z. zhang

Significant progress has been made in understanding the mechanisms and simulations of ice-induced shock vibrations due to continuous experimentation and simulation of vibrations induced by ocean platforms. However, the threat of such vibrations to bridges in cold regions with spring rivers remains significant. Currently, challenges persist in the numerical analysis methods applied to vibrations caused by collisions between ice and bridges in river channels. This difficulty primarily arises from the insufficient consideration of the impact of flow field coupling on ice-induced shock vibrations under various simulation conditions. This paper aims to analyze the influence of ice-induced shock vibrations arising from collisions involving bridges, ice, water, and air. It also compares the Semi-Arbitrary Lagrangian-Eulerian (S-ALE) and Arbitrary Lagrangian-Eulerian (ALE) methods, finding that the S-ALE method is better suited for complex flow-solid coupling analysis under the same model. Comparative analysis shows that the fluid effect period increased by approximately 30%, resulting in an 8% reduction in peak values. This confirms the applicability of the ice-induced shock vibration theory and demonstrates that factors such as velocity and thickness significantly impact these vibrations. The findings offer valuable insights for the numerical simulation of river ice-induced shock vibrations due to bridge-ice collisions in cold areas.

This study aims to investigate the pituitary MRI morphological parameters and alterations in 25-hydroxyvitamin D3 [25-(OH) D3], free thyroxine (FT4), and sex hormone levels in female children with central precocious puberty (CPP) and assess their clinical relevance.

From February 2022 to February 2023, 46 female children with CPP and 46 healthy controls were included. Pituitary MRI morphological parameters, 25-(OH) D3, FT4, and sex hormone levels were compared. Diagnostic values of each parameter were assessed.

Patients with CPP exhibited higher pituitary height and altered morphology compared to controls, with a higher proportion in grades 4 and 5 (P < 0.05). Coronal and sagittal dimensions were increased, while coronal width was decreased in the study group (P < 0.05). Levels of E2, LH, FSH, and FT4 were elevated, while 25-(OH) D3 was reduced in CPP patients (P < 0.05). Pituitary height, coronal height, and hormone levels showed high diagnostic value for CPP, with AUC values ranging from 0.811 to 0.886. Combined diagnosis using these indicators improved AUC to 0.909.

In female children with CPP, significant differences exist in pituitary MRI morphological parameters, sex hormones, 25-(OH) D3 and FT4 levels, providing valuable diagnostic insights for CPP.

A high heat transfer rate and excellent heat transfer uniformity are crucial to the physical tempering manufacturing of glass. In the current study, numerical simulations were conducted to evaluate the influence of nozzle shape (circular, square, or triangular) on the transient heat transfer rate and uniformity during jet impingement heating using a square-array configuration at low nozzle-to-plate distances. The Reynolds number (Re) was varied between 2000 and 10000, the nozzle-to-plate distance to nozzle diameter ratio (H/D) was varied between 0.2 and 2, and the nozzle-to-nozzle spacing to nozzle diameter ratio (S/D) was set to values of 4, 5, and 7. The properties of heat transfer rate and uniformity are evaluated by the surface Nusselt number distribution, the average Nusselt number, and the coefficient of variation of temperature. The results revealed that a higher heat transfer rate and good heat transfer uniformity could be obtained only at H/D = 0.2 or 2. Furthermore, square and triangular nozzles afforded superior heat transfer rates and uniformity to the corresponding circular nozzles in specific jet configurations. Moreover, at low H/D values, non-circular nozzles can obtain a higher local maximum Nusselt number than circular nozzles, and significant axis switching occurs around the impingement hole in the center of the jet impingement wall.

The interior noise caused by the pantograph area is greater than that caused by other areas, and the impact of this pantograph area becomes more significant as the speed of high-speed trains increases, especially above 350 km/h. This study proposes an active jet method for pantograph cavities to control noise at the source. First, a predictive model for the interior noise of pantograph carriages was established by jointly adopting large eddy simulation–statistical energy analysis methods. Then, numerical simulations were conducted to determine the external noise sources and interior sound pressure level at different speeds (300, 350, 400, and 450 km/h). Finally, active jets at different speeds (97.2, 111.1, 125, and 140 m/s) were used to analyze the reduction in interior noise. Results showed that the active jet method decreased the average overall sound pressure level of the acoustic cavity in the horizontal plane. When the train speed reached 450 km/h, the optimal reduction in interior noise was approximately 7.5 dB in the horizontal plane for both the standing and sitting postures. The proposed method can efficiently reduce interior noise in the pantograph area.

