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• A model-based approach is proposed for the design synthesis of autonomous articulated vehicles. • The dynamically coupled subsystems of an autonomous vehicle are devised and evaluated simultaneously. • A prediction vehicle model for articulated vehicles is developed. • The effectiveness of the proposed approached is demonstrated by numerical simulations. • The results presented in the paper may be used as guidelines for devising autonomous articulated vehicles. In conventional autonomous vehicle designs, the mechanical system is first devised, and the automated driving systems are subsequently added. The conventional method can be categorized as a sequential design approach. An autonomous vehicle consists of the subsystems of mechanical assembles, automated driving, etc. There exist dynamic couplings among these subsystems, and the sequential design method may not be the most effective. This observation initiates the motivation of this research, and the objective of this paper is thus to explore a more effective design method for autonomous vehicles and, in particular, autonomous articulated vehicles. To this end, this paper proposes a model-based design synthesis method, i.e., a concurrent design method, for autonomous articulated vehicles. The autonomous articulated vehicle assumes to be composed of the subsystems of a mechanical unit, a trajectory tracking-controller based on a model predictive control technique, and a motion-planner. The design synthesis of the autonomous articulated vehicle is constructed as a bi-level optimization problem. With the proposed concurrent design approach, the subsystems are optimally devised simultaneously. To examine the proposed approach, it is applied to the design of a car-trailer combination with automated steering. The insightful findings attained from the study may be used as guidelines for developing autonomous articulated vehicles. [ABSTRACT FROM AUTHOR]

The objective of this study is to explore the bacterial distribution characteristics of air and bed environment in patients with cerebrovascular diseases and to analyze the relationship between bacterial distribution and nosocomial infection in patients with cerebrovascular diseases. In this study, the inpatients with cerebrovascular diseases who suffer from nosocomial infection are taken as the research objects. The pathogenic characteristics of the air environment in the ward and the environment in the bed unit are monitored, and the samples of cerebrovascular patients are collected for identification and drug sensitivity detection. The changes of the number of pathogens in different seasons are statistically compared, and the drug sensitivity test results of various pathogens are analyzed. In large wards, the number of pathogens in the air environment in winter is significantly higher than that in spring. In summer, the number of pathogens in pillow environment is significantly more than that in small wards. Gram-negative bacilli are the main pathogens in the four seasons, followed by Gram-positive cocci and less fungal infections. Among them, Staphylococcus aureus is the main Gram-positive coccus, which is sensitive to vancomycin and other therapeutic drugs, and resistant to erythromycin and other therapeutic drugs. Gram-negative bacteria are mainly Klebsiella pneumoniae and Pseudomonas aeruginosa. K. pneumoniae is sensitive to imipenem, tekacillin, meropenem and ceftitam, and resistant to ampicillin. P. aeruginosa is sensitive to cefuroxime ester, cefazolin and cefuroxime sodium. It is resistant to ampicillin, ceftitam, compound sinomine and ampicillin plus sulbactam. Candida albicans is the main fungus, which is sensitive to ketoconazole, fluconazole, amphotericin and nystatin. The number of pathogenic bacteria in the ward environment of patients with cerebrovascular disease is affected by the size of the room and season. The main pathogenic bacteria are Gram-negative bacilli, followed by Gram-positive cocci and less fungal infections. [ABSTRACT FROM AUTHOR]

In order to get the high photoelectric conversion efficiency a -Si:H/ c -Si solar cells, high quality intrinsic hydrogenated passivation layer between the a -Si:H emitter layer and the c -Si wafer is necessary. In this work, hot wire chemical vapor deposition (HWCVD) is used to deposite intrinsic oxygen-doped hydrogenated amorphous silicon ( a -SiO x :H) and hydrogenated amorphous silicon ( a -Si:H) films as the intrinsic passivation layer for a -Si:H/c-Si solar cells. The passivation effect of the films on the c -Si surface is shown by the effective lifetime of the samples that bifacial covered by the films with same deposition parameters, tested by QSSPC method. The imaginary part of dielectric constant ( ε 2 ) and bonds structure of the layers are analyzed by Spectroscopic Ellipsometry(SE) and Fourier Transfom Infrared Spectroscopy(FTIR). It is concluded that: (1) HWCVD method can be used to make a -SiO x :H films as the passivation layer for a -Si:H/c-Si cells and the oxidation of the filament can be overcome by optimizing the deposition parameters. In our experiments, the lowest surface recombination velocity of the c -Si wafer is 3.0 cm/s after a -SiO x :H films passivation. (2) Oxygen-doping in the amorphous silicon layers can increase H content and the band-gap of films, similar as the phenomenon of the films deposited by PECVD. [ABSTRACT FROM AUTHOR]

