w. liu

Due to the important strategic position of Pumped Storage Power Plants (PSPP) in global energy upgrading, conducting in-depth research on the various operating conditions of pump turbine units is important for their safe and stable operation. This study sought to clarify the gas–liquid phase motion and the nonlinear chaotic characteristics of the process of exhaust and pressurization in pump mode; with the simplified objective model proposed here, a visualization of the process is achieved using data-driven methods, and the nonlinear characteristics of gas–liquid phase motion during the process are theoretically demonstrated. A method that combines data-driven and chaotic analysis is proposed to qualitatively and quantitatively analyze the force and torque time-series signals of the runner under different exhaust rates. The results indicate that the chaotic characteristics of the force signals and torque signals of the runner are not in a single linear relationship with the exhaust rates. Therefore, this research also provides guidance on exhaust rates with the aim of informing actual engineering practice, the purpose of which is to reduce the vibration amplitude caused by repetitive torque and improve the stability of the unit operations.

To evaluate the diagnostic potential of joint testing of serum tumor markers containing cytokeratin fragment antigen 21-1 (CYFRA21-1), progastrin-releasing peptide (ProGRP), carcinoembryonic antigen (CEA) as well as neuron-specific enolase (NSE) in a variety oflung cancer (LC).

The LC group comprised 150 LC patients who were diagnosed for the first time and were not treated. During the same period, 120 patients harbored benign lung diseases and 120 healthy subjects were respectively designated as the benign group and control group. Immunochemiluminescence assay was implemented to detect tumor markers in serum from three groups and different types of LC.

Levels of four serum tumor markers in LC group were elevated relative to control group. CYFRA21-1 level in lung squamous cell carcinoma (LSCC) group was elevated compared to lung adenocarcinoma (LUAD) and small cell lung cancer (SCLC) groups. ProGRP and NSE levels in SCLC group increased compared to LSCC and LUAD groups. CEA level in LUAD group was higher compared to LSCC and SCLC groups. The highest positive rate of LSCC was CYFRA21-1, the highest positive rate of LUAD was CEA and the highest positive rates of SCLC were ProGRP and NSE. In terms of single tumor marker detection, CYFRA21-1 possessed the best diagnostic efficiency for LSCC, CEA possessed the best diagnostic efficiency for LUAD, NSE and ProGRP possessed the best diagnostic efficiency for SCLC, respectively.

The individual determination of CYFRA21-1, ProGRP, CEA, and NSE has certain clinical application value for the pathological classification of LC.

The study aimed to elucidate the clinical application significance of prospective ECG-gated dual-source CT in central venous (CV) imaging.

Eighty patients who took CT imaging of CV (CTV) check using dual-source Force CT were enrolled. The control group (helical pitch, 0.8; rotation speed, 0.5 s) and the experimental group (rotation speed, 0.25 s). For both groups, image quality and radiation dose were computed.

Cases in the experimental group required longer scanning durations than those in the contro lgroup. In respect to the experimental group, the image quality scores of the superior vena cava and left and right brachiocephalic veins of the patients sharply increased relative to those in the control group. Individuals in the experimental group also presented better image quality scores in left and right subclavian veins, left and right jugular veins, however, this difference was not statistically significant. Lastly, no increase in the radiation dose was bited with the application of prospective ECG gating.

The clinical use of prospective ECG-gated technology significantly reduced cardiovascular pulsing artifact interference on the central vein, especially the superior vena cava segment, and remarkably improved the image quality without increasing the radiation dose to patients.

The Background To explore the influence of centrifugal massage on reducing the incidence of compartment syndrome after contrast extravasation (CM) and reducing the tension.

A total of 62 patients with iodine contrast agent extravasation who underwent CT angiography in our hospital from March 2020 to March 2022 were chosen and separated into observation group (OG, n=31) and control group (CG, n=31) following the nursing plan. Patients in the CG adopted external application of drugs, and patients in the OG received centrifugal massage. The occurrence and duration of swelling, the incidence of compartment syndrome after contrast extravasation, nursing satisfaction, patients’ symptoms, and psychological status were compared between both groups.

The swelling degree and duration and incidence of compartment syndrome after contrast extravasation in the OG were declined relative to the CG (P<0.05). After 24 and 48 hours of intervention, patients in the OG had elevated self-rating scales compared to the CG (P<0.05). The nursing satisfaction of patients in the OG was elevated compared to the CG (P<0.05). After intervention, the anxiety and depression scores of the OG was decreased compared to the CG (P<0.05). The effective rate of treatment in the OG was elevated compared to the CG (P>0.05).

Centrifugal massage for patients with CT enhanced scanning can prevent the incidence of CM after contrast extravasation, reduce the damage of contrast agent to tissues, and improve nursing satisfaction.

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.

The Japanese clinical guidelines and the 2015 American Thyroid Association Management Guidelines recommend that indolent papillary thyroid microcarcinoma (PTMC) be monitored actively and that patients with aggressive PTMC immediately undergo surgery. This study aimed to establish a stage model and provide a reference for the preoperative identification of aggressive PTMC and indolent PTMC, which might guide the treatment of PTMC.

Risk factors for the aggressive PTMC were identified through multivariate logistic regression analysis. According to the regression coefficient, each risk factor was assigned a risk score; thereafter, a risk score (RS) model and a stage model were established.

