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Due to the characteristics of high heap and large volume, the complex layers of waste, high-water level of leachate, environmental pollution, and slope instability are easily produced. Although many researchers have studied landfill two-dimensional leachate migration law, three-dimensional seepage and stability of landfill sites have been rarely studied. This paper focuses on the heterogeneous characteristics of the landfill piles and analyzes the seepage field and slope stability of the landfill using statistical and numerical analysis methods. The calculated results are compared with the field measurement and literature research data to verify the reliability of the model, which may provide the basis for the design and safe and eco-friendly operation of the landfill. Taking an actual landfill as the research object, the saturated–unsaturated transient model of heterogeneous waste is applied to practical engineering. Considering the landfill process and heterogeneous permeability, the calculated maximum water level is higher. Compared with the homogeneous material, the difference in the water level of each waste layer is about 0.08∼1.88 m, which is not good for the stability of the landfill. Combined with the engineering characteristic distribution of a landfill, the heterogeneous stability model is applied to the actual project to study the influence of different unit weight and shear strength distribution on landfill stability. The established model is suitable for the study of two-dimensional and three-dimensional slope stability of landfill sites. Through the slope stability analysis of the three-dimensional landfill site, it is found that the bank slope of the reservoir is steep and prone to instability failure. In most studies, only the instability of the landfill is of concern, but the bank failure is ignored. In the process of landfill operation and management, while considering the capacity of the landfill, the stability of the bank slope should also be paid attention to, and if necessary, bank slope reinforcement or slope ratio improvement should be carried out. [ABSTRACT FROM AUTHOR]

L-type [Ca.sup.2+] channel-mediated, [Ca.sup.2+]-induced [Ca.sup.2+] release (CICR) is the dominant mode of excitation-contraction (E-C) coupling in the mature mammalian myocardium but is thought to be absent in the fetal and newborn mammalian myocardium. Furthermore, the characteristics and contributors of E-C coupling at the earliest developmental stages are poorly understood. In this study, we measured [[sup.3]H](+)PN200-110 dihydropyridine binding capacity, functionality and expression of the L-type [Ca.sup.2+] channel, and cytosolic [[Ca.sup.2+]] ([[[Ca.sup.2+]].sub.i]) at various developmental stages (3, 6, 10, 20, and 56 days old) to characterize ontogenetic changes in E-C coupling. We found that 1) the whole cell L-type [Ca.sup.2+] channel peak current ([I.sub.Ca]) density increased slightly in parallel with cell growth, but the current-voltage relationship, the steady-state activation, and the maximum DHP binding and binding affinity did not exhibit significant developmental changes; 2) sarcoplasmic reticuhun [Ca.sup.2+] dependence of inactivation rates of L-type [Ca.sup.2+] channel and peak of [I.sub.Ca] density were only observed after 10 days of age, which temporally coincides with transverse (T)-tubule formation; 3) the relationship between [[[Ca.sup.2+]].sub.i] and voltage changed from a linear relationship at the earliest developmental stages to a 'bell-shaped' relationship at the later developmental stages, presumably corresponding to a switch from reverse-mode Na/Ca exchange-dependent to [I.sub.Ca]-dependent E-C coupling; and 4) the expression of two different splice variants of [Ca.sub.v] 1.2, IVS3A and IVS3B, switched from predominantly IVS3A at the earliest stages to IVS3B at the later developmental stages. Our data suggest that whereas the density of functional dihydropyridine receptors (DHPRs) increases only slightly during ontogeny, the enhancement of functional coupling between DHPR and ryanodine receptor is dramatic between the second and third weeks after birth. Furthermore, we found that the differential expression of splice variants during development temporally correlated with the appearance of [I.sub.Ca]-dependent E-C coupling and T-tubule formulation. neonate myocardium; contractility; excitation-contraction coupling; dihydropyridine receptor

The reaction between unsaturated polyester (UP) resin and styrene (St) is a heterogeneous free-radical chain-growth cross-linking copolymerization. Curing of the UP/St system in the presence of organically-modified nanoclay was studied by differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. A mechanistic kinetic model based on the free radical copolymerization mechanism was developed to simulate the reaction rate and conversion profiles of UP/St resin mixtures with various nanoclay contents cured at low temperatures. The model parameters were determined from several DSC experiments under isothermal conditions. The model, in conjunction with heat transfer analysis, was able to successfully predict the temperature and conversion profiles during curing in two vacuum-infusion liquid composite molding (e.g., the Seemann composite resin infusion molding process [SCRIMP]) experiments. The presence of nanoclay particles enhanced the tensile modulus, but reduced the tensile strength of the UP nanocomposites. The fracture toughness parameter [K.sub.IC] was improved by 30% with the addition of 5 wt% nanoclay. The system with mixed nanoclay and calcium carbonate was found to possess the highest [K.sub.IC] without sacrificing the tensile strength. POLYM. ENG. SCI., 45:496-509, 2005. © 2005 Society of Plastics Engineers, INTRODUCTION Among various thermoset resins, unsaturated polyesters (UP) resins are the most widely used matrix materials in polymeric composites. They represent approximately 75% of the total thermoset composites market by [...]

