An Autocollimator Axial Measurement Method Based on the Strapdown Inertial Navigation System.

Autocollimators are widely used optical axis-measuring tools, but their measurement errors increase significantly when measuring under non-leveled conditions and they have a limited measurement range due to the limitations of the measurement principle. To realize axis measurement under non-leveled conditions, this paper proposes an autocollimator axis measurement method based on the strapdown inertial navigation system (SINS). First, the measurement model of the system was established. This model applies the SINS to measure the change in attitude of the autocollimator. The autocollimator was then applied to measure the angular relationship between the measured axis and its own axis, based on which the angular relationship of the axis was measured via computation through signal processing and data fusion in a multi-sensor system. After analyzing the measurement errors of the system model, the Monte Carlo method was applied to carry out a simulation analysis. This showed that the majority of the measurement errors were within ±0.002° and the overall measurement accuracy was within ±0.006°. Tests using equipment with the same parameters as those used in the simulation analysis showed that the majority of the measurement errors were within ±0.004° and the overall error was within ±0.006°, which is consistent with the simulation results. This analysis proves that this method solves the problem of the autocollimator being unable to measure the axis under non-leveled conditions and meets the needs of axis measurement with the application of autocollimators under a moving base.

Research on Focal Length Measurement Scheme of Self-Collimating Optical Instrument Based on Double Grating.

In this paper, we propose a scheme for measuring the focal length of a collimating optical instrument. First, a mathematical model for measuring the focal length of a collimator with double gratings is derived based on the moiré fringe formula and the principles of geometric optics. Mathematical simulation shows that a slight difference in the focal length of two collimators has an important influence on the imaging law of moiré fringes. Our solution has a good resolution ability for focal length differences within 5‱, especially in the small angle range below 4°. Thus, the focal length of collimators can be measured by the amplification of the slight difference. Further, owing to the relative reference measurement, the measurement resolution at the symmetrical position of focal length is poor. Then, in the designed experiment, a corresponding moiré image at different angles is acquired using collimators with known focal length. The experimental results indicate that the root mean square error (RMSE) of the collimator corresponding to grating angles of 2°-4° is better than 4.7‱, indicating an ideal measurement accuracy of the proposed scheme. This work demonstrates that our proposed scheme can achieve an ideal accuracy in the measurement of a symmetrical optical path.

Synthesis of Gibberellic Acid Derivatives and Their Effects on Plant Growth.

A series of novel C-3-OH substituted gibberellin derivatives bearing an amide group were designed and synthesized from the natural product gibberellic acid (GA3). Their activities on the plant growth regulation of rice and Arabidopsis were evaluated in vivo. Among these compounds, 10d and 10f exhibited appreciable inhibitory activities on rice (48.6% at 100 µmol/L) and Arabidopsis (41.4% at 100 µmol/L), respectively. These results provide new insights into the design and synthesis of potential plant growth regulators.

Modeling and Implementation of Multi-Position Non-Continuous Rotation Gyroscope North Finder.

Even when the Global Positioning System (GPS) signal is blocked, a rate gyroscope (gyro) north finder is capable of providing the required azimuth reference information to a certain extent. In order to measure the azimuth between the observer and the north direction very accurately, we propose a multi-position non-continuous rotation gyro north finding scheme. Our new generalized mathematical model analyzes the elements that affect the azimuth measurement precision and can thus provide high precision azimuth reference information. Based on the gyro's principle of detecting a projection of the earth rotation rate on its sensitive axis and the proposed north finding scheme, we are able to deduct an accurate mathematical model of the gyro outputs against azimuth with the gyro and shaft misalignments. Combining the gyro outputs model and the theory of propagation of uncertainty, some approaches to optimize north finding are provided, including reducing the gyro bias error, constraining the gyro random error, increasing the number of rotation points, improving rotation angle measurement precision, decreasing the gyro and the shaft misalignment angles. According them, a north finder setup is built and the azimuth uncertainty of 18" is obtained. This paper provides systematic theory for analyzing the details of the gyro north finder scheme from simulation to implementation. The proposed theory can guide both applied researchers in academia and advanced practitioners in industry for designing high precision robust north finder based on different types of rate gyroscopes.

