Due to the requirements of the working environment, the marine axial flow control valve needs to reduce the noise as much as possible while ensuring the flow capacity to meet the requirements. To ...improve the noise reduction effect of the axial flow control valve, this paper proposes a Stacking integrated learning combined with particle swarm optimization (PSO) method to optimize a multi-stage step-down sleeve of the axial flow control valve. The liquid dynamic noise and flow value of the axial flow control valve are predicted by computational fluid dynamics. Based on the preliminary evaluation of its performance, the structural parameters of the multi-stage pressure-reducing sleeve are parameterized by three-dimensional modeling software. The range of design variables is constrained to form the design space, and the design space is sampled by the optimal Latin hypercube method to form the sample space. An automated solution platform is built to solve noise and flow values under different structural parameters. The Stacking method is used to fuse the three base learners of decision tree regression, Kriging, and support vector regression to obtain a structural optimization fusion model with better prediction accuracy, and the accuracy of the fusion model is evaluated by three different error metrics of coefficient of determination (R
), Root Mean Squared Error, and Mean Absolute Error. Then the PSO particle swarm optimization algorithm is used to optimize the fusion model to obtain the optimal structural parameter combination. The optimized multi-stage depressurization structure parameters are as follows: hole diameter t
= 3.8 mm, hole spacing t
= 1 mm, hole drawing angle t
= 6.4°, hole depth t
= 3.4 mm, and two-layer throttling sleeve spacing t
= 4 mm. The results show that the peak sound pressure level of the noise before and after optimization is 91.32 dB(A) and 78.2 dB(A), respectively, which is about 14.4% lower than that before optimization. The optimized flow characteristic curve still maintains the percentage flow characteristic and meets the requirement of flow capacity K
≥ 60 at the maximum opening. The optimization method provides a reference for the structural optimization of the axial flow control valve.
Given the role of the deleted in azoospermia gene in male infertility, whether the somatic deleted in azoospermia methylation status is associated with idiopathic asthenospermia should be determined. ...To investigate the methylation levels of the deleted in azoospermia promoter in peripheral white blood cells from idiopathic asthenospermia patients relative to those in normozoospermia controls, 61 ethylene diamine tetraacetic acid anticoagulant blood samples were drawn from all participants for DNA isolation. The deleted in azoospermia promoter methylation ratio was detected by MassARRAY-based methylation quantification and confirmed by quantitative methylation-specific polymerase chain reaction. A MassARRAY-based methylation analysis showed that the deleted in azoospermia 3 promoter (0 to - 2 kbp) was significantly hypomethylated in peripheral white blood cells from idiopathic asthenospermia males, specifically one CpG site (- 246 to - 247). Quantitative methylation-specific polymerase chain reaction data further confirmed that the methylation level of the deleted in azoospermia 3 promoter region in idiopathic asthenospermia patients was significantly lower than that in normozoospermia males. The area under the receiver operating characteristic curve determined by quantitative methylation-specific polymerase chain reaction was 0.737 (95% confidence interval: 0.552 to 0.924), with a sensitivity of 53.9% and a specificity of 88.2% at a cut-off level of 74.7%. Therefore, our results suggested that methylation ratio detection of the deleted in azoospermia 3 promoter region by real-time polymerase chain reaction assay is a promising and feasible tool for liquid biopsy in the clinical laboratories. The methylation status of other reported infertility-related genes should also be investigated in peripheral white blood cells.
Drug-drug interactions play a vital role in drug research. However, they may also cause adverse reactions in patients, with serious consequences. Manual detection of drug-drug interactions is ...time-consuming and expensive, so it is urgent to use computer methods to solve the problem. There are two ways for computers to identify drug interactions: one is to identify known drug interactions, and the other is to predict unknown drug interactions. In this paper, we review the research progress of machine learning in predicting unknown drug interactions. Among these methods, the literature-based method is special because it combines the extraction method of DDI and the prediction method of DDI. We first introduce the common databases, then briefly describe each method, and summarize the advantages and disadvantages of some prediction models. Finally, we discuss the challenges and prospects of machine learning methods in predicting drug interactions. This review aims to provide useful guidance for interested researchers to further promote bioinformatics algorithms to predict DDI.
Emergence delirium (ED) is a kind of delirium that occured in the immediate post-anesthesia period. Lower body temperature on post-anesthesia care unit (PACU) admission was an independent risk factor ...of ED. The present study was designed to investigate the association between intraoperative body temperature and ED in elderly patients undergoing non-cardiac surgery.
This study was a secondary analysis of a prospective observational study. Taking baseline body temperature as a reference, intraoperative absolute and relative temperature changes were calculated. The relative change was defined as the amplitude between intraoperative lowest/highest temperature and baseline reference. ED was assessed with the confusion assessment method for intensive care unit at 10 and 30 min after PACU admission and before PACU discharge.
