This article proposes a planar magnetoelectric resonator (PMER) as the element of broadband dual-polarized (DP) and circularly polarized (CP) reflectarray antennas (RAs). The PMER is realized by ...introducing a split in dual rhombic rings, which flats the vertical structure for magnetic resonance in common magnetoelectric (ME) element. Due to the isolated magnetic and electric resonant modes of the PMER, anisotropic characteristic is achieved to independently manipulate the reflection phase among two orthogonal polarizations and reflect CP incident wave in a wide bandwidth. Moreover, a simple modification method is presented for further expanding the operating band of CP element. For proof, a DP-RA and CP-RA prototype is fabricated and measured. The measured results reveal that 1-dB gain bandwidths of 17.5%/22.2% and 25.6% are observed for DP-RA and CP-RA, respectively, while maintaining low profiles and high aperture efficiencies. In particular, the measured axial ratio (AR) bandwidth of the PMER-based CP-RA reaches 66.7%.
A metal-loading (ML) method is proposed in this article to increase effective length, near-field magnitude, and radiation efficiency for an acoustically actuated piezoelectric antenna (PEA). A ...field-based circuit model (FBCM) method is utilized to characterize the metal-loaded PEA (MLPEA) by introducing antenna fields into piezoelectric equations and impedance analysis at boundary. Furthermore, current distribution within PE cylinder and on loaded metal rod is calculated by the finite element modeling (FEM) method and formulated with piecewise functions. Also, an antenna effective length is evaluated with different loaded metal lengths, and the effects of the loaded metal are analyzed on antenna near-fields and radiation efficiency. All the methods are validated by measurement of a demonstrated MLPEA on a precise testing vehicle with a frequency error of 0.05% and a near-field magnitude error of 0.97 dB. Finally, a maximum increase of 4.6 dB for near-field magnitude and that of ten times for radiation efficiency are obtained for PEA with a loaded metal length of 0.8 m. Different loss mechanisms in MLPEA are also analyzed, and the radiation efficiency limit for PEA, as estimated by FBCM, is much larger than that of metallic antenna when <inline-formula> <tex-math notation="LaTeX">ka </tex-math></inline-formula> is less than 0.1, leaving far more room for radiation efficiency elevation of PEA for state-of-the-art.
A field-based circuit model (FBCM) is proposed to reveal impedance, near-field, and far-field performance of acoustically actuated piezoelectric (PE) antenna by introduction of electromagnetic ...induction into PE equations and impedance analysis at the boundary. To make the model more practical, induced current on the PE antenna body is analyzed and near-field compression by the large permittivity of PE material is formulated. Closed-form expressions are built to conveniently evaluate model parameters. Furthermore, the FBCM method is validated by precise vehicles, and calculation results agree with the measurement with a maximum frequency error of 0.15% and a near-field magnitude error of 3.9 dB; all measured impedance and near-field components follow the characteristic described by FBCM. Finally, the radiation efficiency of a demonstrated PE antenna is calculated by FBCM to be 1.3e−9 for a single unit and 2.0e−9 for a PE antenna array, which is 5-67 times higher than that of a metallic electrical small antenna of the same size. The FBCM method can be an effective and convenient way for researchers to design and evaluate PE antennas in a short time.
Understanding the temporal trend of the disease burden of stroke and its attributable risk factors in China, especially at provincial levels, is important for effective prevention strategies and ...improvement. The aim of this analysis from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) is to investigate the disease burden of stroke and its risk factors at national and provincial levels in China from 1990 to 2019.
Following the methodology in the GBD 2019, the incidence, prevalence, mortality, and disability-adjusted life-years (DALYs) of stroke cases in the Chinese population were estimated by sex, age, year, stroke subtypes (ischaemic stroke, intracerebral haemorrhage, and subarachnoid haemorrhage), and across 33 provincial administrative units in China from 1990 to 2019. Attributable mortality and DALYs of underlying risk factors were calculated by a comparative risk assessment.
