An Aided Navigation Method Based on Strapdown Gravity Gradiometer.

The gravity gradient is the second derivative of gravity potential. A gravity gradiometer can measure the small change of gravity at two points, which contains more abundant navigation and positioning information than gravity. In order to solve the problem of passive autonomous, long-voyage, and high-precision navigation and positioning of submarines, an aided navigation method based on strapdown gravity gradiometer is proposed. The unscented Kalman filter framework is used to realize the fusion of inertial navigation and gravity gradient information. The performance of aided navigation is analyzed and evaluated from six aspects: long voyage, measurement update period, measurement noise, database noise, initial error, and inertial navigation system device level. When the parameters are set according to the benchmark parameters and after about 10 h of simulation, the results show that the attitude error, velocity error, and position error of the gravity gradiometer aided navigation system are less than 1 arcmin, 0.1 m/s, and 33 m, respectively.

Analysis of the correlation between mechanical and physicochemical properties of particles based on a diesel oxidation catalytic system.

The mechanical and physicochemical properties of diesel engine exhaust particles before and after diesel oxidation catalyst (DOC) treatment are analyzed. It is considered important to explore the interrelationships between these attributes in order to understand their relevance. Understanding of these properties provides insights into the deposition characteristics of particles within the system and the evolution of the particles after the DOC treatment, which may help the selection of appropriate aftertreatment strategies. In this paper, particle samples were collected before and after the DOC to explore the variations in the mechanical and physicochemical properties of the particles under different operating conditions. Atomic force microscopy, thermogravimetric analysis, transmission electron microscopy, and Raman spectroscopy were employed to investigate the attraction force, adhesion force, adhesion energy, oxidative reactivity, primary particle size, nanostructure, and graphitization degree of the particles. The results indicated that under post-injection conditions, the attraction force, adhesion force, and adhesion energy of the particles increased significantly. However, when the particles passed through the DOC, these properties decreased to varying degrees. By analyzing the combination of physicochemical properties, it was determined that the attraction force of the particles was primarily influenced by the primary particle size and the particle's graphite structure. The adhesion force was found to be closely related to the content of soluble organic matter. Additionally, the soluble organic matter affected the degree of particle agglomeration by altering the adhesion energy of the particles.

Key genes and regulatory networks for diabetic retinopathy based on hypoxia-related genes: a bioinformatics analysis.

AIM: To prevent neovascularization in diabetic retinopathy (DR) patients and partially control disease progression. METHODS: Hypoxia-related differentially expressed genes (DEGs) were identified from the GSE60436 and GSE102485 datasets, followed by gene ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Potential candidate drugs were screened using the CMap database. Subsequently, a protein-protein interaction (PPI) network was constructed to identify hypoxia-related hub genes. A nomogram was generated using the rms R package, and the correlation of hub genes was analyzed using the Hmisc R package. The clinical significance of hub genes was validated by comparing their expression levels between disease and normal groups and constructing receiver operating characteristic curve (ROC) curves. Finally, a hypoxia-related miRNA-transcription factor (TF)-Hub gene network was constructed using the NetworkAnalyst online tool. RESULTS: Totally 48 hypoxia-related DEGs and screened 10 potential candidate drugs with interaction relationships to upregulated hypoxia-related genes were identified, such as ruxolitinib, meprylcaine, and deferiprone. In addition, 8 hub genes were also identified: glycogen phosphorylase muscle associated (PYGM), glyceraldehyde-3-phosphate dehydrogenase spermatogenic (GAPDHS), enolase 3 (ENO3), aldolase fructose-bisphosphate C (ALDOC), phosphoglucomutase 2 (PGM2), enolase 2 (ENO2), phosphoglycerate mutase 2 (PGAM2), and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3). Based on hub gene predictions, the miRNA-TF-Hub gene network revealed complex interactions between 163 miRNAs, 77 TFs, and hub genes. The results of ROC showed that the except for GAPDHS, the area under curve (AUC) values of the other 7 hub genes were greater than 0.758, indicating their favorable diagnostic performance. CONCLUSION: PYGM, GAPDHS, ENO3, ALDOC, PGM2, ENO2, PGAM2, and PFKFB3 are hub genes in DR, and hypoxia-related hub genes exhibited favorable diagnostic performance.

[Assessment on ecological integrity of typical lakes, reservoirs and wetlands in Tianjin, China]. / å¤©æ´¥å¸‚å ¸åž‹æ¹–åº“æ¹¿åœ°ç”Ÿæ€å®Œæ•´æ€§è¯„ä»·.

The ecological health assessment of lakes, reservoirs and wetlands can provide decision-making basis for ecosystem restoration and management. We selected 20 typical lakes, reservoirs and wetlands sampling points in Tianjin, based on physical, chemical, and biological community indicators data (zooplankton, phytoplankton, benthos, fish, large aquatic plants, riparian plants) obtained during the survey from August to September 2018. We constructed an index of ecological integrity (IEI) including physical integrity, chemical integrity, and biological integrity to evaluate their ecological health. The reference points were selected based on three aspects using standardized methods: habitat environmental quality index (QHEI), water quality status, and disturbance of human activities. The analytic hierarchy process was used to calculate the weight of the three indicators. The evaluation results of the ecological integrity of typical lakes, reservoirs and wetlands in Tianjin were finally obtained. The results showed that: 1) Among all the samples, "healthy" points accounted for 5.0%, "good" points accounted for 20.0%, "general" points accounted for 35.0%, "worse" points accounted for 30.0%, and "poor" points accounted for 10.0%. Ecological health status of typical lakes, reservoirs and wetlands in Tianjin was at a general level, with a trend that the west was better than the east with significant spatial differences. 2) Reference points were selected based on the combination of habitat score, water quality conditions, and human activity disturbance. Water quality indicators could reduce subjectivity when selecting reference points and promote the application of ecological integrity evaluation. 3) The applicability verification results showed that IEI could better characterize the health status of each point, and the discrimination efficiency was obvious, which was suitable for evaluating the ecological health of lakes, reservoirs and wetlands.

