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Dopamine was used to modify polytetrafluoroethylene (PTFE) in order to obtain functional polydopamine (PDA) surface-modified PTFE microporous film (PTFE@PDA). Ag was deposited on the surface of PTFE@PDA using electroless plating in order to obtain Ag-wrapped PTFE@PDA film (PTFE@Ag). A liquid-phase chemical reduction method was employed to prepare nickel nanochains. A Ni@PVDF cast film was obtained by mechanically blended nickel nanochains and polyimide (PVDF). The above two films were hot pressed to give a flexible, ultra-thin, and highly effective electromagnetic shielding composite film with a “3+2” layered structure. IR, XRD, and TEM results showed the PTFE@PDA film surface was coated by a tight plating layer of Ag particles with a particle size of 100~200 nm. PTFE@Ag+Ni@PVDF composite film exhibited excellent electromagnetic shielding effectiveness, with the conductivity of 7507.5 S/cm and the shielding effectiveness of 69.03 dB in the X-band range. After a 2000-cycle bending, this value still remained at 51.90 dB. Furthermore, the composite film presented excellent tensile strength of 62.1 MPa. It has great potential for applications in flexible and wearable intelligent devices.

Bandit learning has been an increasingly popular design choice for recommender system. Despite the strong interest in bandit learning from the community, there remains multiple bottlenecks that prevent many bandit learning approaches from productionalization. One major bottleneck is how to test the effectiveness of bandit algorithm with fairness and without data leakage. Different from supervised learning algorithms, bandit learning algorithms emphasize greatly on the data collection process through their explorative nature. Such explorative behavior may induce unfair evaluation in a classic A/B test setting. In this work, we apply upper confidence bound (UCB) to our large scale short video recommender system and present a test framework for the production bandit learning life-cycle with a new set of metrics. Extensive experiment results show that our experiment design is able to fairly evaluate the performance of bandit learning in the recommender system.

BackgroundThe incidence of primary lung cancer (LC) in children and adolescence was rare. We analyzed data from a SEER database to better define the incidence, clinical characters, pathology, treatment, and outcomes of rare primary malignant pulmonary tumors in childhood and adolescence.MethodsPatients were chosen from the SEER database (SEER*Stat 8.4.0 software) from 2000 to 2019 and all patients were pathologically diagnosed with primary malignant tumors of the lung and bronchus. Demographic characteristics of patients (age, gender, race, primary site, laterality, location, differentiation grade, operation methods, histology, and history of radiotherapy and chemotherapy), as well as TNM stage and survival time, were collected.ResultsA total of 301 cases of children ≤19 years of age with a primary malignant pulmonary tumor were reported to the SEER database from 2000 to 2019. There were 143 men (47.5%) and 158 women (52.5%). Whites represented majority of patients (79.7%), followed by Black (13.6%) and others (6.7%). As for the primary site, the main site was the lower lobe (33.2%), followed by the upper lobe (26.9%). Most of the patients (80.4%) underwent surgery. Lobectomy (39.9%) is the main operation method. Only 28 (9.3%) patients received radiotherapy and 112 (37.2) patients received chemotherapy. Carcinoid tumor was the most common histology (29.6%), followed by pulmonary blastoma (PB) (22.3%), mucoepidermoid carcinoma (MEC) (12.3%), adenocarcinoma (10.3%), neuroendocrine tumor (NET) (5.7%), squamous cell carcinoma (SCC) (5.3%), atypical carcinoma (2.3%). The mean follow-up time was 100 months. For the entire group of children and adolescents, the 1-year OS was 89.1%, and the 3-year overall survival (OS) was 79.7%. the 5-year OS was 77.9%, the 10-year OS was 75.7%, and the 15-year OS was 73.9%. And 1-year lung cancer specificity survival (LCSS) was 89.8%, and the 3-year LCSS was 80.4%. the 5-year LCSS was 79.4%, the 10-year LCSS was 77.7%, and the 15-year LCSS was 75.9%. The OS of atypical carcinoma, carcinoid tumor, and MEC were in the top three.ConclusionsPrimary LC in children and adolescent were rare and histopathological diverse. Fortunately, children and adolescents with LC had an overall favorable outcome after treatment. Histology, differentiation grade, surgery, TNM stage, and therapeutic modalities have important influence on OS. The further treatment experience of each pathological type would make better evidence-based practice possible.

We describe a method for real-time analysis and quantification of influenza A virus (IAV)-receptor interactions by biolayer interferometry (BLI). Biotinylated synthetic sialoglycans or sialoglycoproteins (biotinylated or Fc-tagged) were immobilized on the tip of biosensors (coated with streptavidin or protein A) that were subsequently dipped into IAV particle solutions in 96-well plates. Association and/or dissociation of IAV particles was recorded in consecutive steps in buffers of choice. From the association and dissociation curves, parameters can be derived that describe IAV particle-receptor interactions in absence or presence of neuraminidase activity. Overall, the method provides a quantitative description of the hemagglutinin-neuraminidase balance that determines the interaction kinetics of IAV with specific sialoglycan receptors.