In 2019, there were 3·94 million (95% uncertainty interval 3·43–4·58) new stroke cases in China. The incidence rate of stroke increased by 86·0% (73·2–99·0) from 1990, reaching 276·7 (241·3–322·0) per 100 000 population in 2019. The age-standardised incidence rate declined by 9·3% (3·3–15·5) from 1990 to 2019. Among 28·76 million (25·60–32·21) prevalent cases of stroke in 2019, 24·18 million (20·80–27·87) were ischaemic stroke, 4·36 million (3·69–5·05) were intracerebral haemorrhage, and 1·58 million (1·32–1·91) were subarachnoid haemorrhage. The prevalence rate increased by 106·0% (93·7–118·8) and age-standardised prevalence rate increased by 13·2% (7·7–19·1) from 1990 to 2019. In 2019, there were 2·19 million (1·89–2·51) deaths and 45·9 million (39·8–52·3) DALYs due to stroke. The mortality rate increased by 32·3% (8·6–59·0) from 1990 to 2019. Over the same period, the age-standardised mortality rate decreased by 39·8% (28·6–50·7) and the DALY rate decreased by 41·6% (30·7–50·9). High systolic blood pressure, ambient particulate matter pollution exposure, smoking, and diet high in sodium were four major risk factors for stroke burden in 2019. Moreover, we found marked differences of stroke burden and attributable risk factors across provinces in China from 1990 to 2019.
The disease burden of stroke is still severe in China, although the age-standardised incidence and mortality rates have decreased since 1990. The stroke burden in China might be reduced through blood pressure management, lifestyle interventions, and air pollution control. Moreover, because substantial heterogeneity of stroke burden existed in different provinces, improved health care is needed in provinces with heavy stroke burden.
National Key Research and Development Program of China and Taikang Yicai Public Health and Epidemic Control Fund.
Chronic inflammation and oxidative stress play an important role in the pathogenesis of PSD. The main purposes of this study were to examine the dynamic changes of cytokines networks in PSD and the ...predictive role of early inflammation and oxidative stress for 2-week PSD.
Patients with ischemic stroke were recruited on day 3, and those with Hamilton Depression Rating Scale 24-Item (HAMD-24) ≥8 were classified as ischemic stroke patients with depressive symptoms and others as ischemic stroke patients without depressive symptoms. Subjects were then followed up at 2 weeks and 3 months, with those meeting diagnostic criteria for depressive symptoms on the HAMD ≥8 and the Statistical Manual of Mental Disorders-V (DSM-V) as the PSD group, and the others as the non-PSD group.
At 3 days, IFN-γ, IL-12(p70), IL-12(p40), IL-2, IL-28A/IFNλ2, and IL-19 were elevated in ischemic stroke patients with depressive symptoms. At 2 weeks, IL-12(p40), IL-19, IL-22, IFN-β and MMP-1 all were increased in PSD patients. At 3 months, IL-2, IFN-β and sCD163 increased in PSD group. Longitudinally, the inflammatory response decreased significantly in PSD group from 2 weeks to 3 months of follow-up, while it gradually decreased in non-PSD group from 3 days to 3 months of follow-up. SOD was positively related to IL-12(p70), IFN-γ and IL-20. Plasma IFN-γ at 3 days may be a potential predictive biomarker for 2-week PSD.
Peripheral inflammation and oxidative stress are involved in the pathogenesis of PSD, providing new insights for its diagnosis and treatment.
•Post stroke depression showed different patterns of inflammation response at several time points.•Plasma IFN-γ at 3 days may be a potential predictive biomarker for 2-week PSD.•Peripheral inflammation and oxidative stress are involved in the pathogenesis of PSD
Multidelay arterial spin labeling (ASL) is a novel perfusion method of ASL, with arterial transit time (ATT) calculated by multiple postlabeling delays to correct cerebral blood flow (CBF). We verify ...the accuracy of multidelay ASL in evaluating the ischemic penumbra and perfusion levels in patients with acute ischemic stroke, compared with computed tomography perfusion (CTP).
