793 research outputs found

    Research on the Status Quo of Entrepreneurship and Policy Support System of Returning College Students Under the Background of Rural Revitalization Strategy:Based on Research in Zhejiang Province

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    In recent times, the proportion of college students returning to their hometowns to start businesses has increased year by year, but the success rate of college students returning to their hometowns to start a business is not impressive. Based on questionnaire surveys and case interviews of college students who have returned to start a business in Zhejiang Province, this article finds that the financing loan policy for college students to return to their hometown to start a business is not yet sound, and the policy supply is out of balance with actual demand; the application conditions and approval process for entrepreneurial subsidies are complicated and it is difficult to obtain subsidies. The satisfaction of entrepreneurs in townships is low; the entrepreneurs who return to their hometowns of college students have little understanding of the content of various policies, and the government does not promote the policies in place. In this regard, it is necessary to increase policy publicity and expand the scope of policy influence, establish financial credit support policies that meet the actual needs of returning home entrepreneurs college students, broaden financing channels, improve entrepreneurship training systems, improve entrepreneurship environment and enhance return home entrepreneurship college students’ satisfaction. Keywords:Rural revitalization,College Students,Return home to start a business,Entrepreneurship policy. DOI: 10.7176/EJBM/12-23-01 Publication date:August 31st 2020

    Topological Crystalline Insulators with C2C_2 Rotation Anomaly

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    Based on first-principles calculations and symmetry-based indicator analysis, we find a class of topological crystalline insulators (TCIs) with C2C_2 rotation anomaly in a family of Zintl compounds, including Ba3Cd2As4\mathrm{Ba}_{3}\mathrm{Cd}_{2}\mathrm{As}_{4}, Ba3Zn2As4\mathrm{Ba}_{3}\mathrm{Zn}_{2}\mathrm{As}_{4} and Ba3Cd2Sb4\mathrm{Ba}_{3}\mathrm{Cd}_{2}\mathrm{Sb}_{4}. The nontrivial band topology protected by coexistence of C2C_2 rotation symmetry and time-reversal symmetry TT leads to two surface Dirac cones at generic momenta on both top and bottom surfaces perpendicular to the rotation axis. In addition, (d−2d-2)-dimensional helical hinge states are also protected along the hinge formed by two side surfaces parallel with the rotation axis. We develop a method based on Wilson loop technique to prove the existence of these surface Dirac cones due to C2C_2 anomaly and precisely locate them as demonstrated in studying these TCIs. The helical hinge states are also calculated. Finally, we show that external strain can be used to tune topological phase transitions among TCIs, strong Z2_2 topological insulators and trivial insulators.Comment: 10 pages, 10 figure

    Interaction-mediating sequences within Class I viral fusion glycoproteins: their roles in viral infection and in applications

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    Class I viral fusion glycoproteins facilitate fusion of the viral envelope with cell membranes and entry of the virus into the cell, through extensive short sequence-specific interactions. Regions mediating these interactions include the N-terminal hydrophobic fusion peptide, a pair of extended 4,3-hydrophobic heptad repeats (HRs), a membrane-active membrane proximal external region (MPER), a hydrophobic transmembrane domain and the cytoplasmic tail region. In particular, the anti-parallel binding of the C-terminal HR to the central N-HR trimeric coiled-coil forms the 6-helix bundle fusion core. These interaction-mediating sequences are generally well preserved sequentially and structurally, allowing their peptidyl analogues to be developed as antiviral therapeutics and/or research reagents (e.g. HR-derived peptides). Novel targets for the development of antiviral drugs and viral detection reagents are required when facing drug-resistant viral strains, viral pathogens without effective and/or economical treatment, and newly emerging viral pathogens. This thesis focuses on the systematic identification of novel interaction-mediating sequences within Class I viral fusion glycoproteins, and the investigation of their involvements in viral replication as well as their potential applications in diagnosis and anti-viral interventions. In Paper I, peptide array scanning identified 34 spike (S) protein-derived peptides that bound to the S protein of severe acute respiratory syndrome-associated coronavirus (SARS-CoV). These putative self-binding peptides contain five core octapeptide consensus sequences, among which the octapeptide GINITNFR was predicted to form β-zipper-mediated amyloid-like fibrils. The peptide C6 containing this sequence was subsequently shown to oligomerize and form amyloid-like fibrils. The potential of C6 to conduct β-zipper-mediated interactions was further applied to detect the S protein expression by immunofluorescence staining. The peptide array scanning in Paper I used the S protein ectodomain without the MPER and beyond. Using chemical crosslinking and immunofluorescence staining, in Paper II we could show that the S protein MPER could oligomerize and further heteromerize with the N-terminal internal fusion peptide (IFP). The MPER-derived peptides also inhibited the coronavirus entry in a dose-dependent manner, potentially through disrupting the MPER-mediated interactions. The ability of peptides derived from the MPER in inhibiting viral entry and infection was subsequently studied in Paper III, in the context of HIV-1. The antiviral activities of the HIV-1 Env MPER-derived peptides were abrogated upon Ala substitution of the Trp residues or deletion of the C-terminal cholesterol-interacting motif. Unexpectedly, Ala substitutions of the Trp residues within HIV-1 Env significantly elevated the biosynthesis of another viral structural protein, the p55/Gag, which led to enhanced viral particle release. In Paper IV, besides the MPER we identified the signal sequence of HIV-1 Env as another region that could negatively regulate the expression of p55/Gag. The HIV-1 Env signal sequence, which mediates the co-translational translocalization of nascent Env polypeptide into the endoplasmic reticulum, inhibited the viral protein expression and production, probably at a post-ER-targeting stage. N-terminal truncations of the Env signal sequence significantly elevated the intracellular and intraviral levels of late viral proteins and the proviral genome transcription in a time- and dose-dependent fashion. Moreover, the truncations suppressed the HIV-1 promotor (LTR)-driven expression of a reporter protein, suggesting that the Env signal sequence inhibited viral genome transcription through LTR-dependent interactions. This thesis focused on three novel interaction-mediating sequences within two Class I viral fusion glycoproteins, which could regulate the viral infectivity, at both viral entry and assembly, through protein-protein, protein-lipid, and/or protein-nucleic acids interactions. These sequences and the interactions that they are meditating could be further targeted by their peptidyl analogues for viral detection and/or inhibition