Integrating molecular catalysts into designed frameworks often enables improved catalysis. Compared with porphyrin-based frameworks, metal-corrole-based frameworks have been rarely developed, although monomeric metal corroles are usually more efficient than porphyrin counterparts for the electrocatalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). We herein report on metal-corrole-based porous organic polymers (POPs) as ORR and OER electrocatalysts. M-POPs (M=Mn, Fe, Co, Cu) were synthesized by coupling metal 10-phenyl-5,15-(4-iodophenyl)corrole with tetrakis(4-ethynylphenyl)methane. Compared with metal corrole monomers, M-POPs displayed significantly enhanced catalytic activity and stability. Co-POP outperformed other M-POPs by achieving four-electron ORR with a half-wave potential of 0.87 V vs. RHE and reaching 10 mA cm-2 OER current density at 340 mV overpotential. This work is unparalleled to develop and explore metal-corrole-based POPs as electrocatalysts.

Autoignition of n-heptane droplet/vapor/air mixtures behind an oblique shock wave are studied, through Eulerian-Lagrangian method and a skeletal chemical mechanism. The effects of gas/liquid equivalence ratio (ER), droplet diameter, flight altitude, and Mach number on the ignition transient and chemical timescales are investigated. The results show that the ratio of chemical excitation time to ignition delay time can be used to predict the oblique detonation wave (ODW) transition mode. When the ratio is relatively high, the combustion heat release is slow and smooth transition is more likely to occur. In heterogeneous ignition, there are direct interactions between the evaporating droplets and the induction/ignition process, and the chemical explosive propensity changes accordingly. The energy absorption of evaporating droplets significantly retards the ignition of n-heptane vapor. In the two-phase n-heptane mixture autoignition process, the ignition delay time decreases exponentially with flight Mach number, and increases first and then decreases with the flight altitude. As the liquid ER increases, both ignition delay time and droplet evaporation time increase. With increased droplet diameter, the ignition delay time decreases, and the evaporation time increases. Besides, for Mach number is less than 10, the ratio of the chemical excitation time to ignition delay time generally increases with the flight altitude or Mach number. It increases when the liquid ER decreases or droplet diameter increases. When Mach number is sufficiently high, it shows limited change with fuel and inflow conditions. The results from this work can provide insights into spray ODW initiation. The ODW is more likely to be initiated with a smooth transition at high altitude or Mach number. Abrupt transition mode tends to happen when fine fuel droplets are loaded.

In enzymes, the active site residues function differently to promote chemical reactions. Such a role-specialized division of labor has been rarely realized by synthetic catalysts. We report herein on catalytic CO2 reduction with Fe porphyrins decorated with two cationic N,N,N-trimethylbenzylamine groups in cis- or trans-arrangement. The cis-isomer outperforms the trans-isomer and reaches a TOFmax of 4.4×105 s−1 in acetonitrile using phenol proton source. Theoretical studies revealed that the two cationic units in the cis-isomer are more effective than a single cationic unit to improve the CO2 binding, and more importantly, they function differently but cooperatively to promote the C-O bond cleavage: one interacts with the CO2-adduct, while the other one interacts with the phenol molecule through electrostatic interactions. This work therefore presents a significant example of synthetic catalysts, which boost chemical reactions using a role-specialized strategy for substrate activation.

University of Technology Sydney. Faculty of Business. International student workers experience precarious work conditions, yet they remain silent about widespread underpayment and other exploitative labour practices. Adopting a labour process theory approach, this research challenges the dominant emphasis on the structural factors within extant international student literature and, by ‘bringing the workers back in’, investigates the multiplicity and complexity of lived experiences of international students. To counter determinist tendencies in the extant literature, this research uses critical narrative inquiry to answer three interrelated questions: why international students engage in work, how they constitute themselves as subjects through work organisation, and to what extent they reproduce conditions they may otherwise resist. The findings of this research reveal how worker consent is constructed, or attempted to be constructed, among international student workers. It confirms that many international students worked for economic incentives, but many other students coming from middle- or upper-class family backgrounds engaged in work to be their own breadwinner. The narratives of independence from their families were found across all participants. Work opportunities remain bounded for international students, and their ‘student before worker’ identity further drove them to casualised, informal, and deskilling work. Moreover, their fragmented work lives led to a high turnover rate, where meaningful social relations were seldom maintained. This research revealed that their worker consent developed through an ideological illusion where work legitimacy did not matter as much as what they thought they were pursuing. The findings also reveal how internalised oppressions and being ‘international’ can contribute to their work consent. International students, most of whom come from Asian countries, were constructed as a racialised subject in opposition to others. Their established sense of inferiority, a desire to be more (White) Australian and intra-group discrimination could form their work strategies. This thesis has made theoretical and practical contributions. It attends to the unique individual identities, agency, resistance and non-resistance of international students. It has explored ways in which their engagement in work is not entirely money driven. This research contributes to labour process theory through its focus on the continuity of the labour process, which centres on studies and transcends national borders. It advances the theorisation of worker consent by interrogating how internalised oppression may contribute to their consent to exploitation from a critical perspective. The practical contribution of this research lies in its insights about measures that can be taken to protect and empower this workforce group.