Patients with acute ischemic stroke with anterior circulation large vessel occlusion received baseline CTP, multidelay ASL, and diffusion-weighted imaging (DWI) in succession. Multidelay ASL image was processed to reconstruct ATT, CBF without ATT correction, and CBF corrected by ATT. The consistency of hypoperfusion and ischemic penumbra volume calculated by CTP and multidelay ASL were quantified by intraclass correlation coefficient (ICC) in 2-way mixed effects, absolute agreement, and single measure. Wilcoxon signed-rank test was used to compare the difference in penumbra volume between CTP, corrected ASL, and uncorrected ASL.
Thirty patients were included. Hypoperfusion volume based on multidelay ASL with different thresholds were 117.95 (87.77-151.49) mL for corrected relative CBF<40%, 130.29 (85.99-249.37) mL for CBF corrected by ATT<20 mL·100g
·min
, no statistical difference (
>0.05) compared with the volume of CTP, and consistency was almost excellent (ICC, 0.91) and substantial consistent (ICC, 0.727). The volumes of ischemic penumbra were 91.00 (42.68-125.27) mL for corrected relative CBF<40%-DWI, 108.94 (62.03-150.86) mL for CBF corrected by ATT<20 mL·100 g
·min
-DWI, which showed no statistical difference compared with the penumbra volume of CTP (
>0.05). The consistency was excellent (ICC, 0.822) and moderate (ICC, 0.501), respectively. The volume of uncorrected relative CBF <40%-DWI was 209.57 (123.21-292.45) mL, statistically larger than corrected relative CBF <40%-DWI (
<0.001) and CTP (
<0.001). The volume of uncorrected CBF<20 mL·100g
·min
-DWI was 186.23 (86.56-298.22) mL, statistically larger than CBF corrected by ATT<20 mL·100g
·min
-DWI (
<0.001) and CTP(
<0.001).
The volume of ischemic penumbra determined by CBF/DWI mismatch based on multidelay ASL is consistent with CTP. The penumbra volume calculated by CBF adjusted by ATT is more accurate.
It is well established that residence migration can negatively affect the mental health of adolescents. However, the related factors that mediate the association between residence migration and ...depression are still uncertain.
The participants were 16,037 adolescents in junior middle schools. A self-administered questionnaire was used for the survey. In addition to collecting general demographic characteristics of the participants, including age, gender, local residence status, only child status, parental marriage status and parent-child relationship, the questionnaire also contained the 9-item Patient Health Questionnaire, the short form of the Childhood Trauma Questionnaire and the Connor-Davidson Resilience Scale. Data analysis was conducted using SPSS software.
A total of 14,059 valid questionnaires were collected, resulting in 12,122 local adolescents, defined as being born and raised locally, and 1937 migrant adolescents, defined as being transferred from other regions. Meanwhile, 53.3 % of local adolescents and 58.2 % of migrant adolescents reported depressive symptoms. This result indicated that residence migration might contribute to depression symptoms(OR = 1.136, 95%CI: 1.013-1.273, p < 0.05). Childhood maltreatment and parental divorce are risk factors for depression in migrant adolescents. For all adolescents, resilience and a good parent-child relationship may reduce the risk of depression. Childhood maltreatment completely mediates residence migration-related depression(95 % bootstrap CI = 0.146, 0.323).
This study revealed that residence migration could contribute to adolescent depression, and childhood maltreatment may largely mediate this process, providing new insight into the relationship between adolescent depressive symptoms and residence migration. Reducing childhood maltreatment may effectively improve the depressive symptoms of migrant adolescents.
