The Chinese Mars exploration mission is planned to be launched in 2020, which includes an orbiter, a lander, and a rover. High precision Martian ephemeris is very important in Mars exploration, ...especially for the Martian orbit insertion and the Martian lander/rover landing. In this paper, we used simulation data to analyze the short-term prediction accuracy of the Martian ephemeris. The simulation results show that the accuracy of Mars position is expected to be better than 50 m for 180-day prediction, when 90-150 days’ range measurements are used to estimate the orbit of the Mars. Range bias affects the prediction accuracy and the arc length for estimation is limited. The prediction accuracy will improve with higher orbit, and the orbit error of probes has an obvious effect on the prediction accuracy of the Martian ephemeris.
This study aimed to characterize soil respiration along eroded sloping land at erosion and deposition area under different soil organic carbon(SOC) levels, and linked the relationship between soil ...respiration and soil temperature, soil moisture, SOC and slope position. Experiments were carried out in the plots of S type slopes include five different soil organic carbon levels in the Loess Hilly Region. The S type slopes were divided into control area at the top of the slope, erosion area at the middle of the slope and deposition area at the toe of the slope. We found that soil temperature had a greater impact on soil respiration in the deposition area, whereas soil moisture had a greater impact on soil respiration in the erosion area compared among control area, erosion area and deposition area. In addition, SOC was the most important factor affecting soil respiration, which can explain soil respiration variation 54. 72%, followed by soil moisture, slope position and soil temperature, which explain soil respi
The numerical simulation of the axial flow impeller blood pump NIVADIII is carried out by using a CFD multiphase flow model. The hydrodynamic performance of the pump and the flow field in the pump ...are analyzed, and the shear stress distribution is obtained. A hemolytic prediction model based on the shear stress is built based on the calculation results, and it can be used for qua- ntitative predictions of the hemolytic behavior of a blood pump. Hemolysis tests in vitro were performed 6 times with fresh bovine blood. At each time, the flow of the pump NIVADIII is 5 L/min and the outflow tract pressure is 100 mmHg. According to the tests, the plasma free hemoglobin （FHB） content and the hematocrit （HCT） are measured after 0 s, 0.5 s, 1 s, 1.5 s 4 s. At the end of each experiment Normal Index of Hemolysis （NIH） of NIVADIII is calculated. The average of NIH is 0.0055 g/100L, almost identi- cal with that obtained from the hemolytic prediction model. This method can be applied in the selection stage of a blood pump.
Recently a new kind of hybrid micro/nanorod top array has become a promising structure to improve the light extraction efficiency (LEE) of GaN-based light emitting diodes, but simulation of the ...hybrid structure is extremely difficult owing to the various limitations of different simulation methods. In this study, a novel approach was explored to calculate the LEE by combining the Finite difference time domain method and the ray tracing method through the gradient refractive index layers. In this novel method, the LEE enhancement mechanism of the hybrid structure was investigated. In addition, we further sought the optimal parameters of the hybrid micro/nanorod structure, and an optimized structure with an enhancement factor of greater than 95 % was achieved.
This study was intended to construct a brand new prognostic nomogram after combine clinical and pathological characteristics to increases prognostic value in patients with esophageal squamous cell ...carcinoma.
A total of 1,634 patients were included. Subsequently, the tumor tissues of all patients were prepared into tissue microarrays. AIPATHWELL software was employed to explore tissue microarrays and calculate the tumor-stroma ratio. X-tile was adopted to find the optimal cut-off value. Univariate and multivariate Cox analyses were used to screen out remarkable characteristics for constructing the nomogram in the total populations. A novel prognostic nomogram with clinical and pathological characteristics was constructed on the basis of the training cohort (n=1,144). What's more performance was validated in the validation cohort (n=490). Clinical-pathological nomogram were assessed by concordance index, time-dependent receiver operating characteristic, calibration curve and decision curve analysis.
The patients can divide into two groups with cut-off value of 69.78 for the tumor-stroma ratio. It is noteworthy that the survival difference was noticeable (
<0.001). A clinical-pathological nomogram was constructed by combining clinical and pathological characteristics to predict the overall survival. In comparison with TNM stage, the concordance index and time-dependent receiver operating characteristic of the clinical-pathological nomogram showed better predictive value (
<0.001). High quality of calibration plots in overall survival was noticed. As demonstrated by the decision curve analysis, the nomogram has better value than the TNM stage.
As evidently revealed by the research findings, tumor-stroma ratio is an independent prognostic factor in patients with esophageal squamous cell carcinoma. The clinical-pathological nomogram has an incremental value compared TNM stage in predicting overall survival.
