A co-design of a wideband circularly polarized (CP) patch antenna is proposed in this paper. The patch antenna is seamlessly integrated with two bandpass filter networks consisting of one and two ...<inline-formula> <tex-math notation="LaTeX">\lambda </tex-math></inline-formula>/2 resonators, respectively, which are designed to excite two orthogonal modes with equal magnitude and quadrature phase over a widened bandwidth. In co-design of this filtering antenna, the patch antenna is equivalently treated as the last-stage resonator and the output port of the filter network. In analysis of its far field, axial ratio (AR) of CP wave is mapped to its magnitude and phase responses. By simultaneously synthesizing the magnitude ratio and phase difference of the two filter networks' transmission coefficients to vary around 1° and 90°, respectively, wideband AR response with three minima is realized. Based on this design method and the theoretically derived results, a CP patch antenna prototype with a height of <inline-formula> <tex-math notation="LaTeX">0.028\lambda _{0} </tex-math></inline-formula> is fabricated and measured. It is experimentally demonstrated that around 8.8%, bandwidth can be achieved with VSWR < 2, AR < 3 dB, and 3 dB gain variation.
A single-layer microstrip-fed patch antenna with capabilities of both bandwidth enhancement and harmonic suppression is proposed. For this purpose, a pair of λ/4 microstrip-line resonators is ...introduced and coupled in proximity to a rectangular patch. The wideband property can be obtained by making effective use of the two resonances introduced by the radiating patch and nonradiating λ/4 resonators. Different from other reported dual-resonance patch antennas, the proposed antenna does not require the electrically thick substrate, so it has attractive low-profile property. Thanks to the good features of λ/4 resonators and capacitive feeding scheme, harmonic radiating modes of the patch antenna can be significantly suppressed as highly demanded in modern highly integrated communication systems. The working principle, equivalent circuit, and design procedure are extensively described. Finally, a prototype antenna operating at 4.9 GHz is designed and fabricated. The measured results show that its bandwidth is 2.7 times wider than that of the traditional insert-fed patch counterpart, and the harmful spurious radiation from other higher order radiating modes has been effectively suppressed.
The approach of estimating the H2O content of basaltic magmas via clinopyroxene (cpx) phenocrysts is a potentially effective way to glimpse the deep Earth water cycle. However, it is difficult to ...ascertain using traditional geochemical methods whether hydrogen (H) measured in cpx phenocrysts represents a primary signature that can ultimately inform estimates of the mantle water content. In this study, we conducted machine learning on the major element compositions and H2O content of cpx phenocrysts (1904 samples in total). Using the support vector machine (SVM), we defined a classifier (overall accuracy >92%) that can separate cpx that have undergone H diffusion, and thus modification of their original water content, from those that have not experienced H diffusion. Our trained SVM model has broad implications for understanding the primary water content of magma, the variations in water content during magma evolution, and the water cycle in the deep Earth.
Plain Language Summary
The H2O content of clinopyroxene (cpx) phenocrysts in basaltic magma has become an important way to evaluate the H2O content of Earth's mantle. However, it remains controversial whether samples collected in the field can truly reflect mantle water contents, particularly given the propensity for hydrogen to diffuse out of the cpx lattice during magma evolution. The support vector machine (SVM) is a powerful and mature machine learning method that can classify samples into one of two groups based on the analysis of high‐dimensional datasets. We have applied SVM to separate cpx into examples that either have, or have not, undergone H‐diffusion, using a database of 1904 known samples. Each sample represents an in‐situ analysis of H2O content and major element composition on a cpx grain. The trained SVM model is effective in distinguishing whether individual cpx phencrysts have preserved their initial H2O content. Moreover, when applied to a suite of well characterized samples, the model predictions are consistent with independent assessments of H‐diffusion. As a complement to traditional geochemical methods, our SVM model is a novel approach with broad implications for understanding variations of water content in magmatic systems and refining estimates of the water content of Earth's mantle.
