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Yang X, Ji Y, Ke D, Li F. Research on the methods and means of action strength training in aerobics training. Lu S. Scientific research and training satisfaction evaluation analysis of postgraduates in science and engineering colleges based on big data. [Extracted from the article]

On the basis of propagation the characteristics of Multi-hop High-Frequency Radio waves in Marine environment, the modeling and analysis method of ocean signal reflection model are firstly introduced from the attenuation of the radio wave. Then the difference between the influence of ocean and earth on wireless communication is studied. By studying the influence of ship on the loss of radio wave propagation, the original ocean model is improved. Finally, an ocean signal reflection model suitable for different marine environments is obtained. [ABSTRACT FROM AUTHOR]

Abstract: Diffusion on random systems above and at their percolation threshold in three dimensions is carried out by a molecular trajectory method and a simple lattice random walk method, respectively. The classical regimes of diffusion on percolation near the threshold are observed in our simulations by both methods. Our Monte Carlo simulations by the simple lattice random walk method give the conductivity exponent for diffusion on the incipient infinite clusters and for diffusion on a percolating lattice above the threshold. However, while diffusion is performed by the molecular trajectory algorithm either on the incipient infinite clusters or on a percolating lattice above the threshold, the result is found to be . In addition, it takes less time step for diffusion based on the molecular trajectory algorithm to reach the asymptotic limit comparing with the simple lattice random walk. [Copyright &y& Elsevier]

Abstract: Random walk simulations based on a molecular trajectory algorithm are performed on critical percolation clusters. The analysis of corrections to scaling is carried out. It has been found that the fractal dimension of the random walk on the incipient infinite cluster is in two dimensions and 3.78 ± 0.02 in three dimensions. If instead the diffusion is averaged over all clusters at the threshold not subject to the infinite restriction, the corresponding critical exponent is found to be for two-dimensional space and 0.199 ± 0.002 for three-dimensional space. Moreover, in our simulations the asymptotic behaviors of local critical exponents are reached much earlier than in other numerical methods. [Copyright &y& Elsevier]

Abstract: The analytical expression for the spectrum of spatially and spectrally partially coherent cosh-Gaussian pulsed (ChGP) beams focused by an aperture lens is derived and used to study their spectral properties at the focal plane and on the axis. The effect of the truncation parameter, spatial correlation parameter, decentered parameter and temporal coherence length on the spectral shifts and spectral switches of spatially and spectrally partially coherent ChGP beams is stressed. The results are illustrated numerically and interpreted physically. [Copyright &y& Elsevier]

Abstract: The spectral and spatiotemporal properties of Bessel–Gauss pulsed beams focused by a dispersive aperture lens are studied, where the dispersion of the first, second, and higher orders is taken into consideration. It is shown that the spectral switches take place at the geometrical focal plane, and the dispersion of the first order leads to a shift of the critical position towards the z-axis. The dispersion plays a noticeable role in the spatiotemporal intensity distribution. The dispersion of the first order results in a decrease of the peak intensity, in a shift and a broadening of the pulse form, and the effect becomes more noticeable with increasing waist width. The dispersion of the second order results in a further broadening and a decrease of the peak intensity, and the effect is larger as the thickness of the lens increases. However, the dispersion of the higher order plays a relatively minor role. The results are illustrated by numerical examples and interpreted physically. [Copyright &y& Elsevier]

Abstract: The spherical MgCl2 supports treated by methylaluminoxane (named MAO-supports) were prepared using MgCl2·2.56C2H5OH adducts as support material subjected to elimination of EtOH by thermal dealcoholization treatments. Then bis(phenoxy-imine) zirconium complex, bis-[N-(3-tert-butylsalicylidence)cyclohexylaminato] zirconium(IV) dichloride (1), was directly impregnated onto these MAO-supports. ICP, EDX, GC, N2-BET, IR and XRD analyses indicated that the texture of the supports and MAO-supports, the elements on solid catalysts, and so on, were greatly relied on dealcoholization temperature. Meanwhile, it was also found that the activities of the supported catalysts for ethylene polymerization and the properties of resultant polymers were strongly dependent on dealcoholization temperature. Finally, PEs with spherical morphology and high bulk density (over 0.35g/ml) were obtained, without reactor fouling. [Copyright &y& Elsevier]