Nonalcoholic fatty liver disease (NAFLD) is seriously affecting the general health due to its high prevalence and associated risk of liver-related consequences and extrahepatic chronic complications. ...New drugs are urgently needed for the treatment of NAFLD. The purpose of this meta-analysis is to assess the efficacy of incretin-based therapies in patients with NAFLD.
We will search 4 databases for relative studies: PubMed, Cochrane Library, Embase, and Web of Science databases and identified all reports of randomized controlled trials (RCTs) published from inception to July 2020. Two authors will independently scan the searched articles, extract the data from included articles, and assess the risk of bias by Cochrane tool of risk of bias. Disagreements will be resolved by discussion among authors. All analysis will be performed based on the Cochrane Handbook for Systematic Reviews of Interventions. Fixed-effects model or random-effects model will be used to calculate pooled estimates of weighted mean difference (WMD) with 95% confidence intervals (CIs) or odds ratio (OR) with 95% CIs.
This systematic review aims to examine the effect of incretin-based therapies on liver histology, liver fat content, liver enzymes, and adverse events in patients with NAFLD.
These findings will provide guidance to clinicians and patients on the use of incretin-based therapies for NAFLD.
Covering is a widely used form of data structures. Covering-based rough set theory provides a systematic approach to this data. In this paper, graphs are connected with covering-based rough sets. ...Specifically, we convert some important concepts in graph theory including vertex covers, independent sets, edge covers, and matchings to ones in covering-based rough sets. At the same time, corresponding problems in graphs are also transformed into ones in covering-based rough sets. For example, finding a minimal edge cover of a graph is translated into finding a minimal general reduct of a covering. The main contributions of this paper are threefold. First, any graph is converted to a covering. Two graphs induce the same covering if and only if they are isomorphic. Second, some new concepts are defined in covering-based rough sets to correspond with ones in graph theory. The upper approximation number is essential to describe these concepts. Finally, from a new viewpoint of covering-based rough sets, the general reduct is defined, and its equivalent characterization for the edge cover is presented. These results show the potential for the connection between covering-based rough sets and graphs.
In single-well production prediction tasks, the achieved forecasting performance is sensitive to various uncertain factors. Most existing methods are either based on trend lines of the production ...history or overall development process data. However, the linkages between diverse data types and models have largely not been considered. In this paper, we construct a novel stacking model to fuse the static geological information, dynamic well production history, and spatial information of adjacent water injection wells. This stacking model consists of three basic modules that serve as encoders to separately extract features from these three types of information. The first is a multilayer perceptron (MLP), which analyzes the static geological properties of the reservoir that might influence the well production rate. The second is a long short-term memory (LSTM) module, which extracts the temporal information that is reflected in dynamic production variations. The third is also an LSTM module, as a spatial information processing module, it considers the time delay of the water flooding response from the injection well to the target well. The information fusion quality of the stacking model is validated from the perspective of causality discovery using symbolic transfer entropy (STE). Experiments are conducted on a block dataset derived from a water flooding oilfield. The results show that the presented model can make full use of its model structure and greatly improve the accuracy and generalizability of prediction.
•Constructing a new stacking model for single well production prediction.•Our model can fuse three types of information influencing single well production.•Validating the information fusion quality of the stacking model.•Experiments show that our model achieves good performance on a block data set.
Soft tissue augmentation using various injectable fillers has gained popularity as more patients seek esthetic improvement through minimally invasive procedures requiring little or no recovery time. ...The currently available injectable skin fillers can be divided into three categories. With careful assessment, stimulatory fillers are the most ideal fillers. In this study, dexamethasone-loaded poly(D, L-lactic acid) (PLA) microspheres of approximately 90 micro m suspended in poly(ethylene glycol)-poly(epsilon-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) micelles were prepared as stimulatory filler for skin augmentation. The biodegradable PECE copolymer can form nano-sized micelles in water, which instantly turns into a non-flowing gel at body temperature due to micellar aggregation. The PECE micelles (making up 90% of composite) served as vehicle for subcutaneous injection were metabolized within 44 days. At the same time, the dexamethasone-loaded PLA microspheres (10% of composite) merely served as stimulus for connective tissue formation. Dexamethasone-loaded PLA microspheres/PECE micelles composite presented great hemocompatibility in vitro. It was demonstrated in the in vive study that the composite was biodegradable, biocompatible, nontoxic and nonmigratory. Histopathological studies indicated that the composite could stimulate collagen regeneration. Furthermore, granuloma, the main complication of the stimulatory fillers, did not appear when the composite was injected into the back of SD rats, because of the dexamethasone controlled release from the composite. All results suggested that dexamethasone-loaded PLA microspheres/PECE micelles composite may be an efficient and promising biomaterial for skin augmentation.
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