Suppressing grating lobes of large-aperture optical phased array with circular array design.

An optical phased array (OPA), especially a two-dimensional (2D) OPA, suffers from the trade-off among steering range, beam width, and the number of antennas. Aperiodic 2D array designs currently aimed to reduce the number of antennas and reduce grating lobes within a wide range fall short when an aperture approaches millimeter size. A circular OPA design is proposed to address this issue. The circular design substantially reduces the number of antennas while achieving the same wide steering range and narrow beam width of optimized aperiodic 2D OPA designs. Its efficient suppression of grating lobes, the key to a wide steering range with minimal number of antennas and large antenna spacing, is theoretically studied and validated by simulation. The novel, to the best of our knowledge, design allows less than 100 antennas, orders of magnitude reduction, for millimeter size aperture OPA designs. It paves the way for commercialization by significantly reducing control complexity and power consumption.

Two-dimensional single-lobe Si photonic optical phased array with minimal antennas using a non-uniform large spacing array design.

We report a two-dimensional Si photonic optical phased array (OPA) optimized for a large optical aperture with a minimal number of antennas while maintaining single-lobe far field. The OPA chip has an optical aperture of ∼200µm by 150 µm comprising a 9×9 antenna array. The two-dimensional spacings between these antennas are much larger than the wavelength and are highly non-uniform optimized by the genetic deep learning algorithm. The phase of each antenna is independently tunable by a thermo-optical phase shifter. The experimental results validate the design and exhibit a 0.39∘×0.41∘ beamwidth within the 3 dB steering range of 14∘×11∘ limited by the numerical aperture of the far-field camera system. The method can be easily extended to a larger aperture for narrower beamwidth and wider steering range.

Effective half-wavelength pitch optical phased array design for aliasing-free 2D beam steering.

We present a method to design an optical phased array (OPA) simultaneously realizing both narrow beam width and aliasing-free 2D beam steering without the need to arrange the antennas at actual half-wavelength pitch. The method realizes an effective half-wavelength pitch in one direction formed by location projection of the antennas. The distances between the antennas in the other direction can be sufficiently large to form an effective large aperture realizing narrow beam width without needing a long grating. The presented method is proven by both theory and numerical simulations to achieve an equivalent grating-lobe-free far field of an ordinary half-wavelength pitch design. One design example exhibits 180° steering with a minimal beam width of 0.4° * 0.032° and a sidelobe suppression ratio of >13d B.

Long non-coding RNA MEG3 inhibits M2 macrophage polarization by activating TRAF6 via microRNA-223 down-regulation in viral myocarditis.

Viral myocarditis (VMC) commonly triggers heart failure, for which no specific treatments are available. This study aims to explore the specific role of long non-coding RNA (lncRNA) maternally expressed 3 (MEG3) in VMC. A VMC mouse model was induced by Coxsackievirus B3 (CVB3). Then, MEG3 and TNF receptor-associated factor 6 (TRAF6) were silenced and microRNA-223 (miR-223) was over-expressed in the VMC mice, followed by determination of ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS). Dual-luciferase reporter assay was introduced to test the interaction among MEG3, TRAF6 and miR-223. Macrophages were isolated from cardiac tissues and bone marrow, and polarization of M1 or M2 macrophages was induced. Then, the expressions of components of NLRP3 inflammatory body (NLRP3, ASC, Caspase-1), M1 markers (CD86, iNOS and TNF-α) and M2 markers (CD206, Arginase-1 and Fizz-1) were measured following MEG3 silencing. In the VMC mouse model, MEG3 and TRAF6 levels were obviously increased, while miR-223 expression was significantly reduced. Down-regulation of MEG3 resulted in the inhibition of TRAF6 by promoting miR-223. TRAF6 was negatively correlated with miR-223, but positively correlated with MEG3 expression. Down-regulations of MEG3 or TRAF6 or up-regulation of miR-223 was observed to increase mouse weight, survival rate, LVEF and LVFS, while inhibiting myocarditis and inflammation via the NF-κB pathway inactivation in VMC mice. Down-regulation of MEG3 decreased M1 macrophage polarization and elevated M2 macrophage polarization by up-regulating miR-223. Collectively, down-regulation of MEG3 leads to the inhibition of inflammation and induces M2 macrophage polarization via miR-223/TRAF6/NF-κB axis, thus alleviating VMC.

Fast Adiabatic Mode Evolution Assisted 2 × 2 Broadband 3 dB Coupler Using Silicon-on-Insulator Fishbone-like Grating Waveguides.

