Exploring Research on the Construction and Application of Knowledge Graphs for Aircraft Fault Diagnosis.

Fault diagnosis is crucial for repairing aircraft and ensuring their proper functioning. However, with the higher complexity of aircraft, some traditional diagnosis methods that rely on experience are becoming less effective. Therefore, this paper explores the construction and application of an aircraft fault knowledge graph to improve the efficiency of fault diagnosis for maintenance engineers. Firstly, this paper analyzes the knowledge elements required for aircraft fault diagnosis, and defines a schema layer of a fault knowledge graph. Secondly, with deep learning as the main method and heuristic rules as the auxiliary method, fault knowledge is extracted from structured and unstructured fault data, and a fault knowledge graph for a certain type of craft is constructed. Finally, a fault question-answering system based on a fault knowledge graph was developed, which can accurately answer questions from maintenance engineers. The practical implementation of our proposed methodology highlights how knowledge graphs provide an effective means of managing aircraft fault knowledge, ultimately assisting engineers in identifying fault roots accurately and quickly.

Upregulation of acetylcholinesterase caused by downregulation of microRNA-132 is responsible for the development of dementia after ischemic stroke.

MicroRNA-132 (miR-132) has been shown to participate in many diseases. This study aimed to understand the correlation between the level of miR-132 and the severity of dementia post-ischemic stroke. An online tool (www.mirdb.org) was used to find the miR-132 binding site in acetylcholinesterase (ACHE) 3'-untranslated region (UTR), followed by a luciferase reporter assay to validate ACHE as a miR-132 target. A similar relationship between miR-132 and ACHE was also established in cerebrospinal fluid samples collected from human subjects. A negative correlation was established between ACHE and miR-132 by measuring the relative luciferase activity. Meanwhile, Western blot analysis and real-time polymerase chain reaction were also conducted to compare the levels of ACHE messenger RNA and protein between two groups (dementia positive, n = 26 and dementia negative, n = 26) or among cells treated with miR-132 mimics, ACHE small interfering RNA, and miR-132 inhibitors. As shown in the results, miR-132 can reduce the expression of ACHE. Further experiments were also carried out to study the effect of miR-132 and ACHE on cell viability and apoptosis, and the results demonstrated that miR-132 enhanced cell viability while suppressing apoptosis. In addition, ACHE reduced cell viability while promoting apoptosis. miR-132 targeted ACHE and suppressed its expression. Additionally, miR-132 and ACHE have been shown to affect the cell viability and apoptosis in the central nervous system.

Retracted: Long noncoding RNA MEG3 inhibits proliferation and migration but induces autophagy by regulation of Sirt7 and PI3K/AKT/mTOR pathway in glioma cells.

Glioma is a common primary brain tumor with high mortality rate and poor prognosis. Long noncoding RNA maternally expressed gene 3 (MEG3) is a tumor suppressor in diverse cancer types. However, the role of MEG3 in glioma remains unclear. We aimed to explore the effects of MEG3 on U251 cells as well as the underlying mechanisms. U251 cells were stably transfected with different recombined plasmids to overexpress or silence MEG3. Effects of aberrantly expressed MEG3 on cell viability, migration, apoptosis, expressions of apoptosis-associated and autophagy-associated proteins, and phosphorylated levels of key kinases in the PI3K/AKT/mTOR pathway were all evaluated. Then, messenger RNA (mRNA) and protein expression of Sirt7 in cells abnormally expressing MEG3 were estimated. In addition, effects of abnormally expressed MEG3 and Sirt7 on U251 cells were determined to reveal the underlying mechanism of MEG3-associated modulation. Cell viability and migration were significantly reduced by MEG3 overexpression whereas cell apoptosis as well as Bax and cleaved caspase-3/-9 proteins were obviously induced. Beclin-1 and LC3-II/LC3-I were upregulated and p62 was downregulated in MEG3 overexpressed cells. In addition, the autophagy pharmacological inhibitor (3-methyladenine, 3-MA) affected the effect of MEG3 overexpression on cell proliferation. Furthermore, the phosphorylated levels of key kinases in the PI3K/AKT/mTOR pathway were all reduced by MEG3 overexpression. Sirt7 was positively regulated by MEG3 expression, and effects of MEG3 overexpression on U251 cells were ameliorated by Sirt7 silence. MEG3 suppressed cell proliferation and migration but promoted autophagy in U251 cells through positively regulating Sirt7, involving in the inhibition of the PI3K/AKT/mTOR pathway.

The Urinary Metabolome of Healthy Newborns.

