In this letter, compact-balanced bandpass filter (BPF) and filtering crossover are proposed with intrinsic common-mode (CM) suppression by using a single-layered substrate-integrated waveguide (SIW) ...cavity. The SIW cavity with low profile is TEn0m mode resonator, which has only one nonzero electric field component. Hence, it is also a natural frequency selection device of the differential signal. Meanwhile, the CM signal cannot excite the cavity due to the characteristics of perfect electric conductor (PEC) and perfect magnetic conductor (PMC). For the design of the balanced SIW BPF, the differential-mode (DM) equivalent half circuit is a single-ended SIW filter with height halved. Furthermore, the microstrip differential transition structure is designed to excite the SIW cavity and has little conversion between DM and CM. On this basis, a compact SIW-balanced filtering crossover is proposed using the degenerate modes TE 102 and TE 201 . Finally, compact third-order SIW-balanced BPF and filtering crossover are designed and fabricated, and the measured results show good agreement with the simulated ones.
In this letter, a compact dual-band dual-mode substrate integrated waveguide (SIW) balanced band-pass filter (BPF) with intrinsic common-mode (CM) suppression is designed by using a single perturbed ...SIW circular cavity. The vias and slot perturbations are introduced to tune the resonant modes TE 010 , TE 110 (a pair of degenerate modes), and TE 210 of a circular cavity. Thus, they can be used to form two differential-mode (DM) passbands with independently adjustable center frequencies and bandwidths. The SIW can be seen as a natural balun with intrinsic CM suppression. Furthermore, the planar differential excitation structure is designed to excite the perturbed SIW cavity. The CM noise cannot excite SIW cavity due to the characteristics of hybrid electromagnetic boundary. Finally, a compact dual-band dual-mode SIW balanced BPF at 8 and 10 GHz is designed and fabricated, and the measured results show good agreement with the simulated ones.
In this letter, a multilayer balanced substrate-integrated waveguide (SIW) bandpass filter (BPF) using the TE₁₀₂ and TE₂₀₁ modes is designed with an aperture etched on the common ground between two ...stacked SIWs. Under common-mode (CM) operation, the aperture is a perfect magnetic conductor (PMC). When the height is less than λg/4, the space between the perfect electric conductor (PEC) and the PMC cannot transmit the electromagnetic wave, so the structure can effectively cutoff the CM noise in a wide frequency range. Under differential-mode (DM) operation, the aperture is the PEC and has less effect on the DM frequency responses by properly selecting the location and size. Two transmission zeros near the passband edges can be generated to improve the selectivity. Finally, a compact dual-mode balanced SIW BPF with high selectivity and CM suppression has been designed and fabricated, and the measured results show good agreement with the simulated ones.
In this article, a compact triple‐mode balanced passband filter with intrinsic common‐mode (CM) suppression is designed by using a single isosceles right triangle perturbed half‐mode substrate ...integrated waveguide (HMSIW) cavity. The perturbation metallic vias are introduced to tune the first three resonant modes of HMSIW cavity to form a passband. Furthermore, the planar differential microstrip‐pin feed structure is designed to excite the perturbed substrate integrated waveguide cavity. Under CM operation, when the substrate's height is less than λg/4, the space between perfect electric conductor and perfect magnetic conductor cannot transmit electromagnetic wave, so CM noise can effectively cut off at the planar differential feed structure in a wide frequency range. Finally, a prototyped prototype at 4.5 GHz is designed and fabricated, and measured results show good agreement with simulated ones.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In this letter, the compact multilayer differential corrugated substrate integrated waveguide (CSIW) and half-mode CSIW (HMCSIW) are designed by two vertically stacked identical CSIW and HMCSIW, ...respectively, and an aperture is etched on the common ground between them. Both the CSIW and HMCSIW have only one nonzero vertical electric field component in host waveguide. Under the common-mode (CM) operation, the aperture is a perfect magnetic conductor (PMC). When the height of the single substrate is less than <inline-formula> <tex-math notation="LaTeX">\lambda _{g} </tex-math></inline-formula>/4, the space between the perfect electric conductor (PEC) and PMC cannot transmit electromagnetic waves, and the edge of the aperture is an open circuit. Therefore, the etched aperture in differential CSIW can effectively cutoff CM noise. For the HMCSIW, the spoof surface plasmon polariton (SPP) is loaded in the aperture near the open circuit plane to suppress the slot line mode. Under the differential-mode (DM) operation, the aperture has less effect on the DM frequency responses. For verification, the differential HMCSIW is fabricated, and good agreement between the measured and simulated results demonstrates the validity of proposed configurations.