MicroRNAs (miRNAs) have crucial roles in human cancers. Many studies have certified that miRNAs are implicated in tumor progression via exosomes. Nevertheless, whether miRNA-339 is derived by exosomes and its effects in gastric cancer (GC) presents obscure. Therefore, our study attempted to clarify the functional role and molecular mechanism of miRNA-339 in GC.

In this research, the potential of miRNA-339 in GC was verified through miRNA-339 elevation with cell function assays. Bioinformatics analysis together with mechanical assay was implemented for assessing the regulatory relation between miRNA-339 and zinc finger protein 689 (ZNF689). Moreover, the existence of exosomes was determined via transmission electron microscopy together with nanoparticle tracking analysis.

miRNA-339 presented significant down-regulation in GC. miRNA-339 elevation suppressed GC cell proliferation, invasion along with migration while elevated GC cell apoptosis. miRNA-339 targeted ZNF689 3’UTR to repress ZNF689 expression, thereby hindering GC progression. Finally, miRNA-339 was majorly incorporated into exosomes to hinder GC progression.

In summary, exosome-delivered miRNA-339 may act to be a tumor repressor in GC by targeting ZNF689, which might be an underlying therapeutic target for GC.

Superhydrophobic surfaces have garnered attention for their ability to decrease fluid resistance, which can significantly reduce energy consumption. This study aims to accurately capture critical flow phenomena in a microchannel and explore the internal drag-reduction mechanism of the flow field. To achieve this, the three-dimensional (3D) superhydrophobic surface flow field with conical microstructure is numerically simulated using the gas–liquid two-phase flow theory and Volume of Fluid (VOF) model, combined with a Semi-implicit method for the pressure-linked equation (SIMPLE) algorithm. The surface drag-reduction effect of the conical microstructure is investigated and compared it to that of the V-longitudinal groove and V-transverse groove surfaces. Additionally, the changes in the drag-reduction effect during the wear of the conical microstructure were explored. The numerical results reveal that the drag-reduction effect improves with a larger period spacing of the conical microstructure, the drag reduction rate can reach 25.23%. As the height of the conical microstructure increases, the aspect ratio (ratio of width to height) decreases, and the dimensionless pressure drop ratio and the drag-reduction ratio increase. When the aspect ratio approaches 1, the drag reduction rate can reach over 28%. indicating a more effective drag-reduction. The microstructure is most effective in reducing drag at the beginning of the wear period but becomes less effective as the wear level increases, when the high wear reaches 10, the drag reduction rate decreases to 3%. Compared to the V-shaped longitudinal groove and V-shaped transverse grooves, the conical microstructure is the most effective in reducing drag.

Piezoelectric beams are widely used in micro-electromechanical systems. At the microscale, the influence of the size effect on a piezoelectric beam cannot be ignored. In this paper, higher-order elasticity theories are considered to predict the behaviors of piezoelectric micro-structures and a size-dependent dynamic model of a laminated piezoelectric microbeam is established. The governing equations for the laminated piezoelectric microbeam are derived using the variational principle. The natural frequencies of piezoelectric microbeams are obtained by size-dependent dynamic models. The results reveal that the size effect can enhance the structural stiffness at the microscale. The natural frequency obtained by using the classical model is smaller than that obtained using the size-dependent model. Compared with the modified couple stress model, the modified couple stress model underestimates the size-dependent response. Thus, the modified couple stress model is a simplification of the modified strain gradient model. The influence of beam thickness on the natural frequency is also discussed. With increasing the thickness, the natural frequency of the size-dependent models gradually approaches the result of the classical model. If the value of h/l is greater than 15, the influence of the size effect can be neglected. Additionally, the relative thickness can influence the natural frequency, and if the relative thickness is greater than 5 or less than −5, the bilayer beam can be simplified to a single-layer beam.

This paper aimed to assess the clinical effects of abdominal aortic balloon occlusion (AABO) under color Doppler ultrasound guidance in treating pelvic tumors.

Various databases, which contained China National Knowledge Infrastructure, Wanfang Data, Chinese Biomedical Literature Database, PubMed, Excerpta Medica Database (Embase), and Cochrane Library, were used for searching randomized controlled studies published from 2010 to present. The quality of the literature was assessed using the Newcastle-Ottawa Scale (NOS). Outcome measurements included intraoperative blood loss, transfusion volume, operative time, hospital stay, recurrence, and postoperative complications.

