, which is a key enzyme that is responsible for the biosynthesis of agarwood sesquiterpenes in A. sinensis. However, little is known about this molecular regulation mechanism. Here, we characterized a basic helix-loop-helix transcription factor, AsMYC2, from A. sinensis as an activator of ASS1 expression. AsMYC2 is an immediate-early jasmonate-responsive gene and is co-induced with ASS1. Using a combination of yeast one-hybrid assays and chromatin immunoprecipitation analyses, we showed that AsMYC2 bound the promoter of ASS1 containing a G-box motif. AsMYC2 activated expression of ASS1 in tobacco epidermis cells and up-regulated expression of sesquiterpene synthase genes (TPS21 and TPS11) in Arabidopsis, which was also promoted by methyl jasmonate. Our results suggest that AsMYC2 participates in the regulation of agarwood sesquiterpene biosynthesis in A. sinensis by controlling the expression of ASS1 through the JA signaling pathway.

Computational probing protein-protein interactions targeting small molecules.

MOTIVATION: With the booming of interactome studies, a lot of interactions can be measured in a high throughput way and large scale datasets are available. It is becoming apparent that many different types of interactions can be potential drug targets. Compared with inhibition of a single protein, inhibition of protein-protein interaction (PPI) is promising to improve the specificity with fewer adverse side-effects. Also it greatly broadens the drug target search space, which makes the drug target discovery difficult. Computational methods are highly desired to efficiently provide candidates for further experiments and hold the promise to greatly accelerate the discovery of novel drug targets. RESULTS: Here, we propose a machine learning method to predict PPI targets in a genomic-wide scale. Specifically, we develop a computational method, named as PrePPItar, to Predict PPIs as drug targets by uncovering the potential associations between drugs and PPIs. First, we survey the databases and manually construct a gold-standard positive dataset for drug and PPI interactions. This effort leads to a dataset with 227 associations among 63 PPIs and 113 FDA-approved drugs and allows us to build models to learn the association rules from the data. Second, we characterize drugs by profiling in chemical structure, drug ATC-code annotation, and side-effect space and represent PPI similarity by a symmetrical S-kernel based on protein amino acid sequence. Then the drugs and PPIs are correlated by Kronecker product kernel. Finally, a support vector machine (SVM), is trained to predict novel associations between drugs and PPIs. We validate our PrePPItar method on the well-established gold-standard dataset by cross-validation. We find that all chemical structure, drug ATC-code, and side-effect information are predictive for PPI target. Moreover, we can increase the PPI target prediction coverage by integrating multiple data sources. Follow-up database search and pathway analysis indicate that our new predictions are worthy of future experimental validation. CONCLUSION: In conclusion, PrePPItar can serve as a useful tool for PPI target discovery and provides a general heterogeneous data integrative framework. AVAILABILITY AND IMPLEMENTATION: PrePPItar is available at http://doc.aporc.org/wiki/PrePPItar. CONTACT: ycwang@nwipb.cas.cn or ywang@amss.ac.cn SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

[Prokaryotic expression and purification of Aquilaria sinensis(Lour.) Gilg AsMYC2 protein].

The MYC2 transcription factor is a member of the important plant b HLH transcription factor families, and it is also the core regulatory elements in jasmonate（JA） signaling pathway. However, there is a little information about AsMYC2 gene in Aquilaria sinensis. In this study, with the total RNA isolated from A. sinensis leave as template, the full-length coding sequence (CDS) of AsMYC2 gene was amplified using RT-PCR method and subcloned into pGEX-4T-1 vector by the gene recombination technique. The recombinant vector pGEX-4T-1-AsMYC2 was verified by restriction enzyme digestion and nucleotide sequencing, and was transformed into E. coli BL21（DE3） to express the protein. A maximum expression of soluble protein was observed with induction by 0.1 mmol·L(-1) IPTG at 37 ℃ for 4 hours. The fusion protein was purified through a Sepharose-Glutathione column, and verified by SDS-PAGE and Western blotting using an anti-GST polyclonal antibody. We successfully constructed the GST-AsMYC2 plasmid, produced and purified the GST-AsMYC2 fusion protein, which would provide the basic material for polyclonal antibody preparation, interactive factors screening and gene function research. According to the tissue-specific expression pattern analysis by q RT-PCR method, the AsMYC2 gene in A. sinensis tissues is mainly expressed in roots and stems, the main agarwood formation parts, and lowest expressed in leaves. These results indicate that AsMYC2 gene likely play some roles in agarwood formation in A. sinensis.