• We re-examine the controversial issue about whether or not high-quality bus service can significantly reduce car use while increasing bus use. • A SEM model is constructed that contains bus service quality, car ownership, bus use and car use. • Improving bus service quality can indeed reduce car use by attracting more travelers to the bus. • The extent of reducing car use by improving bus service quality is far less than that of increasing car use caused by car ownership. The State Council of China hopes to alleviate traffic congestion by implementing the bus priority policy. However, the policy consequences have not been satisfactory. Whether a good bus service can significantly reduce car use while increasing bus use is a confusing issue, hereto this study re-examines the interactions among bus service quality, car ownership, car use and bus use by constructing a SEM model. A sample of 334 individuals in Changzhou is used in the study. Results show that although high-quality bus service can cause a decrease in car use, the total negative effect of bus service quality on car use is far less than the positive effect of car ownership. Thus, when car ownership is growing rapidly, only a comprehensive and substantial improvement in bus service can alleviate and ultimately eliminate the enormous pressure on urban traffic resulted from the increasing car ownership. This study provides empirical evidence to explain why traffic congestion is still serious with the strong support in public transport from governments and gives policy implications on how to control urban traffic. [ABSTRACT FROM AUTHOR]

Two kinds of WO3 powders with average size of 100 nm and 5 μm have been used to prepare Pt–WO3 porous composite ceramics, whose WO3 grains are around 1 and 5 μm, respectively. The ceramics with 1 μm WO3 grains show a sensitivity of 755 to 0.08% H2 – 20% O2 – N2 in air of 30% relative humidity (RH) at room temperature, but show no response to this concentration of hydrogen in air of 50% RH due to the depression effect of water, which indicate a relatively low humidity tolerance for the ceramics. In contrast, the ceramics with 5 μm WO3 grains show sensitivities of 1200 and 80 to 0.08% H2 – 20% O2 – N2 at room temperature in air of 30% and 50% RH, respectively, and a sensitivity of 8 to 0.02% H2 – 20% O2 – N2 in air of 70% RH, which represent an ultrahigh humidity tolerance. These results clearly demonstrate that the microstructure of room-temperature hydrogen sensitive metal oxide (MOX) materials exerts a decisive influence on their humidity tolerance. Much attention should be paid to MOX materials with large and even ultra-large MOX grains when room-temperature MOX gas sensors with high humidity tolerance are being developed. [ABSTRACT FROM AUTHOR]

Myasthenia gravis (MG) is a rare autoimmune disease. Although the impact of immune cell disorder in MG has been extensively studied, little is known about the transcriptomes of individual cells. Here, we assessed the transcriptional profiles of 39,243 cells by single-cell sequencing and identified 13 major cell clusters, along with 39 subgroups of cells derived from patients with new-onset myasthenia gravis and healthy controls. We found that B cells, CD4+ T cells, and monocytes exhibited more heterogeneity in MG patients. CD4+ T cells were expanded in MG patients. We reclustered B cells and CD4+ T cells, and predict their essential regulators. Further analyses demonstrated that B cells in MG exhibited higher transcriptional activity towards plasma cell differentiation, CD4+ T cell subsets were unbalanced, and inflammatory pathways of monocytes were highly activated. Notably, we discovered a disease-relevant subgroup, CD180− B cells. Increased CD180− B cells in MG are indicative of a high IgG composition and were associated with disease activity and the anti-AChR antibody. Together, our data further the understanding of the cellular heterogeneity involved in the pathogenesis of MG and provide large cell-type-specific markers for subsequent research. [ABSTRACT FROM AUTHOR]

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The seepage characteristics of clay core walls are crucial for the seepage safety of core rockfill dams, with the permeability coefficient in the unsaturated zone being nonlinear. To accurately determine the unsaturated seepage parameters in clay core rockfill dams, this paper first proposes an enhanced reptile search algorithm (ERSA) by applying three improvement strategies: Arnold's cat chaotic map, nonlinear evolutionary factor, and adaptive Cauchy–Gaussian mutation with variable weight. Then, by integrating the ERSA with the unsaturated seepage finite element method, an inverse modeling approach is developed. This approach is applied to an actual rockfill dam with operational monitoring data to determine the unsaturated seepage parameters of the clay core. Results indicate that the ERSA outperforms the original RSA in test functions, and the calculation results of the seepage parameters determined through inversion are consistent with the monitoring data, showing an overall mean absolute error of 1.086 m. The inverse modeling approach provides a valuable reference for determining unsaturated seepage parameters in similar clay core rockfill dams. [ABSTRACT FROM AUTHOR]