The tumor’s largest diameter > 6 mm, BRAFV600E (v-Raf murine sarcoma viral oncogene homolog B1, V600E) mutation, ultrasound-suspected lymph node metastasis, ultrasound-suspected extrathyroidal extension, and microcalcification were identified as risk factors for aggressive PTMC. The stage model was divided into three stages: stage I (RS=0.0; predictive probability for PTMC aggressiveness <10%), stage II (RS=1.0–2.3; predictive probability for PTMC aggressiveness, 10–50%), stage III (RS=3.2–7.6; predictive probability for PTMC aggressiveness, >50%). Based on the abovementioned results, stages I and II were considered to be probably indolent PTMC, and stage III was considered as probably aggressive PTMC.

We suggest that patients with stages I and II PTMC be recommended for active surveillance, while those with stage III PTMC be recommended for immediate surgery.

Artemisia argyi and Houttuynia cordata Thunb are common herbs in most regions of China. In order to test their composite effect as additives on fish, the effects of their extracts mixture on growth performance, antioxidant activity, serum and hepatic lipid levels, and gut bacteria in juvenile grass carp were evaluated. 180 fish were divided into 9 tanks with 3 replicate tanks per treatment, and fed with a control diet (A0) or one of two treatment diets containing 500 (A1) or 1000 mg/kg (A2) mixture of extracts, with equal mass of A. argyi and H. cordata, for 8 weeks. Water flow rate was 8.0 L/min, and water quality parameters were in normal range. At the end of feeding trial, fish weight gain, feed conversion ratio, and survival rate showed no difference among all groups. Significantly higher catalase (CAT) activity and lower malondialdehyde (MDA) content were observed in A1 and A2 groups. Serum triglyceride content was much lower in the A1 group and total cholesterol was lower in experimental groups compared with the control group. Transmission electron microscopy showed that the hepatic lipid droplets were smaller in the experimental groups. High-throughput sequencing identified 10 predominant phyla from gut samples, and Fusobacteria, Bacteroidetes, and Proteobacteria were the most dominant groups. Compared with the control group, in A1 group operational taxonomic unit (OTU) number, species richness (Chao1, and ACE), and α diversity (Shannon index) were higher, and gut bacteria composition was altered in A1 and A2 groups at phylum and genus levels. These results indicated that the extracts mixture of A. argyi and H. cordata can increase antioxidant activity, lower serum and hepatic lipid levels, and improve gut bacteria composition, which can be used as a green additive for grass carp.

Linguistic Z-numbers (LZNs), as a more rational extension of linguistic description, not only consider the fuzzy restriction of assessment information but also take the reliability of the information into account. Maclaurin symmetric mean (MSM) operator has the advantage which can take account of interrelationship of different attributes and there are a lot of research results on it. However, it has not been used to handle multi-attribute decision-making (MADM) problems expressed by LZNs. To sum up the advantages of LZNs and MSM, in this paper, we present the linguistic Z-Numbers MSM (LZMSM) and linguistic Z-Numbers weight MSM (LZWMSM) operators, respectively, and several characters and several special cases of them are explored. Moreover, we propose an approach to handle some MADM problems by using LZWMSM operator. In the end, an example is given to illustrate the effectiveness and superiority of this new presented approach by comparing with several existing approaches.

The development of high-performance aero engines put forward higher performance requirements for compressor components, and the improvement of aerodynamic performance of compressors has important engineering application value. The blade tip recess has great potential and advantages in improving the aerodynamic performance of compressors. In order to better understand the effect of the blade tip recess on the compressor aerodynamic performance, in this paper, the influence mechanism of the blade tip recess on the aerodynamic performance of the isolated rotor of a transonic axial compressor stage is discussed. Under the premise that the numerical method's results are almost consistent with the experimental test results, the full three-dimensional unsteady numerical results show that the main reason for the original blade rotor stall is the leading edge of the blade tip blockage, which is caused by blade tip clearance leakage vortex breakage. After adopting the measures of the blade tip recess, the study shows that the blade tip recess can increase the rotor stall margin by 2.10% without reducing the rotor efficiency and the total pressure ratio. A detailed analysis of the blade tip flow field shows that the blade tip recess can reduce the intensity of the tip clearance leakage flow by increasing the turbulence intensity of the blade tip near the casing wall, and reduces the leading edge of blade tip blockage, improves the rotor blade tip flow field, thereby achieving the purpose of enhancing rotor stability.

In this paper, a numerical investigation was conducted on a subsonic compressor rotor with blade angle slot casing treatments. The purpose of the investigation is to reveal the influence of axial overlap of blade angle slot on the compressor stability. Six kinds of blade angle slot casing treatments with different axial overlap rates were investigated in this paper. The results show that with the increasing of axial overlap rates, the stall margin improvement firstly increased and then decreased. And the optimal blade angle slot can obtain 62.51% improvement of stall margin. The flow field analyses show that the bleeding flows formed inside slots can restrain the adverse tip leakage flow, which is the critical factor making the onset of the rotor stall. With the increasing of axial overlap rate of the slots, the relative position between bleeding flows in the slots and tip leakage flow plays an important role in the stall margin improvement.