Computation Bits Maximization for IRS-Aided Mobile-Edge Computing Networks With Phase Errors and Transceiver Hardware Impairments

Intelligent reflecting surface (IRS) is a hopeful technique to improve the computation offloading efficiency for mobile-edge computing (MEC) networks. However, the phase errors (PEs) of IRS and transceiver hardware impairments (THIs) will greatly degrade the performance of IRS-assisted MEC networks. To overcome this bottleneck, this paper first investigates the computation bits maximization problem for IRS-assisted MEC networks with PEs, where multiple Internet of Things (IoT) devices can offload their computation tasks to access points with the aid of IRS. By exploiting the block coordinate descent method, we design a multi-block optimization algorithm to tackle the non-convex problem. In particular, the optimal IRS phase shift, time allocation, transmit power and local computing frequencies of IoT devices are derived in closed-form expressions. Moreover, we further study the joint impact of PEs and THIs on the total computation bits of considered systems, where same methods in the scenario with PEs are used to obtain the optimal IRS phase shift and local computing frequencies of IoT devices, while an approximation algorithm and the variable substitution method are used to acquire the optimal transmit power and time allocation strategy. Finally, numerical results validate that our proposed methods can significantly outperform benchmark methods in terms of total computation bits

Human respiratory syncytial virus subgroups A and B outbreak in a kindergarten in Zhejiang Province, China, 2023

BackgroundIn May–June 2023, an unprecedented outbreak of human respiratory syncytial virus (HRSV) infections occurred in a kindergarten, Zhejiang Province, China. National, provincial, and local public health officials investigated the cause of the outbreak and instituted actions to control its spread.MethodsWe interviewed patients with the respiratory symptoms by questionnaire. Respiratory samples were screened for six respiratory pathogens by real-time quantitative polymerase chain reaction (RT-PCR). The confirmed cases were further sequenced of G gene to confirm the HRSV genotype. A phylogenetic tree was reconstructed by maximum likelihood method.ResultsOf the 103 children in the kindergarten, 45 were classified as suspected cases, and 25 cases were confirmed by RT-PCR. All confirmed cases were identified from half of classes. 36% (9/25) were admitted to hospital, none died. The attack rate was 53.19%. The median ages of suspected and confirmed cases were 32.7 months and 35.8 months, respectively. Nine of 27 confirmed cases lived in one community. Only two-family clusters among 88 household contacts were HRSV positive. A total of 18 of the G gene were obtained from the confirmed cases. Phylogenetic analyses revealed that 16 of the sequences belonged to the HRSV B/BA9 genotype, and the other 2 sequences belonged to the HRSV A/ON1 genotype. The school were closed on June 9 and the outbreak ended on June 15.ConclusionThese findings suggest the need for an increased awareness of HRSV coinfections outbreak in the kindergarten, when HRSV resurges in the community after COVID-19 pandemic

BNIP3-induced mitochondrial release of EndoG.

<p>Freshly isolated mitochondria were incubated with the indicated recombinant proteins for 1 h and then separated into mitochondrial and supernatant fractions. In the group treated with both Bcl-2 and BNIP3, both were used at 0.5 µM. A and B, Western blotting analysis of BNIP3 and EndoG in the mitochondrial and supernatant fractions. Loading controls were performed with Cox IV and HSP60 antibodies. Results shown represent the mean ±SD for combined data from three independent experiments. ΔTM ^#, = BNIP3ΔTM; *, p<0.05; **, p<0.01. C, Amino acid sequence of EndoG. The tryptic peptide identified from the supernatant samples by mass fingerprinting is indicated in bold and underlined. D, Western blot analysis of cytochrome <i>c</i> and AIF. Both were not detectable in the supernatant samples.</p

Expression of BNIP3 results in EndoG translocation.

<p>A, SH-SY5Y human neuroblastoma cells cells transfected with the full length BNIP3 or the mutant BNIP3ΔTM plasmids were immune-labeled with antibodies to BNIP3 and EndoG and counterstained with Hoechst 33342. Majority of BNIP3 expressing cells (82%) showed nuclear translocation of EndoG, while only 12% of cells expressing BNIP3ΔTM showed EndoG translocation. B and C, Western blot analysis of EndoG in mitochondrial and nuclear samples prepared from SH-SY5Y cells transfected with the indicated plasmids. Results shown represent the mean ±SD for combined data from 4 independent experiments. **, p<0.01.</p

Blocking VDAC abolishes BNIP3-induced mitochondrial release of EndoG.