Influenza A viruses (IAVs) occasionally cross the species barrier and adapt to novel host species. This requires readjustment of the functional balance of the sialic acid receptor-binding hemagglutinin (HA) and the receptor-destroying neuraminidase (NA) to the sialoglycan-receptor repertoire of the new host. Novel techniques have revealed mechanistic details of this HA–NA–receptor balance, emphasizing a previously underappreciated crucial role for NA in driving the motility of receptor-associated IAV particles. Motility enables virion penetration of the sialylated mucus layer as well as attachment to, and uptake into, underlying epithelial cells. As IAVs are essentially irreversibly bound in the absence of NA activity, the fine-tuning of the HA–NA–receptor balance rather than the binding avidity of IAV particles per se is an important factor in determining host species tropism., Highlights Functional properties of the IAV HA and NA proteins need to be balanced to allow penetration of the heavily sialylated mucus layer, attachment to and endocytic uptake into underlying epithelial cells, and efficient spread of progeny virions. The HA–NA–receptor balance is readjusted upon cross-species transmission as the sialoglycan repertoire differs between species. This adjustment is achieved via mutations in the receptor-binding site of HA, but may also be achieved by adaptation of the receptor-binding and -sialidase activity properties of NA. IAVs are continuously in a receptor-bound state, which is highly dynamic resulting from multivalent, low-affinity HA–SIA interactions combined with NA activity and which allows virion movement on a receptor-containing surface. Novel technological developments allow detailed kinetic analysis of the HA–NA–receptor balance.

Meiyu Wu,1,2 Hongbo Guo,3 Lin Liu,1,2 Ying Liu,2,3 Liming Xie1,2,41CAS Key Laboratory of Standardization and Measurement for Nanotechnology, Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, People’s Republic of China; 2NCNST-NIFDC Joint Laboratory for Measurement and Evaluation of Nanomaterials in Medical Applications, National Center for Nano Science and Technology, Beijing 100190, People’s Republic of China; 3CAS Key Laboratory for Biological Effects of Nanomaterials and Nano safety, CAS Center for Excellence in Nanoscience, National Center for Nano Science and Technology, Beijing 100190, People’s Republic of China; 4University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of ChinaPurpose: Silver nanoparticles (AgNPs) have been widely applied in various fields as excellent antibacterial reagents over the past decades. Although the particle size is considered as the most crucial factor influencing cellular uptake, transportation, and accumulation behaviors, there are still many controversies regarding the correlation between size and uptake of AgNPs. In this study, size-dependent cellular uptake of AgNPs with different diameters was investigated in B16 cells.Methods: The uptake of AgNPs was investigated by inductively coupled plasma-mass spectrometry (ICP-MS) and transmission electron microscopic (TEM) imaging in B16 cells.Results: Twenty nanometer and 100 nm AgNPs had the lowest and highest uptake efficiency at both 12 hours and 24 hours, respectively. Smaller AgNPs crossed the plasma membrane faster with uniform distribution: 5 nm AgNPs were detected in both cytoplasm and nucleus at 0.5 hours after incubation. Larger AgNPs were extremely difficult to migrate: 100 nm AgNPs were detected in the nucleus at 12 hours after incubation. Internalization of AgNPs was directly observed, mainly within membrane-bound structures, such as intracellular vesicles and late endosomes. The uptake of all four-sized AgNPs (5 nm, 20 nm, 50 nm, 100 nm) decreased significantly after the pre-treatment with chlorpromazine hydrochloride, which can specifically inhibit the clathrin-mediated endocytosis. The internalization efficiencies of AgNPs (5 nm, 20 nm, 50 nm) were markedly reduced by methyl-β-cyclodextrin, a specific caveolin-mediated endocytosis inhibitor, whereas 5-(N-ethyl-N-isopropyl) amiloride as an inhibitor of macropinocytosis inhibited the uptake of larger sizes of AgNPs (50 nm and 100 nm).Conclusion: The results suggest that the size of AgNPs can not only affect the efficiency of cellular uptake, but also the type of endocytosis. The clathrin-mediated endocytosis may be the most common endocytic pathway for AgNPs in B16 cells, and AgNPs at each size were likely to enter cells by a major internalization pathway.Keywords: silver nanoparticles, size-dependence, cellular uptake, B16 cells

Morel is a delicious and nutritious edible fungus with high economic value and increasing social demand.To scientifically resolve the contradiction between morel resource protection and development and utilization, artificial cultivation is one of the important ways.In recent years, China has made major breakthroughs in the artificial cultivation of morels.This article will review the biological characteristics of morels, the main varieties in China, the general situation of cultivation in China, and the prospects of cultivation in Belarus.

Additional file 1. Supplement A. The details of the patient characteristics. Supplement B. Representative nasopharyngeal carcinoma examples of auto-segmentation and dose distribution. Supplement C. The correlation analysis between the geometric metrics and dosimetric differences. Supplement D. More rectal cancer and nasopharyngeal carcinoma examples of auto-segmentation and dose distribution.

As one of the origins of citrus in the world, China has a large number of excellent citrus resources and mature cultivation techniques. Pests and diseases have become an important constraint on citrus harvest and quality. At present, deep learning has been widely used in many fields, and its application in agricultural research is gradually becoming mature. The use of deep learning convolutional neural networks to identify citrus pests is an effective and high-discrimination recognition technology. In this paper, based on a small amount of self-collected citrus pests dataset, including Blowing scale, Moth, Starscream, Star beetle, Citrus fruit fly, a total of 5 common pests and diseases, and propose a combination of Inceptionv3 network feature extraction model and migration learning According to the classification and recognition method, the final recognition accuracy can reach 96.81%.

