Resonance characteristics of substrate-integrated rectangular cavity (SIRC) are systematically analyzed in this paper. Synthesis design techniques of substrate-integrated waveguide (SIW) dual-band ...bandpass filters (BPFs) and wide stopband BPFs are demonstrated on the basis of these characteristics. The design concept of dual-band BPFs is to add some extra single-mode SIRC resonators to dual-mode resonator filters to increase the degrees of freedom in extracting direct-coupling coefficients, while the external quality factors Qe and crosscoupling coefficients desired in two passbands can be realized simultaneously by determining proper offset position of the I/O ports and cross-coupling window, respectively. Consequently, all the design parameters including Qe and coupling coefficients Mi j required for both the passbands could be satisfied. The principle of wide-stopband BPFs is to select the constitutive SIRC resonators with identical fundamental frequency but staggered higher order ones to suppress multispurious peaks to low levels and narrow bandwidths. Then emphasis is placed on the rejection of TE202 mode, with its resonant frequency two times of TE101 for all SIRC resonators, by centered I/O ports and coupling windows. Several experimental prototypes of SIW dual-band BPFs and wide-stopband BPFs are designed and fabricated to validate these concepts. The measured results are in excellent agreement with the simulations.
A realization method, named the design parameters ratio technique, of substrate-integrated waveguide (SIW) dualmode dual-band bandpass filters (DM-DBBPFs) with widely controllable bandwidth ratios is ...presented when TE 101 and TE 201 modes in substrate-integrated rectangular cavities are exploited to dominate the first and second passbands, respectively. Emphasis is placed on filters design to simultaneously realize the design parameters including the external quality factors Q e and coupling coefficients M ij required for both passbands by determining proper offset positions of the feeding ports and coupling windows, which can easily be fixed by ratios of synthesized Q e and M ij for the two bands, respectively. Consequently, the fractional bandwidths (FBWs) of the two passbands can be allocated flexibly over a wide range of ratios, typically with the FBW ratio of 0.2-1.5. Three SIW DM-DBBPFs including a thirdorder direct-coupled one operating at 12 and 16 GHz with the identical absolute bandwidths, a third-order cross-coupled one operating at 12 and 15 GHz with the same FBWs, and a fourth-order cross-coupled one operating at 12 and 17 GHz with the FBW ratio of 0.6 are designed and fabricated to demonstrate the method.
Rumination is strongly and consistently correlated with depression. Although multiple studies have explored the neural correlates of rumination, findings have been inconsistent and the mechanisms ...underlying rumination remain elusive. Functional brain imaging studies have identified areas in the default mode network (DMN) that appear to be critically involved in ruminative processes. However, a meta-analysis to synthesize the findings of brain regions underlying rumination is currently lacking. Here, we conducted a meta-analysis consisting of experimental tasks that investigate rumination by using Signed Differential Mapping of 14 fMRI studies comprising 286 healthy participants. Furthermore, rather than treat the DMN as a unitary network, we examined the contribution of three DMN subsystems to rumination. Results confirm the suspected association between rumination and DMN activation, specifically implicating the DMN core regions and the dorsal medial prefrontal cortex subsystem. Based on these findings, we suggest a hypothesis of how DMN regions support rumination and present the implications of this model for treating major depressive disorder characterized by rumination.
•Rumination is strongly and consistently correlated with depression.•Meta-analyze the findings of brain regions regarding to rumination.•Specifically examined the contribution of three DMN subsystems to rumination.•Rumination is specifically correlated with the DMN core regions and the dorsal medial prefrontal cortex subsystem.
The performance of aqueous Zn ion batteries (AZIBs) is highly dependent on inner Helmholtz plane (IHP) chemistry. Notorious parasitic reactions containing hydrogen evolution reactions (HER) and Zn ...dendrites both originate from abundant free H2O and random Zn deposition inside active IHP. Here, we report a universal high donor number (DN) additive pyridine (Py) with only 1 vol. % addition (Py‐to‐H2O volume ratio), for regulating molecule distribution inside IHP. Density functional theory (DFT) calculations and molecular dynamics (MD) simulation verify that incorporated Py additive could tailor Zn2+ solvation sheath and exclude H2O molecules from IHP effectively, which is in favor of preventing H2O decomposition. Consequently, even at extreme conditions such as high depth of discharge (DOD) of 80 %, the symmetric cell based on Py additive can sustain approximately 500 h long‐term stability. This efficient strategy with high DN additives furnishes a promising direction for designing novel electrolytes and promoting the practical application of AZIBs, despite inevitably introducing trace organic additives.
The performance of aqueous Zn‐ion batteries is improved by regulating the inner Helmholtz plane (IHP) chemistry. Pyridine (Py) as high donor number organic electrolyte additive (only 1 vol. % addition) is used to efficiently regulate the solvation sheath structure, which results in depressed H2O activity at the IHP interface. The thus‐formed IHP interface enables a superior stable Zn anode with high reversibility and utilization rate.
Functionalizing carbon cathode surfaces with oxygen functional groups is an effective way to simultaneously tailor the fundamental properties and customize the electrochemical properties of aqueous ...Zn‐ion hybrid capacitors. In this work, the oxygen functional groups of chemically reduced graphene oxide (rGO) are systematically regulated via a series of reductants and varied experimental conductions. Carboxyl and carbonyl have been proven to significantly enhance the aqueous electrolyte wettability, Zn‐ion chemical adsorption, and pseudocapacitive redox activity by experimental study and computational analysis. The rGO cathode produced through hydrogen peroxide assisted hydrothermal reduction exhibits a specific capacitance of 277 F g−1 in 1 m ZnSO4 after optimization of surface oxygen functional groups. In addition, a quasi‐solid‐state flexible Zn‐ion hybrid capacitor (ZHC) with a polyacrylamide gel electrolyte and a high loading mass of 5.1 mg cm−2 are assembled. The as‐prepared quasi‐solid state ZHC can offer a superior areal capacitance of 1257 mF cm−2 and distinguished areal energy density of 342 µW h cm−2. The significant enhancement of redox activity and Zn‐ion storage capability by regulating the oxygen functional groups can shed light on the promotion of electrochemical charge storage properties even beyond protic electrolyte systems.
