Chamber System Research Articles

Effect of Particulate Matter on Achilles Tendon Healing: An Experimental Study in Rats

Category: Basic Sciences/Biologics; Ankle; Sports; Trauma Introduction/Purpose: Exposure of particulate matter (PM) has been linked to several diseases including pulmonary, cardiovascular, oncology, neurology system, and etc. Even though tendon injury has become increasingly common recently, there has been no study of relationship between tendon healing and PM. Hence, we performed experimental study in rats to evaluate whether PM has significant effect on tendon healing. We hypothesized that PM exposure may substantially influence Achilles tendon healing. Here, we evaluated whether PM exposure led to deleterious effect on tendon healing in a rat model of Achilles tendon rupture (ATR). Methods: All experiments with rats were approved by the Institutional Animal Care and Use Committee. The Achilles tendons of 20 Sprague-Dawley rats were transected by open tenotomy. The animals were divided into two groups according to exposure of PM 2.5 (particulate matter less than 2.5µm): control group (Non-PM group) or PM exposure group (PM group). 30 minutes of PM inhalational exposure was performed 3 days a week for 6 weeks in closed chamber systems. After 6 weeks, histologic study of lung, laboratory test and enzyme-linked immunosorbent assay (ELISA) of blood samples, histologic study, transmission electron microscopy (TEM) analysis, biomechanical study, RNA sequencing, and western blot analysis of Achilles tendon was performed. Results: Hematoxylin and eosin (H&E) stain of lung tissue in PM group showed inflammation of alveolar wall and increased macrophage. Laboratory test and ELISA of blood samples from PM group showed significantly higher expression of white blood cell count and tissue necrosis factor alpha (TNF-α) than those from non-PM group, respectively. Histologic study of Achilles tendon in PM group exhibited increased lymphocyte and ossification findings with inflammatory change of cell morphology. TEM analysis showed decreased collagen fibril in PM group than non-PM group. Load to failure was decreased in the PM group than non-PM group. RNA sequencing and ingenuity pathway analysis showed increased cAMP-PKA-CREB signal pathway in PM group and the results were consistent with western blot outcomes. Conclusion: Achilles tendon healing was substantially affected by the PM exposure. Based on the present data, PM exposure induces detrimental histological and biomechanical results on Achilles tendon healing through cAMP-PKA-CREB pathway. Further in-vitro study and larger in-vivo study with longer time period are needed to support the present data.

Thermal tolerance, density, and distribution of mangrove crabs, Perisesarma guttatum and Uca urvillei at Gazi Bay, Kenya

Abstract. Kipyegon JK, Obudho PA, Kairo JG. 2019. Thermal tolerance, density, and distribution of mangrove crabs, Perisesarma guttatum and Uca urvillei at Gazi Bay, Kenya. Indo Pac J Ocean Life 3: 38-50. Mangrove crabs are fundamental for the viability of mangrove forests. Therefore, the effects of climate change can impact mangrove ecosystems. The aim of this study was to determine the thermal tolerance, density, and distribution of the mangrove crabs Perisesarma guttatum (A.Milne-Edwards, 1869) and Uca urvillei (H.Milne Edwards, 1852) within Gazi Bay, Kenya. Field activities included collecting data on the density and distribution of the two crab species and environmental variables in the Rhizophora mucronata Lam., Ceriops tagal (Perr.) C.B.Rob. and Avicennia marina (Forssk.) Vierh. monospecific stands. The crabs were maintained at temperatures between 17-37°C in the laboratory, and respiration rate measurements were performed in closed chamber systems after the crabs were acclimated for 8 hours at a temperature of 27°C. The results indicate the temperature ranges for P. guttatum and U. urvillei adult crabs were 27-31°C and 27-33°C, respectively, beyond which the crabs got stressed as indicated by increased metabolism. Findings suggest that P. guttatum is more sensitive to temperature variation than U. urvillei. At the highest average densities of U. urvillei and P. guttatum crabs were recorded at 66.25±7.7/m² and 11.75±4.1/m², respectively, in the R. mucronata zone. The densities of U. urvillei and P. guttatum were strongly related to the temperature, fine sand, and organic matter using stepwise regression analysis (P<0.05). This study has increased the understanding of mangrove crab populations' physiological responses and possible distribution patterns to the expected impacts of climate change on these species.