We report a novel 2 × 2 broadband 3 dB coupler based on fast adiabatic mode evolution with a compact footprint and large bandwidth. The working principle of the coupler is based on the rapid adiabatic evolution of local eigenmodes of fishbone-like grating waveguides. Different from a traditional adiabatic coupling method realized by the slow change of the cross-section size of a strip waveguide, a fishbone waveguide allows faster adiabatic transition with proper structure and segment designs. The presented 3 dB coupler achieves a bandwidth range of 168 nm with an imbalance of no greater than ±0.1 dB only for a 9 µm coupling region which significantly improves existing adiabatic broadband couplers.

Si Photonics FMCW LiDAR Chip with Solid-State Beam Steering by Interleaved Coaxial Optical Phased Array.

LiDAR has attracted increasing attention because of its strong anti-interference ability and high resolution. Traditional LiDAR systems rely on discrete components and face the challenges of high cost, large volume, and complex construction. Photonic integration technology can solve these problems and achieve high integration, compact dimension, and low-cost on-chip LiDAR solutions. A solid-state frequency-modulated continuous-wave LiDAR based on a silicon photonic chip is proposed and demonstrated. Two sets of optical phased array antennas are integrated on an optical chip to form a transmitter-receiver interleaved coaxial all-solid-state coherent optical system which provides high power efficiency, in principle, compared with a coaxial optical system using a 2 × 2 beam splitter. The solid-state scanning on the chip is realized by optical phased array without a mechanical structure. A 32-channel transmitter-receiver interleaved coaxial all-solid-state FMCW LiDAR chip design is demonstrated. The measured beam width is 0.4° × 0.8°, and the grating lobe suppression ratio is 6 dB. Preliminary FMCW ranging of multiple targets scanned by OPA was performed. The photonic integrated chip is fabricated on a CMOS-compatible silicon photonics platform, providing a steady path to the commercialization of low-cost on-chip solid-state FMCW LiDAR.

[Value of red blood cell distribution width in evaluating the severity of illness of novel coronavirus Delta variant].

OBJECTIVE: To explore the value of red blood cell distribution width (RDW) in evaluating the severity of patients infected with novel coronavirus Delta variant. METHODS: A total of 28 patients infected with novel coronavirus Delta variant in designated hospital treated by the First Affiliated Hospital of Xi'an Jiaotong University medical team from December 2021 to January 2022 were enrolled (23 cases of common type, 4 severe and 1 critical cases). The detailed clinical data of patients was collected. Then, Pearson's correlation analysis was used to identify the blood examination indexes which affected the arterial partial pressure of oxygen (PaO2) and arterial partial pressure of carbon dioxide (PaCO2). According to the median standard deviation of red blood cell distribution width (RDW-SD, 42.5 fL), 28 patients were divided into low RDW-SD group (≤ 42.5 fL, 16 cases) and high RDW-SD group (> 42.5 fL, 12 cases), and the immune related indexes of the two groups were compared. Receiver operator characteristic curve (ROC) was drawn to evaluate the predictive value of RDW-SD on the severity of illness of coronavirus disease 2019 (COVID-19). RESULTS: Correlation analysis showed that RDW-SD was the only index related to PaO2 and PaCO2 on the first day of admission, which was negative correlation with PaO2 (r = -0.379, P = 0.047) and positive correlation with PaCO2 (r = 0.509, P = 0.006). The results of effects of different clinical characteristics on RDW-SD level showed that there was no statistically significant difference in RDW-SD between groups with different clinical characteristics (including male/female, ≥ 65 years old/< 65 years old, having/without hypertension, having/without diabetes, smoking/not smoking, having/without hyperpyrexia, with/without fever for 3 days, with/without respiratory symptoms, with/without digestive symptoms). It was suggested that RDW-SD be relatively stable and not affected by the patient's baseline level. The percentage of B cells in low RDW-SD group was higher than that in high RDW-SD group (23.01±3.01 vs. 15.34±5.34, P < 0.05), immunoglobulin G (IgG) level in low RDW-SD group was lower than that in high RDW-SD group (g/L: 11.43±3.20 vs. 15.42±1.54, P < 0.05). The area under ROC curve (AUC) of RDW-SD in evaluating severe cases was 0.83 [95% confidence interval (95%CI) was 0.59-1.06], which was close to multilobularinltration, hypo-lymphocytosis, bacterial coinfection, smoking history, hyper-tension and age (MuL BSTA score; AUC = 0.82, 95%CI was 0.51-1.12) and better than British Thoracic Society's modified pneumonia score (CURB-65 score; AUC = 0.70, 95%CI was 0.50-0.91). CONCLUSIONS: RDW-SD has significant evaluative effect on the severity of COVID-19 patients with Delta variants.