Tumor-derived exosomes are capable of inducing immune dysfunction and favoring the formation and progression of tumor. The major histocompatibility complex class I (MHC-I) plays a key role in antitumor immune responses by presenting tumor antigens to cytotoxic T lymphocytes. However, the role of tumor-derived circulating exosomal MHC-I on immune system activation remains unclear. We demonstrated that low level of glioma cells-derived exosomal MHC-I was associated with the dysfunction of CD8+ T cells in immune activation and cytotoxicity. MHC-I upregulation in exosomes restored antigen presentation of glioma cells and activated CD8+ T cells to exert robust antitumor immune response in combination with immune checkpoint blockade. Collectively, these data provided evidences for an important interplay between exosomal MHC-I and CD8+ T cells to activate systemic antitumor immune response, and interpreted how glioma cells evaded immunosurveillance, induced immunosuppression and were resistant to immunotherapy from the perspective of systemic immunity. Lower level of MHC-I in exosomes derived from glioma cells resulted in lower tumor immunogenicity reflected by decreased CD8+ T cells recognition, activation and cytotoxicity, consequently leading to escape of tumor cells from immunosurveillance. Upregulated expression of MHC-I in exosomes derived from glioma cells restored antigen presentation and activated CD8+ T cells to execute antitumor immune response. [Display omitted] [ABSTRACT FROM AUTHOR]

Cronobacter sp., an opportunistic foodborne pathogen, can cause high mortality in neonatal and premature infants because this pathogen is associated with powdered infant formula (PIF) contamination. Biofilm formation is recognized as the most effective means to help Cronobacter survive throughout the long shelf-life of PIF, thus promoting resistance to cleaning agents and disinfectants. Crystal violet (CV) staining and fluorescence microscopy analyses were used to compare the biofilm formation ability among different Cronobacter strains, and then the weak biofilm former Cronobacter sakazakii ATCC 29544 and the strong biofilm former Cronobacter dubliniensis DSM 18707 were selected for further proteomic analysis. Two-dimensional liquid chromatography–tandem mass spectrometry, which was coupled with isobaric tags for relative and absolute quantification (iTRAQ) labeling, was employed to quantitatively identify the proteins that were differentially expressed in C . sakazakii ATCC 29544 compared to C . dubliniensis DSM 18707. In total, 1190 proteins were detected. Gene Ontology (GO) analysis indicated that these differentially expressed proteins are related to biological binding, cell structure, signal transduction, cell adhesion, and cellular interaction. Among these differential proteins, the expression levels of 177 non-redundant proteins were altered significantly by more than 5-fold, with 96 up-regulated proteins and 81 down-regulated. This study provides important information regarding the cellular requirements for the underlying mechanism of Cronobacter biofilm formation and its survival in harsh environments. [ABSTRACT FROM AUTHOR]

Abstract: We carry out a computational investigation to show how the exponential concentration dependence of hydrogen diffusion, which was recently verified in a combined experimental and analytical study, could affect the characteristics of hydrogenation and dehydrogenation of a vanadium-coated magnesium nanoblade. A reaction model is built that separates hydrogen surface sorption and interior diffusion during the hydrogenation/dehydrogenation process. For the hydrogenation process, the hydrogen surface adsorption is much faster than the hydrogen diffusion, resulting in high hydrogen concentration buildup at the surface at a relatively low temperature. With increasing temperature, the hydrogen diffusion time decreases more rapidly than the hydrogen surface adsorption time. This leads to a relatively low-gradient diffusion field in the nanoblade during most time of the hydrogenation process, and no shell–core structure with a finite hydride layer is observed. However, for the dehydrogenation process, when hydrogen molecules are released at the surface, a hydride core is formed inside the nanoblade and the interface recedes gradually. The receding rate of the hydride core is determined by the hydrogen molecule release rate. In a two-dimensional simulation with decorated vanadium catalyst islands on the surface, isolated interior hydride islands are sometimes observed before the hydride core entirely fades away. The hydride core boundary is sharper at lower temperature when the surface reaction rate is high relative to the interior diffusion rate. [Copyright &y& Elsevier]

