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With the advancement of multi-GNSS systems, the field calibration of GNSS receiver antennas has been updated at Wuhan University. Benefiting from the use of a six-axis robot that can change its position and attitude precisely, multisession calibration experiments were implemented for several antennas of two types. The calibrations show a high stability of 1 mm for both the phase center offset and phase variation estimation. Compared to the models disclosed in igs14.atx and igsR3.atx, phase center correction differences at the 1 mm level can be obtained for most signals for elevation angles above 15°. For lower elevations, the consistency with the reference model increases to 2–3 mm or more. The consistency of calibrations with different receivers was investigated, and root mean square of differences between these models was better than 0.15 mm. In a short-baseline positioning experiment, the coordinate discrepancies introduced by an antenna phase center (APC) model between GPS and BDS-3 signals could be significantly reduced to the 1 mm level. Compared to the reference coordinates, the positioning accuracies for GPS and BDS-3 were both less than 2 mm with the adoption of the calibrated APC model. The multi-GNSS calibration system tested in this experiment is preliminarily proven reliable and could be applied to future antenna calibration for multi-GNSS applications. [ABSTRACT FROM AUTHOR]

For the same antenna type, numerical differences among the phase center correction (PCC) models released by different institutes can reach several millimeters, which is far beyond the nominal calibration accuracy. This contribution introduces a new method to evaluate the consistency of these PCC models. We first investigated the coupling of phase center offset (PCO) and phase center variation (PCV) through simulation experiments, and the results show that the calibrated PCO values under different strategies may result in large differences, and so do PCV values due to strong coupling with PCO. This is further confirmed by field calibration experiments. Moreover, a new datum parameter is introduced to equivalently transform the PCC models to assess the consistency of PCC models of the same antenna type calibrated under different strategies or by different facilities. It is also essential to perform consistency analysis of PCC models in the coordinate domain. We further investigated these PCC models through a simulated positioning experiment. The results show that millimeter-level consistency of PCC models will lead to the same level of positioning precision in the coordinate domain. Moreover, as a comparison, both baseline positioning and PPP were performed with an antenna-type JAV_RINGANT_G3T NONE based on real observations. Multiday results showed that the average RMS of the positioning differences between PCC models from robot and anechoic chamber calibration is less than 1 mm for the baseline solution and 4 mm for the PPP solution, although the PCC model differences can reach 6 mm in L1 and 4 mm in L2, respectively. Finally, we also investigated the distribution of position biases without PCC or with inaccurate PCC. Considering the actual GPS constellation, we found that position biases have a strong correlation with latitude, if PCV values fluctuate greatly with the users' elevation angle. [ABSTRACT FROM AUTHOR]

Accurate measurement of irrigation water consumption in small channels is an important link in achieving reasonable irrigation area management and agricultural water pricing and improving agricultural irrigation water use efficiency. Fixed water measuring flumes have a high construction cost and are prone to causing local channel sedimentation, compromising the safety of channel water transmission and flow measurement accuracy. Portable water measuring flumes can be used repeatedly in channels within a certain contraction ratio, and the duration of one water measurement is short (generally less than 5 min), which will not cause sedimentation. A new portable primary and subsidiary fish-shaped flume has been proposed by dividing 1 fish-shaped cylinder into 3. The flow measurement and hydraulic performance of measuring flumes with different contraction ratios in a U-shaped channel under different working conditions were studied using prototype experiments and numerical simulation. Compared to the existing portable flume, the primary and subsidiary fish-shaped flumes have achieved high flow measurement accuracy, a large critical submergence degree, a low backwater height, and low head loss. The head loss can be reduced by selecting a suitable length-width ratio and column spacing distance. • A new portable primary and subsidiary fish-shaped flume is designed for canal flow measuring. • Compared with the previous single-cylinder measuring flume, the number of cylinders is increased to 3 in this paper, and the number of flow channels is increased to enhance the flow capacity. • The suitable range of the length-width ratio and the distance between the measuring cylinders of the measuring flume are studied to reduce energy loss. [ABSTRACT FROM AUTHOR]

