Influence of ultrasonic vibration on friction and wear performance of brake disc

In order to effectively improve the friction and wear performance of the brake disc without changing the raw materials and process flow, ultrasonic vibration was proposed and verified in this paper. During the casting process, ultrasonic waves with excitation frequency of 20 kHz and 25 kHz were applied to prepare the sample of the brake disc. Based on the Link3900 NVH test bench, the pressure, speed and temperature sensors were installed to obtain the variation rules of the average friction coefficient and friction stability coefficient under different working conditions. The friction samples were processed by ultrasonic cleaner and measured by high-precision electronic balance, the wear quality change rule at different times was obtained. The hardness study was carried out synchronously with the metallographic test by using the sample test method, thus the influence of ultrasonic vibration on the microstructure and surface hardness was obtained. Combining with the element distribution test results, the influence mechanism of ultrasonic vibration on wear resistance was explained by analyzing the micro wear morphology with electron probe microscope. The results show that applying ultrasonic vibration to the brake disc casting process can significantly improve the hardness, wear resistance and friction stability of the product, especially when the excitation frequency is 20 kHz, better effect can be achieved

The immunomodulatory mechanisms for acupuncture practice

The system physiology approaches that emerge in western countries in recent years echo the holistic view of ancient Traditional Chinese Medicine (TCM) practices that deal with the root, rather than only the symptoms of diseases. Particularly, TCM practices, including acupuncture, emphasize the mobilization of self-healing mechanisms to bring back body homeostasis. Acupuncture has been practiced for over two thousand years to modulate body physiology via stimulation at specific body regions (acupoints). With the development of various research on acupuncture therapy, its regulatory effect on the immune system has been gradually recognized, especially on immunological diseases, including infectious and allergic diseases. In this study, we reviewed the immunomodulatory mechanism of acupuncture and systematically integrates existing research to respectively elucidate the modulatory mechanisms of acupuncture on the innate immune system, adaptive immune system, and well-known neuroanatomical mechanisms, including intact somatosensory-autonomic reflex pathway. With the advances made in recent systems physiology studies, we now have a great opportunity to gain insight into how acupuncture modulates immunity, and subsequently improves its efficacy

Increasing importance of regional emission controls for further reduction of PM2.5 in Beijing

Over the past decade, Beijing has achieved positive results in controlling fine particulate matter (PM2.5) pollution. However, it remains a challenge to further reduce PM2.5 concentrations to a lower level, such as the World Health Organization's air quality guidelines (5 μg/m3). In this study, PM2.5 concentrations and emission reductions over eight years covering two policy periods of air pollution abatement (2013–2017 and 2018–2020) were compared to investigate the efficiency of emission controls in Beijing and surrounding areas. An approach based on observational data, particularly including data from a regional atmospheric background station, was employed to calculate the relative contributions of the local emissions and regional transport. Results show that local emission reductions play a more important role in decreasing PM2.5 in Beijing. However, following a substantial decrease in local emissions over the first period, the relative contribution of regionally transported PM2.5 reached more than 50 % during the second period. The results indicate that joint regional prevention and control of air pollution are needed for Beijing in the future. In addition, the background PM2.5 concentrations over the North China Plain show an increasing trend in recent years, which may be attributed to the increased atmospheric oxidation capacity, thereby posing a challenge for further regional air quality management

Role of Ammonia on the Feedback Between AWC and Inorganic Aerosol Formation During Heavy Pollution in the North China Plain

Atmospheric NH3 plays a vital role not only in the environmental ecosystem but also in atmosphere chemistry. To further understand the effects of NH3 on the formation of haze pollution in Beijing, ambient NH3 and related species were measured and simulated at high resolutions during the wintertime Air Pollution and Human Health-Beijing (APHH-Beijing) campaign in 2016. We found that the total NHx (gaseous NH3+particle NH4 +) was mostly in excess of the SO4 2−-NO3 −-NH4 +-water equilibrium system during our campaign. This NHx excess made medium aerosol acidity, with the median pH value being 3.6 and 4.5 for polluted and nonpolluted conditions, respectively, and enhanced the formation of particle phase nitrate. Our analysis suggests that NH4NO3 is the most important factor driving the increasing of aerosol water content with NO3 − controlling the prior pollution stage and NH4 + the most polluted stage. Increased formation of NH4NO3 under excess NHx, especially during the nighttime, may trigger the decreasing of aerosol deliquescence relative humidity even down to less than 50% and hence lead to hygroscopic growth even under RH conditions lower than 50% and the wet aerosol particles become better medium for rapid heterogeneous reactions. A further increase of RH promotes the positive feedback “aerosol water content-heterogeneous reactions” and ultimately leads to the formation of severe haze. Modeling results by Nested Air Quality Prediction Monitor System (NAQPMS) show the control of 20% NH3 emission may affect 5–11% of particulate matter PM2.5 formation under current emissions conditions in the North China Plain

Next-Generation Sequencing of Cerebrospinal Fluid for the Diagnosis of Neurocysticercosis

Background: Neurocysticercosis (NCC) is the most common helminthic infection of the central nervous system (CNS). The diagnosis of NCC is sometimes challenging due to its heterogenous clinical manifestations and the variable sensitivity and specificity of neuroimaging and serological tests.Methods: Next-generation sequencing (NGS) of cerebrospinal fluid (CSF) was used to detect pathogens in patients with clinically suspected CNS infections. A series of patients diagnosed with NCC is reviewed here.Results: Using NGS of CSF, four patients were diagnosed with NCC. The reads corresponding to Taenia solium ranged from 478 to 117,362, with genomic coverage of 0.0564–11.15%. Reads corresponding to T. solium were not found in non-template controls and far exceeded those of the background microorganisms in patients with NCC, facilitating the interpretation of the NGS results.Conclusions: This case series demonstrates that NGS of CSF is promising in the diagnosis of NCC in difficult to diagnose cases. Larger studies are needed in the future

lncRNA LOC100911717-targeting GAP43-mediated sympathetic remodeling after myocardial infarction in rats

ObjectiveSympathetic remodeling after myocardial infarction (MI) is the primary cause of ventricular arrhythmias (VAs), leading to sudden cardiac death (SCD). M1-type macrophages are closely associated with inflammation and sympathetic remodeling after MI. Long noncoding RNAs (lncRNAs) are critical for the regulation of cardiovascular disease development. Therefore, this study aimed to identify the lncRNAs involved in MI and reveal a possible regulatory mechanism.Methods and resultsM0- and M1-type macrophages were selected for sequencing and screened for differentially expressed lncRNAs. The data revealed that lncRNA LOC100911717 was upregulated in M1-type macrophages but not in M0-type macrophages. In addition, the lncRNA LOC100911717 was upregulated in heart tissues after MI. Furthermore, an RNA pull-down assay revealed that lncRNA LOC100911717 could interact with growth-associated protein 43 (GAP43). Essentially, immunofluorescence assays and programmed electrical stimulation demonstrated that GAP43 expression was suppressed and VA incidence was reduced after lncRNA LOC100911717 knockdown in rat hearts using an adeno-associated virus.ConclusionsWe observed a novel relationship between lncRNA LOC100911717 and GAP43. After MI, lncRNA LOC100911717 was upregulated and GAP43 expression was enhanced, thus increasing the extent of sympathetic remodeling and the frequency of VA events. Consequently, silencing lncRNA LOC100911717 could reduce sympathetic remodeling and VAs