Abstract: Using a glancing angle (co)deposition technique, ∼4.6at.% V has been coated on the surface of individual Mg nanoblades and doped into Mg nanostructures fabricated at different deposition angles. The hydrogen storage properties of the formed V-decorated and V-doped Mg nanostructures depend strongly on how the nanocatalyst V is surrounded by the host Mg. The V-doped Mg sample has lower activation energies for hydrogen absorption (E a a =35.3±0.9kJ/mol H2) and hydrogen desorption (E a d =38.9±0.3kJ/mol H2) than the V-decorated Mg sample when deposited at the same deposition angle of θ =70°. The activation energies of the doped samples increase gradually with the decrease of the θ angle. We also find that the porosity of the Mg nanostructures plays a secondary role. A phenomenological model based on a heterogeneous reaction is proposed to explain the different hydrogen desorption activation energies obtained for different V–Mg nanostructured samples. [Copyright &y& Elsevier]

In this work we performed interlaboratory validation of a Taqman real-time PCR method for the identification of bovine and ovine material. The Bos taurus beta-actin gene (ACTB) and Ovis aries prolactin receptor gene (PRLR) were selected as the bovine and ovine species-specific amplifying target sequences, and primers and TaqMan probes were designed accordingly. The precision, efficiency, false positive rate, limit of detection (LOD 95% ) and probability of detection (POD) were determined, and the results demonstrated that both bovine and ovine detection methods performed well. The high homogeneity of the results indicates that the detection methods are suitable for a wide range of applications, and the tools developed herein could be applied by official and third-party detection institution to maintain quality in the food and feedstuff industries. [ABSTRACT FROM AUTHOR]

Inactive myocyte enhancer factor 2D (MEF2D) and alpha-synuclein (α-syn) aggregation will cause neuronal death. MEF2D or α-syn degradation is also associated with macroautophagy, chaperone-mediated autophagy (CMA) and heat-shock protein 70 (HSP70). We found that β-asarone had positive effects on treating 6-hydroxydopamine (6-OHDA)-induced rats, but mechanisms of β-asarone affecting on MEF2D and α-syn via regulating the HSP70/MAPK/MEF2D/Beclin-1 pathway remain unclear. Unilateral 6-OHDA injection into the medial forebrain bundle was used to create PD rats, which were divided into four groups and administered for 30 days: 6-OHDA model group, MEF2D inhibitor-treated group (SB203580, 0.5 mg/kg, i.p.), MEF2D activator-treated group (LiCl, 100 mg/kg, i.p.), β-asarone-treated group (15 mg/kg, p.o.). Expressions of tyrosine hydroxylase (TH), α-syn, heat-shock cognate protein 70 (HSC70), lysosome-associated membrane protein type 2a (LAMP-2A), MEF2D, HSP70, Beclin-1, light chain 3 B (LC3B) and p62 in the mesencephalon were measured after 30-day administration. α-syn, Beclin-1 and LC3 B levels were higher in the 6-OHDA model group, while TH, MEF2D, HSC70, LAMP-2A, p62 levels were lower compared to the sham-operated group. Our results also showed thatβ-asarone treatment reduced protein and mRNA levels of α-syn, Beclin-1 and LC3B, but increased HSP70, TH, MEF2D, HSC70, LAMP-2A and p62 levels compared to the 6-OHDA model group. Additionally, certain correlations among α-syn, TH, Beclin-1, LC3B, p62, HSP70, LAMP-2A and MEF2D were also discovered in this study. These findings suggested that β-asarone treatment could increase MEF2D and TH as well as reduce α-syn to protect against 6-OHDA induced damage in PD rat mesencephalon via modulating the HSP70/MAPK/MEF2D/Beclin-1 pathway. [ABSTRACT FROM AUTHOR]