Long-term outcomes of delayed percutaneous coronary intervention for patients with ST-segment elevation myocardial infarction: A propensity score-matched retrospective study.

ABSTRACT: The best time window of percutaneous coronary intervention (PCI) is within 12 hours for ST-segment elevation myocardial infarction (STEMI). However, there is limited evidence about the proper time of PCI for delayed STEMI patients.From June 2014 to June 2015, a total of 268 patients receiving PCI with second-generation drug-eluting stent in a Chinese hospital after 3 days of STEMI onset were enrolled in this retrospective study, who were divided into the early group (3-14 days) and the late group (>14 days). A propensity score match was conducted to reduce the baseline difference. The primary endpoint of all-cause death and secondary endpoints of major adverse cardiac and cerebrovascular event (myocardial infarction [MI], stroke, emergent revascularization, and rehospitalization due to heart failure) were compared using survival analysis.At last, 182 cases were matched after propensity score match, with no statistical difference in baseline characteristics and PCI data. Kaplan-Meier survival curve demonstrated no difference in all-cause death of the 2 groups (P = .512). However, the early group presented a higher incidence of MI than the late group (P = .036). The multivariate Cox regression analysis also demonstrated that the early PCI was an independent risk factor for MI compared with late PCI (hazard ratio = 3.83, 95%CI [1.91-8.82], P = .001). There was no statistical difference in other major adverse cardiac and cerebrovascular event, including stroke, emergent revascularization, and rehospitalization due to heart failure.Using the 2nd drug-eluting stent, early PCI (3-14 days) and late PCI (>14 days) have comparable efficacy and outcomes. However, patients receiving early PCI are subjected to a relatively higher risk of recurrent MI.

Sediment Microbial Communities and Their Potential Role as Environmental Pollution Indicators in Xuande Atoll, South China Sea.

In this study, 39 sediment samples were collected from Qilian Island, Iltis Bank, and Yongxing Island in Xuande Atoll in the South China Sea (SCS), and the microbial community structures and distribution were analyzed. The microbial community was influenced by both natural environmental factors and human activities. The abundance of genera Vibrio and Pseudoalteromonas, which are associated with pathogenicity and pollutant degradation, were significantly higher in Qilian Island than in Yongxing Island and Iltis Bank, suggesting possible contamination of Qilian Island area through human activities. Pathogenic or typical pollutants-degrading bacteria were found to be negatively correlated with most of the commonly occurring bacterial populations in marine sediment, and these bacteria were more likely to appear in the sediment of deep water layer. This co-occurrence pattern may be due to bacterial adaptation to environmental changes such as depth and contaminations from human activities, including garbage disposal, farming, and oil spills from ships. The findings of this study could help in understanding the potential influences of human activities on the ecosystem at the microbial level.

The proportion of peripheral regulatory T cells in patients with Multiple Sclerosis: A meta-analysis.

BACKGROUND: Accumulating evidence indicates that regulatory T cells (Tregs) play an important role in the maintenance of immune tolerance. And dysfunction or deficiency of Tregs is thought to be involved in the pathogenesis of Multiple Sclerosis (MS). Nevertheless, previous studies reporting Tregs in patients were controversial due to the different markers adopted to identify Tregs. To clarify the status of Tregs in the pathogenesis of MS patients, we did a meta-analysis of the results published previously to assess the proportion of Tregs in peripheral blood (PB) in patients with MS. METHODS: We systematically searched Embase, PubMed, Cochrane, Web of Knowledge, FDA.gov, and Clinical Trials.gov for the studies reporting the proportion of Tregs in MS patients. Our main endpoints were the proportion of Tregs among CD4+ T cells in PB defined by different markers. We assessed pooled data by using a random-effects model. Our meta-analysis had been registered at International Prospective Register of Systematic Reviews (PROSPERO) (number CRD42017064906). RESULTS: Of 885 identified studies, a total 16 studies were selected in our analysis. There was no significant difference between MS patients and control subjects in Tregs identified by all Tregs definition methods [-0.07, (-0.46, 0.31, p = 0.706)] and Tregs defined by "CD4+ CD25+" [0.24, (-0.18, 0.65), p = 0.263]. Compared with control subjects, MS patients had a lower proportion of Tregs defined by "CD4+ CD25+ FOXP3+" [-0.75, (-0.46,0.31), p = 0.001]. CONCLUSION: Under random effect model of meta-analysis, the data showed that the results of Tregs in MS were different according to the definition method; and the proportion of Tregs defined by "CD4+ CD25+ FOXP3+" was decreased in MS. That result demonstrates that FOXP3 may be a vital definition of Tregs, and Tregs defined by stricter definition methods should be involved in the pathogenic mechanisms of MS.

