g. wang

The combination of radiotherapy and surgery is used to treat locally advanced non-small cell lung cancer (NSCLC). The aim of this study was to analyze IIIA/B NSCLC patients treated with chemotherapy from the Surveillance, Epidemiology, and End Results (SEER) database to clarify whether patient prognosis correlated with surgery and radiotherapy.

The IIIA/B NSCLC patients were selected from the SEER database and classified into IIIA (N0-1), IIIA (N2), IIIB (N2), and IIIB (N3). Cox analyses and Kaplan–Meier method were used to estimate the prognostic factors and lung cancer specific survival (LCSS) curves.

We divided 7933 cases into IIIA (N0-1), IIIA (N2), IIIB (N2), and IIIB (N3). Cox regression showed that age, sex, primary site, grade, treatment, T stage, and marriage were independent risk factors for IIIA (N0-1); age, sex, treatment, and T stage had prognostic significance for IIIA (N2); age, sex, primary site, grade, treatment, and T stage were prognostic factors for IIIB (N2); and age and primary site had effect on the prognosis of IIIB(N3). The effect of chemotherapy-surgery was better than that of chemotherapy-preoperative radiotherapy-surgery and chemotherapy-surgery-postoperative radiotherapy for IIIA (N0-1). In IIIA (N2) and IIIB, radiotherapy did not improve the LCSS.

Surgery offered more survival benefits for IIIA (N0-1) patients. Radiotherapy did not improve the LCSS of IIIA (N2) and IIIB patients.

Synthetic jet has been confirmed as a novel flow control technology. However, the existing application research on synthetic jet in axial flow compressor is still confined to cascade or low-speed axial flow compressors, and rarely high-speed axial flow compressor. The effects of three vital parameters (i.e., the action position, frequency, peak velocity) on the aerodynamic performance and stability margin are systematically studied, with a high-speed compressor rotor as the object of numerical simulation. An optimal excitation position is determined, corresponding to the core position of the compressor top blockage, as indicated by the results, which increases the stability margin and efficiency of the compressor by 13.2% and 1.15% respectively. The excitation frequency has a threshold ranging from 300Hz to 600Hz. Only when the frequency of synthetic jet exceeds this threshold can it suppress the tip leakage flow. Besides, the jet peak velocity may not have a threshold. However, the higher the peak velocity, the greater the mixing loss between the jet and the mainstream of the compressor rotor will be, thus limiting the further increase of the compressor efficiency.

To deepen the understanding of COVID-19 and provide a theoretical basis for clinical diagnosis and treatment, the clinical manifestations, laboratory test findings and chest computed tomography (CT) signs of this disease and the correlations among them were explored in this study.

A total of 85 patients with confirmed cases of COVID-19 were included, and their disease courses, symptoms and laboratory test results were recorded.

The main characteristics of COVID-19 infection were fever (56 cases), respiratory symptoms (47 cases), normal or decreased white blood cell count (84 cases), decreased lymphocyte count (43 cases), and increased C-reactive protein (CRP) level (37 cases). There was a positive correlation between fever and each of white blood cell count, lymphocyte count, and CRP level (P<0.05). Age, disease course, fever, lymphocyte count, CRP level and CT findings were statistically correlated. In the CT-positive group, the lesions were often multiple (57 cases) and peripherally distributed (53 cases). The main manifestations included ground-glass density shadows (61 cases), grid-like changes (47 cases), abnormal pleural changes (53 cases), abnormal blood vessels (52 cases) and bronchial abnormalities (40 cases).

Mild and common COVID-19 cases have certain characteristics, clinical manifestations and laboratory parameters are correlated with CT manifestations. The comprehensive diagnosis according to clinical manifestations, laboratory and CT characteristics can minimize the missed diagnosis rate.

Centrifugal pumps often deviate from its design condi-tion during its operation and work at low mass flow conditions. Under such circumstances, unstable flow phenomena may be generated, affecting the efficient and stable operation of pumps. In this paper, a self-circulating casing treatment in U-tube shape is employed on a centrifugal pump to study its effects on the pump’s performance by computational and experi-mental studies. CFD results show that as the flow rate decreases, the back-flow in the inlet pipe of the studied pump without casing treatment increases in intensity and spreads over an growing distance, interfering with the main flow. CFD results also reveal that the casing treatment has a sucking function to the back-flow due to the blade loading of the pump, and when the inlet bleed of the U-tube is placed above (in front of) the leading edge of the blades, the sucking is the strongest, and the control of the back-flow and the improvement to the head coefficient under low mass flow conditions is the best, as the vortex blockage caused by the sucked back-flow in the U-tube is the smallest; when the bleed is under (after) the leading edge of the blades, the effect of the casing treatment is the second best; and when the bleed is across the leading edge of the blades, the blockage in the U-tube is most severe, and the sucking function is the weakest, so there is little improvement to the back-flow and head coefficient. Finally, the relia-bility of this study was demonstrated employing an open pump experimental system with the original pump and the same pump with the casing treatment whose bleed is located above the leading edge of the impeller.

In this paper, the conception of centroid of $n$-dimensional fuzzy number is introduced viaregarding its membership function as the density function on its support set, and some properties of it are obtained. Compared with the mean of the multi dimensional fuzzy number, the centroid takes into account the overall relationship between the edge membership functions of the membership function of the multi dimensional fuzzy number. Therefore, it can approximate (characterize) the fuzzy number more objectively and reasonably than using the mean of the multi dimensional fuzzy number. The most important work of this paper is that for two special kinds of multi dimensional fuzzy numbers (fuzzy $n$-cell numbers and fuzzy $n$-ellipsoid numbers), we respectively give calculation formulas, which can be used conveniently in application since the formulas are based on a definite integral of the level set functions of the multi dimensional fuzzy number on the unit interval $[0,1]$, rather than the multiple integral of the membership function of the multi dimensional fuzzy number itself on its support set. Then, by using the calculation formulas, we obtain another special property of the centroid for fuzzy $n$-cell number and fuzzy $n$-ellipsoid number. Finally, as an example of application, by using the centroid of multi dimensional fuzzy number, we define a fuzzy order on $n$-dimensional fuzzy number space, which can be used to rank uncertain or imprecise multichannel digital information.

In order to improve the performance of a high-load transonic axial compressor, this paper proposes a method of applying endwall synthetic jet to the casing for active flow control. Taking NASA Rotor35 as the research object, the aerodynamic performance of the compressor is numerically calculated by applying three sets of synthetic jets with different excitation parameters at five different axial positions of 0%Ca, 25%Ca, 50%Ca, 75%Ca and 96.15%Ca. The results show that the three parameters of excitation position, jet peak velocity and jet frequency all have an effect on the performance of the compressor. The excitation position has the greatest influence on the flow margin of the compressor, and the best position is 25%Ca. After the jet peak velocity is increased from 100m/s to 150m/s, the flow margin, total pressure ratio and efficiency of the compressor are not greatly improved, which shows that the impact of the jet peak velocity is not as good as the excitation position. After continuing to increase the excitation frequency of the synthetic jet from 600Hz to 1200Hz, although the flow margin of the compressor is slightly reduced, the total pressure ratio and efficiency are further improved. This shows that there may be a threshold for the jet frequency, and only when the jet frequency is greater than the threshold can the overall aerodynamic performance of the compressor be improved