Quality Control Considering Assembly Order for Two Stage Processes

Variation reduction in multistage assembly processes is an important but challenging issue for quality control. It is desirable to minimize the final product variance from a system level. Fruitful research has been conducted on this issue based on the fixed assembly order. However, the variability of parts can be affected by different assembly order. In this paper, we propose a quality control strategy that takes into account the assembly order in two stage assembly processes. Specifically, we analyzed the relationship between the final product variation targets and the assembly order. A case study in conducted on a two stage assembly process of vessel diaphragm to illustrate the developed methodology.disastrous

Occurrence Rates and Heating Effects of Tangential and Rotational Discontinuities as Obtained from Three-dimensional Simulation of Magnetohydrodynamic Turbulence

In solar wind, magnetohydrodynamic (MHD) discontinuities are ubiquitous and often found to be at the origin of turbulence intermittency. They may also play a key role in the turbulence dissipation and heating of the solar wind. The tangential (TD) and rotational (RD) discontinuities are the two most important types of discontinuities. Recently, the connection between turbulence intermittency and proton thermodynamics has been being investigated observationally. Here we present numerical results from three-dimensional MHD simulation with pressure anisotropy and define new methods to identify and to distinguish TDs and RDs. Three statistical results obtained about the relative occurrence rates and heating effects are highlighted: (1) RDs tend to take up the majority of the discontinuities along with time; (2) the thermal states embedding TDs tend to be associated with extreme plasma parameters or instabilities, while RDs do not; (3) TDs have a higher average T as well as perpendicular temperature $T_\perp$. The simulation shows that TDs and RDs evolve and contribute to solar wind heating differently. These results will inspire our understanding of the mechanisms that generate discontinuities and cause plasma heating.Comment: 5 Figures, Submitted to Astrophys. J. Lett., in the process of refereein

Formation of Rotational Discontinuities in Compressive three-dimensional MHD Turbulence

Measurements of solar wind turbulence reveal the ubiquity of discontinuities. In this study, we investigate how the discontinuities, especially rotational discontinuities (RDs), are formed in magnetohydrodynamic (MHD) turbulence. In a simulation of the decaying compressive three-dimensional (3-D) MHD turbulence with an imposed uniform background magnetic field, we detect RDs with sharp field rotations and little variations of magnetic field intensity as well as mass density. At the same time, in the de Hoffman-Teller (HT) frame, the plasma velocity is nearly in agreement with the Alfv\'{e}n speed, and is field-aligned on both sides of the discontinuity. We take one of the identified RDs to analyze in details its 3-D structure and temporal evolution. By checking the magnetic field and plasma parameters, we find that the identified RD evolves from the steepening of the Alfv\'{e}n wave with moderate amplitude, and that steepening is caused by the nonuniformity of the Alfv\'{e}n speed in the ambient turbulence.Comment: Five figures enclosed. Submitted to Astrophys. J., Under referrin

Microglia exacerbate white matter injury via complement C3/C3aR pathway after hypoperfusion.

Microglial activation participates in white matter injury after cerebral hypoperfusion. However, the underlying mechanism is unclear. Here, we explore whether activated microglia aggravate white matter injury via complement C3-C3aR pathway after chronic cerebral hypoperfusion. Methods: Adult male Sprague-Dawley rats (n = 80) underwent bilateral common carotid artery occlusion for 7, 14, and 28 days. Cerebral vessel density and blood flow were examined by synchrotron radiation angiography and three-dimensional arterial spin labeling. Neurobehavioral assessments, CLARITY imaging, and immunohistochemistry were performed to evaluate activation of microglia and C3-C3aR pathway. Furthermore, C3aR knockout mice were used to establish the causal relationship of C3-C3aR signaling on microglia activation and white matter injury after hypoperfusion. Results: Cerebral vessel density and blood flow were reduced after hypoperfusion (p<0.05). Spatial learning and memory deficits and white matter injury were shown (p<0.05). These impairments were correlated with aberrant microglia activation and an increase in the number of reactive microglia adhering to and phagocytosed myelin in the hypoperfusion group (p<0.05), which were accompanied by the up-regulation of complement C3 and its receptors C3aR (p<0.05). Genetic deletion of C3ar1 significantly inhibited aberrant microglial activation and reversed white matter injury after hypoperfusion (p<0.05). Furthermore, the C3aR antagonist SB290157 decreased the number of microglia adhering to myelin (p<0.05), attenuated white matter injury and cognitive deficits in chronic hypoperfusion rats (p<0.05). Conclusions: Our results demonstrated that aberrant activated microglia aggravate white matter injury via C3-C3aR pathway during chronic hypoperfusion. These findings indicate C3aR plays a critical role in mediating neuroinflammation and white matter injury through aberrant microglia activation, which provides a novel therapeutic target for the small vessel disease and vascular dementia