Analysis of Verlos Kamer Register System and Surgical Room Desktop-Based at Baliméd Hospital Denpasar

The hospital conducts a patient registration procedure with the intent of collecting information on all patients to enable the reporting of a renewable hospital information system based on information requirements. Based on study observations of the manual Verlos Kamer and surgical room registers at BaliMéd Hospital Denpasar, it was determined that data imbalances existed. This study aims to develop a desktop-based verlos chamber and surgical room register system for the BaliMéd Hospital Denpasar. The system development life cycle is the system development analysis method. The research approach is quasi-experimental, consisting of a single-group pre- and post-test. The findings of the questionnaire-based usability test were 77.79%. The outcomes of the study utilizing the Paired T-test for the Verlos Kamer database. As the p-value is known to be 0.0328 0.05, it can be concluded that the Verlos Kamer register system and desktop-based surgical room at BaliMéd Hospital Denpasar are effective in reducing the incidence of imbalanced data in the register. Given that the p-value for registering surgical rooms using the Paired T-test is 0.0034 0.05, it can be concluded that the Verlos Kamar register system and desktop-based surgical room at BaliMéd Hospital Denpasar are effective in reducing the incidence of imbalanced data in the surgical room register. Web- and mobile-enabled, certified electronic signature-affixed system development recommendations for generating birth certificates from Verlos chamber and surgical room register data.

307 Effects of Incorporating Malted Barley in a Finishing Ration on Intake, Performance, and Enteric Methane Emission of Beef Steers

Abstract Incorporations of malted barley (MB), as an exogenous source of α-amylase, demonstrated the potential to reduce methane (CH4) emissions in an in vitro experiment. However, this finding had not been confirmed in vivo. Forty-two mixed breed (predominately Bos taurus) influenced yearling steers (initial BW = 521.7 ± 31.4 kg) were used in a randomized complete block design experiment. Steers were blocked by BW and assigned to one of two pens, each containing an automated head chamber system (GreenFeed; C-Lock Inc., Rapid City, SD). Each steer was assigned to an individual feed bunk with Calan gates (American Calan, Northwood, NH) and fed a finishing ration for 92 days. Within each block, animals were assigned to 1 of 3 treatments based on MB inclusion level (DM basis): 0% MB (CON), 10% MB (10MB), or 20% MB (20MB), which were formulated to be iso-nitrogenous and energetic. All data were analyzed using orthogonal polynomial contrasts. There was no significant effect of MB inclusion on DMI or ADG (P ≥ 0.20); however, due to numerical differences, there was a linear reduction (P = 0.02) in feed efficiency with increasing MB inclusion. Further, there was a significant (P = 0.05) quadratic increase in CH4 production (g CH4/d) with increasing MB inclusion, such that MB fed steers had, on average, 7% greater CH4 emissions compared with the CON steers. Increasing MB did not affect CH4 yield (P ≥ 0.13; g CH4/kg DMI), but there was a tendency for a linear increase in emission intensity (g CH4/kg ADG; P = 0.09) with increasing MB inclusion. We speculate that the discrepancy between the previous in vitro experiment and the current experiment may be related to grain processing (diets ground for in vitro vs. MB not processed in current experiment); highlighting the need for further research.

