Evaluating the role of interleukin-2 and interleukin-12 in pediatric patients with concurrent Mycoplasma pneumoniae and Epstein-Barr virus infections

BACKGROUND Mycoplasma pneumoniae(MP)frequently causes respiratory infections in children,whereas Epstein-Barr virus(EBV)typically presents subclinical manifestations in immunocompetent pediatric populations.The incidence of MP and EBV coinfections is often overlooked clinically,with the contributory role of EBV in pulmonary infections alongside MP remaining unclear.AIM To evaluate the serum concentrations of interleukin-2(IL-2)and interleukin-12(IL-12)in pediatric patients with MP pneumonia co-infected with EBV and assess their prognostic implications.METHODS We retrospectively analyzed clinical data from patients diagnosed with MP and EBV co-infection,isolated MP infection,and a control group of healthy children,spanning from January 1,2018 to December 31,2021.Serum IL-2 and IL-12 levels were quantified using enzyme-linked immunosorbent assay.Logistic regression was employed to identify factors influencing poor prognosis,while receiver operating characteristic(ROC)curves evaluated the prognostic utility of serum IL-2 and IL-12 levels in co-infected patients.RESULTS The co-infection group exhibited elevated serum IL-2 and C-reactive protein(CRP)levels compared to both the MP-only and control groups,with a reverse trend observed for IL-12(P<0.05).In the poor prognosis cohort,elevated CRP and IL-2 levels,alongside prolonged fever duration,contrasted with reduced IL-12 levels(P<0.05).Logistic regression identified elevated IL-2 as an independent risk factor and high IL-12 as a protective factor for adverse outcomes(P<0.05).ROC analysis indicated that the area under the curves for IL-2,IL-12,and their combination in predicting poor prognosis were 0.815,0.895,and 0.915,respectively.CONCLUSION Elevated serum IL-2 and diminished IL-12 levels in pediatric patients with MP and EBV co-infection correlate with poorer prognosis,with combined IL-2 and IL-12 levels offering enhanced predictive accuracy.

Analyze interleukin-1β,interleukin-6,and tumor necrosis factor-αlevels in dry eye and the therapeutic effect of cyclosporine A

BACKGROUND Dry eye is a common eye disease.Artificial tears supplements are widely used for the treatment of dry eyes.However,multiple adverse effects have been observed in patients receiving long-term treatment with artificial tears,which may affect the therapeutic effect.AIM To analyze the characteristics of interleukin-1β(IL-1β),interleukin-6(IL-6),and tumor necrosis factor-alpha(TNF-α)levels in patients with dry eye and the therapeutic effect of artificial tears combined with cyclosporine A.METHODS A total of 124 dry eye patients treated at The First People’s Hospital of Xining from April 2020 to April 2022 were selected as the observation group,while 20 healthy individuals served as the control group during the same period.Levels of inflammatory markers,including IL-1β,IL-6,and TNF-α,were analyzed.The observation group was further divided into a study group and a control group,each consisting of 62 patients.The control group received artificial tears,whereas the study group received a combination of artificial tears and cyclosporine A.Inflammatory markers,Schirmer’s test(SIT),tear break-up time(TBUT),corneal fluorescein staining(CFS),National Eye Institute Visual Function Questionnaire-25(NEI-VFQ-25)scores,and adverse events(AEs)were compared between the two groups.RESULTS The observation group exhibited significantly elevated serum levels of IL-1β,IL-6,and TNF-αin comparison to the healthy group.Following treatment,the study group demonstrated substantial reductions in IL-1β,IL-6,and TNF-αlevels relative to the control group.Moreover,after treatment,the study group experienced a marked decrease in CFS scores and significant increases in both SIT and BUT levels when compared to the control group.Additionally,significant improvements were observed in the primary symptom of dry eye and secondary symptoms such as photophobia,foreign body sensation,fatigue,red eye,and burning sensation within the study group.Furthermore,post-treatment NEI-VFQ-25 scores across all dimensions exhibited significant enhancements in the study group compared to the control group(P<0.05).It is noteworthy that significant AEs were reported in both groups throughout the treatment period.CONCLUSION Cyclosporine A combined with artificial tears is effective in treating dry eye,yielding enhanced outcomes by improving SIT and TBUT levels,reducing CFS scores,and ameliorating vision-related quality of life.