Six reference articles were obtained, including 223 patients who underwent AABO and 300 patients who did not. The NOS score was greater than 7 points in both groups. Meta-analysis showed that the intraoperative blood loss, transfusion volume, and surgery duration of patients undergoing pelvic tumor resection with AABO were all reduced (95% confidence interval (CI): -1504.53~-762.10, P<0.00001; 95% CI: -902.22~-575.45, P<0.00001; 95% CI: -80.20~-26.54, P<0.0001). No difference was discovered in the occurrence of postoperative complications, including nerve injury (95% CI: 0.30~1.34, P=0.23) and urethral injury (95% CI: 0.19~1.97, P=0.41) between both groups. The incidence of wound infection was relatively low (95% CI: 0.22~0.81, P=0.010). Additionally, no difference was discovered in hospital stay (95% CI: -6.85~0.79, P=0.12) and recurrence (95% CI: 0.45~1.53, P=0.12) between both groups (P>0.05).

AABO under color Doppler ultrasound guidance can reduce intraoperative blood loss, transfusion volume, and operative time during pelvic tumor resection and can also reduce the incidence of some postoperative complications.

Preoperative assessment of lymph node metastasis (LNM) status is the basis of individual treatment for rectal cancer (RC). However, conventional imaging methods are not accurate enough.

We collected 282 RC patients who were divided into the training dataset (n=225) and the test dataset (n=57) with an 8:2 scale. A large number of deep learning (DL) features and hand-crafted radiomics (HCR) features of primary tumors were extracted from the arterial and venous phases of the computed tomography (CT) images. Three machine learning models, including support vector machine (SVM), k-nearest neighbor (KNN),and multi-layer perceptron (MLP) were utilized to predict LNM status in RC patients. A stacking nomogram was constructed by selecting optimal machine learning models for arterial and venous phases, respectively, combined with predictive clinical features.

The stacking nomogram performed well in predicting LNM status, with an area under the curve (AUC) of 0.914 [95% confidence interval (CI): 0.874-0.953] in the training dataset, and an AUC of 0.942 (95%CI: 0.886-0.997) in the test dataset. The AUC of the stacking nomogram were higher than those of CT_reported_N_status, ASVM, and VSVM model in the training dataset (P <0.05). However, in the test dataset, although the AUC of the stacking nomogram was higher than the VSVM, the difference was not obvious (P =0.1424).

The developed deep learning radiomics stacking nomogram showed to be effective in predicting the preoperative LNM status in RC patients.

To investigate whether features of 5-mm peritumoral regions could significantly improve the predictive efficacy of a radiomics model based on solid pulmonary tumors at distinguishing lung adenocarcinoma(LAC) from granuloma(GR).

We retrospectively evaluated 167 lung tumors pathologically proven to be LAC (96) or GR (71) and divided them into training group (116) and testing (51) group. We delineated each tumor with three different measures using the tumor and its 5-mm peritumoral region. Then, we extracted 465 features from each volume of interest(VOI) and chose the optimal features to build the diagnostic models. We built four different models using different methods. Finally, we compared the performance of the four models in the test set.

The area under the curve(AUC) of each model in the test group was 0.765 (95% confidence interval(CI): 0.620–0.909), 0.797 (95%CI: 0.670–0.924), and 0.784 (95%CI: 0.647–0.920), respectively. Results of the DeLong test showed that the differences between model 2, model 3, and model 1 were not significant. Results of net reclassification improvement(NRI) showed that model 2 and model 3 had better differential diagnostic efficacy than model 1, with accuracies(ACCs) of 0.784, 0.745, and 0.686, respectively, but the differences were not significant (P>0.05). Moreover, the nomogram had good diagnostic and predictive abilities, with an AUC of 0.848 (95%CI: 0.736–0.961) and an ACC of 0.804.

Features of 5-mm peritumoral regions improved the predictive ability of the radiomics model based on the solid pulmonary tumor, but the difference was not significant.

The cylindrical volute intake structure possesses some advantages including convenient processing, convenient installation & uninstallation and high machining efficiency. The helium turboexpander with this novel intake structure in a superconducting cryogenic device is investigated deeply in this study. Based on the established mathematical model and the corresponding numerical computation methods, the whole flow passage internal flow of the helium turboexpander is numerically simulated. And then the distribution characteristics of total pressure, static pressure, static temperature, relative velocity and total enthalpy in the cylindrical volute, nozzle, impeller and diffuser are explored, and loss mechanism of the internal flow is analyzed. The results indicate that the novel cylindrical volute intake structure has obvious pre-rotation effect on the inlet flow field of the nozzle, and this intake structure has little loss. In addition, the expansion effect in downstream components including nozzle and impeller is obvious, and the flow field changes uniformly. The overall efficiency of the turboexpander is up to 84.8%, which indicates that it is reasonable that the novel cylindrical volute is used as the intake structure of turboexpander.

To investigate the difference between CT-guided three‑dimensional brachytherapy using insertion needles and Fletcher applicator brachytherapy.