PSXIV-18 Fecal dry-Matter Output Determination from Irregular Marker Doses

Abstract Automated head chamber systems (AHCS) configured to offer known quantities of feed to individual animals may potentially be used to dose animals with an indigestible marker. Fecal marker analysis commonly assumes steady-state fecal concentration represented by average measured concentration. Due to irregular voluntary use of an AHCS, it’s not likely steady-state fecal concentrations would be achieved. Our objective was to determine whether steady-state assumptions could be relaxed and fit measured concentrations to multi-dose digesta kinetics models to produce reliable fecal output estimates when dose times and amounts are known but irregular. We used individually penned, rumen fistulated Dexter steers (n = 4, initial BW = 322 ±15 kg) limit fed a diet of hay and protein supplement in two experiments. First, after a 7-d acclimation period, steers were given a dose of TiO2 through the rumen fistula. On d 14, the steers received another dose. Over a period of 120 h after each dose, 14 fecal samples were collected. In Exp. 2, 7-d after the steers had received their 2nd dose, steers received the first of 6 daily doses, then on d 7 no dose, and on days 8 to 12 daily doses resumed. Beginning on d 7, when dose was skipped, fecal sampling began and over a 120-hr period, 14 fecal samples were collected. During both experiments total fecal collections were also made. For Exp. 1, marker concentration data were fit to a G2 digesta kinetics models and for Exp. 2, concentration data were fit to a multi-dose G2 digesta kinetics model. The multi-dose approach models over time, the sum of each known pulse, assuming identical digesta kinetics for each dose. Measured fecal output in Exp. 2 averaged 2,525 g/d, but the estimates obtained from fitting measured concentrations to multi-dose digesta kinetics models was significantly less (P = 0.005, 2,265 g/d).

Cell counting chamber vs. Sysmex XN-1000 for determining white blood cell count and differentiation for body fluids

Abstract Objectives Sterile body fluids (BFs) include key information for the diagnosis and monitoring of a variety of diseases. A cornerstone test is the total white blood cell (WBC) count, which comprises the differential of WBC of body fluid analysis. It is important to test automated hematology analyzers that should be verified using patient samples. The aim of this study is to compare both the performance of the Sysmex XN-1000 system’s body fluid module for cell counting and differentiation to the results of a cell counting chamber. Methods This study was performed on 200 routinely laboratory sent BFs. Cell counts and differentiation were determined with both bright-lined Neubauer Cell Counting Chamber and Sysmex XN-1000 system body fluid mode. Results The correlation coefficients of WBC count by two methods indicated very strong correlation (r≥0.90, p<0.0001) for any specimen except pleural fluid. According to Passing-Bablok regression analysis, Sysmex XN-1000 showed acceptable performance according to bias of the slope criteria (<±20%). Conclusions The XN-1000 hematological analyzer’s body fluid mode can rapidly count and identify cells, and it can be used as a simple and rapid screening method for laboratory testing of sterile body fluids, particularly in laboratories with a massive quantity of biological fluids.

Whole-Canopy Photosynthetic Characterization of Apple Tree and the Effects Induced by Grafting on Rootstocks with Different Vigor

Leaf photosynthesis is pivotal for the synthesis of carbohydrates; however, the growth and development of horticultural crops are more closely related to canopy photosynthetic capacity. Measurements of canopy photosynthesis allow a better evaluation of the fruit tree performance at the canopy scale. Therefore, an open chamber system to determine instantaneous canopy apparent photosynthesis (CAPi) was investigated. CAPi slightly overestimated the biomass accumulation by 5.9%, which revealed that the CAPi method is valuable for quantifying canopy photosynthesis. Further, many woody horticultural plants are usually grafted for propagation, such as apples, whereas the rootstocks always influence the canopy size and photosynthesis. In this study, the effect of dwarfing, semi-dwarfing, and vigorous apple rootstocks on canopy photosynthesis was studied. Compared to vigorous rootstock, dwarfing rootstock significantly reduced the leaf net photosynthetic rate and total leaf area by 20.8% and 53.1%, respectively, and resulted in a 59.7% reduction in CAPi. Throughout the study, CAPi was an effective method that should be considered for canopy photosynthesis measurement of horticultural crops in the future.

Size-dependent transfer of microplastics across the intestinal wall of the echinoid Paracentrotus lividus.

The fate and toxicity of ingested marine microplastics (MPs) have been of major concern in aquatic ecotoxicology for the last decade. Although their ingestion by a wide range of marine organisms has been proven, the uptake of MPs within organs is not yet fully understood and relies on the ability of ingested microplastics to transfer from the gut to tissues beyond the digestive wall (i.e., translocation). The present study investigates the in vitro transfer of fluorescent high-density polyethylene particles of different sizes classes (1-5µm; 10-29µm; 38-45µm) across the intestinal wall of the sea urchin Paracentrotus lividus using Ussing chambers. Small microplastics (1-5µm) were proven to be able to cross the intestinal wall of P. lividus and reach the coelomic fluid, while larger microplastics (≥ 10µm) were not observed to cross the intestinal wall. Results demonstrate a size-dependent passage of polyethylene microparticles across the intestinal walls of P. lividus for the first time, highlighting the suitability of Ussing chamber systems to study the transfer of MPs across the intestinal wall of animals.

