y. luo

Centrifugal pumps are widely used across various industries, and the design of high-efficiency centrifugal pumps is essential for energy savings and emission reductions. The development of centrifugal pump models primarily uses an iterative design approach combining direct and inverse problem-solving based on one-dimensional flow theory. However, this semi-empirical, semi-theoretical design process is time-consuming and costly. To reduce development time and costs, this paper proposes a rapid impeller design method focused on hydraulic performance, integrating traditional similarity design theory with machine learning. The proposed model uses neural networks to predict empirical coefficients, determine key dimensions such as the impeller’s inlet diameter, outlet diameter, outlet width, and axial distance. Once these parameters are defined, the main dimensions of the impeller can be calculated. The blade profile is defined using a 5-point B´ezier curve. Variations in the cross-sectional area of the flow passage influence the internal flow state of the centrifugal pump, ultimately impacting its hydraulic efficiency. A genetic algorithm, guided by variations in the cross-sectional area of the flow passage, optimizes the blade profile, achieving an improved impeller flow path and completing the rapid design of the centrifuge. This method significantly shortens the development cycle and lowers design costs, making it a promising technique for future impeller designs.

The purpose of this study is to enhance the cutting efficiency of high-pressure abrasive water jet (AWJ) by optimizing nozzle structure and jet hydraulic parameters. To achieve nozzle structure optimization, CFD models of various nozzle shapes were established. The results indicate that the conduit length of conical nozzles has minimal impact on the cutting ability of the jet, while the conical nozzle with a taper angle of 40° exhibits excellent guiding characteristics. Furthermore, an infinite SPH AWJ cutting model with different hydraulic parameter settings was developed for the coupled numerical analysis of pump pressure, flow rate, and nozzle diameter. Through extensive numerical simulations, the study plotted curves of cutting depth and volume against pump pressure, flow rate, abrasive concentration, and nozzle diameter. The results show that, under specific hydraulic parameters, there exists an optimal abrasive concentration; and increasing the displacement leads to an increase in this optimal concentration. Furthermore, under constant pump pressure, increasing the nozzle diameter leads to an increase in flow rate. Additionally, both cutting depth and volume initially increase and then decrease, reaching their maximum values when the nozzle diameter ranges from 4mm to 5mm. The research findings provide a solid theoretical basis for abrasive jet cutting technology.

Building a risk prediction model, validating it, and researching the risk variables for radiation dermatitis in patients receiving post-operative radiotherapy for early breast cancer. A total of 326 patients with early-stage breast cancer who underwent postoperative radiotherapy in hospital between August 2020 and August 2023 were selected and divided into 198 in the modeling group and 128 in the validation group; and the modeling group was divided into an occurrence group and a non-occurrence group according to whether they had radiation dermatitis. Logistic regression was used to investigate the risk factors for the development of dermatitis, and the predictive effect of the model was tested by the receiver operating characteristic curve (ROC). Combined diabetes, conventional split radiotherapy, compensatory membrane application, and albumin <40g/L were independent risk factors for radiation dermatitis (P < 0.05); the area under the curve (AUC) was 0.821 and 0.908 in the modeling and validation groups, respectively, P < 0.001, with goodness-of-fit test (Hosmer-Leme-show, H-L) validity. Clinically, it is important to consider the risk factors of radiation dermatitis among patients who receive postoperative radiotherapy for early-stage breast cancer. Utilizing a risk prediction model, doctors can identify and evaluate patients' risk levels, aiding in the timely implementation of preventive measures.

To explore the value of two-dimensional color ultrasonography (US) in the evaluation of treatment effect of arthroscopic humeral insertion displacement for massive rotator cuff tears (MRCTs).

From February 2021 to April 2022, 42 patients diagnosed as MRCTs by shoulder magnetic resonance imaging (MRI) were selected and separated into the control group (CG, n=21) and study group (SG, n=21). Patients in the SG received rotator cuff humeral insertion displacement and patients in the CG were treated with traditional suture bridge. The reliability of US imaging was examined and the clinical outcomes in two groups were compared.

The sensitivity and specificity of two-dimensional color ultrasonography reached 87.1% and 100% in detecting postoperative repair of MRCTs. Three months after surgery, compared with the CG, the university of California at Los Angeles shoulder rating scale (UCLA) scores in the SG were elevated (P<0.05), and the visual analogue scale (VAS) scores in the SG were declined (P<0.05). Degrees of external rotation, internal rotation, back extension and forward flexion of shoulder joint in both groups were increased after surgery, and those in the SG were higher relative to the CG (P<0.05). The retear rate of the SG was reduced compared with the CG (P<0.05). SG showed higher patient satisfaction rate compared with the CG (P<0.05).

Two-dimensional color ultrasonography is a reliable approach to evaluate the repair of MRCT after arthroscopic rotator cuff internal displacement, which can reduce shoulder pain, improve patient life quality, and is valuable for promotion.

The To discuss the application value of ultrasonography (US) and 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) scintigraphy in hyperparathyroidism (HPT), so as to provide a more reliable guarantee for surgery or thermal ablation.

Sixty-four HPT patients admitted to our hospital and the Tenth People's Hospital of Tongji University from January 2018 to February 2023 were selected as research participants. All patients underwent cervical US, dual-phase 99mTc-MIBI planar scintigraphy, single photon emission computed tomography (SPECT), and pathological examination. The diagnostic efficiency of the above three imaging modalities was evaluated with pathological findings as the gold standard. In addition, the influence of parathyroid position, size and histological type on imaging results was evaluated.

Among the 64 patients, 71 positive lesions were pathologically confirmed. The analysis showed that 99mTc-MIBI SPECT/CT (Kappa=0.806) and US (Kappa=0.686) had high consistency with pathological findings, while dual-phase 99mTc-MIBI planar scintigraphy had moderate consistency with pathological examination results (Kappa=0.594).