Risk prediction models for postoperative delirium in elderly patients with hip fracture: a systematic review

ObjectivesTo systematically evaluate the risk prediction models for postoperative delirium in older adult hip fracture patients.MethodsRisk prediction models for postoperative delirium in older adult hip fracture patients were collected from the Cochrane Library, PubMed, Web of Science, and Ovid via the internet, covering studies from the establishment of the databases to March 15, 2023. Two researchers independently screened the literature, extracted data, and used Stata 13.0 for meta-analysis of predictive factors and the Prediction Model Risk of Bias Assessment Tool (PROBAST) to evaluate the risk prediction models for postoperative delirium in older adult hip fracture patients, evaluated the predictive performance.ResultsThis analysis included eight studies. Six studies used internal validation to assess the predictive models, while one combined both internal and external validation. The Area Under Curve (AUC) for the models ranged from 0.67 to 0.79. The most common predictors were preoperative dementia or dementia history (OR = 3.123, 95% CI 2.108–4.626, p &lt; 0.001), American Society of Anesthesiologists (ASA) classification (OR = 2.343, 95% CI 1.146–4.789, p &lt; 0.05), and age (OR = 1.615, 95% CI 1.387–1.880, p &lt; 0.001). This meta-analysis shows that these were independent risk factors for postoperative delirium in older adult patients with hip fracture.ConclusionResearch on the risk prediction models for postoperative delirium in older adult hip fracture patients is still in the developmental stage. The predictive performance of some of the established models achieve expectation and the applicable risk of all models is low, but there are also problems such as high risk of bias and lack of external validation. Medical professionals should select existing models and validate and optimize them with large samples from multiple centers according to their actual situation. It is more recommended to carry out a large sample of prospective studies to build prediction models.Systematic review registrationThe protocol for this systematic review was published in the International Prospective Register of Systematic Reviews (PROSPERO) under the registered number CRD42022365258

Nucleated red blood cells as a novel biomarker in the diagnosis and prediction of sepsis severity in children

IntroductionSepsis is a vitally serious disease leading to high mortality. Nucleated red blood cells (NRBCs) are present in some noninfectious diseases, but the relationship between NRBCs and sepsis in children remains unknown. The purpose of this study was to compare the clinical characteristics and outcomes of sepsis with positive NRBCs and negative NRBCs in children, and to further explore whether the count of NRBCs has a relationship with the severity of sepsis.MethodsWe enrolled children with sepsis who were admitted to the Children’s Hospital of Chongqing Medical University between January 2020 and December 2022. The children’s clinical data, laboratory data and outcomes were recorded and analyzed.ResultsOne hundred and fifteen children met the inclusion criteria in our study. Compared to negative NRBCs patients, the C-reactive protein, alanine transaminase, urea nitrogen values, mortality rate and length of hospitalization were found to be significantly increased, while platelet counts, and hemoglobin were significantly decreased in sepsis patients with positive NRBC (P &lt; 0.05). Receiver operating characteristic (ROC) curves analysis showed that the optimal cutoff value of the NRBC count in the diagnosis of severe sepsis was 3, with a sensitivity of 87.5% and specificity of 94.9%. The area under the ROC curve was 0.877 (95% CI: 0.798-0.957).DiscussionThese findings demonstrated that NRBC count has the potential to be a biomarker for the diagnosis of sepsis in children, especially an NRBC count greater than 3, which may predict the severity and poor prognosis in children suffering from sepsis