Dephosphorylation of eIF-2α Mediated by the γ(1)34.5 Protein of Herpes Simplex Virus Type 1 Is Required for Viral Response to Interferon but Is Not Sufficient for Efficient Viral Replication

The γ(1)34.5 protein of herpes simplex virus type 1 (HSV-1) functions to block the shutoff of protein synthesis involving double-stranded RNA-dependent protein kinase (PKR). In this process, the γ(1)34.5 protein recruits cellular protein phosphatase 1 (PP1) to form a high-molecular-weight complex that dephosphorylates eIF-2α. Here we show that the γ(1)34.5 protein is capable of mediating eIF-2α dephosphorylation without any other viral proteins. While deletion of amino acids 1 to 52 from the γ(1)34.5 protein has no effect on eIF-2α dephosphorylation, further truncations up to amino acid 146 dramatically reduce the activity of the γ(1)34.5 protein. An additional truncation up to amino acid 188 is deleterious, indicating that the carboxyl-terminal domain alone is not functional. Like wild-type HSV-1, the γ(1)34.5 mutant with a truncation of amino acids 1 to 52 is resistant to interferon, and resistance to interferon is coupled to eIF-2α dephosphorylation. Intriguingly, this mutant exhibits a similar growth defect seen for the γ(1)34.5 null mutant in infected cells. Restoration of the wild-type γ(1)34.5 gene in the recombinant completely reverses the phenotype. These results indicate that eIF-2α dephosphorylation mediated by the γ(1)34.5 protein is required for HSV response to interferon but is not sufficient for viral replication. Additional functions or activities of the γ(1)34.5 protein contribute to efficient viral infection

A Continuous-Time-Based MILP Model for Production and Transportation Scheduling in Nonpipelined Wells in Low-Permeability Oil Fields

AbstractThe marginal wells in low-permeability oilfields are characterized by small storage size, scattered distribution, large regional span, low production, intermittent production, etc. The production mode of these wells is nonpipeline mode. In our previous work (Zhang et al., 2019), a novel mixed-integer linear programming (MILP) model using a discrete-time representation was presented for the operation scheduling of nonpipelined wells. However, too many discretization time points are required to ensure the accuracy of the model. Even for moderately sized problems, computationally intractable models can arise. The present paper describes a new continuous-time representation method to reformulate this schedule optimization problem. By introducing the continuous-time representation, the binary variables are largely reduced. The solution effect for different model sizes is also investigated. When the model size increases to a certain degree, a feasible solution cannot be obtained within a limited time. The results of a case study originated from a real oilfield in China show that the continuous-time model requires less time to obtain the optimal solution compared to the discrete-time model. In details, considering a same scale problem, the solution based on the continuous-time model saves 52.25% of the time comparing with the discrete-time model. The comparison validates the new model’s superiority

A Triple-Band Hybridization Coherent Perfect Absorber Based on Graphene Metamaterial

In this paper, a triple-band hybridization coherent perfect absorber based on graphene metamaterial is proposed, which consists of graphene concentric nanorings with different sizes and a metallic mirror separated by SiO2 layer. Based on the finite-difference time-domain (FDTD) solution, triple-band coherent perfect absorption is achieved at frequencies from 0.6 THz to 1.8 THz, which results from the surface plasmon resonance hybridization. The wavelength of the absorption peak can be rapidly changed by varying the Fermi level of graphene. Most importantly, the wavelength of the absorption peak can be independently tuned by varying the Fermi level of the single graphene nanoring. Moreover, the triple hybridization perfect absorber is angle-insensitive because of the perfect symmetry structure of the graphene nanorings. Therefore, our results may widely inspire optoelectronic and micro-nano applications, such as cloaking, tunable sensor, etc

Salinity Sensing Characteristics Based on Optical Microfiber Coupler Interferometer

In this paper, we report a novel and compact sensor based on an optic microfiber coupler interferometer (OMCI) for seawater salinity application. The OMCI device is fabricated by connecting Faraday rotating mirrors to the two out-ports of the microfiber coupler, respectively. The sensor signal processing is based on a wavelength demodulation technique. We theoretically analyze the sensing characteristics with different device structure parameters. Besides, the results show that the date reading error decreases with the thinner waist region and longer arm difference. Through the experiment, the reflection spectra red-shifted as the sea water salinity increased; the highest response sensitivity of the OMCI salinity sensor reached 303.7 pm/‰ for a range of 16.6–23.8‰, and the resolution was less than 0.03‰. This study provides a new technical solution for the development of practical optical fiber seawater salinity sensors