<p>A, Mitochondria (1 mg/ml) were incubated with a recombinant GST-BNIP3 in the presence of 0.3 mg/ml of an anti-VDAC antibody or normal rabbit IgG in control. Incubation with the trunked BNIP3 (BNIP3ΔTM) was used as a control. The samples were separated into mitochondrial and supernatant fractions by centrifugation. a), Blocking VDAC prevented BNIP3 from integration into mitochondria. b) Analysis of EndoG from the supernatant showed that levels of EndoG released from mitochondria was reduced by the VDAC antibody blocking. c) Co-immunoprecipitation with a BNIP3 antibody to pull down BNIP3-interacting proteins showed that blocking VDAC abolished the integration of BNIP3 with mitochondria. B, Quantification of BNIP3 integration with mitochondria and mitochondrial release of EndoG affected by the VDAC antibody blocking. Results shown represent the mean ±SD for combined data from three independent experiments. **, p<0.01.</p

BNIP3 induces MPT by interacting with VDAC.

<p>A, BNIP3-induced MPT. Calcein release was presented as the percentage of calcein escaped from mitochondria during the 30-minute incubation. **, p<0.01 when compared with the control. B, Inhibition of PT pores reduced BNIP3-induced EndoG release. Cyclosporine A (2 µM) was added to mitochondria in CFS buffer 10 min before the BNIP3-GST protein at different final concentrations as indicated. BNIP3, CoxIV and EndoG in mitochondrial and supernatant fractions were detected by Western blotting. C, Distribution of EndoG was determined by analyzing the total intensities of the EndoG bands. D, Identification of VDAC as an interacting partner of BNIP3. After mitochondria-BNIP3 incubation, interacting proteins of BNIP3 were precipitated with a BNIP3 antibody and analyzed by Mass spectrometry fingerprinting. The amino acid sequence of VDAC with the tryptic peptide identified from the immunoprecipitates is labelled in bold and underlined. E Western bloting analyses show interaction between BNIP3 and VDAC. a) Levels of GST-BNIP3 in the mitochondrial fraction after mitochondria-BNIP3 incubation as determined by Western blotting. b) After co-immunoprecipitation with a BNIP3 antibody, immunoblotting with a VDAC antibody reveals the presence of VDAC in the BNIP3 immunoprecipitates. c) BNIP3 was present in the precipitates when a VDAC antibody was used for co-immunoprecipitation. Shown are samples from three independent experiments. Cell lysates without BNIP3 treatment were used as controls.</p

EndoG released from isolated mitochondria following BNIP3 induction is enzymatically active.

<p>Freshly isolated mitochondria were incubated with various recombinant proteins for 1 h at 37°C. The supernatants were collected and incubated with HEK293 nuclei for 2 h at 37°C. The DNA samples were loaded on a horizontal 1.8% agarose gel for DNA laddering assay. Shown is a representative image selected from three independent experiments.</p

Boosting the Acidic Oxygen Reduction Activity of p‐Block Single‐Atomic Catalyst via p–p Orbital Coupling and Pore Engineering

Atomically dispersed main group element single‐atom catalysts (SACs) have recently attracted increasing attention in electrocatalysis. However, their performances in acidic oxygen reduction reaction (ORR) remain unsatisfactory owing to the suboptimal coordination environment, limited mass transfer, and active site exposure. Herein, a series of p‐block Sn SACs with hierarchical pore structures are prepared by a dual melting salt‐mediated soft template method. By deliberately regulating the pore structures, highly exposed Sn active sites with N/O coordination are obtained, which endow SnN3O‐50 with exceptional ORR performances, especially in acidic medium. The half‐wave potential of SnN3O‐50 is up to 0.816 V, with a loss of only 15 mV after 10 000 potential cycles. Furthermore, the peak power densities of the fuel cell and zinc–air battery assembled using SnN3O‐50 as cathodes reach 502 and 173.5 mW cm−2, respectively, demonstrating great potential for practical applications. Density functional theory (DFT) calculations reveal that the N/O coordination of Sn induces localization of 5p electrons, which leads to strong coupling with the p orbit of O2. Meanwhile, the presence of defects synergistically regulates the adsorption of reaction intermediates, thereby optimizing the free energy of the four successive ORR steps

A High-Order Load Model and the Control Algorithm for an Aerospace Electro-Hydraulic Actuator

It is difficult to describe precisely, and thus control satisfactorily, the dynamics of an electro-hydraulic actuator to drive a high thrust liquid launcher engine, whose structural resonant frequency is usually low due to its heavy inertia and complicated mass distribution, let alone one to drive a heavy kerolox engine with high-order dynamics. By transforming classic control block diagrams, a baseline two-mass-two-spring load model and a normalized actuator-engine system model were developed for understanding the basic physics and methodology, where a fourth-order transfer function is used to model the multi-resonance-frequency engine body outside of the rod position loop, another fourth-order transfer function with two pairs of conjugated zeros and poles to represent the composite hydro-mechanical resonance effect in the closed rod position loop. A sixth-order model was thereafter proposed for even higher dynamics. The model parameters were identified and optimized by a full factor search approach. To meet the stringent specification of static and dynamic performances, it was demonstrated that a notch filter network combined with other controllers is needed since the traditional dynamic pressure feedback (DPF) is difficult to handle the high-order dynamics. The approach has been validated by simulation, experiments and successful flights. The models, analysis, data and insights were elaborated