Silencing of STAT4 Protects Against Autoimmune Myocarditis by Regulating Th1/Th2 Immune Response via Inactivation of the NF-κB Pathway in Rats.

Signal transducer and activator of transcription 4 (STAT4) has been implicated in the progression of myocarditis. The aim of the current study was to investigate the role by which STAT4 influences autoimmune myocarditis in an attempt to identify a theoretical therapeutic perspective for the condition. After successful establishment of an autoimmune myocarditis rat model, the expression patterns of STAT4, NF-κB pathway-related genes, Th1 inflammatory cytokines (IFN-γ and IL-2), and Th2 inflammatory cytokines (IL-6 and IL-10) were subsequently determined. The rats with autoimmune myocarditis were treated with oe-STAT4 or sh-STAT4 lentiviral vectors to evaluate the role of STAT4 in autoimmune myocarditis, or administrated with 1 mL 10 µmol/L of BAY11-7082 (the NF-κB pathway inhibitor) via tail vein to investigate the effect of the NF-κB pathway on autoimmune myocarditis. Finally, cell apoptosis was evaluated. The serum levels of IFN-γ and IL-2, extent of IκBα and P65 phosphorylation, and the expression of STAT4 were elevated, while the serum levels of IL-6 and IL-10 as well as the expression of IκBα were reduced among the rats with autoimmune myocarditis, which was accompanied by an increase in the apoptotic cells. More importantly, the silencing of STAT4 or the inhibition of the NF-κB pathway was detected to result in a decrease in the serum levels of IFN-γ and IL-2 and an elevation of the serum levels of IL-6 and IL-10, and inhibited myocardial cell apoptosis in rats with autoimmune myocarditis. Moreover, STAT4 silencing was also observed to decrease the extent of IκBα and P65 phosphorylation while acting to elevate the expression of IκBα. Taken together, silencing of STAT4 could hinder the progression of autoimmune myocarditis by balancing the expression of Th1/Th2 inflammatory cytokines via the NF-κB pathway, which may provide a novel target for experimental autoimmune myocarditis (EAM) treatment.

Levels of peripheral Th17 cells and serum Th17-related cytokines in patients with multiple sclerosis: A meta-analysis.

BACKGROUND: Multiple reports have described the proportion of Th17 cells in peripheral blood and serum levels of Th17-related cytokines in patients with multiple sclerosis (MS). To clarify the status of Th17 cells and Th17-related cytokines in MS patients, we did a meta-analysis of the results published previously to assess the levels of peripheral Th17 cells and serum Th17-related cytokines in patients with MS. METHODS: We searched Embase, PubMed, Cochrane, Web of Knowledge, FDA.gov, and Clinical Trials.gov systematically for studies reporting the proportion of Th17 cells and the serum levels of Th17-related cytokines (IL-17, IL23) in MS patients. Our main endpoints were the proportion of Th17 cells among CD4+ T cells in peripheral blood (PB), serum IL-17 levels, and serum IL-23 levels. We assessed pooled data by using a random-effects model. It has been registered at International Prospective Register of Systematic Reviews (PROSPERO) (number CRD42017059113). RESULTS: Of 560 identified studies, a total of 12 studies were selected in our analysis. Compared with control subjects, MS patients had a higher proportion of Th17 cells [1.37, (0.53, 2.21)] in PB, an elevated levels of serum IL-17 [2.48, (1.25, 3.71)] and an increased IL-23 levels in serum [2.29, (0.58, 4.00)]. CONCLUSION: Under random effect model of meta-analysis, the data showed that the proportion of Th17 cells in PB and levels of serum IL-17 and IL-23 increased among MS patients compared to control subjects. This result demonstrated that Th17 cells and Th17-related cytokines may be involved in the pathogenic mechanisms of MS.