As an important non-destructive testing equipment of concrete structure, the concrete reinforcement position measuring instrument has the characteristics of small volume and simple operation, which can quickly determine the thickness of the protective layer, the diameter and the spacing of reinforcement, and provide reliable data for detection and evaluation of concrete structure. The quality of the concrete reinforcement position measuring instrument directly affects the accuracy of the concrete structure detection and evaluation, so it is particularly important to measure and verify the concrete reinforcement position measuring instrument. In this paper, a kind of integrated and portable standard device for concrete reinforcement position measuring instrument is developed to solve the problems of accuracy and portability of measurement and verification, and provides technical support for the accuracy and reliability of reinforced concrete structure detection and evaluation, and make the measurement technology of concrete reinforcement position measuring instrument really enter the practical stage.

Influenza A viruses (IAVs) occasionally cross the species barrier and adapt to novel host species. This requires readjustment of the functional balance of the sialic acid receptor-binding hemagglutinin (HA) and the receptor-destroying neuraminidase (NA) to the sialoglycan-receptor repertoire of the new host. Novel techniques have revealed mechanistic details of this HA-NA-receptor balance, emphasizing a previously underappreciated crucial role for NA in driving the motility of receptor-associated IAV particles. Motility enables virion penetration of the sialylated mucus layer as well as attachment to, and uptake into, underlying epithelial cells. As IAVs are essentially irreversibly bound in the absence of NA activity, the fine-tuning of the HA-NA-receptor balance rather than the binding avidity of IAV particles per se is an important factor in determining host species tropism.

Thermal barrier coatings (TBCs) are the key technologies for hot-components in advanced gas turbine and land-based engines. Yttria stalized zirconia (YSZ) is now extensively used as ceramic topcoat in TBC system. However, YSZ cannot be used for next generation aircraft engines due to its limitation in high-temperature capabilities and thermal barrier performances. In this paper, recent research progress of several novel TBC ceramic candidates covering multiple oxide co-doped zirconia, A2B2O7-type compounds, magnetoplumbite compounds, garnet-type compounds, perovskites and other new oxides ceramics is overviewed. And the development tendencies and challenges of ultra-high temperature TBC materials for future applications are prospected.

Along with the increase of operating temperature of aero-engine, thermal barrier coatings （TBCs） used in the engine are highly susceptible to the attack of glassy silicate deposits, the chemical composition of which is mostly CaO-MgO-Al2O3-SiO2 （CMAS）. The deposition of CMAS on TBCs tends to cause blocking of cooling holes in turbine blades, which results in decrease of cooling efficiency, change of temperature and stress distribution in blades. On the other hand, the durability of TBCs is significantly reduced due to the CMAS deposition. It is very important to make the strategy to constrain the absorption and infiltration of glassy CMAS on TBCs at high temperature to ensure the development of advanced aero-engine. In this paper, the failure mechanisms of TBCs which are thermochemistry, densification and phase transformation caused by CMAS are summarized, and the solutions to CMAS, such as coating structure optimization, adding permeability barrier layer and sacrificial layer are briefly overviewed.

Plasma spray physical vapor deposition (PS-PVD) is a newly developed processing technology for advanced functional coatings and films. PS-PVD is featured with the advantages of plasma spray (PS) and physical vapor deposition (PVD) and can be used for high efficient co-deposition of vapor phases, liquid droplets and solid particles, with the capability of highly flexibility in building up various microstructure architectures. Besides, uniform deposition of the coatings or films can be achieved by this technology even on the non-line-of-sight areas of those components with complex geometry. Owing to the above merits, PS-PVD shows very promising potential in the fields of thermal barrier coatings (TBCs), environmental barrier coatings (EBCs), super-hard and wear-resistant coatings or films, oxygen permeable membranes and electrode membranes. Further, PS-PVD is recognized as the processing technology for advanced TBCs in the future. In this paper, physical principles and recent research progress in preparation and deposition mechanisms of PS-PVD TBCs are briefly introduced and summarized. The future development trends of PS-PVD in new thermal barrier coatings are prospected.

In order to study the effects of La2O3 content and rolling on microstructure and mechanical properties of Mo-La2O3 alloys, Mo-0.5% (1%) La2O3 alloys were prepared by liquid-solid doping technique, subsequently rolled either by a single-direction rolling or a cross-rolling. As a result, three different materials were prepared for this study. After being annealed at 1800 °C, the single-directionally rolled Mo-1% La2O3 alloy shows the best mechanical properties in terms of strength, hardness, and sagging deformation among the three materials. This is attributed to the observation that the alloy is only recovered with a microstructure of subgrains and dislocations. The single-directionally rolled Mo-0.5% La2O3 exhibits the worst mechanical property among the three materials. In this material, coarse grains, but no subgrains and dislocations, can be observed after annealing, indicating that it is fully recrystallized. For the cross-rolled Mo-1% La2O3 alloy, grains of dispersed sizes, but no dislocations, are visible after annealing, implying that this alloy is partially recrystallized. Accordingly, the mechanical property of this material is in between the other two materials. Thus, the mechanical properties of the three materials can be well understood based on OM, SEM, and TEM results. Overall, the single-directionally rolled Mo-1% La2O3 alloy possesses good mechanical properties and is more suitable for high-temperature applications.

Background Distinguishing among species in the genus Lepista is difficult because of their similar morphologies. Methods To identify a suitable DNA barcode for identification of Lepista species, we assessed the following five regions: internal transcribed spacer (ITS), the intergenic spacer (IGS), nuclear ribosomal RNA subunit, mitochondrial small subunit rDNA, and tef1. A total of 134 sequences from 34 samples belong to eight Lepista species were analyzed. The utility of each region as a DNA barcode was assessed based on the success rates of its PCR amplification and sequencing, and on its intra- and inter-specific variations. Results The results indicated that the ITS region could distinguish all species tested. We therefore propose that the ITS region can be used as a DNA barcode for the genus Lepista. In addition, a phylogenetic tree based on the ITS region showed that the tested eight Lepista species, including two unrecognized species, formed eight separate and well-supported clades.