A Flexible Chamber for Time-Lapse Live-Cell Imaging with Stimulated Raman Scattering Microscopy.

Stimulated Raman scattering (SRS) microscopy is a label-free chemical imaging technology. Live-cell imaging with SRS has been demonstrated for many biological and biomedical applications. However, long-term time-lapse SRS imaging of live cells has not been widely adopted. SRS microscopy often uses a high numerical aperture (NA) water-immersion objective and a high NA oil-immersion condenser to achieve high-resolution imaging. In this case, the gap between the objective and the condenser is only a few millimeters. Therefore, most commercial stage-top environmental chambers cannot be used for SRS imaging because of their large thickness with a rigid glass cover. This paper describes the design and fabrication of a flexible chamber that can be used for time-lapse live-cell imaging with transmitted SRS signal detection on an upright microscope frame. The flexibility of the chamber is achieved by using a soft material - a thin natural rubber film. The new enclosure and chamber design can be easily added to an existing SRS imaging setup. The testing and preliminary results demonstrate that the flexible chamber system enables stable, long-term, time-lapse SRS imaging of live cells, which can be used for various bioimaging applications in the future.

An ANN-PSO-Based Method for Optimizing Agricultural Tractors in Field Operation for Emission Reduction

Aiming at the serious problem of agricultural tractor emission pollution, especially the limitation of nitrogen dioxide (NOx) and soot emissions, we took an agricultural diesel engine as the research object, and a diesel engine combustion chamber model was established for both simulated calculations and experimental verification analysis. The in-cylinder pressure and heat release obtained from the combustion chamber model simulation calculations were within 6% error of the experimental data. The overall trend of change was basically consistent. The established model can simulate the working conditions of the experimental engine relatively well. An artificial neural network (ANN) was also established as an agent model based on the indentation rate, tab depth, and combustion chamber depth as the input, and NOx and soot as the output. The decision coefficients of the ANN model were R2 = 0.95 and 0.93, with corresponding Mean Relative Error (MRE) values of 10.13 and 8.18%, respectively, which are within the generally required interval, indicating that the obtained ANN model has good adaptability and accuracy. On the basis of the general particle swarm optimization (PSO) algorithm, an improved PSO algorithm was proposed, in which the inertia factor is continuously adjusted with the help of the skip line function in the optimization process so that the inertia factor adapts to different rates and adjusts the magnitude of the corresponding values in different periods. The improved PSO algorithm was used to optimize the optimal input parameter matching of the agent model to form a new combustion chamber structure, which was imported into CONVERGE CFD software for emission simulation and comparison with the emissions of the original combustion chamber. It was found that the NOx reduction was about 1.21 g·(kW·h)−1, and the soot reduction was about 0.06 g·(kW·h)−1 with the new combustion chamber structure. The ANN + PSO optimization method proved to be effective in reducing the NOx and soot emissions of diesel engine pollutants, and it may also provide a reference and ideas for the design and development of relevant agricultural engine combustion chamber systems.

Sunlight–Triggered Synergetic Facilitation of Hematite and Lactobacillus: A Vital Enhanced Carbon Conversion Pathway in Nature

Sunlight–triggered mineral–microbial interaction is extensively involved in the material circulation and energy flow process in the global system, accompanied by element cycle including carbon, nitrogen, and sulfur. Here, the phenomenon of enhanced carbon conversion efficiency between Lactococcus lactis (L. lactis) and natural hematite was demonstrated for the first time. In dual–chamber system, the average speed of glucose consumption would promote above 109% and the electrons transfer efficiency was promoted 17.9%, which compared with ‘L. lactis (Dark).’ It indicated a burgeoning electron transfer pathway between the L. lactis and hematite under light illumination. To simulate a blend system in nature, there was also almost 2 times promotion under the light condition in shake–flask system. Furthermore, for further close to natural environments about sunlight triggered facilitation, the systems of the hybrid colony (Lactobacillus)–hematite and hybrid colony–red soil were structured. Notably, glucose consumption in light–hematite condition (0.38 ± 0.085 g/L) was 2.23 times higher than ‘L. lactis (Dark)’ condition, which verified that the facilitated carbon source consumption process of Lactobacillus occurring in nature was prevalent widely. Nevertheless, it was an underappreciated carbon conversion pathway in nature, our research may have great significance for a more comprehensive understanding of the carbon cycle in nature.