99mTc-MIBI scintigraphy can significantly improve the diagnostic rate of parathyroid lesions. US is first recommended for patients suspected of HPT, followed by 99mTc-MIBI scintigraphy for confirmation.

For the purpose of automatic generation control (AGC), a portion of the propeller hydro-turbine units in China is adjusted to operate within a restricted range of 75%-85% load using computer-controlled AGC strategies. In engineering applications, it has been observed that when a propeller hydro-turbine unit operates under off-design conditions, a large-scale vortex rope would occur in the draft tube, leading to significant pressure fluctuations. Injecting air into the draft tube to reduce the amplitude of pressure fluctuations is a common practice, but its effectiveness has not been proven on propeller hydro-turbine units. In this study, a CFD model of a propeller hydro-turbine was established, and 15 cases with different guide vane openings (GVO, between 31° and 45°) under unsteady conditions were calculated and studied. Two air admission measures were introduced to suppress the vortex rope oscillation in the draft tube and to mitigate pressure fluctuations.  The reason for the additional energy loss due to air admission was then explained by the entropy production theory, and its value was quantified. This study points out that when injecting air, it is necessary to first consider whether the air will obstruct the flow in the draft tube. Finally, based on simulation and experimental data under various load conditions, pressure fluctuation analysis (based on fast Fourier transform, FFT) was conducted to assess the effectiveness of air admission measures. This study can provide an additional option for balancing unit efficiency and stability when scheduling units using an AGC strategy.

The Background Currently, surgical resection of the small and sub-centimeter pulmonary nodules (< 2 cm) is quite challenging via the thoracoscopic procedure. Our retrospective study aimed to evaluate the clinical efficiency of pre-operative CT-guided hook-wire localization of targeted pulmonary nodule patients prior to video-assisted thoracoscopic surgery (VATS) or surgery.

60 patients comprising pre-operative computed tomography (CT)-guided hook-wire localization of pulmonary nodules with < 2 cm diameter were retrospectively enrolled. Herein, we evaluated clinical variables, pathological outcomes, hook-wire localization procedure-related features, and complications from targeted pulmonary nodules patients.

Pre-operative CT-guided hook-wire localization was carried out successfully in 60 (100%) patients with wedge resection 41 (68%), segmentectomy 10 (16.7%), and lobectomy 9 (15%). Hook-wire localization procedure had mean time of 0.91±0.29 h, and 11 (18.3%) blood loss. All pulmonary nodule patients were positive pathological diagnoses for benign or malignant lesions, such as 5 (8.3%) benign lesions, 29 (48.3%) minimal adenocarcinoma (MIA) or invasive adenocarcinoma (IAC), and 21 (33.3%) adenocarcinoma in situ (AIS) malignant lesions. The majority of patients with hook-wire localization were either asymptomatic 19 (31.7%) or shown to have mild pain 25 (41.7%) and irritable cough 7 (11.7%).

Preoperative CT-guided hook-wire localization of pulmonary nodules is safe and effective, which can reduce the operative time of targeted pulmonary nodules, and improvise the safety and outcomes of surgery.

To investigate the effects of different radiotherapy regimens on the prognosis of patients with brain metastases.

Patients with brain metastases undergoing radiotherapy from January 2016 to December 2020 were retrospectively analyzed. The patients were divided into a whole-brain radiotherapy (WBRT) group, stereotactic ablative radiotherapy (SABR) group, and WBRT+SABR group, and overall survival (OS) and progression-free survival (PFS) were analyzed.

Forty patients were candidates for the analysis, with a median age of 57.5 years and a median follow-up time of 27.4 months. The median OS and PFS were 35.7 and 13.5 months, respectively, and the median radiotherapy dose was 41.7 Gy. The median OS times for patients who received WBRT (n = 12), SABR (n = 21), and WBRT+SABR (n = 7) were 41.8, 70.6, and 56.8 months, respectively (p = 0.7). The median PFS times were 10.2 months, 34.3 months, and 25.9 months, respectively (p = 0.322). Subgroup analysis indicated that the OS times were 25.4 months after WBRT (n = 7), 79.1 months after SABR (n = 11), and 65.9 months after WBRT+SABR (n = 5) among patients with brain metastases from lung cancer (p = 0.028). The patients had PFS times of 7.1, 33.4, and 29.1 months after irradiation with WBRT, SABR, and combination therapy, respectively (p = 0.009).

The three different radiotherapy regimens had no significant effects on the prognosis of patients with brain metastases. SBAR was superior to WBRT and WBRT+SABR with respect to the prognosis of patients with brain metastases from lung cancer. The sample size of this retrospective study was small; therefore, larger, prospective studies are needed.

Pigmented villonodular synovitis (PVNS) is a rare benign proliferative disease of the synovium which most commonly affects the knee. It is regarded as a benign disease, but has a local invasion. Postoperative adjuvant radiotherapy is very necessary for PVNS, but there is no consensus on the total dose of radiotherapy. 

 A 22-year-old young male with diffuse PVNS of right knee was referred to our hospital with ongoing right knee swelling and limitation of motion of the knee. Preoperative magnetic resonance imaging (MRI) showed synovium of the joint was obviously thickened with multiple nodular low signals of long T1 and short T2 which is the typical characteristic of PVNS. The patient was treated with arthroscopic synovectomy combined with adjuvant postoperative low-dose external radiotherapy (20 Gy).

 Based on related literature about radiotherapy of PVNS, arthroscopic synovectomy combined with postoperative low-dose external radiotherapy is an ideal treatment and prevents the recurrence for PVNS of the knee.