[Construction and expression of prokaryotic vector of AsJAZ1 gene from Aquilaria sinensis].

The full-length coding sequence (cds) of jasmonate-zim-domain protein (AsJAZ1) gene was cloned from Aquilaria sinensis, the prokaryotic vector was constructed and the recombinant proteins expression was induced to provide the basic material for interactive proteins screen and gene function research. In this study, with the total RNA isolated from A. sinensis leave as template, the full-length cds of AsJAZ1 gene was amplified using RT-PCR method and subcloned into pET-28a vector. The recombinant plasmid identified by restriction enzyme digestion and nucleotide sequencing was transformed into E. coli BL21(DE3). Inducing with 0.5 mmol•L⁻¹ IPTG at 37 ℃ for 4 hours, a fusion protein about 39 kDa was maximumly obtained. AsJAZ1 fusion protein had been expressed successfully mainly in the form of inclusion bodies and only a very small amount was secreted into the cytoplasm in the supernatant.

Network predicting drug's anatomical therapeutic chemical code.

MOTIVATION: Discovering drug's Anatomical Therapeutic Chemical (ATC) classification rules at molecular level is of vital importance to understand a vast majority of drugs action. However, few studies attempt to annotate drug's potential ATC-codes by computational approaches. RESULTS: Here, we introduce drug-target network to computationally predict drug's ATC-codes and propose a novel method named NetPredATC. Starting from the assumption that drugs with similar chemical structures or target proteins share common ATC-codes, our method, NetPredATC, aims to assign drug's potential ATC-codes by integrating chemical structures and target proteins. Specifically, we first construct a gold-standard positive dataset from drugs' ATC-code annotation databases. Then we characterize ATC-code and drug by their similarity profiles and define kernel function to correlate them. Finally, we use a kernel method, support vector machine, to automatically predict drug's ATC-codes. Our method was validated on four drug datasets with various target proteins, including enzymes, ion channels, G-protein couple receptors and nuclear receptors. We found that both drug's chemical structure and target protein are predictive, and target protein information has better accuracy. Further integrating these two data sources revealed more experimentally validated ATC-codes for drugs. We extensively compared our NetPredATC with SuperPred, which is a chemical similarity-only based method. Experimental results showed that our NetPredATC outperforms SuperPred not only in predictive coverage but also in accuracy. In addition, database search and functional annotation analysis support that our novel predictions are worthy of future experimental validation. CONCLUSION: In conclusion, our new method, NetPredATC, can predict drug's ATC-codes more accurately by incorporating drug-target network and integrating data, which will promote drug mechanism understanding and drug repositioning and discovery. AVAILABILITY: NetPredATC is available at http://doc.aporc.org/wiki/NetPredATC. CONTACT: ycwang@nwipb.cas.cn or ywang@amss.ac.cn SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

[Cloning and expression analysis of cinnamate 4-hydroxylase (C4H) reductase gene from Aquilaria sinensis].

The study aimed to clone the open reading frame of cinnamate 4-hydroxylase (C4H) from Aquilaria sinensis and analyze the bioinformatics and expression of the gene. One unique sequence containing C4H domain was discovered in our previous reported wound transcriptome dataset of A. sinensis. The open reading frame of C4H was cloned by RT-PCR strategy with the template of mixed RNA extracted from A. sinensis stem which treated by different wound time. The bioinformatic analysis of this gene and its corresponding protein was performed. C4H expression profiles in responds to MeJA (methyl jasmonate) application were analyzed by real-time PCR. The length of C4H open reading frame (ORF) was 1 515 bp, encoding 514 amino acids. The GenBank accession number is KF134783. Inducible-experiments showed that the genes were induced by mechanical wound as well as MeJA induction, and reached the highest expression level at 8 h and 20 h, respectively. The full-length cDNA of C4H and its expression patterns will provide a foundation for further research on its function in the molecular mechanisms of aromatic compounds and flavonoids biosynthesis.

Compound-protein interaction prediction based on heterogeneous network reveals potential antihepatoma agents.