Influenza A virus (IAV) neuraminidase (NA) receptor-destroying activity and hemagglutinin (HA) receptor-binding affinity need to be balanced with the host receptor repertoire for optimal viral fitness. NAs of avian, but not human viruses, contain a functional 2nd sialic acid (SIA)-binding site (2SBS) adjacent to the catalytic site, which contributes to sialidase activity against multivalent substrates. The receptor-binding specificity and potentially crucial contribution of the 2SBS to the HA-NA balance of virus particles is, however, poorly characterized. Here, we elucidated the receptor-binding specificity of the 2SBS of N2 NA and established an important role for this site in the virion HA-NA-receptor balance. NAs of H2N2/1957 pandemic virus with or without a functional 2SBS and viruses containing this NA were analysed. Avian-like N2, with a restored 2SBS due to an amino acid substitution at position 367, was more active than human N2 on multivalent substrates containing α2,3-linked SIAs, corresponding with the pronounced binding-specificity of avian-like N2 for these receptors. When introduced into human viruses, avian-like N2 gave rise to altered plaque morphology and decreased replication compared to human N2. An opposite replication phenotype was observed when N2 was combined with avian-like HA. Specific bio-layer interferometry assays revealed a clear effect of the 2SBS on the dynamic interaction of virus particles with receptors. The absence or presence of a functional 2SBS affected virion-receptor binding and receptor cleavage required for particle movement on a receptor-coated surface and subsequent NA-dependent self-elution. The contribution of the 2SBS to virus-receptor interactions depended on the receptor-binding properties of HA and the identity of the receptors used. We conclude that the 2SBS is an important and underappreciated determinant of the HA-NA-receptor balance. The rapid loss of a functional 2SBS in pandemic viruses may have served to balance the novel host receptor-repertoire and altered receptor-binding properties of the corresponding HA protein., Author summary Influenza A viruses infect birds and mammals. They contain receptor-binding (HA) and receptor-destroying (NA) proteins, which are crucial determinants of host tropism and pathogenesis. It is generally accepted that the functional properties of HA and NA need to be well balanced to enable virion penetration of the receptor-rich mucus layer, binding to host cells, and release of newly assembled particles. This HA-NA-receptor balance is, however, poorly characterized resulting in part from a lack of suitable assays to measure this balance. In addition, NA is much less studied than HA. NA contains, besides its receptor-cleavage site, a 2nd receptor-binding site, which is functional in avian, but not in human viruses. We now show that this 2nd receptor-binding site prefers binding to avian-type receptors and promotes cleavage of substrates carrying this receptor. Furthermore, by using novel assays, we established an important role for this site in the HA-NA-receptor balance of virus particles as it contributes to receptor binding and cleavage by virions, the latter of which is required for virion movement and self-elution from receptors. The results may provide an explanation for the rapid loss of a functional 2nd receptor-binding site in human pandemic viruses.

The polished stone value (PSV) of a coarse aggregate indicates its ability to resist the polishing action of tires. In the measurement tests of PSV of coarse aggregates, due to the complicated process, artificial factors or instrumental performances may cause measurement deviations. In order to explore the influences of instrumental factors, based on the features and working principle of a pendulum friction coefficient tester, the main influencing factors were firstly analyzed and then experimentally verified through measuring PSV of andesite and basalt. With the one-variable linear regression method, the testing data were fitted in order to determine the variations of the PSV of coarse aggregates with the hardness of rubber strip used in the slider block and the axial deformation distance of the slider block corresponding to the maximum positive static pressure on the tested surface. With the increase in the hardness of rubber strip, the measured PSV increased. With the increase in the axial deformation distance of slider block corresponding to the maximum positive static pressure on the tested surface, the measured PSV decreased. The quantitative analysis of the factors affecting PSV can improve its determination accuracy.

Enterovirus D68 (EV-D68) is an emerging pathogen that can cause severe respiratory disease and is associated with cases of paralysis, especially among children. Heretofore, information on host factor requirements for EV-D68 infection is scarce. Haploid genetic screening is a powerful tool to reveal factors involved in the entry of pathogens. We performed a genome-wide haploid screen with the EV-D68 prototype Fermon strain to obtain a comprehensive overview of cellular factors supporting EV-D68 infection. We identified and confirmed several genes involved in sialic acid (Sia) biosynthesis, transport, and conjugation to be essential for infection. Moreover, by using knockout cell lines and gene reconstitution, we showed that both α2,6- and α2,3-linked Sia can be used as functional cellular EV-D68 receptors. Importantly, the screen did not reveal a specific protein receptor, suggesting that EV-D68 can use multiple redundant sialylated receptors. Upon testing recent clinical strains, we identified strains that showed a similar Sia dependency, whereas others could infect cells lacking surface Sia, indicating they can use an alternative, nonsialylated receptor. Nevertheless, these Sia-independent strains were still able to bind Sia on human erythrocytes, raising the possibility that these viruses can use multiple receptors. Sequence comparison of Sia-dependent and Sia-independent EV-D68 strains showed that many changes occurred near the canyon that might allow alternative receptor binding. Collectively, our findings provide insights into the identity of the EV-D68 receptor and suggest the possible existence of Sia-independent viruses, which are essential for understanding tropism and disease.