CD45 in ocular tissues during larval and juvenile stages and early stages of V. anguillarum infection in young lumpfish (Cyclopterus lumpus)

Immune responses to infectious diseases impacting lumpfish (Cyclopterus lumpus) eye tissue are only starting to be studied at a molecular and histopathological level. In this study, we extend our understanding of lumpfish sensory organ anatomy, of components of the lumpfish nasal and ocular immune system and the nature of the intraocular response to Vibrio anguillarum infection. We have evaluated the expression of cluster of differentiation (CD) 45 protein, a tyrosine phosphatase, in larval and juvenile lumpfish tissues in order to spatially survey ocular and related head structures that may participate in early stages of intraocular immune responses. We provide here a histological mapping of the larval lumpfish nasal chamber system since its connectively with the eye though mucosal epithelia have not been explored. These results build upon our growing understanding of the lumpfish intraocular immune response to pathogens, exemplified herein by experimental nasally delivered V. anguillarum infection. CD45 is developmentally regulated in lumpfish eyes and periocular anatomy with early expression appearing in larvae in corneal epithelium and in nasal structures adjacent to the eye. Normal juvenile and adult lumpfish eyes express CD45 in the corneal epithelium, in leukocyte cells within blood vessel lumens of the rete mirabile, choroid body and choriocapillaris vasculatures. Experimental nasally delivered V. anguillarum infection led to qualitative and quantitative changes in CD45 expression in head kidney renal tubule tissues by 7 days post infection (dpi). The same animals showed redistribution and upregulation of corneal epithelial CD45 expression, corneal epithelial dysplasia and an increased frequency of CD45+ cells in ocular vasculature. Interestingly, while CD45 upregulation and/or CD45+ cell infiltration into inner ocular and retinal tissues was not observed under this experimental scenario, subtle neural retinal changes were observed in infected fish. This work provides new fundamental knowledge on North Atlantic teleost visual systems and vision biology in general.

The Ocean Plastic Incubator Chamber (OPIC) system to monitor in situ plastic degradation at sea

Marine plastic pollution is a global and pervasive environmental issue. Knowledge on plastic degradation in natural settings is still very limited due to current technological limitations, hampering our understanding of plastic fate (including its breakdown into micro- and nanoplastics) and of its risk for marine ecosystems. Here we present the proof of concept of the Ocean Plastic Incubator Chamber (OPIC), a novel equipment to follow plastic degradation in situ at sea over time. OPIC consists of a frame containing a motorised rotating stage with transparent tubes sub-assemblies where reference plastic materials are incubated and exposed to natural weathering conditions for defined time multi-years period. OPIC has been designed, tested and adapted for deployment with mooring line platforms in the open ocean with potential future application in remote environments at different depths (from shallow waters to deep sea environments). This incubator will allow us to measure different markers of plastic aging in situ in the ocean for the first time, providing new insights into the multiple and locally driven dynamics regulating plastic transformations and fate at sea.

Conceptual design and performance analysis of water electrolysis propulsion system with catalytic igniter for CubeSats

Water electrolysis propulsion systems generate thrust by burning the hydrogen and oxygen generated by the electrolysis of water. Such systems combine the advantages of electric and chemical propulsion without the use of toxic substances. In this study, a water electrolysis propulsion system was conceptually designed for a 3U cube satellite (CubeSat) that performs a low-orbit mission at an altitude of 300 km. The system involved a polymer electrolyte membrane water electrolyzer and catalyst igniter. The catalyst igniter is suitable for use in CubeSats to decrease the size and weight of the combustion chamber and entire system. Excellent ignition performance was observed in experiments. According to the experimental results, the ignition delay time of the thruster was assumed. And with the performance analysis of the water electrolysis propulsion system, the satellite lifetime was extended by up to 12 years when loaded with 1 kg of water, higher than that of other propulsion systems equipped with the same volume of propellant, and also has high efficiency compared to general electric thrusters.