Key Points
A machine learning model for judging H diffusion was built by learning of the data on the H2O content of cpx phenocrysts in mafic rocks
The trained model can effectively distinguish whether H in cpx phenocrysts diffused or not (overall accuracy >92%)
The model contributes to constraining the primary H2O content of basaltic magma and elucidates the variations in H2O during magma evolution
The impacts of wavelengths in 500-600 nm on plant response and their underlying mechanisms remain elusive and required further investigation. Here, we investigated the effect of light quality on leaf ...area growth, biomass, pigments content, and net photosynthetic rate (Pn) across three Arabidopsis thaliana accessions, along with changes in transcription, photosynthates content, and antioxidative enzyme activity. Eleven-leaves plants were treated with BL; 450 nm, AL; 595 nm, RL; 650 nm, and FL; 400-700 nm as control. RL significantly increased leaf area growth, biomass, and promoted Pn. BL increased leaf area growth, carotenoid and anthocyanin content. AL significantly reduced leaf area growth and biomass, while Pn remained unaffected. Petiole elongation was further observed across accessions under AL. To explore the underlying mechanisms under AL, expression of key marker genes involved in light-responsive photosynthetic reaction, enzymatic activity of antioxidants, and content of photosynthates were monitored in Col-0 under AL, RL (as contrast), and FL (as control). AL induced transcription of GSH2 and PSBA, while downregulated NPQ1 and FNR2. Photosynthates, including proteins and starches, showed lower content under AL. SOD and APX showed enhanced enzymatic activity under AL. These results provide insight into physiological and photosynthetic responses to light quality, in addition to identifying putative protective-mechanisms that may be induced to cope with lighting-stress in order to enhance plant stress tolerance.
A wideband circularly polarized (CP) patch antenna with enhanced axial ratio (AR) bandwidth via co-design of feeding network is proposed in this paper. One <inline-formula> <tex-math ...notation="LaTeX">\pmb \lambda/4 </tex-math></inline-formula> resonator and one <inline-formula> <tex-math notation="LaTeX">\pmb \lambda/2 </tex-math></inline-formula> resonator are introduced and coupled in proximity to two orthogonal points of a square patch radiator to excite two orthogonal modes. These two resonators not only function as impedance matching elements to achieve equal magnitude of two orthogonal modes in a wide frequency band but also provide the required 90° phase difference. In this way, two minima in the AR response appear, resulting in extended AR bandwidth. The wideband design of the antenna is carried out based on the equivalent circuit model, where the patch radiator is treated as a conductance, inductance, and capacitance parallel resonator. In particular, the feeding network and the patch are jointly considered as a three-port network for synthesis design. By mapping the radiated far field to the magnitude and phase on the radiation conductance in the circuit model, the AR response of the antenna becomes predictable in a straightforward manner. Measured results experimentally demonstrate that the 3-dB AR bandwidth of our proposed CP patch antenna is 2.7 times that of the traditional one fed with two 90° offset lines.
Chronic exercise has been reported to improve cognitive function. However, whether and how different types of exercise affect
various learning and memory tasks remain uncertain. To address this ...issue, male BALB/c mice were trained for 4 weeks under
two different exercise protocols: moderate treadmill running or voluntary wheel running. After exercise training, their spatial
memory and aversive memory were evaluated by a Morris water maze and by one-trial passive avoidance (PA), respectively. Levels
of neural plasticity-related proteins, i.e. brain-derived neurotrophic factor (BDNF), tropomyosin-related kinase B (TrkB)
and synaptotagmin I (Syt I), in hippocampus and amygdala were determined by ELISA or immunoblotting. Finally, the functional
roles of these proteins in the basolateral amygdala were verified by locally blocking them with K252a (a TrkB kinase inhibitor),
or lentivirus expressing Syt I shRNA. We found that (1) although both moderate treadmill running and wheel running improved
the Morris water maze performance, only the former improved PA performance; (2) likewise, both exercise protocols upregulated
the BDNFâTrkB pathway and Syt I in the hippocampus, whereas only treadmill exercise upregulated their expression levels in
the amygdala; (3) local injection of K252a abolished the treadmill exercise-facilitated PA performance and upregulation of
amygdalar TrkB and Syt I; and (4) local administration of Syt I shRNA abolished the treadmill exercise-facilitated PA performance
and upregulation of amygdalar Syt I. Therefore, our results support the notion that different forms of exercise induce neuroplasticity
changes in different brain regions, and thus exert diverse effects on various forms of learning and memory.