According to the low cost and high safety, aqueous zinc ion hybrid capacitors have attracted extensive attention in flexible and wearable electronics. Herein, the oxygen functional groups of chemically reduced graphene oxide and study the pseudocapacitive redox activity by experimental study and computational analysis are systematically regulated.
Understanding ecological niches of major tick species and prevalent tick-borne pathogens is crucial for efficient surveillance and control of tick-borne diseases. Here we provide an up-to-date review ...on the spatial distributions of ticks and tick-borne pathogens in China. We map at the county level 124 tick species, 103 tick-borne agents, and human cases infected with 29 species (subspecies) of tick-borne pathogens that were reported in China during 1950-2018. Haemaphysalis longicornis is found to harbor the highest variety of tick-borne agents, followed by Ixodes persulcatus, Dermacentor nutalli and Rhipicephalus microplus. Using a machine learning algorithm, we assess ecoclimatic and socioenvironmental drivers for the distributions of 19 predominant vector ticks and two tick-borne pathogens associated with the highest disease burden. The model-predicted suitable habitats for the 19 tick species are 14‒476% larger in size than the geographic areas where these species were detected, indicating severe under-detection. Tick species harboring pathogens of imminent threats to public health should be prioritized for more active field surveillance.
There is clear evidence that micro- and nanoplastics are accumulating in the environment, and their increasing concern of potential harm to wildlife has been identified as a major global issue. ...However, identification of nanoplastics in environmental samples remains a great challenge, and thus highlighting the great need for new approach. Herein, for the first time, we show that surface enhanced Raman spectroscopy (SERS) offered a feasible approach to identify trace polystyrene (PS) nanoplastics, which is the most produced nanoplastics and also widely presented in the natural environment. We found that when PS nanoplastics were surrounded by SERS-active silver nanoparticles (AgNPs), a set of Raman spectra with chemical information could be obtained via SERS mapping. This map showed the potential PS distribution of the nanoplastics on a silicon wafer, allowing a quick and detailed analysis of the nanoplastics. Moreover, the proposed method was able to identify previously undetectable plastic particles as small as ~50 nm spiked in real water, demonstrating the power of SERS to probe nanoplastics. Our work is thus an important step in nanoplastic research, and we believe that this approach can be further developed to study the occurrence, formation, and transports of nanoplastics in the natural environment.
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•SERS was for the first time demonstrated to be a facile and efficient approach for the identification of nanoplastics.•Previously undetectable plastic particles as small as ~50 nm was identified.•Applicable for real environmental waters.
Polyinosinic:polycytidylic acid (poly(I:C)) is a ligand of toll-like receptor (TLR) 3 that has been used as an immunostimulant in humans and mice against viral diseases based on its ability to ...enhance innate and adapt immunity. Antiviral effect of poly(I:C) has also been observed in teleost, however, the underling mechanism is not clear. In this study, we investigated the potential and signaling mechanism of poly(I:C) as an antiviral agent in a model of Japanese flounder (Paralichthys olivaceus) infected with megalocytivirus. We found that poly(I:C) exhibited strong antiviral activity and enhanced activation of head kidney macrophages and peripheral blood leukocytes. In vivo studies showed that (i) TLR3 as well as MDA5 knockdown reduced poly(I:C)-mediated immune response and antiviral activity to significant extents; (ii) when Myd88 was overexpressed in flounder, poly(I:C)-mediated antiviral activity was significantly decreased; (iii) when Myd88 was inactivated, the antiviral effect of poly(I:C) was significantly increased. Cellular study showed that (i) the NF-κB activity induced by poly(I:C) was upregulated in Myd88-overexpressing cells and unaffected in Myd88-inactivated cells; (ii) Myd88 overexpression inhibited and upregulated the expression of poly(I:C)-induced antiviral genes and inflammatory genes respectively; (iii) Myd88 inactivation enhanced the expression of the antiviral genes induced by poly(I:C). Taken together, these results indicate that poly(I:C) is an immunostimulant with antiviral potential, and that the immune response of poly(I:C) requires TLR3 and MDA5 and is negatively regulated by Myd88 in a manner not involving NK-κB. These results provide insights to the working mechanism of poly(I:C), TLR3, and Myd88 in fish.
A synthesis design method for substrate-integrated waveguide (SIW) multiband bandpass filters (BPFs) with flexible frequency and bandwidth allocations is presented by incorporating SIW dual-mode ...resonances with split-type dual- and triple-band symmetrical frequency responses. By different combinations of the split-type dual- or triple-band responses for two virtual wide passbands dominated by TE 101 and TE 201 modes in SIW rectangular cavities, SIW tri-/ quad-/quint-/sext-band BPFs with improved band assignments can all theoretically be implemented. In addition, by introducing our previously proposed dual-mode coupling controlling technique, the bandwidths of the two virtual wide passbands can also be allocated flexibly. Three experimental prototypes, including a quad-band BPF based on four dual-mode SIW cavities, a quad-band and quint-band BPFs based on two dual-mode SIW cavities coupled with multiple single-mode ones, are synthesized, designed, fabricated, and tested to demonstrate and validate the collaborative design concept.
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