[Oxidative stress induces autophagy to inhibit the proliferation and apoptosis of human bone marrow mesenchymal stem cells (hBMSCs)].

Objective To investigate the effect of H2O2-induced oxidative stress on autophagy and apoptosis of human bone marrow mesenchymal stem cells (hBMSCs). Methods hBMSCs were isolated and cultured. The cells were divided into control group, 3-MA group, H2O2 group, H2O2 combined with 3-MA group. DCFH-DA staining was used to analyze the level of reactive oxygen species (ROS). hBMSCs were treated with 0, 50, 100, 200, 400 µmol/L H2O2, and then the cell viability was detected by CCK-8 assay. The level of autophagy was detected by monodansylcadaverine (MDC) staining and LysoTracker Red staining. The cell apoptosis was detected by flow cytometry. Western blotting was used to detect the expression of beclin 1, mTOR, phosphorylated mTOR (p-mTOR), cleaved caspase-3(c-caspase-3) and caspase-3 proteins. Results Compared with the control group and 3-MA group, ROS level and autophagosomes were increased and the proliferation and apoptosis were decreased in H2O2 group. The protein expression of beclin 1, mTOR, c-caspase-3 was up-regulated, while the p-mTOR was down-regulated. Compared with the 3-MA group, the H2O2 combined with 3-MA group also had an increased ROS level and autophagosomes, but not with significantly increased apoptosis rate; The protein expression of beclin 1, mTOR, c-caspase-3 was up-regulated, and the p-mTOR was down-regulated. Conclusion H2O2 can induce hMSCs to trigger oxidative stress response. It enhances the autophagy and inhibits the proliferation and apoptosis of hBMSCs.

Data-Independent Acquisition Proteomics Unravels the Effects of Iron Ions on Coronatine Synthesis in Pseudomonas syringae pv. tomato DC3000.

Coronatine (COR) is a new type of plant growth regulator that is produced by Pseudomonas syringae pathovars and plays an important role in modulating plant growth, development, and tolerance to multiple stresses. However, the factors affecting COR production are not very clear. In this study, the effects of FeCl3 on COR production were researched. The data-independent acquisition (DIA) approach, which is a proteomic quantitative analysis method, was applied to quantitatively trace COR production and proteomic changes in P. syringae pv. tomato DC3000 under different FeCl3 culture conditions. The results showed that COR production increased with the addition of FeCl3 and that there was significant upregulation in the expression of proteins related to COR synthesis and regulation. In addition, FeCl3 also affected the expression of related proteins involved in various metabolic pathways such as glycolysis and the tricarboxylic acid cycle. Moreover, various precursors such as isoleucine and succinate semialdehyde, as well as other related proteins involved in the COR synthesis pathway, were significantly differentially expressed. Our findings revealed the dynamic regulation of COR production in response to FeCl3 at the protein level and showed the potential of using the DIA method to track the dynamic changes of the P. syringae pv. tomato DC3000 proteome during COR production, providing an important reference for future research on the regulatory mechanism of COR biosynthesis and theoretical support for COR fermentation production.

Improved synthetic route of exo-16,17-dihydro-gibberellin A5-13-acetate and the bioactivity of its derivatives towards Arabidopsis thaliana.

BACKGROUND: The use of exo-16,17-dihydro-gibberellin A5-13-acetate (DHGA5 ) in agriculture has been limited by its low synthetic yield. This study was aimed at optimizing the synthetic route of DHGA5 , designing and synthesizing new derivatives with strong plant growth inhibitory activities. RESULTS: Previous synthetic methods were replaced with a shorter, milder and faster reaction route with higher yield (76.3%) of DHGA5 . Based on this novel route, a series of new derivatives were designed and synthesized using DHGA5 as a lead compound and characterized and evaluated for biological activities in Arabidopsis thaliana. Among the 15 tested derivatives, compound 14j showed a lower medium inhibition concentration (IC50 , 73 µm) in Arabidopsis than that of DHGA5 (91 µm). Gibberellin deficient mutant assay further revealed that 14j had very different activities compared to DHGA5 as it specifically inhibits gibberellin biosynthetic pathways. In addition, 14j does not influence the interaction between gibberellin receptors (GID1) and the master growth repressor (RGA) based on yeast two-hybrid assay. CONCLUSION: The optimized synthetic route provides a promising method for large-scale preparation of DHGA5 . Our biological assays indicate that 14j likely acts on gibberellin signaling elements other than GID1. These results indicate that novel plant growth regulators can be developed. © 2019 Society of Chemical Industry.