Preeclampsia (PE) is a life‐threatening disease of pregnant women associated with severe hypertension, proteinuria, or multi‐organ injuries. Mitochondrial‐mediated placental oxidative stress plays a ...key role in the pathogenesis of PE. However, the underlying mechanism remains to be revealed. Here, we identify Rnd3, a small Rho GTPase, regulating placental mitochondrial reactive oxygen species (ROS). We showed that Rnd3 is down‐regulated in primary trophoblasts isolated from PE patients. Loss of Rnd3 in trophoblasts resulted in excessive ROS generation, cell apoptosis, mitochondrial injury, and proton leakage from the respiratory chain. Moreover, Rnd3 overexpression partially rescues the mitochondrial defects and oxidative stress in human PE primary trophoblasts. Rnd3 physically interacts with the peroxisome proliferators‐activated receptor γ (PPARγ) and promotes the PPARγ‐mitochondrial uncoupling protein 2 (UCP2) cascade. Forced expression of PPARγ rescues deficiency of Rnd3‐mediated mitochondrial dysfunction. We conclude that Rnd3 acts as a novel protective factor in placental mitochondria through PPARγ‐UCP2 signaling and highlight that downregulation of Rnd3 is a potential factor involved in PE pathogenesis.
Computed tomography perfusion (CTP) and computed tomography angiography (CTA) have been recommended to select acute ischemic stroke (AIS) patients for endovascular thrombectomy (EVT) but are not ...widely used for post-treatment evaluation. We aimed to observe abnormalities in CTP and CTA before and after EVT and evaluate post-EVT CTP and CTA as potential tools for improving clinical outcome prediction.
Patients with AIS who underwent EVT and received CTP and CTA before and after EVT were retrospectively evaluated. The ischemic core was defined as the volume of relative cerebral blood flow <30% and hypoperfusion as the volume of Tmax >6 s. A reduction in hypoperfusion volume >90% between baseline and post-EVT CTP was defined as tissue optimal reperfusion (TOR). The 90-day modified Rankin scale was used to evaluate the clinical outcome.
Eighty-three patients were included. Patients with an absent ischemic core or with TOR after EVT had a higher rate of modified Thrombolysis in Cerebral Ischemia score 2c-3 and recanalization of post-treatment vessel condition based on follow-up CTA. Multivariable logistic regression revealed that the baseline ischemic core volume (OR:0.934, p=0.009), TOR (OR:8.322, p=0.029) and immediate NIHSS score after EVT (OR:0.761, p=0.012) were factors significantly associated with good clinical outcome. Combining baseline ischemic core volume and TOR with immediate NIHSS score after EVT showed greatest performance for good outcome prediction after EVT(AUC=0.921).
The addition of pretreatment and post-treatment CTP information to purely clinical NIHSS scores might help to improve the efficacy for good outcome prediction after EVT.
Post-stroke depression (PSD) is one of the most common neuropsychiatric complications after stroke. However, the underlying mechanisms of PSD remain ambiguous, and no objective diagnosis tool is ...available to diagnose PSD. Previous metabolomic studies on PSD included patients with ischemic and hemorrhagic stroke indiscriminately, which is not conducive to elucidating and predicting the occurrence of PSD. The aim of this study is to elucidate the pathogenesis of PSD and provide potential diagnostic markers for PSD in ischemic stroke patients.
In total, 51 ischemic stroke patients at 2 weeks were included in this study. Those with depressive symptoms were assigned to the PSD group, while the others were assigned to the non-PSD group. Plasma metabolomics based on liquid chromatography-mass spectrometry (LC-MS) was performed to explore the differential plasma metabolites between the PSD and non-PSD groups.
Principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) showed significant metabolic alterations between PSD patients and non-PSD patients. In total, 41 differential metabolites were screened out, mainly including phosphatidylcholines (PCs), L-carnitine and acyl carnitines, succinic acid, pyruvic acid and L-lactic acid. Metabolite-related pathway analysis revealed that alanine, aspartate and glutamate metabolism, glycerophospholipid metabolism and the citrate cycle (TCA cycle) may contribute to the pathogenesis of PSD. A panel of three signature metabolites PC(22:5(7Z,10Z,13Z,16Z,19Z)/15:0), LysoPA(18:1(9Z)/0:0) and 1,5-anhydrosorbitol was determined as potential biomarkers for PSD in ischemic stroke patients.
These findings are conducive to providing new insights into the pathogenesis of PSD and developing objective diagnostic tools for PSD in ischemic stroke patients.
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