This paper expands our previous work on planar tunable capacitive coupling structures in substrate-integrated cavities using lumped components. We demonstrate both frequency and bandwidth tunable ...filters with adjustable transmission zeros (TZs). By the appropriate choice of the absolute and relative strength of magnetic and electric coupling coefficients, we demonstrate: 1) tunable bandwidth and the ability to maintain either a constant absolute bandwidth or a constant fractional bandwidth; 2) adjustable TZ location at a prescribed bandwidth; and 3) the ability to switch OFF the filter with high isolation. Filter design methodologies based on a dispersive coupling structure are presented using lumped circuit models, coupling matrix, and full-wave simulations. With this planar capacitive coupling, it is also convenient to realize cross-coupling in higher order filters to produce additional TZs for rejecting spurious resonances or interferes. Fabricated two-pole filters with one or two TZs and four-pole filters with three or four TZs validate the filter design. A two-pole filter with tunable center frequency and tunable bandwidth along with a four-pole filter with tunable center frequency and tunable TZs are also demonstrated.
RF fingerprinting is an emerging technology for identifying hardware-specific features of wireless transmitters and may find important applications in wireless security. In this study, the authors ...present a new RF fingerprinting scheme using deep neural networks. In particular, a long short-term memory based recurrent neural network is proposed and used for automatically identifying hardware-specific features and classifying transmitters. Experimental studies using identical RF transmitters showed very high detection accuracy in the presence of strong noise (signal-to-noise ratio as low as $-12$−12 dB) and demonstrated the effectiveness of the proposed scheme.
This paper presents a shunt protection technique to improve the hot-switching reliability of metal-contact radio-frequency microelectromechanical systems (RF-MEMS) switches. The proposed technique ...places shunt protection contacts in front of the main contact of an RF-MEMS metal contact switch to block RF signal while the main contact is switching ON or OFF. The shunt protection contact creates a local cold-switching condition for the main contact to increase the lifetime of the switch under hot-switching condition. The shunt protection technique can also increase the overall isolation of the switch. To demonstrate the technique, RF-MEMS switches with and without shunt protection were fabricated using all metal process. Compared with the unprotected switch, the protected switch has longer lifetime under hot-switching condition. The protected switch has >100-million cycles and up to 500-million cycles lifetime under the 1-W hot-switching condition, measured in open-air laboratory environment. Besides, the isolation of the shunt-protected switch is 70 dB at 1.0 GHz and 36 dB at 40 GHz, and the insertion loss is 0.30 dB at 1.0 GHz and 0.43 dB at 40 GHz.
► High-solid anaerobic digestion of sewage sludge was conducted in batch mode. ► Changes of heavy metal fractions and major parameters were investigated. ► The relationship between heavy metal ...fractions and these parameters were discussed.
The sequential extraction procedure developed by Tessier et al. was used in sludge anaerobic digestion to determine the heavy metal speciation. Sludge samples were taken every three days to investigate humic substances, VS/TS, pH, VFA, alkalinity, ammonia, the total content of Zn, Pb, Cu, Ni, and Cr, and also their distribution into EXCH, CARB, FeMnOx, OMB and RESI fractions. Results showed that, (1) Heavy metals were concentrated during the anaerobic digestion process. The concentration of all five kinds of heavy metals increased by about 50%. (2) The distribution of these heavy metals differed. (3) High-solid anaerobic digestion much or less increased the bioavailability of Cu, Zn, Ni and Cr while decreased the bioavailability of Pb. (4) There were significant degrees of correlation between heavy metal fractions and changes of some selected parameters (for example, pH, VS/TS, and VFA content). Except for Pb, the contents of total mobile fractions for Cu, Zn, Ni, Cr could be predictable from its total content.
Ferroptosis, a form of regulated cell death caused by lipid peroxidation, was recently identified as a natural tumor suppression mechanism. Here, we show that ionizing radiation (IR) induces ...ferroptosis in cancer cells. Mechanistically, IR induces not only reactive oxygen species (ROS) but also the expression of ACSL4, a lipid metabolism enzyme required for ferroptosis, resulting in elevated lipid peroxidation and ferroptosis. ACSL4 ablation largely abolishes IR-induced ferroptosis and promotes radioresistance. IR also induces the expression of ferroptosis inhibitors, including SLC7A11 and GPX4, as an adaptive response. IR- or KEAP1 deficiency-induced SLC7A11 expression promotes radioresistance through inhibiting ferroptosis. Inactivating SLC7A11 or GPX4 with ferroptosis inducers (FINs) sensitizes radioresistant cancer cells and xenograft tumors to IR. Furthermore, radiotherapy induces ferroptosis in cancer patients, and increased ferroptosis correlates with better response and longer survival to radiotherapy in cancer patients. Our study reveals a previously unrecognized link between IR and ferroptosis and indicates that further exploration of the combination of radiotherapy and FINs in cancer treatment is warranted.
Recent studies on enzymes and reader proteins for histone crotonylation support a function of histone crotonyla- tion in transcription. However, the enzyme（s） responsible for histone decrotonylation ...（HDCR） remains poorly de- fined. Moreover, it remains to be determined if histone crotonylation is physiologically significant and functionally distinct from or redundant to histone acetylation. Here we present evidence that class I histone deacetylases （HDACs） rather than sirtuin family deacetylases （SIRTs） are the major histone decrotonylases, and that histone erotonylation is as dynamic as bistone acetylation in mammalian cells. Notably, we have generated novel HDAC1 and HDAC3 mutants with impaired HDAC but intact HDCR activity. Using these mutants we demonstrate that selective HDCR in mammalian cells correlates with a broad transcriptional repression and diminished promoter association of cro- tonylation but not acetylation reader proteins. Furthermore, we show that histone erotonylation is enriched in and required for self-renewal of mouse embryonic stem cells.
•We studied the effect of public education on willingness to classify waste.•We combined SPSS macro INDIRECT and Bootstrap methods to test the mediating effect.•Hierarchical Regression Method was ...used to test moderating effect.•Attitude, SN, and PBC were found to play a partial mediating role.•Conscientious personality was found to play a moderating role.
On the basis of the theory of planned behavior, persuasion theory, and big five personality theory, this study constructed a mechanism model of the influence of public education on residents’ willingness to classify household waste and analyzed the role of attitude, subjective norms, perceived behavior control, and conscientious personality. The model was validated using a questionnaire survey of 378 ordinary residents via hierarchical regression analysis. Results corroborate that attitude, subjective norms, and perceived behavior control partially mediate the relationship between public education and willingness to classify household waste. Conscientious personality moderates the relationship between public education and perceived behavioral control, but not the relationship of public education and attitude. In addition, the relationship between public education and subjective norms is not moderated by conscientious personality.
This paper presents octave-tunable resonators and filters with surface mounted lumped tuning elements. Detailed theoretical analysis and modeling in terms of tuning range and unloaded quality factor ...(Qu) are presented in agreement with simulated and measured results. Based on the models, a systematic design method to maximize tuning ratio and optimize Qu of the resonator is suggested. A resonator tuning from 0.5 to 1.1 GHz with Qu ranging from 90 to 214 is demonstrated using solid-state varactors. A two-pole filter with a tuning range of 0.5-1.1 GHz with a constant 3-dB fractional bandwidth (FBW) of 4±0.1% and insertion loss of 1.67 dB at 1.1 GHz is demonstrated along with a three-pole filter with a tuning range of 0.58-1.22 GHz with a constant 3-dB FBW of 4±0.2% and insertion loss of 2.05 dB at 1.22 GHz. The measured input third-order intermodulation is better than 17 dBm over the frequency range for the two-pole filter.
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