Despite the development of an increasing number of multi-kinase and immune checkpoint inhibitors for hepatocellular carcinoma (HCC), improvement in cancer survival remains limited due to their similar structures and targets. Natural products (NPs) maintain diverse structures and activities and are important sources of drug discovery. Currently, most of active NPs exhibit ambiguous binding targets and mechanisms. Herein, we proposed the CIPHEN (compound-protein interactions prediction based on the heterogeneous network) to predict potential antihepatoma NPs and their targets. The evaluation of canonical compound-protein interactions (CPIs) databases and independent test demonstrated the good ability of CPIHN to reveal known and unreported CPIs. Both prediction and experiment results indicated that CIPHEN could unveil relationships between actively antihepatoma sesquiterpenoid dimers (SDs) and anti-HCC targets. In conclusion, the CIPHEN provides a promising choice to investigate the mode of action of compounds, which will help to accelerate the process of drug research and development against HCC.

Artemyriantholides A-K, guaiane-type sesquiterpenoid dimers from Artemisia myriantha var. pleiocephala and their antihepatoma activity.

Artemyriantholides A-K (1-11) as well as 14 known compounds (12-25) were isolated from Artemisia myriantha var. pleiocephala (Asteraceae). The structures and absolute configuration of compounds 2 and 8-9 were confirmed by the single crystal X-ray diffraction analyses, and the others were elucidated by MS, NMR spectral data and electronic circular dichroism calculations. All compounds were chemically characterized as guaiane-type sesquiterpenoid dimers (GSDs). Compound 1 was the first example of the GSD fused via C-3/C-11' and C-5/C-13' linkages, and compounds 2 and 5 were rare GSDs containing chlorine atoms. Eleven compounds showed obvious inhibitory activity in HepG2, Huh7 and SK-Hep-1 cell lines by antihepatoma assay to provide the IC50 values ranging from 7.9 to 67.1 µM. Importantly, compounds 5 and 8 exhibited the best inhibitory activity with IC50 values of 14.2 and 18.8 (HepG2), 9.0 and 11.5 (Huh7), and 8.8 and 11.3 µM (SK-Hep-1), respectively. The target of compound 5 was predicted to be MAP2K2 by a computational prediction model. The interaction between compound 5 and MAP2K2 was conducted to give docking score of -9.0 kcal/mol by molecular docking and provide KD value of 43.7 µM by Surface Plasmon Resonance assay.

MRI findings in patients with defecatory dysfunction after surgical correction of anorectal malformation.

BACKGROUND: Postoperative anorectal malformation patients frequently have defecatory dysfunction. MRI may be useful in the management of these patients. OBJECTIVE: To analyze static and dynamic MRI findings in patients with defecatory dysfunction after correction of anorectal malformation (ARM), and compare differences between patients with constipation and fecal incontinence. MATERIALS AND METHODS: Pelvic MRI studies of 20 constipated and 32 incontinent postoperative ARM patients were analyzed retrospectively to determine the location and morphology of the neorectum, presence of peritoneal fat herniation, presence of scarring, development of the striated muscle complex (SMC) and any other abnormalities. The two groups were then compared using χ(2)-test. Eighteen patients also underwent MRI defecography to evaluate pelvic floor function and abnormalities are reported. RESULTS: The children with incontinence were more likely to have abnormal location of the neorectum (P = 0.031), increased anorectal angle (ARA) (P = 0.031) and peritoneal fat herniation (P = 0.032), and less likely to have dilation of the neorectum (P = 0.027), than the children with constipation. There were no significant differences between the two groups in incidence of focal stenosis of the neorectum (P = 0.797), presence of extensive scarring (P = 0.591) and developmental agenesis of the SMC (P > 0.05). MRI defecography showed 6 anterior rectoceles, 6 cystoceles and 18 pelvic floor descents. CONCLUSIONS: MRI is a helpful imaging modality in postoperative ARM patients with defecatory dysfunction, and it shows distinct differences between the children with constipation and incontinence and provides individualized information to guide further treatment.

Characteristics of Electrocardiogram Findings in Fulminant Myocarditis.