Expression profile analysis of long non-coding RNA in skeletal muscle of osteoporosis by microarray and bioinformatics.

BACKGROUND: Osteoporosis (OP) is a condition featured by bone mass loss and bone tissue microarchitectural alterations due to impaired tissue homeostasis favoring excessive bone resorption versus deposition. The trigger of such an impairment and the downstream molecular pathways involved are yet to be clarified. Long non-coding RNA (lncRNA) plays a role in gene transcription, protein expression and epigenetic regulation; and altered expression results in immune or metabolism related desease development. To determine whether lncRNAs are involved in osteoporosis, we analyzed the expression profile of lncRNAs and mRNAs in osteoporosis. METHOD: Three pairs of osteoporosis patients (OP group) and healthy people controls (NC group) were screened by microarray. Quantitative polymerase chain reaction (qRT-PCR) was performed to confirm dysregulated lncRNA expressions in 5 pairs of OP and NC group tissues samples. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to construct the lncRNA-mRNA co-expression network. RESULT: Through co-expression analysis, differently expressed transcripts were divided into modules, and lncRNAs were functionally annotated. We further analyzed the clinical significance of crucial lncRNAs from modules in public data. Finally, the expression of five lncRNAs, CUST_44695_PI430048170-GeneSymbol:CTA-384D8.35;CUST_39447_PI430048170,CUST_73298_PI430048170,CUST_108340_PI430048170,CUST_118927_PI430048170,this four lncRNAs have not been annotation genes and have not found GeneSymbols, and by quantitative RT-PCR, which may be associated with osteoporosis patients' overall survival. CONCLUSION: Analysis of this study revealed that dysregulated lncRNAs and mRNAs in osteoporosis patients and health people controls could affect the immune or metabolism system and musculoskeletal cell differentiation. The biological functions of those lncRNAs need to be further validated.

Reflector automatic acquisition and pointing based on auto-collimation theodolite.

An auto-collimation theodolite (ACT) for reflector automatic acquisition and pointing is designed based on the principle of autocollimators and theodolites. First, the principle of auto-collimation and theodolites is reviewed, and then the coaxial ACT structure is developed. Subsequently, the acquisition and pointing strategies for reflector measurements are presented, which first quickly acquires the target over a wide range and then points the laser spot to the charge coupled device zero position. Finally, experiments are conducted to verify the acquisition and pointing performance, including the calibration of the ACT, the comparison of the acquisition mode and pointing mode, and the accuracy measurement in horizontal and vertical directions. In both directions, a measurement accuracy of ±3″ is achieved. The presented ACT is suitable for automatic pointing and monitoring the reflector over a small scanning area and can be used in a wide range of applications such as bridge structure monitoring and cooperative target aiming.

Evaluation of quality of life in Chinese patients with gynaecological cancer: assessments by patients and nurses.

Quality of life (QOL) has recently become one of the most important focuses in oncology nursing practice and research. The aims of this study were to evaluate the QOL in Chinese cancer patients under chemotherapy and to explore the discrepancy between patients' and nurses' assessments of the patients' conditions. The study participants included gestational trophoblastic disease patients (n = 68), ovarian cancer patients (n = 105), patients with other gynaecological cancer (n = 18), and their attending nurses (n = 25) at hospitals affiliated with universities in Beijing. The high level of some symptom subscales/items in patients suggested that innovative and more effective interventions should be developed and utilised in nursing practice. Patients with metastasis reported lower levels of QOL than those without metastasis. The nurses in this study tended to estimate the patients' QOL inaccurately, except for a few objective aspects. The results of this study can help nurses in planning interventions to enhance the QOL of patients with gynaecological cancer undergoing chemotherapy. The nurses need to be trained to become more sensitive and competent in assessing patients' subjective information.