Cryptic subterranean diversity: regional phylogeography of the sand termite Psammotermes allocerus Silvestri, 1908 in the wider Namib region

Psammotermes allocerus Silvestri, 1908 is the only described species representing the genus Psammotermes Desneux, 1902 in Southern Africa. The large geographical range of this subterranean termite covers both summer and winter rainfall regimes. Deadwood is the preferred food when available, but in more arid habitats, both live and dead grasses form the major dietary component. Along the Namib Desert margins, the species’ localised herbivory creates circular bare patches known as fairy circles. For a regional phylogeographic study of this species, we sampled 65 sand termite populations within drier parts of Namibia, South Africa, and Angola. Based on combined molecular and ecological data, we found considerable genetic diversification within P. allocerus. Analyses of two mitochondrial markers (COI, COII), including a Bayesian inference tree, haplotype analysis and genetic distances suggest a delineation into seven highly differentiated genetic groups. The ‘Succulent Karoo’ group is additionally characterised by unique features of the royal chamber, nest and tunnel system. In conclusion, our data suggest that P. allocerus should be not regarded as one species but as a species complex. Termites of each analysed group ‘Northern Namib’, ‘Western Kalahari Basin’, ‘Nama’, ‘Southwestern Kalahari’, ‘East Gariep’, ‘Southern Namib’ and ‘Succulent Karoo’ should be considered as distinct species. The species name P. allocerus should be used for termites of the ‘Succulent Karoo’.

Translating CO_2 variability in a plant growth system into plant dynamics

Plant growth occurs owing to the continuous interactions between environmental and genetic factors, and the analysis of plant growth provides crucial information on plant responses. Recent agronomic and analytical methodologies for plant growth require various channels for capturing broader and more dynamic plant traits. In this study, we provide a method of non-invasive growth analyses by translating CO_2 variability around a plant. We hypothesized that the cumulative coefficient of variation (CCV) of plant-driven ambient CO_2 variation in a plant growth system could yield a numerical indicator that is connected to the plant growth dynamics. Using the system outside-plant growth system-plant coupled dynamic model, we found that the CCV could translate dynamic plant growth under environmental and biophysical constraints. Furthermore, we experimentally demonstrated the application of CCV by using non-airtight growth chamber systems. Our findings may enrich plant growth information channels and assist growers or researchers to analyze plant growth comprehensively.

Ammonia and greenhouse emissions from cow's excreta are affected by feeding system, stage of lactation and sampling time

Decomposition of dairy cows' excreta on housing floor leads to ammonia and greenhouse gases production, yet factors affecting total emissions have not been fully disclosed. This work aimed to assess the impact of lactation stage, feeding system and sampling time on gaseous emission potential of cow's faeces and urine in laboratory chambers systems. Individual faeces and urine were collected from two groups of four cows, at peak and post peak lactation, from three commercial farms with distinct feeding systems: total mixed ration (TMR), total mixed ration plus concentrate at robot (TMR + robot), and total mixed ration plus concentrate in automatic feeders (TMR + AF). Samples were collected before a.m. (T8h), at middle day (T12h), and before p.m. (T17h) milking. In a laboratory chambers system, faeces and urine were mixed in a ratio of 1.7:1, and ammonia and greenhouse gases emissions were monitored during 48-h. Cumulative N–N2O emissions were the highest in TMR + robot system, post peak cows and sampling time T17h. An interaction between stage of lactation and sampling time was detected for N–NH3 and N–N2O (g/kg organic soluble N) emissions. Post peak cows also produced the highest cumulative N–NH3 emissions. Overall results contribute for the identification of specific on-farm strategies to reduce gaseous emissions from cows' excreta.