Fulminant myocarditis (FM) is an acute and severe form of myocarditis with rapid progression and poor clinical outcomes in the absence of acute or chronic coronary artery disease. Electrocardiogram (ECG) abnormalities can provide preliminary clues for diagnosis; however, there is a lack of systemic descriptions on ECG changes in FM populations. Thus, a retrospective analysis of 150 consecutive FM patients and 300 healthy controls was performed to determine the characteristic ECG findings in FM. All patients included had markedly abnormal ECG findings. Specifically, 83 (55.33%) patients had significantly lower voltage with remarkably decreased QRS amplitudes in all leads compared with healthy controls (p < 0.01), and 77 (51.33%) patients had a variety of arrhythmias with lethality ventricular tachycardia/ventricular fibrillation in 21 (14.00%) patients and third-degree atrioventricular block in 21 (14.00%) patients, whereas sinus tachycardia was only found in 43 (28.67%) patients with the median heart rate (HR; 88.00 bpm, IQR: 76.00-113.50) higher than that of controls (73.00 bpm, IQR: 68.00-80.00) (p = 0.000). Conduction and repolarization abnormalities were common in patients. A longer QTc interval (452.00 ms, IQR: 419.00-489.50) and QRS duration (94.00 ms, IQR: 84.00-119.00) were observed in patients compared to controls (QTc interval = 399.00 ms, IQR: 386.00-414.00; QRS duration = 90.00 ms, IQR: 86.00-98.00) (p < 0.05). Additionally, HR > 86.50 bpm, QTc > 431.50 ms, and RV5 + SV1 < 1.715 mV can be used to predict FM. Thus, marked and severe ECG abnormalities provide preliminary clues for the diagnosis of FM.

[Effect of invisible appliance without bracket and self-locking bracket appliance on periodontal and subgingival flora in patients with periodontitis].

PURPOSE: To observe the effect of non-bracket invisible appliance and self-locking bracket appliance on periodontal health and subgingival flora in patients with periodontitis. METHODS: One hundred and ten patients with periodontitis who received orthodontic treatment were divided into invisible group and self-locking bracket group. The periodontal index including probing depth (PD), gingival index (GI), sulcular bleeding index (SBI) and plaque index (PLI) ，and the levels of inflammatory factors in the gingival crevicular fluid were examined. Visual analogue scale (VAS) was used to evaluate periodontal pain before and after correction, and the curative effect was evaluated. The status of common pathogenic bacteria in the subgingival plaque of patients after correction was detected by PCR. The data were analyzed with SPSS19.0 software package. RESULTS: Twelve months after treatment and at the end of treatment, PLI of the self-locking bracket group was significantly higher than the invisible group(P＜0.05), but PD, GI and SBI between the two groups had no significant difference. After correction, the inflammatory factors in the invisible group were significantly lower than those in the self-locking bracket group(P＜0.05). At 1d after treatment, pain index in the invisible group was significantly lower than the self-locking group(P＜0.05). The clinical total effective rate of the invisible group was significantly higher than the self-locking group (89.10% vs 76.36%). After treatment, the detection rate and the content of subgingival pathogenic bacteria in the self-locking bracket group were significantly higher than the invisible group(P＜0.05). CONCLUSIONS: During orthodontic treatment of periodontitis, wearing non-bracket invisible appliance can effectively inhibit inflammatory response and proliferation of subgingival pathogens, which is more conducive to the maintenance of periodontal health and oral hygiene.

Research on supporting mechanism of ancillary service of PV system to grid energy efficiency based on multi-time and space-time operation.

Under the background of high-energy penetration of new energy into the power grid, this paper takes the ancillary service capability of photovoltaic energy integrated into the grid as the starting point and builds a photovoltaic system reactive power service impact evaluation model on the grid energy efficiency. This is based on the multi-temporal and spatial scale operation mode, in order to study the supporting principles of photovoltaic system reactive power services on the energy efficiency of grid operation and the law of influence on system energy efficiency changes. In this way, the space for power system energy efficiency improvement and the reactive power service market value of renewable energy are explored to improve the renewable energy auxiliary services participation in the theoretical system of electric power spot market transactions. The research conclusions can provide a decision-making reference for system dynamic energy efficiency management and can assist relevant market entities to make optimal decisions in spot market transactions, and provide empirical data for improving the theory of renewable energy participation in auxiliary service market transactions.

Improving accuracy of protein-protein interaction prediction by considering the converse problem for sequence representation.