    An Intelligent Weighing System based on Editable Formula and Alterable Resolution

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    This paper is to design an intelligent weighing system to solve the problems in enterprises, such as incompatibility with hardware and software environment in different enterprise scenarios, the fixed interface layout and the dilemma that a single-way computational formulas can not fit the workflow of complementation of weighing system flexibly . A self-defining formula method is proposed to meet different demands from variable enterprises, which is solved by infix expression algorithm. The interface layout is screen self-adaptation by using an alterable resolution algorithm. The result of the experimental study reveals that the intelligent weighing system is more flexible in self-adaptation of environment than the traditional weighing system

    Polymorphisms of the _ENPP1_ gene are not associated with type 2 diabetes or obesity in the Chinese Han population

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    *Objective:* Type 2 Diabetes mellitus is a metabolic disorder characterized by chronic hyperglycemia and with a major feature of insulin resistance. Genetic association studies have suggested that _ENPP1_ might play a potential role in susceptibility to type 2 diabetes and obesity. Our study aimed to examine the association between _ENPP1_ and type 2 diabetes and obesity.

*Design:* Association study between two SNPs, rs1044498 (K121Q) and rs7754561 of ENPP1 and diabetes and obesity in the Chinese Han population.

*Subjects:* 1912 unrelated patients (785 male and 1127 female with a mean age 63.8 ± 9 years), 236 IFG/IGT subjects (83 male and 153 female with a mean age 64 ± 9 years) and 2041 controls (635 male and 1406 female with a mean age 58 ± 9 years).
 
*Measurements:* Subjects were genotyped for two SNPs using TaqMan technology on an ABI7900 system and tested by regression analysis.

*Results:* By logistic regression analysis, rs1044498 (K121Q) and rs7754561 showed no statistical association with type 2 diabetes, obesity under additive, dominant and recessive models either before or after adjusting for sex and age. Haplotype analysis found a marginal association of haplotype C-G (p=0.05) which was reported in the previous study.

*Conclusion:* Our investigation did not replicated the positive association found previously and suggested that the polymorphisms of _ENPP1_ might not play a major role in the susceptibility to type 2 diabetes or obesity in the Chinese Han population

    High channel count and high precision channel spacing multi-wavelength laser array for future PICs

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    Multi-wavelength semiconductor laser arrays (MLAs) have wide applications in wavelength multiplexing division (WDM) networks. In spite of their tremendous potential, adoption of the MLA has been hampered by a number of issues, particularly wavelength precision and fabrication cost. In this paper, we report high channel count MLAs in which the wavelengths of each channel can be determined precisely through low-cost standard μm-level photolithography/holographic lithography and the reconstruction-equivalent-chirp (REC) technique. 60-wavelength MLAs with good wavelength spacing uniformity have been demonstrated experimentally, in which nearly 83% lasers are within a wavelength deviation of ±0.20 nm, corresponding to a tolerance of ±0.032 nm in the period pitch. As a result of employing the equivalent phase shift technique, the single longitudinal mode (SLM) yield is nearly 100%, while the theoretical yield of standard DFB lasers is only around 33.3%

    Roles of circulating soluble interleukin (IL)-6 receptor and IL-6 receptor expression on CD4+ T cells in patients with chronic hepatitis B

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    SummaryObjectivesThe objective of this study was to investigate the potential clinical roles of circulating soluble interleukin (IL)-6 receptor (sIL-6R) and IL-6R expression on CD4+ T cells (CD4+ IL-6R+ T cells) in chronic hepatitis B (CHB) patients.MethodsOne hundred and thirty-three subjects, including 72 CHB patients, 27 asymptomatic carriers, eight acute hepatitis B (AHB) patients, and 26 healthy donors were included in this study. Plasma IL-6 and sIL-6R levels were measured by enzyme-linked immunosorbent assay (ELISA); the frequency of CD4+ IL-6R+ T cells was detected by flow cytometry analysis.ResultsOur data showed a significant increase in plasma sIL-6R levels and the frequency of CD4+ IL-6R+ T cells in peripheral blood in CHB patients compared to asymptomatic carriers and healthy controls (both p<0.05). The elevated prevalence of CD4+ IL-6R+ T cells was positively associated with increased serum alanine aminotransferase levels in CHB patients (r = 0.316, p = 0.007), but was not correlated with serum hepatitis B virus (HBV) DNA load. Moreover, CHB patients with an HBV DNA load >1.0×106 copies/ml had a lower level of plasma sIL-6R than those with an HBV DNA load <1.0×106 copies/ml.ConclusionsCirculating sIL-6R and CD4+ IL-6R+ T cells were increased in CHB patients. Elevated plasma sIL-6R is probably associated with HBV elimination, and CD4+ IL-6R+ T cells in peripheral blood might contribute to the pathogenesis of liver injury in CHB patients
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