Background: Triple-negative breast cancer (TNBC) is the most heterogenous and aggressive subtype of breast cancer. Chemotherapy remains the standard treatment option for patients with TNBC owing to the unavailability of acceptable targets and biomarkers in clinical practice. Novel biomarkers and targets for patient stratification and treatment of TNBC are urgently needed. It has been reported that the overexpression of DNA damage-inducible transcript 4 gene (DDIT4) is associated with resistance to neoadjuvant chemotherapy and poor prognosis in patients with TNBC. In this study, we aimed to identify novel biomarkers and therapeutic targets using RNA sequencing (RNA-seq) and data mining using data from public databases. Methods: RNA sequencing (RNA-Seq) was performed to detect the different gene expression patterns in the human TNBC cell line HS578T treated with docetaxel or doxorubicin. Sequencing data were further analyzed by the R package "edgeR" and "clusterProfiler" to identify the profile of differentially expressed genes (DEGs) and annotate gene functions. The prognostic and predictive value of DDIT4 expression in patients with TNBC was further validated by published online data resources, including TIMER, UALCAN, Kaplan–Meier plotter, and LinkedOmics, and GeneMANIA and GSCALite were used to investigate the functional networks and hub genes related to DDIT4, respectively. Results: Through the integrative analyses of RNA-Seq data and public datasets, we observed the overexpression of DDIT4 in TNBC tissues and found that patients with DDIT4 overexpression showed poor survival outcomes. Notably, immune infiltration analysis showed that the levels of DDIT4 expression correlated negatively with the abundance of tumor-infiltrating immune cells and immune biomarker expression, but correlated positively with immune checkpoint molecules. Furthermore, DDIT4 and its hub genes (ADM, ENO1, PLOD1, and CEBPB) involved in the activation of apoptosis, cell cycle, and EMT pathways. Eventually, we found ADM, ENO1, PLOD1, and CEBPB showed poor overall survival in BC patients. Conclusion: In this study, we found that DDIT4 expression is associated with the progression, therapeutic efficacy, and immune microenvironment of patients with TNBC, and DDIT4 would be as a potential prognostic biomarker and therapeutic target. These findings will help to identify potential molecular targets and improve therapeutic strategies against TNBC. [ABSTRACT FROM AUTHOR]

Precise point positioning (PPP) can measure ground motions with a centimetre-level accuracy using only one receiver. It has been widely used in earthquake monitoring and earthquake early warning (EEW) systems. However, traditional PPP highly depends on well-established and robust internet infrastructure for data communication. Along with the broadcast ephemeris, the orbit and clock corrections transmitted by the B2b signals of BeiDou Navigation Satellite System (BDS) can be used to recover the precise products of GPS and BDS. Since the B2b products, namely the satellite state parameter messages, are accessible even without internet infrastructure, PPP with B2b signals is more suitable for real-time applications. This study witnesses the application of PPP with B2b products in seismic monitoring for the first time. The shake table experiments demonstrate that PPP with B2b can reach a millimetre-level accuracy in horizontal in earthquake monitoring for GPS-only, BDS-only and GPS/BDS combination. The application to the 2021 M w 7.4 Maduo earthquake shows that the accuracies of seismic displacements derived from GPS-only PPP with B2b products are 1.7, 2.4 and 1.7 cm in east, north and vertical components, compared with those from GPS-only PPP with final precise products. We therefore conclude that PPP with B2b products has a promising prospect in seismogeodesy and related applications such as EEW and rapid hazard response. [ABSTRACT FROM AUTHOR]

Immune checkpoint blockade (ICB) has been explored as a therapeutic strategy to recover the antitumor immune activities against endometrial cancer (EC) escaping from immune surveillance. Increasing evidence has indicated that microsatellite instability (MSI) is a promising biomarker to stratify patients for the ICB therapy. However, even in patients with MSI-High (MSI-H) endometrial cancers, PD-L1 inhibitors, avelumab, and durvalumab have shown only 27% of response rates. Therefore, there is an urgent need to discover new biomarkers for a predictive response to ICB therapy. In this study, we demonstrated that the immune cytolytic activity (CYT) index was significantly correlated with the development and response to immunotherapy in EC. The data showed that higher CYT was significantly associated with better clinical outcome, more antitumor infiltrating immune cells, fewer somatic copy number alterations, but a higher TMB (Tumor mutational burden) status. Furthermore, CYT-high EC was notably relevant to the high expression of various immune checkpoint molecules and showed more effective responses to ICB treatment. Taken together, this study provided new insights into the connection between diverse genetic events and the immune microenvironment in EC and indicated that the CYT status might be a promising biomarker to stratify patients with EC for ICB therapy. [ABSTRACT FROM AUTHOR]