A total of 874 patients were analyzed with a mean age of 71.8 ± 5.3 years. The incidence of ED was 38.4% (336/874). When taking 36.0°C, 35.5°C, and 35.0°C as thresholds, the incidences of absolute hypothermia were 76.7% (670/874), 38.4% (336/874), and 17.5% (153/874), respectively. In multivariable logistic regression analysis, absolute hypothermia (lowest value <35.5°C) and its cumulative duration were respectively associated with an increased risk of ED after adjusting for confounders including age, education, preoperative mild cognitive impairment, American Society of Anesthesiologists grade, duration of surgery, site of surgery, and pain intensity. Relative hypothermia (decrement >1.0°C from baseline) and its cumulative duration were also associated with an increased risk of ED, respectively. When taking the relative increment >0.5°C as a threshold, the incidence of relative hyperthermia was 21.7% (190/874) and it was associated with a decreased risk of ED after adjusting above confounders.
In the present study, we found that intraoperative hypothermia, defined as either absolute or relative hypothermia, was associated with an increased risk of ED in elderly patients after non-cardiac surgery. Relative hyperthermia, but not absolute hyperthermia, was associated with a decreased risk of ED.
Chinese Clinical Trial Registry (No. ChiCTR-OOC-17012734).
Leaf nutrient content (nitrogen, phosphorus) and their stoichiometric ratio (N/P) as key functional traits can reflect plant survival strategies and predict ecosystem productivity responses to ...environmental changes. Previous research on leaf nutrient traits has primarily focused on the species level with limited spatial scale, making it challenging to quantify the variability and influencing factors of forest leaf nutrient traits on a macro scale. This study, based on field surveys and literature collected from 2005 to 2020 on 384 planted forests and 541 natural forests in China, investigates the differences in leaf nutrient traits between forest types (planted forests, natural forests) and their driving factors. Results show that leaf nutrient traits (leaf nitrogen content (LN), leaf phosphorus content (LP), and leaf N/P ratio) of planted forests are significantly higher than those of natural forests (P< 0.05). The impact of climatic and soil factors on the variability of leaf nutrient traits in planted forests is greater than that in natural forests. With increasing forest age, natural forests significantly increase in leaf nitrogen and phosphorus content, with a significant decrease in N/P ratio (P< 0.05). Climatic factors are key environmental factors dominating the spatial variability of leaf nutrient traits. They not only directly affect leaf nutrient traits of planted and natural forest communities but also indirectly through regulation of soil nutrients and stand factors, with their direct effects being more significant than their indirect effects.
Due to the large pressure difference between the front and back of the valve, the pilot-operated regulating valve is prone to blocking flow, and there are multiple closed cavities connected by small ...holes in the valve, and the flow channel is complex. If the structure design of the spool component is improper, it will seriously affect the safe and stable operation of the regulating valve. In this paper, based on the principle of multi-stage step-down and compressible medium throttling equation, the structure of the pilot valve spool assembly is preliminarily designed to prevent blocking flow. The main influencing parameters affecting the stability of the valve core of the pilot regulating valve are analyzed, and the sample space is designed by the orthogonal method. The numerical simulation analysis of the force of different test samples under different openings is carried out to study the influence of different structural parameters on the force of the valve core. Based on the trend analysis of range and influencing factors, the influence of structural parameters of regulating valve on the stability of the valve core and the optimal structural parameters of valve core assembly under this working condition are studied. ANSYS CFX software was used to calculate the flow field in the valve under the optimal working opening of different experimental samples of the control valve, and the flow field in the valve and the force of the valve core of different test samples were obtained. The analysis results show that the structural parameters affecting the stability of the spool mainly include the equivalent diameter of the main spool opening, the effective diameter of the pilot valve seat throttling, and the pilot valve damping hole. The experimental sample 16 has a large force in the whole adjustment range, floating around 12 % of 1700 N. Under the small opening of the pilot-operated regulating valve, the equivalent diameter d of the main spool opening has the greatest influence on the force of the spool. When the opening is 40 %–80 %, the structural parameter that has the greatest influence on the force of the pilot control valve spool is the main spool lifting height h. In the optimal working range of the regulating valve (30%–70%), the structural parameter that has the greatest influence on the force of the pilot regulating valve spool is the lifting height of the pilot valve spool, and its optimal size is 4.0 mm. The opening diameter of the main valve core has the second influence on the force of the valve core, and its optimal size is 2.0 mm.
•The influence parameters and structural parameters of the pilot-operated control valve spool were optimized.•The main influencing parameters affecting the pilot control valve spool stability are analyzed.•The optimal structural parameters of valve core assembly under this working condition are studied.
