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Air traffic complexity is the essential attribute of air traffic situation,and it is therefore one of the drivers for air traffic controller′s workload.Scientific evaluation of air traffic complexity is the key to realize air traffic refined management,and is a research hot-spot of air traffic management.The Chinese and global research teams on air traffic complexity is introduced in this paper.The differences and associations of air traffic complexity with workload and safety level are summarized,and the concrete clues in the existing research are elaborated,which are based on control cognitive perspective,geometric structure perspective and complex system perspective and the main contents and relative merits are concluded.The future research trends and directions of air traffic complexity are prospected on the basis of characterization of new-generation air traffic management system.

With the rapid growth of civil aviation, the increasing expansion of air traffic flow has brought serious challenges to the service capacity of the current airspace system, making the operation of the control sector increasingly complex. The accurate quantification of sector situational complexity is the basis for improving the service capability of airspace systems. The existing research on complexity ignores the resilience of the air traffic system in case of flight change, which cannot fully describe the dynamic characteristics of the air traffic situation. For this reason, a new air traffic complexity evaluation algorithm based on system resilience is proposed. Firstly, an air traffic situation network based on between-flight interaction is established. Then an overall sector complexity index based on network efficiency, average network failure rate, and average network recovery rate is built. Then, the complexity index is verified by analyzing the real radar number of ZSSSAR01 (sector 1 of Shanghai). By establishing a sector complexity optimization model, the complexity of sector air traffic and its volatility can be greatly reduced by changing the departure time of some flights. Finally, by optimizing the complexity of the sector, the workload of controllers is reduced, and the safety and efficiency of air traffic operations are improved., Author(s): Hongyong Wang (corresponding author) [1]; Jiawen Huang (corresponding author) [1]; Taotao Deng [2]; Ziqi Song [3] 1. Introduction Along with the stable development of the global economy, the demand [...]

Enormous success has been achieved in antitumor therapy with PD-1/PD-L1 inhibitors; however, less than 3 out of 10 patients show clinical benefits. An interesting phenomenon of patients who experienced durable clinical responses to PD-L1 blockade usually being the patients with high PD-L1 expression was noticed. Accordingly, the evaluation of PD-L1 is of great benefit to predict the immunotherapy response against PD-1/PD-L1. A small-molecule single photon emission computed tomography (SPECT) tracer [99mTc]Tc-SG2C-CBM containing a biphenyl moiety was designed and synthesized for the measurement of PD-L1 expression. The radiolabeling yield (RLY) and radiochemical purity (RCP) of [99mTc]Tc-SG2C-CBM were detected to be over 93% under the optimized labeling conditions. [99mTc]Tc-SG2C-CBM was discovered to be equipped with not only good stability but also suitable lipophilicity. In the cellular assays, [99mTc]Tc-SG2C-CBM showed moderate affinity to PD-L1 and 6.87-fold higher uptake in A375-hPD-L1 cells than in A375 cells. Then, the in vivo biodistribution results of the A375-hPD-L1 tumor-bearing mice showed that the radioactivity uptake in tumors was about 2.96 ± 0.76 and 2.31 ± 0.26 fold that in muscles and bones at 2 h post-injection, respectively. SPECT imaging was consistent with the biological distribution of [99mTc]Tc SG2C-CBM, with the uptake being mainly in the liver and less pronounced in tumors. The results of these studies indicate that [99mTc]Tc-SG2C-CBM may be a probe for imaging PD-L1 expression, but further research is needed. [ABSTRACT FROM AUTHOR]

Objective To explore the role of Dickkopf-related protein 1 (DKK1) in hypertension and its effect on urinary sodium excretion. Methods Twelve rats with normal blood pressure (Wister Kyoto rats, WKY), and 12 primary hypertension rats (spontaneously hypertensive rats, SHRs), all male, at an age of 8~10 weeks, weighing 190~210 g, were employed in this study. The expression of DKK1 and β-catenin in the kidney of WKY and SHR rats was detected by Western blotting. Then 12 WKY rats were randomly divided into WKY+DKK1 group and WKY control group (n=6), and so were the 12 SHR rats. Recombinant protein DKK 16 ng/(g·d) was pumped into the rats from the DKK1 groups via micro-syringe. The blood pressure of all the rats was measured by non-invasive tail-cuff method. And the urine was collected by metabolic cages for 24-hour urinary volume and urinary sodium, which were adjusted with their weight. The expression of DKK1 and β-catenin protein in renal proximal tubule epithelial (RPT) cells (WKY-RPT and SHR-RPT) was detected by Western blotting. After intervention with recombinant protein DKK1, DKK1 siRNA (siDKK1), and β-catenin nuclear signal inhibitor (inhibitor of β-catenin-responsive transcription, ICRT 14), inhibitor of GSK3β (6-bromoindirubin-3′-oxime, BIO), the expression of DKK1 and β-catenin and the activity of Na+-K+-ATPase were measured. Results The expression level of DKK1 was lower, while that of β-catenin (indicating Wnt/β-catenin was activated) was higher in the renal tissue of SHR rats than of WKY rats. When the SHR+ DKK1 group was compared with the SHR group, the systolic blood pressure was significantly decreased at 2 weeks after implantation (145.21±2.83 vs 156.07±3.08 mmHg, P < 0.05), and both urine volume (37.40±3.76 vs 27.24±2.30 mL/kg, P < 0.05) and urinary sodium excretion (0.79±0.09 vs 0.51±0.09 mmol/kg, P < 0.05) within 24 h were increased. There were no significant differences in above indexes between WKY+DKK1 group and WKY group. The expression of DKK1 was lower in the SHR-RPT cells than the WKY-RPT cells, and that of β-catenin was opposite. Intervention of DKK1 expression would cause the change of β-catenin (indicating the alteration of Wnt/β-catenin pathway), and thus affect the activity of Na+-K+-ATPase, and the activity of Na+-K+-ATPase was negatively correlated with DKK1. Conclusion DKK1 can reduce Na+-K+-ATPase activity at least partially by inhibiting the Wnt/β-catenin pathway, promote urinary sodium excretion and lower blood pressure.