The knowledge of normal metabolite values for neonates is key to establishing robust cut-off values to diagnose diseases, to predict the occurrence of new diseases, to monitor a neonate's metabolism, or to assess their general health status. For full term-newborns, many reference biochemical values are available for blood, serum, plasma and cerebrospinal fluid. However, there is a surprising lack of information about normal urine concentration values for a large number of important metabolites in neonates. In the present work, we used targeted tandem mass spectrometry (MS/MS)-based metabolomic assays to identify and quantify 136 metabolites of biomedical interest in the urine from 48 healthy, full-term term neonates, collected in the first 24 h of life. In addition to this experimental study, we performed a literature review (covering the past eight years and over 500 papers) to update the references values in the Human Metabolome Database/Urine Metabolome Database (HMDB/UMDB). Notably, 86 of the experimentally measured urinary metabolites are being reported in neonates/infants for the first time and another 20 metabolites are being reported in human urine for the first time ever. Sex differences were found for 15 metabolites. The literature review allowed us to identify another 78 urinary metabolites with concentration data. As a result, reference concentration values and ranges for 378 neonatal urinary metabolites are now publicly accessible via the HMDB.

Formaldehyde degradation by UV/TiO2/O3 process using continuous flow mode.

The degradation of formaldehyde gas was studied using UV/TiO2/O3 process under the condition of continuous flow mode. The effects of humidity, initial formaldehyde concentration, residence time and ozone adding amount on degradation of formaldehyde gas were investigated. The experimental results indicated that the combination of ozonation with photocatalytic oxidation on the degradation of formaldehyde showed a synergetic action, e.g., it could considerably increase decomposing of formaldehyde. The degradation efficiency of formaldehyde was between 73.6% and 79.4% while the initial concentration in the range of 1.84-24 mg/m3 by O3/TiO2/UV process. The optimal humidity was about 50% in UV/TiO2/O3 processs and degradation of formaldehyde increases from 39.0% to 94.1% when the ozone content increased from 0 to 141 mg/m3. Furthermore, the kinetics of formaldehyde degradation reaction could be described by Langmuir-Hinshelwood model. The rate constant k of 46.72 mg/(m3 x min) and Langmuir adsorption coefficient K of 0.0268 m3/mg were obtained.

[Stream ecosystem health assessment based on the measurement of leaf litter breakdown: a case study in Hengshishui River of Guangdong Province].

Based on the Gessner' s model of leaf litter breakdown, the functional integrity and ecosystem health of Hengshishui River in Guangdong Province were assessed, and the breakdown rates of Castanopsis fissa and Schima superba leaf litters at the sites unpolluted and polluted by acid mine drainage were compared. The leaf litters of the two tree species had a significantly lower breakdown rate at polluted than at unpolluted sites (P < 0.05). According the Gessner's model, all polluted sites had an ecosystem health score 0, while all unpolluted sites had a score 2, indicating that the health status of polluted river reaches were severely damaged. The biological assessment of stream ecosystem health was consistent with the results of water quality analysis, indicating that the leaf litter breakdown model was a suitable index of stream status.

[Roles of infochemicals in host-selection process of Anastatus japonicus].

By using a Y-tube olfactometer, this paper studied the selection behavior's responses of Anastatus japonicus to the volatiles and their individual components emitted from isolated leaves and live plants of different litchi varieties, and to Tessaratoma papillosa. The results showed that among the test litchi varieties, Sanyuehong and Huaizhi had more significant attracting effects to A. japonicus than Nuomici, Guiwei, Feizixiao and Heiye. The two main components of the volatiles from litchi leaves, alpha-humulene and beta-caryophyllene, had no distinct attraction to A. japonicus, but displayed synergistic effect on the host-searching process of natural enemy. When the two components were mixed in equal concentration of 0.3 microl x microl(-1), the attracting effect was most remarkable. In a dual-choice experiment, the selectivity of A. japonicus to T. papillosa eggs was not significant, but very remarkable to T. papillosa female adults and to the water extracts from adult abdomen-tip. In a vessel experiment, the numbers of A. japonicus which made selection to T. papillosa eggs and the settling frequency of A. japonicus on the place of T. papillosa eggs were more than those of other treatments. (E)-2-hexenal, one of the most important components of the volatiles of T. papillosa adult, didn't have evident attracting effect on the adults of A. japonicus.

A non-natural dinucleotide containing an isomeric L-related deoxynucleoside: dinucleotide inhibitors of anti-HIV integrase activity.

The first X-ray crystal structure of a non-natural dinucleotide, 5'-O-phosphoryl-1'-deoxy-2'-isoadenylyl-(3' --> 5')-cytidine 6.5-hydrate (pIsodApC), C19H26N8O13P2 x 6.5H2O, belonging to a family of dinucleotides that contain an isomeric nucleoside component, is described. A complex system of hydrogen bonds between water molecules and various sites on the dinucleotide was found. All H atoms were located from electron-density difference maps, which allowed identification of protonation sites. Compounds of this family have been found to bind at the active site of HIV integrase and to be inhibitors of this key viral enzyme. These dinucleotides are completely resistant to cleavage by exonucleases; an abnormal dihedral angle twist in an internucleotide phosphate bond revealed in the X-ray crystal structure may be contributing to this unusual stability towards nucleases.