The poor opening dynamic characteristics of molten salt check valves, used in concentrating solar thermal systems, constitute the main cause of valve disc oscillation and low pressure difference ...difficulty in opening during molten salt delivery. A molten salt swing check valve is designed to meet the requirements of high-temperature and high-pressure sealing and anti-crystallization flow channels. A transient dynamics model of the valve motion components is established, dynamic mesh and UDF (user-defined function) techniques are used to simulate the non-constant flow of hot molten salt and the opening process of the check valve and to analyze the dynamic characteristics of the opening process. Topological optimization of the valve motion components is proposed for the first time in order to improve the opening performance of the check valve, and the topological optimization of the valve motion components is based on the solid isotropic material penalty (SIMP) model with the variable density method and thermal–fluid–mechanical coupling method. The design is also verified for the dangerous working condition of a molten salt hammer. The results show that the mass of the valve motion component is reduced by 57.76% after optimization while meeting the requirements of strength and stiffness. The optimized molten salt check valve achieves a larger angle and faster opening, the full opening angle is increased by 6°, the positive resting pressure difference of the valve is reduced by 5 kPa, the minimum opening pressure difference is reduced by 8.9 kPa, the optimized flow characteristics are smoother, and the valve disc oscillation problem is avoided. The study provides a method for researchers to use to optimize the design of a molten salt swing check valve and its dynamic characteristics for concentrating solar power, which is of great significance in efforts to improve the stability of the molten salt transport system.
Chronic viral hepatitis (CH) is a stage prior to cirrhosis and primary cancer. Standard protocols for CH assessment during the long follow-up period are of great importance for precise treatment and ...living quality improvement. In this study, we aimed to analyze multiple serum indexes in chronic hepatitis B (CHB)-infected patients and to discuss their combined values in clinical applications.
Total 503 lines of laboratory data from 2012 to 2021 were extracted from103 CHB patients who were followed-up in our hospital. They were divided into the remission group and the progression group according to their complete clinical information and laboratory data. A series of models of serum indexes were analyzed to illustrate the fluctuation trend of @ach index in a time-dependent manner.
The models revealed that abundant serum alpha-fetoprotein (AFP) in the remission group was characteristically associated with hepatocyte destruction markers aspartate aminotransferase (AST) and alanine aminotransferase and favored a much longer progression-free period (P 0.0001). A model-derived equation consisting of serum AFP and AST values showed a good performance (83% reliability) to distinguish the two groups.
This study clearly demonstrates the intrinsic quantitative relationship between serum AFP and liver aminotransferases involving antivirus treatment response. The model-based equation compensates for serum hepatitis B virus DNA detection during outpatient follow-up and it may serve as a useful laboratory tool for CHB progression assessment.
Human cytomegalovirus (HCMV) is a double-stranded DNA virus that belongs to the β-herpesvirus family and infects 40-90% of the adult population worldwide. HCMV infection is usually asymptomatic in ...healthy individuals but causes serious problems in immunocompromised people. We restricted this narrative review (PubMed, January 2022) to demonstrate the interaction and molecular mechanisms between the virus and host immune cells with a focus on HCMV-encoded miRNAs. We found a series of HCMV-encoded miRNAs (e.g., miR-UL112 and miR-UL148D) are explicitly involved in the regulation of viral DNA replication, immune evasion, as well as host cell fate. MiRNA-targeted therapies have been explored for the treatment of atherosclerosis, cardiovascular disease, cancer, diabetes, and hepatitis C virus infection. It is feasible to develop an alternative vaccine to restart peripheral immunity or to inhibit HCMV activity, which may contribute to the antiviral intervention for serious HCMV-related diseases.
The rapid development of virtual reality and augmented reality technology has brought significant changes to many industries in modern society. In the field of product packaging design, the use of ...virtual reality and augmented reality technology in product packaging design is becoming more common in the field. Researchers are exploring the use of VR and AR technology in children’s drug packaging, employing augmented reality research that leverages natural features and artificial recognition to construct a model of children’s drug packaging that incorporates VR and AR technology. We analyze the impact of VR+AR on children’s drug packaging. Consumers’ main requirements for children’s drug packaging are bright, strong, practical, fun, novelty, and ease of understanding. The paper’s model, sample Z, ranks 5th in market competitiveness and 1st in technical competitiveness, outperforming competitors A, B, C, and D. This suggests that VR+AR children’s drug packaging still needs improvement in market competitiveness despite its high technical content. In descending order, the design evaluation dimensions score the VR+AR children’s drug packaging as follows: vivid picture (3.193)> texture (3.154) > easy to hold (3.142) > Moderate capacity (3.129) > simple and generous (3.105) > conform to the production process (3.047) > harmonious color (3.044) > convenient for transportation (3.028) > low production cost (3.012). The average score for each dimension of the VR+AR children’s drug packaging experience is approximately 4.46 points.
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