Abstract: Trialkylaluminums as cocatalysts for bis(phenoxy-imine)Zr complexes, bis[N-(3-tert-butylsalicylidene)-anilinato]zirconium dichloride (1) and bis[N-(3-tert-butylsalicylidene)-cyclohexylaminato]zirconium dichloride (2), are investigated for ethylene polymerization without MAO or Ph3CB(C6F5)4. The effects of alkylaluminums, Al/Zr molar ratio, polymerization temperature and time as well as the comonomer 1-hexene on polymerization performance are examined. In appropriate range of Al/Zr molar ratio, the catalyst system bis(phenoxy-imine)Zr complex/trialkylaluminum shows high activity for ethylene polymerization, which approximates to bis(phenoxy-imine)Zr complex/MAO system. Their catalytic activities depend on not only the nature, but also the amount, of the trialkylaluminum. Both the molecular weights and the polydispersities (M w/M n) of PEs produced by 1 with Et3Al, He3Al, or Me3Al are higher than those with MAO. The nature, rather than the amount, of alkylaluminum determines the M w and the polydispersity of polymer in polymerization with the same complex. Unexpectedly, M w of the polyethylenes produced with complex 1/triethylaluminum increases with polymerization time. The catalyst system bis(phenoxy-imine)Zr complex/trialkylaluminum has low capacity of copolymerization. [Copyright &y& Elsevier]

Abstract: Different alkylaluminums (triethyl-, tri-iso-butyl-, n-trihexylaluminum) were tested as activator for the iron complex LFeCl2 (1) (L=2,6-bis[(2,4,6-trimethylphenylimino)ethyl]pyridine) in ethylene polymerization. Various polymerization temperatures and the molar ratios of Al/Fe prepared polyethylene (PE) with different molecular weights, molecular weight distributions, polymerization activities and polyethylene structures. Through the analysis of in situ UV–vis absorption spectra, ethylene polymerization results and prepared polyethylene structures, the distinctive behaviors of the catalytic system could result from a new applicable mechanism involving two different kinds of catalytic species LFeRCl (a) and LFeR2 (b) (R=Et, i-Bu or He), the ratio of which varied with changing Al/Fe mole ratio when alkylaluminums were used as activators. The catalytic species (a) with very high activity mainly produced linear PE with high molecular weight in the bimodal PE. The catalytic species (b) with low activity mainly produced branched PE of low molecular weight in the bimodal PE. [Copyright &y& Elsevier]

Stability is an important property of solutions to many fluid flow equations. In this paper, we focus on the stability problem for two-dimensional Boussinesq equations with only vertical viscosity and horizontal thermal diffusion near a stratified, hydrostatic equilibrium in the domain Ω = T × R , where T = [ − 1 2 , 1 2 ] is a 1D periodic box. We are mainly concerned with the H2-stability of global solutions when the initial data are closed to an equilibrium state and sufficiently small. Due to the lack of horizontal viscosity in velocity equations and vertical thermal diffusion in temperature equation, this problem seems to be not trivial and becomes particularly difficult. In order to achieve our main goal, we divide the velocity field and temperature into two parts: the horizontal average and the remaining oscillation part. Besides, we fully exploit the L t 2 L x 2 -norm of ∂xu2 to help us dominate the nonlinear parts. Our result shows that with a small initial perturbation, there exists a unique global solution to the stated Boussinesq equations. In addition, the perturbation remains small for all time. In particular, our result also demonstrates the stabilizing effect of internal gravity waves, which are induced by the stratified background hydrostatic state. [ABSTRACT FROM AUTHOR]