Effect of autophagy regulation on hypoxia/reoxygenation injury of mouse spermatogonia / 重庆医学

Objective To study the effect of autophagy regulation on hypoxia/reoxygenation injury(H/RI)in mouse spermatogonia,and to explore the effect of autophagy on ischemia-reperfusion injury(IRI)in mouse testicular tissue.Methods The mouse spermatogonial cell line GC1 spg was used as the research object to construct the H/RI model.Rapamycin(RAPA)and 3-methyladenine(3-MA)were used as autophagy ago-nists and inhibitors.The control group,the model group,the autophagy agonist intervention group(H/RI+autophagy agonist intervention),and the autophagy inhibitor intervention group(H/RI+autophagy inhibitor intervention)were set up.The cells proliferation ability of each group was detected by methyl thiazol tetrazoli-um(MTT)method.The release level of reactive oxygen species(ROS)and apoptosis level of each group were detected by flow cytometry.The expression levels of autophagy-related gene Beclin1 and apoptosis-relat-ed genes Bcl-2 and Bax mRNA in each group were detected by real-time fluorescence quantitative PCR(qPCR).The expression levels of autophagy-related proteins LC3-Ⅰ,LC3-Ⅱ,Beclin1,p62 and apoptosis-relat-ed proteins Bcl-2,Bax,caspase-3 in each group were detected by Western blot.Results Compared with the control group,the proliferation abiliy,the expression levels of Beclin1 and Bcl-2 mRNA in the model group were significantly decreased(P＜0.01),the relative expression levels of p62 and Bcl-2 proteins were significantly decreased(P＜0.01).The ROS level,apoptosis rate and the mRNA expression level of Bax were significantly increased(P＜0.01),and the protein expresion levels of Beclin1,Bax,caspase-3 and the protein ratio of LC3-Ⅱ/LC3-Ⅰ were significantly increased(P＜0.01).Compared with the model group,the cell proliferation a-bility,the expression levels of Beclin1 and Bcl-2 mRNA in the autophagy agonist intervention group were the protein ratio of significantly increased(P＜0.01),the protein expression levels of Beclin1 and Bcl-2 and the protein ration of LC3-Ⅱ/LC3-Ⅰ were significantly increased(P＜0.01).The ROS level,apoptosis rate and the expression level of Bax mRNA were significantly decreased(P＜0.01),and the protein expression levels of p62,Bax,caspase-3 and the protein ratio of LC3-Ⅱ/LC3-Ⅰ were significantly decreased(P＜0.01).Com-pared with the model group,the cell proliferation ability,the mRNA expression levels of Beclin1 and Bcl-2 in the autophagy inhibitor intervention group were significantly decreased(P＜0.01),the protein expression lev-els of Beclin1 and Bcl-2 protein were significantly decreased(P＜0.01).The ROS level,apoptosis rate and the mRNA expression level of Bax were significantly increased(P＜0.01),and the protein expression levels of p62,Bax,caspase-3 and the protein ratio of LC3-Ⅱ/LC3-Ⅰwere significantly iecreased(P＜0.01).Conclusion Enhanced au-tophagy can inhibit apoptosis of spermatogonia and repair H/RI in mice,which provides a theoretical basis for the treatment of testicular tissue IRI.

Curative effect analysis of hysteroscopy combined with laparoscopy in the diagnosis and treatment of refrac-tory polycystic ovarian syndrome complicated with infertility / 中国基层医药

Objective To investigate the effect and necessity of hysteroscopy combined with laparoscopy in the diagnosis and treatment of refractory polycystic ovarian syndrome complicated with infertility.Methods 80 cases of patients with polycystic ovary syndrome (PCOS)combined with infertility were randomly divided into two groups with 40 cases in each group.The testing group used hysteroscopy combined with laparoscopy in diagnosis and treatment while the laparoscopy was only used in the control group.The changes of ovary,ovarian follicles and serum hormone level of the two groups which before and after operation were compared,and the data of postoperative normal ovulation rate,pregnancy rate and abortion rate of the two groups were recorded.Results The follicle number and ovarian volume of the testing group were significantly decreased than that before treatment,and were significantly lower than that of the control group,with statistical difference (t =3.82,3.80,3.74,3.75,all P <0.05).The serum T,LH and LH/FSH of the testing group were significantly decreased than the data before surgery,and were significantly lower compared to the control group with statistical difference (t =9.32,4.06,3.80,all P <0.05).The normal ovulation rate,pregnancy rate and abortion rate of the testing group were significantly higher compared to the control group (90.0%,62.5% and 7.5% vs.72.5%,50% and 15%)χ2 =4.02,4.10,3.90,all P <0.05).Conclusion Hyste-roscopy combined with laparoscopy has an obvious curative effect in the diagnosis and treatment of polycystic ovary syndrome combined with infertility,which can effectively improve ovulation rate and pregnancy rate and reduce the abortion rate,is worthy of clinical application.