BACKGROUND: With the development of genome-sequencing technologies, protein sequences are readily obtained by translating the measured mRNAs. Therefore predicting protein-protein interactions from the sequences is of great demand. The reason lies in the fact that identifying protein-protein interactions is becoming a bottleneck for eventually understanding the functions of proteins, especially for those organisms barely characterized. Although a few methods have been proposed, the converse problem, if the features used extract sufficient and unbiased information from protein sequences, is almost untouched. RESULTS: In this study, we interrogate this problem theoretically by an optimization scheme. Motivated by the theoretical investigation, we find novel encoding methods for both protein sequences and protein pairs. Our new methods exploit sufficiently the information of protein sequences and reduce artificial bias and computational cost. Thus, it significantly outperforms the available methods regarding sensitivity, specificity, precision, and recall with cross-validation evaluation and reaches ~80% and ~90% accuracy in Escherichia coli and Saccharomyces cerevisiae respectively. Our findings here hold important implication for other sequence-based prediction tasks because representation of biological sequence is always the first step in computational biology. CONCLUSIONS: By considering the converse problem, we propose new representation methods for both protein sequences and protein pairs. The results show that our method significantly improves the accuracy of protein-protein interaction predictions.

The Influence of Internal and External Stakeholder Mechanisms on Entrepreneurial Success: The Moderating Role of Digital Technology Adoption.

The purpose of this research is to investigate the associations of internal and external support mechanisms with entrepreneurial success, in the context of China's entrepreneurial sector from network theory perspective. The role of digital technology, as a moderator, has also been analyzed. Data has been obtained from 500 entrepreneurs in Jiangsu, a province in China. All hypotheses were tested using structural equation modeling. It has been found that family support, business partner support, community support and external stakeholder relationships have positive effects on entrepreneurial success. It has also been discovered that digital technology adoption strengthens the positive relationship between business partner support and entrepreneurial success. Theoretical and practical implications have been highlighted and future research suggestions have been provided.

Identification of differences in N6-methyladenosine-related genes in steroid-induced femoral head necrosis / 中国组织工程研究

BACKGROUND:It is known that N6-methyladenosine(m6A)plays a role in the pathogenesis of various diseases and studies have suggested its involvement in the pathologic changes of steroid-induced femoral head necrosis(SNFH).However,research on m6A methylation modifications in steroid-induced femoral head necrosis is limited. OBJECTIVE:Using bioinformatics methods to identify the differential expression of m6A-related genes in steroid-induced femoral head necrosis and to predict miRNAs associated with these genes to further elucidate the role and mechanism of m6A methylation in steroid-induced femoral head necrosis. METHODS:Differential gene expression between steroid-induced femoral head necrosis and control groups was analyzed using GSE123568 gene expression data and identified using the"limma"package in R.Functional enrichment analysis was performed on the differentially expressed genes.Differential analysis of the related genes was carried out using the"ggstatsplot"package in R.The differential genes were cross-validated using the GSE74089 dataset.An mRNA-miRNA regulatory network was constructed,and co-expression analysis was performed on the module genes followed by enrichment analysis.Differences in immune cell infiltration between steroid-induced femoral head necrosis and control groups were quantified using the ssGSEA method. RESULTS AND CONCLUSION:Correlation analysis revealed 13 m6A-related genes,and further analysis through the protein-protein interaction network identification and receiver operating characteristic curve analysis showed that YTHDF2 was expected to be a core differential gene as a potential early biomarker.Enrichment analysis indicated that differentially expressed genes were mainly involved in inflammation and immune response and were closely related to osteoclasts.Cross-validation analysis showed that differential gene expression results between the two datasets were consistent.mRNA-miRNA regulatory network analysis revealed that YTHDF2 was negatively correlated with miRNA-27a.Immune infiltration analysis revealed an increase in immune cell infiltration in steroid-induced femoral head necrosis,and YTHDF2 was positively correlated with the infiltration of CD4+T cells.To conclude,m6A-related gene YTHDF2 can serve as a potential biomarker of steroid-induced femoral head necrosis and is valuable for the early clinical diagnosis and treatment of steroid-induced femoral head necrosis.The negative correlation between YTHDF2 and mir-27a and the positive correlation between YTHDF2 and CD4+T cell infiltration provide new insights into the early diagnosis and treatment of steroid-induced femoral head necrosis and shed light on the mechanism of m6A in steroid-induced femoral head necrosis.