Abstract Gastric cancer (GC) is a highly heterogeneous disease with multiple cellular types and poor prognosis. However, the cellular evolution and molecular basis of GC at the individual intra-tumor level has not been well demonstrated. We performed single-cell whole exome sequencing to detect somatic single-nucleotide variants (SNVs) and significantly mutated genes (SMGs) among 34 tumor cells and 9 normal cells from a patient with GC. The Complete Prediction for Protein Conformation (CPPC) approach directly predicting the folding conformation of the protein 3D structure with Protein Folding Shape Code, combined with functional experiments were used to confirm the characterization of mutated SMGs in GC cells. We identified 201 somatic SNVs, including 117 non-synonymous mutations in GC cells. Further analysis identified 24 significant mutated genes (SMGs) in single cells, for which a single amino acid change might affect protein conformation. Among them, two genes (CDC27 and FLG) that were mutated only in single cells but not in the corresponding tumor tissue, were recurrently present in another GC tissue cohort, and may play a potential role to promote carcinogenesis, as confirmed by functional characterization. Our findings showed a mutational landscape of GC at intra-tumor level for the first time and provided opportunities for understanding the heterogeneity and individualized target therapy for this disease. [ABSTRACT FROM AUTHOR]

Combined iron (II) and nickel (II) olefin polymerization catalysts could produce a kind of PE having the characters of ideal bimodal PE with appropriate conditions and catalysts. In the ethylene homopolymerization with triethylalkylaluminum (AIEt3) as the activator, the prepared bimodal PE contained not only branched PE of high molecular weight, but also linear PE of low molecular weight. And the amounts of both fractions were similar. Ideal bimodal PE resin was prepared in one polymerization reactor. [ABSTRACT FROM AUTHOR]

Background Global disparities in prostate cancer (PCa) incidence highlight the urgent need to identify genomic abnormalities in prostate tumors in different ethnic populations including Asian men. Objective To systematically explore the genomic complexity and define disease-driven genetic alterations in PCa. Design, setting, and participants The study sequenced whole-genome and transcriptome of tumor-benign paired tissues from 65 treatment-naive Chinese PCa patients. Subsequent targeted deep sequencing of 293 PCa-relevant genes was performed in another cohort of 145 prostate tumors. Outcome measurements and statistical analysis The genomic alteration landscape in PCa was analyzed using an integrated computational pipeline. Relationships with PCa progression and survival were analyzed using nonparametric test, log-rank, and multivariable Cox regression analyses. Results and limitations We demonstrated an association of high frequency of CHD1 deletion with a low rate of TMPRSS2-ERG fusion and relatively high percentage of mutations in androgen receptor upstream activator genes in Chinese patients. We identified five putative clustered deleted tumor suppressor genes and provided experimental and clinical evidence that PCDH9 , deleted/loss in approximately 23% of tumors, functions as a novel tumor suppressor gene with prognostic potential in PCa. Furthermore, axon guidance pathway genes were frequently deregulated, including gain/amplification of PLXNA1 gene in approximately 17% of tumors. Functional and clinical data analyses showed that increased expression of PLXNA1 promoted prostate tumor growth and independently predicted prostate tumor biochemical recurrence, metastasis, and poor survival in multi-institutional cohorts of patients with PCa. A limitation of this study is that other genetic alterations were not experimentally investigated. Conclusions There are shared and salient genetic characteristics of PCa in Chinese and Caucasian men. Novel genetic alterations in PCDH9 and PLXNA1 were associated with disease progression. Patient summary We reported the first large-scale and comprehensive genomic data of prostate cancer from Asian population. Identification of these genetic alterations may help advance prostate cancer diagnosis, prognosis, and treatment. [ABSTRACT FROM AUTHOR]