Interleukin-1β:Friend or foe for gastrointestinal cancers

Gastrointestinal(GI)cancer is a malignancy arising in the digestive system and accounts for approximately a third of increasing global cancer-related mortality,especially in the colorectum,esophagus,stomach,and liver.Interleukin-1β(IL-1β)is a leukocytic pyrogen recognized as a tumor progression-related cytokine.IL-1βsecretion and maturation in inflammatory responses could be regulated by nuclear factor-kappaB-dependent expression of NLR family pyrin domain containing 3,inflammasome formation,and activation of IL-1 converting enzyme.Several studies have documented the pro-tumorigenic effects of IL-1β in tumor microenvironments,promoting proliferation and metastatic potential of cancer cells in vitro and tumorigenesis in vivo.The application of IL-1β inhibitors is also promising for targeted therapy development in some cancer types.However,as a leukocytic pro-inflammatory cytokine,IL-1β may also possess anti-tumorigenic effects and be type-specific in different cancers.This editorial discusses the up-to-date roles of IL-1β in GI cancers,including underlying mechanisms and down-stream signaling pathways.Understanding and clarifying the roles of IL-1β would significantly benefit future therapeutic targeting and help improve therapeutic outcomes in patients suffering from GI cancer.

Exploring the role of interleukin-6 receptor blockade in epilepsy and associated neuropsychiatric conditions through a mendelian randomization study

BACKGROUND The interplay between inflammation,immune dysregulation,and the onset of neurological disorders,including epilepsy,has become increasingly recognized.Interleukin(IL)-6,a pro-inflammatory cytokine,is suspected to not only mediate traditional inflammatory pathways but also contribute to neuroinflammatory responses that could underpin neuropsychiatric symptoms and broader psychiatric disorders in epilepsy patients.The role of IL-6 receptor(IL6R)blockade presents an intriguing target for therapeutic intervention due to its potential to attenuate these processes.neuropsychiatric conditions due to neuroinflammation.METHODS Mendelian randomization(MR)analysis employing single nucleotide poly-morphisms(SNPs)in the vicinity of the IL6R gene(total individuals=408225)was used to evaluate the putative causal relationship between IL6R blockade and epilepsy(total cases/controls=12891/312803),focal epilepsy(cases/controls=7526/399290),and generalized epilepsy(cases/controls=1413/399287).SNP weights were determined by their effect on C-reactive protein(CRP)levels and integrated using inverse variance-weighted meta-analysis as surrogates for IL6R effects.To address potential outlier and pleiotropic influences,sensitivity analyses were conducted employing a variety of MR methods under different modeling assumptions.RESULTS The genetic simulation targeting IL6R blockade revealed a modest but significant reduction in overall epilepsy risk[inverse variance weighting:Odds ratio(OR):0.827;95%confidence interval(CI):0.685-1.000;P=0.05].Subtype analysis showed variability,with no significant effect observed in generalized,focal,or specific childhood and juvenile epilepsy forms.Beyond the primary inflammatory marker CRP,the findings also suggested potential non-inflammatory pathways mediated by IL-6 signaling contributing to the neurobiological landscape of epilepsy,hinting at possible links to neuroinflammation,psychiatric symptoms,and associated mental disorders.CONCLUSION The investigation underscored a tentative causal relationship between IL6R blockade and decreased epilepsy incidence,likely mediated via complex neuroinflammatory pathways.These results encouraged further in-depth studies involving larger cohorts and multifaceted psychiatric assessments to corroborate these findings and more thoroughly delineate the neuro-psychiatric implications of IL-6 signaling in epilepsy.The exploration of IL6R blockade could herald a novel therapeutic avenue not just for seizure management but also for addressing the broader psychiatric and cognitive disturbances often associated with epilepsy.