The purpose of this study was to investigate the association between the expression of programmed cell death ligand 1 (PD-L1) and the survival of patients with small cell lung cancer (SCLC) who had undergone complete resection. Formalin-fixed, paraffin-embedded tumor tissue samples from 61 patients with resected SCLC were stained with an anti-PD-L1 antibody (SP142) by immunohistochemistry (IHC) and scored according to staining intensity and the percentage of tumor cells staining positive for PD-L1. The PD-L1 positive threshold in tumor cells was defined as ≥ 5%. The percentage of positive PD-L1 staining in all SCLC specimens was 44.3% (27/61). The median survival time of patients with PD-L1-positive tumors was significantly longer than those with PD-L1-negative tumors (not reached vs. 34 months, P = 0.032). Multivariate analysis indicated that postoperative chemotherapy (HR = 0.322, P = 0.023) and PD-L1 expression ≥ 5% (HR = 0.253, P = 0.008) were independent prognostic factors for overall survival. The results suggest that PD-L1 expression is readily detectable in the tumor tissues of SCLC, and that PD-L1 expression can predict the survival of these patients.

Acute hemorrhagic conjunctivitis (AHC) is a painful, contagious eye disease, with millions of cases in the last decades. Coxsackievirus A24 (CV-A24) was not originally associated with human disease, but in 1970 a pathogenic "variant" (CV-A24v) emerged, which is now the main cause of AHC. Initially, this variant circulated only in Southeast Asia, but it later spread worldwide, accounting for numerous AHC outbreaks and two pandemics. While both CV-A24 variant and nonvariant strains still circulate in humans, only variant strains cause AHC for reasons that are yet unknown. Since receptors are important determinants of viral tropism, we set out to map the CV-A24 receptor repertoire and establish whether changes in receptor preference have led to the increased pathogenicity and rapid spread of CV-A24v. Here, we identify ICAM-1 as an essential receptor for both AHC-causing and non-AHC strains. We provide a high-resolution cryo-EM structure of a virus-ICAM-1 complex, which revealed critical ICAM-1-binding residues. These data could help identify a possible conserved mode of receptor engagement among ICAM-1-binding enteroviruses and rhinoviruses. Moreover, we identify a single capsid substitution that has been adopted by all pandemic CV-A24v strains and we reveal that this adaptation enhances the capacity of CV-A24v to bind sialic acid. Our data elucidate the CV-A24v receptor repertoire and point to a role of enhanced receptor engagement in the adaptation to the eye, possibly enabling pandemic spread.

Porcine epidemic diarrhea virus (PEDV) causes enteric disease in pigs, resulting in significant economic losses to the swine industry worldwide. Current vaccination approaches against this emerging coronavirus are only partially effective, though natural infection protects pigs against reinfection and provides lactogenic immunity to suckling piglets. The viral spike (S) glycoprotein, responsible for receptor binding and cell entry, is the major target for neutralizing antibodies. However, knowledge of antibody epitopes, their nature and location in the spike structure, and the mechanisms by which the antibodies interfere with infection is scarce. Here we describe the generation and characterization of 10 neutralizing and nonneutralizing mouse monoclonal antibodies raised against the S1 receptor binding subunit of the S protein. By expression of different S1 protein fragments, six antibody epitope classes distributed over the five structural domains of the S1 subunit were identified. Characterization of antibodies for cross-reactivity and cross-neutralization revealed antigenic differences among PEDV strains. The epitopes of potent neutralizing antibodies segregated into two epitope classes and mapped within the N-terminal sialic acid binding domain and in the more C-terminal receptor binding domain. Antibody neutralization escape mutants displayed single amino acid substitutions that impaired antibody binding and neutralization and defined the locations of the epitopes. Our observations picture the antibody epitope landscape of the PEDV S1 subunit and reveal that its cell attachment domains are key targets of neutralizing antibodies. IMPORTANCE Porcine epidemic diarrhea virus (PEDV), an emerging porcine coronavirus, causes an economically important enteric disease in pigs. Effective PEDV vaccines for disease control are currently lacking. The spike (S) glycoprotein on the virion surface is the key player in virus cell entry and, therefore, the main target of neutralizing antibodies. To understand the antigenic landscape of the PEDV spike protein, we developed monoclonal antibodies against the spike protein's S1 receptor binding region and characterized their epitopes, neutralizing activity, and cross-reactivity toward multiple PEDV strains. Epitopes of antibodies segregated into six epitope classes dispersed over the multidomain S1 structure. Monoclonal antibodies revealed antigenic variability in B-cell epitopes between PEDV strains. The epitopes of neutralizing antibodies mapped to two distinct domains in S1 that are involved in binding to carbohydrate and proteinaceous cell surface molecules, respectively, indicating the importance of these cell attachment sites on the PEDV spike protein in eliciting a protective humoral immune response.