Rapid technology development in controlled environment (CE) plant production has been applied to a large variety of plants. In recent years, strawberries have become a popular fruit for CE production ...because of their high economic and nutritional values. With the widespread use of light-emitting diode (LED) technology in the produce industry, growers can manipulate strawberry growth and development by providing specific light spectra. Manipulating light intensity and spectral composition can modify strawberry secondary metabolism and highly impact fruit quality and antioxidant properties. While the impact of visible light on secondary metabolite profiles for other greenhouse crops is well documented, more insight into the impact of different light spectra, from UV radiation to the visible light spectrum, on strawberry plants is required. This will allow growers to maximize yield and rapidly adapt to consumer preferences. In this review, a compilation of studies investigating the effect of light properties on strawberry fruit flavonoids is provided, and a comparative analysis of how light spectra influences strawberry's photobiology and secondary metabolism is presented. The effects of pre-harvest and post-harvest light treatments with UV radiation and visible light are considered. Future studies and implications for LED lighting configurations in strawberry fruit production for researchers and growers are discussed.
This paper proposes an all‐metal wideband circularly polarized (CP) single‐patch antenna based on TM11 mode. The conventional square patch is divided into four small square patch units by loading ...metal shorting walls under the two vertical centerlines. The shorting walls are windowed to facilitate coupling between the adjacent units. When the TM11 mode is excited, the coupling windows not only distribute energy but also provide the 90° phase difference required for CP radiation. An additional feeding network is not required, and its profile is less than 0.05λ0 (λ0 is the free space wavelength at the center frequency). Three minima in the axial ratio (AR) response are present. The results show that right‐hand circularly polarized (RHCP) radiation is achieved. The measured 3 dB AR bandwidth is 6.9%, ranging from 1.52 to 1.62 GHz, and the RHCP realized peak gain is 7.72 dBic. An all‐metal construction suitable for satellite communication systems is designed that has superior performance in harsh space environments.
An all‐metal wideband circularly polarized (CP) single‐patch antenna based on TM11 mode is proposed. The proposed design is primarily derived from the conventional square patch antenna, with the introduction of windowed shorting metal walls. These walls divide the patch into four parts, and the coupling window can alter the surface current distribution of each part to achieve CP radiation.
The aggressive immunological activity elicited by acute viral myocarditis contributes to a large amount of cardiomyocytes loss and poor prognosis of patients in clinic. Low‐intensity pulsed ...ultrasound (LIPUS), which is an effective treatment modality for osteoarthropathy, has been recently illustrated regulating the overactive inflammatory response in various diseases. Here, we aimed to investigate whether LIPUS could attenuate coxsackievirus B3 (CVB3) infection‐induced injury by coordinating the inflammatory response. Male BALB/c mice were inoculated intraperitoneally with CVB3 to establish the model of acute viral myocarditis. LIPUS treatment was given on Day 1, Day 1, 3 and Day 1, 3, 5 post‐inoculation, respectively. All mice were followed up for 14 days. Day 1, 3, 5 LIPUS treatment significantly improved the survival rate, attenuated the ventricular dysfunction and ameliorated the cardiac histopathological injury of CVB3‐infected mice. Western blotting analysis showed Day 1, 3, 5 LIPUS treatment decreased pro‐inflammatory cytokines, increased the activation of caveolin‐1 and suppressed p38 mitogen‐activated protein kinase (MAPK) and extracellular signal‐regulated kinase (ERK) signallings in heart tissue. RAW264.7 cells were treated with lipopolysaccharides (LPS) to simulate the augmented inflammatory response in vivo. LIPUS treatment on RAW264.7 inhibited the expression of pro‐inflammatory cytokines, activated caveolin‐1 and suppressed p38 MAPK and ERK signallings. Transfecting RAW264.7 with caveolin‐1 siRNA blunted the suppression of pro‐inflammatory cytokines and MAPK signallings by LIPUS treatment. Taken together, we demonstrated for the first time that LIPUS treatment attenuated the aggressive inflammatory response during acute viral myocarditis. The underlying mechanism may be activating caveolin‐1 and suppressing MAPK signallings.
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