In this study, the differential substrate integrated waveguide (SIW) slot antenna array is proposed with intrinsic common-mode (CM) rejection. Through field analysis, it is found that the SIW is a ...natural differential transmission line which can only transmit differential signal due to the characteristics of hybrid electromagnetic boundary perfect electrical conductor and perfect magnetic conductor. Hence, it can also be seen as a natural balun with intrinsic CM suppression. Thus, a compact 1 × 4 differential SIW slot antenna array with high CM rejection can be designed using the differential microstrip transition structure which has little conversion between differential-mode (DM) and CM. For the design of differential SIW passive device, the DM equivalent half circuit is a single-ended SIW device with height halved. Further, the 4 × 4 differential SIW antenna array with high CM rejection can be designed with a T-shaped differential SIW four-way power divider. The 1 × 4 and 4 × 4 differential SIW antenna arrays are fabricated and good agreements between the simulated and measured results demonstrate the validity of proposed configurations.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Objective To evaluate the performance of vaporized hydrogen peroxide （VHP） for the bio-decontamination of the high efficiency particulate air （HEPA） filter unit. Methods Self-made or commercially ...available bioindicators were placed at designated locations in the HEPA filter unit under VHP fumigation. The spores on coupons were then extracted by 0.5 h submergence in eluent followed by 200- time violent knocks. Results Due to the presence of HEPA filter in the box, spore recovery from coupons placed at the bottom of the filter downstream was significantly higher than that from coupons placed at the other locations. The gap of decontamination efficiency between the top and the bottom of the filter downstream became narrower with the exposure time extended. The decontamination efficiency of the bottom of the filter downstream only improved gently with the injection rate of H202 increased and the decontamination efficiency decreased instead when the injection rate exceeded 2.5 g/min. The commercially available bioindicators were competent to indicate the disinfection efficiency of VHP for the HEPA filter unit. Conclusion The HEPA filter unit is more difficult than common enclosure to decontaminate using VHP fumigation. Complete decontamination can be achieved by extending fumigation time. VHP fumigation can be applied for in-situ biodecontamination of the HEPA filter unit as an alternative method to formaldehyde fumigation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This is the first randomised controlled trial for assessment of the immunogenicity and safety of a candidate non-replicating adenovirus type-5 (Ad5)-vectored COVID-19 vaccine, aiming to determine an ...appropriate dose of the candidate vaccine for an efficacy study.
This randomised, double-blind, placebo-controlled, phase 2 trial of the Ad5-vectored COVID-19 vaccine was done in a single centre in Wuhan, China. Healthy adults aged 18 years or older, who were HIV-negative and previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-free, were eligible to participate and were randomly assigned to receive the vaccine at a dose of 1 × 1011 viral particles per mL or 5 × 1010 viral particles per mL, or placebo. Investigators allocated participants at a ratio of 2:1:1 to receive a single injection intramuscularly in the arm. The randomisation list (block size 4) was generated by an independent statistician. Participants, investigators, and staff undertaking laboratory analyses were masked to group allocation. The primary endpoints for immunogenicity were the geometric mean titres (GMTs) of specific ELISA antibody responses to the receptor binding domain (RBD) and neutralising antibody responses at day 28. The primary endpoint for safety evaluation was the incidence of adverse reactions within 14 days. All recruited participants who received at least one dose were included in the primary and safety analyses. This study is registered with ClinicalTrials.gov, NCT04341389.
603 volunteers were recruited and screened for eligibility between April 11 and 16, 2020. 508 eligible participants (50% male; mean age 39·7 years, SD 12·5) consented to participate in the trial and were randomly assigned to receive the vaccine (1 × 1011 viral particles n=253; 5 × 1010 viral particles n=129) or placebo (n=126). In the 1 × 1011 and 5 × 1010 viral particles dose groups, the RBD-specific ELISA antibodies peaked at 656·5 (95% CI 575·2–749·2) and 571·0 (467·6–697·3), with seroconversion rates at 96% (95% CI 93–98) and 97% (92–99), respectively, at day 28. Both doses of the vaccine induced significant neutralising antibody responses to live SARS-CoV-2, with GMTs of 19·5 (95% CI 16·8–22·7) and 18·3 (14·4–23·3) in participants receiving 1 × 1011 and 5 × 1010 viral particles, respectively. Specific interferon γ enzyme-linked immunospot assay responses post vaccination were observed in 227 (90%, 95% CI 85–93) of 253 and 113 (88%, 81–92) of 129 participants in the 1 × 1011 and 5 × 1010 viral particles dose groups, respectively. Solicited adverse reactions were reported by 183 (72%) of 253 and 96 (74%) of 129 participants in the 1 × 1011 and 5 × 1010 viral particles dose groups, respectively. Severe adverse reactions were reported by 24 (9%) participants in the 1 × 1011 viral particles dose group and one (1%) participant in the 5 × 1010 viral particles dose group. No serious adverse reactions were documented.
The Ad5-vectored COVID-19 vaccine at 5 × 1010 viral particles is safe, and induced significant immune responses in the majority of recipients after a single immunisation.
National Key R&D Programme of China, National Science and Technology Major Project, and CanSino Biologics.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Bats carry a variety of viruses, and some of them cause public health problems. Macau, which is famous for its gambling industry, has a complex population structure. The globalization in such an ...international metropolis has enhanced the chance of disease transmission. Therefore, surveillance of zoonotic viruses is necessary for the early warning of potential emerging infectious diseases.Here, we report the first surveillance of bat viruses in Macau. In this study, we collected 1004 samples involving 10 bat species from 7 sites from April 2015 to May 2016, and examined the presence of viruses using nucleic acid-based methods. Coronaviruses, adenoviruses and paramyxoviruses were detected in these samples, with a high prevalence of coronaviruses. While,none was positive for hepatitis A virus, hepatitis E virus or hantavirus. Co-infections are not common in those bat species, but coronavirus HKU6 and adenovirus can be found commonly occurred in Myotis ricketti.
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FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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