Emergence and intercontinental spread of highly pathogenic avian influenza A(H5Nx) virus clade 2.3.4.4 is unprecedented. H5N8 and H5N2 viruses have caused major economic losses in the poultry industry in Europe and North America, and lethal human infections with H5N6 virus have occurred in Asia. Knowledge of the evolution of receptor-binding specificity of these viruses, which might affect host range, is urgently needed. We report that emergence of these viruses is accompanied by a change in receptor-binding specificity. In contrast to ancestral clade 2.3.4 H5 proteins, novel clade 2.3.4.4 H5 proteins bind to fucosylated sialosides because of substitutions K222Q and S227R, which are unique for highly pathogenic influenza virus H5 proteins. North American clade 2.3.4.4 virus isolates have retained only the K222Q substitution but still bind fucosylated sialosides. Altered receptor-binding specificity of virus clade 2.3.4.4 H5 proteins might have contributed to emergence and spread of H5Nx viruses.

The phase stability and thermophysical properties of InFeO 3 (ZnO) m ( m = 2, 3, 4, 5) compounds were investigated, which are a general family of homologous layered compounds with general formula InFeO 3 (ZnO) m ( m = 1–19). InFeO 3 (ZnO) m ( m = 2, 3, 4, 5) ceramics were synthesized using cold pressing followed by solid-state sintering. They revealed an excellent thermal stability after annealing at 1450 °C for 48 h. No phase transformation occurred during heating to 1400 °C. InFeO 3 (ZnO) 3 exhibited a thermal conductivity of 1.38 W m −1 K −1 at 1000 °C, which is about 30% lower than that of 8 wt.% yttria stabilized zirconia (8YSZ) thermal barrier coatings. The thermal expansion coefficients (TECs) of InFeO 3 (ZnO)m bulk ceramics were in a range of (10.97 ± 0.33) × 10 −6 K −1 to (11.46 ± 0.35) × 10 −6 K −1 at 900 °C, which are comparable to those of 8YSZ ceramics.

Water samples were collected from the Changjiang River (Yangtze River) in May 2005, after the impoundment of the Three Gorges Reservoir (TGR), to examine the influence of the TGR and large lakes on material delivery to the estuary of the Changjiang River. The concentrations of suspended particle material (SPM), dissolved silica (DSi) and biogenic silica (BSi) in the main stream were analyzed. The concentrations of DSi and BSi in the main channel of the Changjiang varied between 73 and 100 and 1.1–15 μmol/l, with a distance weighted average of 81 and 8.0 μmol/l, respectively. A calculation shows that live diatom comprises only an average value of 5.2 % of the BSi in the Changjiang River, and most of BSi may come from drainage basin. The concentrations of BSi and the ratios of BSi/SPM were relatively low in the Changjiang River compared to other rivers throughout the world, but the BSi carried in suspension by the Changjiang River was an important component of the rivers silicon load (i.e. ~13 %). SPM, DSi and BSi concentrations as observed in the Changjiang River tend to decrease from the upper sections of the river to the Three Gorges Dam (TGD), reflecting sedimentation associated with BSi trapping and DSi retention in the TGR in the normal-water period. SPM and BSi retention are more strongly influenced by the TGD compared to DSi. About 98 % of SPM, 72 % of BSi and 16 % of DSi were retained within the TGR in May 2005. The fluxes variations of DSi, BSi and SPM suggested that the large lakes and dams had a coupled effect on the transportation of DSi, BSi and SPM in the normal-water period. Such a change in silicon (DSi and BSi) balances of the Changjiang River will affect the ecological environment of the Changjiang estuary and its adjacent sea to some extent.

A retrospective analysis was conducted to investigate outcomes of elderly patients with resectable esophageal squamous cell carcinoma (ESCC) who underwent surgery or chemoradiotherapy (CRT). We performed a retrospective review of the records of elderly patients (≥70 years) with resectable ESCC who underwent esophagectomy or CRT between January 2009 and March 2013. According to the main treatment strategy, patients were allocated into either surgery group or CRT group. Overall survival (OS), cancer-specific survival and progression-free survival were calculated by the Kaplan–Meier method. Univariate and multivariate survival analyses were performed by the Kaplan–Meier method and Cox proportional hazards model, respectively. A total of 188 patients were enrolled. Eighty-eight patients underwent esophagectomy, and 100 patients underwent CRT. The median age of the patients was 73 years (range, 70–81 years) in the surgery group and 76 years (range, 70–88 years) in the CRT group. The median survival time (MST) for the whole cohort was 25.6 months, and 1-, 3-, and 5-year survival rates were 69.2%, 36.1%, and 21.9%, respectively. The MST in the surgery group and the CRT group was 36 months and 15 months, respectively. The 1-, 3-, and 5-year survival rates in the surgery group were 82.4%, 49.0%, and 33.3%, compared to 58.0%, 24.1%, and 7.8% in the CRT group (P

Emergence and intercontinental spread of highly pathogenic avian influenza A(H5Nx) virus clade 2.3.4.4 is unprecedented. H5N8 and H5N2 viruses have caused major economic losses in the poultry industry in Europe and North America, and lethal human infections with H5N6 virus have occurred in Asia. Knowledge of the evolution of receptor-binding specificity of these viruses, which might affect host range, is urgently needed. We report that emergence of these viruses is accompanied by a change in receptor-binding specificity. In contrast to ancestral clade 2.3.4 H5 proteins, novel clade 2.3.4.4 H5 proteins bind to fucosylated sialosides because of substitutions K222Q and S227R, which are unique for highly pathogenic influenza virus H5 proteins. North American clade 2.3.4.4 virus isolates have retained only the K222Q substitution but still bind fucosylated sialosides. Altered receptor-binding specificity of virus clade 2.3.4.4 H5 proteins might have contributed to emergence and spread of H5Nx viruses.