Background: CD70 is a costimulatory molecule that is transiently expressed on a small set of activated lymphocytes and is involved in T‐cell‐mediated immunity. However, the role of CD70 in B‐cell malignancies remains controversial. Methods: We investigated the clinical relevance of CD70 genetic alterations and its protein expression in two diffuse large B‐cell lymphoma (DLBCL) cohorts with different ethnic backgrounds. We also performed transcriptomic analysis to explore the role of CD70 alterations in tumour microenvironment. We further tested the blockade of CD70 in combination with PD‐L1 inhibitor in a murine lymphoma model. Results: We showed that CD70 genetic aberrations occurred more frequently in the Chinese DLBCL cohort (56/233, 24.0%) than in the Swedish cohort (9/84, 10.8%), especially in those with concomitant hepatitis B virus (HBV) infection. The CD70 genetic changes in DLBCL resulted in a reduction/loss of protein expression and/or CD27 binding, which might impair T cell priming and were independently associated with poor overall survival. Paradoxically, we observed that over‐expression of CD70 protein was also associated with a poor treatment response, as well as an advanced disease stage and EBV infection. More exhausted CD8+ T cells were furthermore identified in CD70 high‐expression DLBCLs. Finally, in a murine lymphoma model, we demonstrated that blocking the CD70/CD27 and/or PD1/PD‐L1 interactions could reduce CD70+ lymphoma growth in vivo, by directly impairing the tumour cell proliferation and rescuing the exhausted T cells. Conclusions: Our findings suggest that CD70 can play a role in either tumour suppression or oncogenesis in DLBCL, likely via distinct immune evasion mechanisms, that is, impairing T cell priming or inducing T cell exhaustion. Characterisation of specific dysfunction of CD70 in DLBCL may thus provide opportunities for the development of novel targeted immuno‐therapeutic strategies. [ABSTRACT FROM AUTHOR]

Comprehensive molecular analyses of metastatic hepatocellular carcinoma (HCC) are lacking. Here, we generate multi-omic profiling of 257 primary and 176 metastatic regions from 182 HCC patients. Primary tumors rich in hypoxia signatures facilitated polyclonal dissemination. Genomic divergence between primary and metastatic HCC is high, and early dissemination is prevalent. The remarkable neoantigen intratumor heterogeneity observed in metastases is associated with decreased T cell reactivity, resulting from disruptions to neoantigen presentation. We identify somatic copy number alterations as highly selected events driving metastasis. Subclones without Wnt mutations show a stronger selective advantage for metastasis than those with Wnt mutations and are characterized by a microenvironment rich in activated fibroblasts favoring a pro-metastatic phenotype. Finally, metastases without Wnt mutations exhibit higher enrichment of immunosuppressive B cells that mediate terminal exhaustion of CD8+ T cells via HLA-E:CD94-NKG2A checkpoint axis. Collectively, our results provide a multi-dimensional dissection of the complex evolutionary process of metastasis. [Display omitted] • Multi-regional and multi-omic profiles of paired primary and metastatic HCC tumors • Polyclonal, early dissemination and APM defects result in high ITH in metastases • Wnt-wt subclones show stronger selection for metastasis than Wnt-mut counterparts • Focal and arm-level SCNA deletion events are genomic drivers of HCC metastasis Sun et al. characterize multi-regional and multi-omics (genomics, transcriptomics, scRNA-seq, spatial transcriptomics, and IHC) profiles for paired primary and metastatic hepatocellular carcinoma from 182 patients. They reveal high intratumor heterogeneity in metastatic HCCs, complex evolutionary trajectories, subclonal selection, and crucial roles of tumor microenvironment (cancer-associated fibroblast and B cells) during metastasis. [ABSTRACT FROM AUTHOR]

Hollow polyethylene spheres were achieved from solution-based ɑ-diimine nickel catalyst system with morphological controllable one-step synthesis. • Homogenous ɑ- diimine nickel complexes often produce bulk viscous polyethylene. • Spherical hollow polyethylene produced by coordination dispersion polymerization. • Tri-nuclear nickel complex show high activity for ethylene polymerization. In this paper, ɑ-diimine nickel catalyst without immobilization was successfully used for one-step synthesis of spherical hollow polyethylene particles at mild condition (1.0 MPa, 25 °C) by conducting coordination dispersion polymerization. It was found 2-methyl-2-pentanol (MP) played a key role in the formation of the unusual hollow particular morphology. By varying the addition amount of MP, changing the bulky groups of alkyl aluminum, and adjusting the concentration of nickel catalyst, the particle size was finely tuned. A plausible mechanism was proposed to interpret the formation of these polyethylene hollow particles. [ABSTRACT FROM AUTHOR]