Experimental and numerical study of the effects of N2 dilution and CH4 addition on the laminar burning characteristics of syngas

The study of combustion characteristics of complex biomass syngas under changing conditions is helpful for its practical utilization. In this paper, the effects of N2 dilution (dilution rates from 0% to 60%) and CH4 addition (mixing ratios from 0% to 20%) on the laminar flame properties of H2/CO/N2 syngas were researched. The laminar burning velocities (LBVs) were obtained by constant volume combustion chamber system. Five common mechanisms were used for numerical simulation using the CHEMKIN software package and the results were compared with the measurement data. The Li mechanism that was well matched with the experimental data was selected for kinetic analysis. The results indicate that the LBVs of H2/CO/N2/air mixtures decrease due to the dilution of N2. The addition of CH4 decreases the LBVs of H2/CO/N2/CH4/air mixtures and the LBVs of fuel-rich mixtures decrease faster. Sensitivity analysis illustrates that R29 is the most important branching reaction affecting LBV in H2/CO/N2/air premixed flame, the net reaction rate of all branched reactions and the mole fraction of H and OH in the mixture decrease due to the increase of N2 content. After adding CH4, the dominant branching reaction becomes R1. Due to the increase of CH4 addition ratio, the concentrations of H and O decrease, but the concentrations of OH and CH3 increase slightly. The chemical effect of adding CH4 increases LBV, but the physical effect decreases LBV. The reduction in the proportion of chemical effect is the reason for the faster reduction of LBV in the fuel-rich region. Finally, the formation of NO was analyzed in detail using the GRI 3.0 mechanism. The results show that N2 dilution reduces the mole fraction of NO, but CH4 addition increases the mole fraction of NO. Pathway analysis shows that N2 dilution and CH4 addition decrease and increase the effect of thermal mechanism on NO generation, respectively.

Longevity study on the CMS resistive plate chambers for HL-LHC

The CMS Resistive Plate Chamber (RPC) system has been certified for 10 years of LHC operation. In the next years, during the High luminosity LHC (HL-LHC) phase, the LHC instantaneous luminosity will increase to a factor five more than the existing LHC luminosity. This will subject the present CMS RPC system to background rates and operating conditions much higher with respect to those for which the detectors have been designed. Those conditions could affect the detector properties and introduce nonrecoverable aging effects. A dedicated longevity test is set up in the CERN Gamma Irradiation Facility (GIF++) to determine if the present RPC detectors can survive the hard background conditions during the HL-LHC running period. During the irradiation test, the RPC detectors are exposed to a high gamma radiation for a long period and the detector main parameters are monitored as a function of the integrated charge. Based on collecting a large fraction of the expected integrated charge at the LH-LHC. The results of the irradiation test will be presented.

A PI3KCIIALPHA/primary cilium-dependent autophagy program protects endothelial cells in response to atheroprone shear stress

Background and Aims : The ability to generate and respond to mechanical forces is a basic requirement for maintaining cell homeostasis. This is of particular importance for the cardiovascular system which is subjected to different mechanical forces such as Low and High shear stresses (LSS and HSS). Autophagy is involved in endothelial cells (ECs) response to HSS generated by blood flow. However, it is still unclear whether the variability of shear stress triggers specific autophagic response in ECs. Methods: We used fluid flow chamber system to generate different mechanical forces on ECs in vitro and we specifically studied LSS and HSS artery territories, referred as aortic arch and descending aorta respectively, in mice susceptible to atherosclerosis. Results: We found that LSS and HSS mobilize two different signalling modules relying on class II PI3K (PI3KCIIα) and III PI3K/Vps34 respectively to induce autophagy. We demonstrated that LSS-induced autophagy required the primary cilium and is critical to prevent ECs permeability and integrity. Accordingly, atherogenic stress or reduced PI3KCIIα expression led to a decrease in the ciliated ECs associated with decreased autophagic flux and accelerated plaque deposition in the LSS regions. Furthermore, we revealed that PI3KCIIα controls mTORC1 activation. Notably, mTORC1 inhibition impaired atherosclerosis development in ApoE-/- PI3KCIIα+/- mice and led to primary cilium restoration suggesting a crosstalk between primary cilium biogenesis and autophagy in LSS context. Conclusions: Our data reveal that mechanical forces variability within arterial system determine ECs autophagic response and support a central role of PI3KCIIα/mTOR axis in EC mechanosensing in atheroprone regions.