Mannose binding lectin (MBL) is a serum collagenous C-type lectin that plays an important role in the innate immune protection against pathogens. Previously, human and mouse studies have demonstrated that MBL binds a broad range of pathogens that results in their neutralization through agglutination, enhanced phagocytosis, and/or complement activation via the lectin pathway. The role of MBL in chicken is not well understood although the MBL concentration in serum seems to correlate with protection against infections. To investigate the role of MBL in chicken further, recombinant chicken MBL (RcMBL) was produced in HeLa R19 cells and purified using mannan affinity chromatography followed by gel filtration. RcMBL was shown to be structurally and functionally similar to native chicken MBL (NcMBL) isolated from serum. RcMBL is expressed as an oligomeric protein (mixture of trimers and oligomerized trimers) with a monomeric mass of 26kDa as determined by mass spectrometry, corresponding to the predicted mass. Glycan array analysis indicated that RcMBL bound most strongly to high-mannose glycans but also glycans with terminal fucose and GlcNac residues. The biological activity of RcMBL was demonstrated via its capacity to agglutinate Salmonella Typhimurium and to inhibit the hemagglutination activity of influenza A virus. The production of a structurally well-characterized and functionally active RcMBL will facilitate detailed studies into the protective role of MBL in innate defense against pathogens in chicken and other avian species.

The internal transcribed spacer (ITS) sequences alignment and proteomic difference of Anoectochilus interspecies have been studied by means of ITS molecular identification and surface enhanced laser desorption ionization time of flight mass spectrography. Results showed that variety certification on Anoectochilus by ITS sequences can not determine species, and there is proteomic difference among Anoectochilus interspecies. Moreover, proteomic finger printings of five Anoectochilus species have been established for identifying species, and genetic relationships of five species within Anoectochilus have been deduced according to proteomic differences among five species.

In 2014, novel highly pathogenic avian influenza A H5N2, H5N5, H5N6, and H5N8 viruses caused outbreaks in Asia, Europe, and North America. The H5 genes of these viruses form a monophyletic group that evolved from a clade 2.3.4 H5N1 variant. This rapid emergence of new H5Nx combinations is unprecedented in the H5N1 evolutionary history.

Influenza A virus (IAV) attachment to and release from sialoside receptors is determined by the balance between hemagglutinin (HA) and neuraminidase (NA). The molecular determinants that mediate the specificity and activity of NA are still poorly understood. In this study, we aimed to design the optimal recombinant soluble NA protein to identify residues that affect NA enzymatic activity. To this end, recombinant soluble versions of four different NA proteins from H5N1 viruses were compared with their full-length counterparts. The soluble NA ectodomains were fused to three commonly used tetramerization domains. Our results indicate that the particular oligomerization domain used does not affect the K m value but may affect the specific enzymatic activity. This particularly holds true when the stalk domain is included and for NA ectodomains that display a low intrinsic ability to oligomerize. NA ectodomains extended with a Tetrabrachion domain, which forms a nearly parallel four-helix bundle, better mimicked the enzymatic properties of full-length proteins than when other coiled-coil tetramerization domains were used, which probably distort the stalk domain. Comparison of different NA proteins and mutagenic analysis of recombinant soluble versions thereof resulted in the identification of several residues that affected oligomerization of the NA head domain (position 95) and therefore the specific activity or sialic acid binding affinity ( K m value; positions 252 and 347). This study demonstrates the potential of using recombinant soluble NA proteins to reveal determinants of NA assembly and enzymatic activity. IMPORTANCE The IAV HA and NA glycoproteins are important determinants of host tropism and pathogenicity. However, NA is relatively understudied compared to HA. Analysis of soluble versions of these glycoproteins is an attractive way to study their activities, as they are easily purified from cell culture media and applied in downstream assays. In the present study, we analyzed the enzymatic activity of different NA ectodomains with three commonly used tetramerization domains and compared them with full-length NA proteins. By performing a mutagenic analysis, we identified several residues that affected NA assembly, activity, and/or substrate binding. In addition, our results indicate that the design of the recombinant soluble NA protein, including the particular tetramerization domain, is an important determinant for maintaining the enzymatic properties within the head domain. NA ectodomains extended with a Tetrabrachion domain better mimicked the full-length proteins than when the other tetramerization domains were used.

The goal of this thesis is to study the industrial concentration in Hebei Province of China since 90s. The study was conducted by using modern theories in industrial organization and applying statistical methods for a systematic investigation. ​Master of Science (Managerial Economics)

The thermal barrier coatings (TBCs) are widely used in gas turbines which could lower the surface operating temperature and improve the service life of the coated part component. When repair or refurbishment of these coated components, it is necessary to remove the coating and replace it with a new coatings. The CoCrAlY coatings were deposited by EB-PVD on the directionally solidified nickel-based superalloy DZ125. The coatings were removed via physical methods in varying thicknesses and recoated subsequently. The results showed that the depth of the removal had a significant impact on the inter-diffusion behavior as well as the oxidation resistance. The thickness of Al-depleted zone formed in the recoated coatings after oxidation are thinner than the first coated coatings. Moreover, the more the coating was removed, the thinner the Al-depleted zone was formed. The recoated coatings deposited on the substrate removed the entirely inter-diffusion zone (IDZ) showed the best oxidation resistance, and the IDZ formed after oxidation was similar to the first coated coatings.