Wide-angle X-ray diffraction on large-scale laser facility is a well-established experimental method, which is used to study the shock response of single crystal materials by recording X-rays diffracted from numerous lattice planes. We present a three-dimensional graphical method for extracting physical understanding from the raw diffraction data in shocked experiments. This method advances beyond the previous iterative process by turning abstract diffraction theories in shock physics into mathematic issues, providing three-dimensional visualization and quick extraction of data characteristics. The capability and versatility of the method are exhibited by identifying lattice planes for single crystal samples with different orientations and quantitatively measuring the lattice compression and rotation under dynamic loading. [ABSTRACT FROM AUTHOR]

In addition to the widely used monochromatic X-ray source, the polychromatic X-ray source may also be used in many cases of propagation-based phase-contrast imaging (PB-PCI). It is not sufficient to investigate the optimization procedure only for the monochromatic applications. The focus of this paper is to investigate the effects of spectrum and imaging geometry on the image quality of PB-PCI, for applications involving propagation in vacuum and air. The quality of phase contrast image has been quantitatively characterized by using contrast and SNR as quality metrics in this paper. The optimal geometry has been investigated in three situations, where four cases are considered. Based on the numerical simulation, it is observed that the contrast and SNR in the case of polychromatic X-ray are lower than the monochromatic X-ray. Therefore, the influence of the X-ray spectrum on the contrast and SNR must not be neglected. The contrast in the case of polychromatic X-ray, and the SNR in both polychromatic and monochromatic X-ray, is lower for propagation in air compared to the propagation in vacuum. Evidently, the air absorption is an important factor in the propagation-based phase-contrast imaging. The experimental and numerical results for all three situations are presented to verify the effect of the geometry on the image quality in the air condition. It is found that the experimental results confirm the validity of numerical results for both the quality metrics. The object specification and the X-ray scattering have obvious influence on the image quality, as seen in the experimental results. [ABSTRACT FROM AUTHOR]

Neutron penumbral imaging is a significant diagnostic technique in laser-driven inertial confinement fusion experiment. It is very important to develop a new reconstruction method to improve the resolution of neutron penumbral imaging. A new nonlinear reconstruction method based on total variation (TV) regularization is proposed in this paper. A TV-norm is used as regularized term to construct a smoothing functional for penumbral image reconstruction in the new method, in this way, the problem of penumbral image reconstruction is transformed to the problem of a functional minimization. In addition, a fixed point iteration scheme is introduced to solve the problem of functional minimization. The numerical experimental results show that, compared to linear reconstruction method based on Wiener filter, the TV regularized nonlinear reconstruction method is beneficial to improve the quality of reconstructed image with better performance of noise smoothing and edge preserving. Meanwhile, it can also obtain the spatial resolution with 5 μm which is higher than the Wiener method. [ABSTRACT FROM AUTHOR]

Abstract: A series of bridged bis(pyridinylimino) ligands were efficiently synthesized through the condensation reaction of 4,4′-methylene-bis(2,6-disubstituted aniline) with 2-pyridinecarboxaldehyde or 2-benzoylpyridine. They reacted with (DME)NiBr2 to form dinuclear Ni(II) complexes. All resultant compounds were characterized by elemental analysis, IR spectra as well as the single-crystal X-ray diffraction to confirm the structures of ligands and complexes. Activated with methylaluminoxane (MAO), these nickel complexes showed considerably good activities for ethylene oligomerization and polymerization. Their catalytic activities and the properties of PEs obtained were depended on the arched environment of ligand and reaction conditions. [Copyright &y& Elsevier]