Abstract: Magnesium nickel hydrides (Mg2NiH4) are the prospective candidates for hydrogen storage and switchable mirror. The hydrides exist in two typical crystallographic forms, the low temperature (LT) phase in monoclinic structure, and the high temperature (HT) phase in cubic structure. LT has two modifications–untwinned (LT1) and microtwinned (LT2) structures. The electronic structures of the three polymorphs of Mg2NiH4 are investigated using ab initio calculations based on density functional theory. The calculated band gaps of LT1 and HT are in reasonable agreement with experimental observations and other theoretical predications, while the calculated band gap of LT2 is slightly lower than those of LT1 and HT. Electronic-structure analysis shows that strong interactions exist between Ni and H, whereas the interactions between Mg and H are negligible. The strong ionic character between Mg and NiH4 complex can be viewed as the origin of the semiconducting ground-state. [Copyright &y& Elsevier]

Alzheimer′s disease (AD) is an age related and progressive neurodegenerative disease. Autophagy is a self-degradative process and plays a critical role in removing long-lived proteins and damaged organelles. Recent evidence suggests that autophagy might be involved in the pathogenesis of AD. β-asarone have various neuroprotective effects. However, the effect of β-asarone on autophagy in amyloid β-peptide (Aβ) induced cell injury is unclear, and little is known about the signaling pathway of β-asarone in autophagy regulation. The aim of the present study was to determine whether β-asarone protects cells from Aβ 1–42 induced cytotoxicity via regulation of Beclin-1 dependent autophagy and its regulating signaling pathway. We examined effects of β-asarone on cell morphology, cell viability, neuron specific enolase (NSE) levels, autophagosomes and regulating Beclin-1, p-Akt and p-mTOR expressions in Aβ 1–42 treated PC12 cells. We found that β-asarone could maintain the original morphology of cells and increase cell viability and decrease NSE levels significantly. Meanwhile, β-asarone decreased Beclin-1 expression significantly. In addition, β-asarone can increase levels of p-Akt and p-mTOR. These results showed that β-asarone protected cells from Aβ 1–42 induced cytotoxicity and attenuated autophagy via activation of Akt-mTOR signaling pathway, which could be involved in neuroprotection of β-asarone against Aβ toxicity. Our findings suggest that β-asarone might be a potential preventive drug for AD. [ABSTRACT FROM AUTHOR]

• The analytical models of TVMS for profile-shifted spur gears are established. • The positive shift decreases the TVMS so that it causes stronger vibrations in the gear system. • The negative shift increases the TVMS so that it weakens vibrations in the gear system. • The positive compound shift decreases TVMS and increases the vibration. • The negative compound shift leads to TVMS rising and significantly reducing vibration. Nowadays, profile shift is one of the most powerful techniques to achieve high-performance spur gear transmission system. Although this technique has been widely used in industry, its influence on time-varying meshing stiffness (TVMS) and dynamic characteristics is still unclear. This paper presents a novel analytical model of TVMS for profile-shifted spur gears. The modification coefficient and transition curve revise the proposed model. Afterward, numerical simulations are carried out to analyze individual and compound shifts based on a six-degree of freedom gear model. For individual shifts, the positive shift can decrease the gear tooth's stiffness and TVMS so that it causes stronger vibrations in the gear system. On the contrary, the negative shift can improve the gear tooth's stiffness and TVMS, thereby mitigating the gear system's vibration. For compound shift, S 0 -gearing poses a slight impact on TVMS, but an unneglectable effect on dynamic characteristics. Besides, the S-gearing with the positive compound shift can decrease TVMS and increase vibration. In contrast, the S-gearing with the negative compound shift leads to TVMS rising and significantly reducing vibration. The insightful findings derived from the study can help engineers and manufacturers better understand the operation performance and dynamic features of profile-shifted spur gears. [ABSTRACT FROM AUTHOR]