Ninety-three patients with cervical squamous cell carcinoma were included. Insertion needle or Fletcher applicators were used depending on tumor conditions. The target volume, target and organs at risk (OAR) dose, and treatment-related complications, in patients receiving the different brachytherapy techniques were compared.

The mean volume of the high-risk clinical target volume (HR-CTV) and intermediate-risk clinical target volume (IR-CTV) in the Fletcher applicator group were smaller compared with the insertion needle group (P<0.05). The mean values of D90 per fraction of the HR-CTV and IR-CTV in the Fletcher applicator group were 101 cGy and 60 cGy lower, respectively, compared with the insertion needle group (P<0.05). The mean bladder and rectum D0.1cm3 per fraction, the mean sigmoid and small intestine D2cm3 per fraction were statistically different between two groups( all P<0.05), the remaining dosimetric parameters were no significant differences (P>0.05). Following dose normalization, with the exception of the mean normalized sigmoid D0.1cm3 per fraction for the received by the OAR in the Fletcher applicator group and the insertion needle group were significantly different (P<0.05). There was no serious complication in the brachytherapy of two types applicators.

Brachytherapy using insertion needles enables the treatment of larger target volumes with higher target doses when compared with conventional Fletcher applicator brachytherapy. In addition, the doses received by the OAR are lower, indicating that it is a safe and effective technique that warrants wide adoption.

To retrospectively evaluate whether quantitative information derived from spectral imaging can improve the differential diagnosis of pancreatic cystic masses including pancreatic solid pseudopapillary epithelial neoplasms (SPENs), mucin- producing cysts and pseudocysts.

From June 2015 to October 2017, 56 patients (22 pseudocysts, 18 mucin-producing cysts and 16 SPENs) who underwent spectral CT imaging were included in the study. Conventional characteristics and quantitative parameters were compared among the three groups. The receiver-operating characteristic curve was used to evaluate the diagnostic performance of parameters which had statistical significance among the three groups. Two radiologists diagnosed the pancreatic cystic masses blinded in consensus, without and with the information of the statistical analysis.

The conventional characteristics including age, contour, nodule and septum were the independent factors correlated with category. The quantitative parameters including effective-Z, slope of energy spectral curve (slope), iodine (water) concentration and calcium (water) concentration demonstrated significantly lower values in pseudocysts group when compared with mucin-producing cysts and SPENs groups. Slope in portal venous phase, threshold of less than 0.50, was the best discriminator between pseudocysts group and mucin-producing cysts group, with a sensitivity of 95.5%, and a specificity of 88.9%. The best quantitative parameter for differentiate SPENs from mucin-producing cysts was the iodine (water) concentration in portal venous phase. With the knowledge of statistical analysis, the accuracy of the two radiologists increased from 78.5% to 90.9%.

Multi-parametric analysis with the combination of quantitative parameters derived from CT spectral imaging could improve the diagnostic performance.

This paper analyzes the effects of structures and loads on the static bending and free vibration problems of bilayer beams. Based on static mechanical equilibrium and energy equilibrium, the static and dynamic governing equations of bilayer beam are established. It is found that the value of the thickness ratio has a significant effect on the static and dynamic responses of the beam, and the structure factors have their own critical value. When the value of the relative thickness is lower than its critical value or the length thickness ratio is greater than its critical value, the static and dynamic responses of the beam increase obviously. The results reveal that a critical value exists in bilayer beam, the value has noticeable influence on the mechanical properties of bilayer beams. Therefore, investigators should predict the critical structures accurately, when they design the bilayer beam.

In textile printing and dyeing industry, a novel type of separator called high gravity rotary gas-liquid separator (HGRGS) is designed, which includes a rotary drum with multi-layer fins and an impeller. First, the structure and separation principle of HGRGS are introduced in this paper. Then, the flow field and separation efficiency are studied by CFD techniques. To ensure the accuracy of the numerical simulation, the results are verified by the available experimental data. Compared with the typical cyclone, the maximum pressure drop reduction rate in HGRGS is 64.7% when the gas enters at 10 m/s. Besides, for droplets less than 5 μm, the separation performance in HGRGS is more efficient and it will be greatly improved by 30% for 1 μm droplets. The numerical results also show that the tangential velocity inside the rotary drum is linear with the radius and the higher the rotating speed, the greater the tangential velocity. Moreover, the maximum tangential velocity between the forced and quasi-free vortex has moved to the vicinity of the outer wall, which is beneficial for droplets to move outward. Additionally, the droplets in HGRGS can be captured with enough residence time owing to the lower axial velocity than that in a typical cyclone.