Low interleukin-10 level indicates a good prognosis in Salmonella enterica serovar typhimurium-induced pediatric hemophagocytic lymphohistiocytosis:A case report

BACKGROUND Secondary hemophagocytic lymphohistiocytosis(sHLH)triggered by Salmonella enterica serovar Typhimurium is rare in pediatric patients.There is no consensus on how to treat S.typhimurium-triggered sHLH.CASE SUMMARY A 9-year-old boy with intermittent fever for 3 d presented to our hospital with positive results for S.typhimurium,human rhinovirus,and Mycoplasma pneumoniae infections.At the time of admission to our institution,the patient’s T helper 1/T helper 2 cytokine levels were 326 pg/mL for interleukin 6(IL-6),9.1 pg/mL for IL-10,and 246.7 pg/mL for interferon-gamma(IFN-γ),for which the ratio of IL-10 to IFN-γwas 0.04.In this study,the patient received meropenem,linezolid,and cefoperazone/sulbactam in combination with high-dose methylprednisolone therapy(10 mg/kg/d for 3 d)and antishock supportive treatment twice.After careful evaluation,this patient did not receive HLH chemotherapy and recovered well.CONCLUSION S.Typhimurium infection-triggered sHLH patient had a ratio of IL-10 to IFN-γ≤1.33,an IL-10 concentration≤10.0 pg/mL,and/or an IFN-γconcentration≤225 pg/mL at admission.Early antimicrobial and supportive treatment was sufficient,and the HLH-94/2004 protocol was not necessary under these conditions.

Interleukin-35: A key player managing pre-diabetes and chronic inflammatory type 1 autoimmune diabetes

Interleukin-35(IL-35)is a novel protein comprising IL-12αand IL-27βchains.The IL12A and EBI3 genes are responsible for its production.The study of IL-35 has experienced a substantial increase in interest in recent years,as demonstrated by many research papers.Recent clinical studies have shown that individuals who do not have a C-peptide have notably reduced amounts of IL-35 in their blood serum.This is accompanied by a drop in the percentage of IL-35+Treg cells,regulatory B cells,and CD8+FOXP3+cells that produce IL-35.This article em-phasizes the potential significance of IL-35 expression in governing the immune response and its involvement in chronic inflammatory autoimmune diabetes in pancreatic inflammation.It demonstrates IL-35's ability to regulate cytokine proportions,modulate B cells,and protect against autoimmune diabetes.However,further investigation is necessary to ascertain the precise mechanism of IL-35,and meticulous planning is essential for clinical studies.

Diagnostic value of serum vascular endothelial growth factor and interleukin-17 in primary hepatocellular carcinoma

BACKGROUND Despite significant advancements in the medical treatment of primary hepato-cellular carcinoma(PHC)in recent years,enhancing therapeutic effects and im-proving prognosis remain substantial challenges worldwide.AIM To investigate the expression levels of serum vascular endothelial growth factor(VEGF)and interleukin(IL)-17 in patients with PHC and evaluate their diagnostic value while exploring their relationship with patients’clinical characteristics.METHODS The study included 50 patients with confirmed PHC who visited Wuhan Han-yang Hospital from January 2021 to January 2022,and 50 healthy individuals from the same period served as the control group.Serum VEGF and IL-17 levels in both groups were measured by Enzyme-Linked Immunosorbent Assay,and their diagnostic value was assessed using receiver operating characteristic(ROC)curves.Pearson correlation analysis was performed to examine the relationship between serum VEGF and IL-17 levels.Pathological data of the PHC patients were analyzed to determine the relationship between serum VEGF and IL-17 levels and pathological characteristics.RESULTS Serum VEGF and IL-17 levels were significantly higher in the study group com-pared to the control group(P<0.05).No significant association was observed between serum VEGF and IL-17 levels and gender,age,combined cirrhosis,tumor diameter,or degree of differentiation(P>0.05).However,there was a significant relationship between clinical TNM stage,tumor metastasis,and serum VEGF and IL-17 levels(P<0.05).Correlation analysis revealed a positive correlation between serum VEGF and IL-17(P<0.05).ROC analysis demonstrated that both serum VEGF and IL-17 had good diagnostic efficacy for PHC.CONCLUSION Serum VEGF and IL-17 levels were significantly higher in PHC patients compared to healthy individuals.Their levels were closely related to pathological features such as tumor metastasis and clinical TNM stage,and there was a significant positive correlation between VEGF and IL-17.These biomarkers may serve as valuable reference in-dicators for the early diagnosis and treatment guidance of PHC.

Effects of interleukin-10 treated macrophages on bone marrow mesenchymal stem cells via signal transducer and activator of transcription 3 pathway

BACKGROUND Alveolar bone defects caused by inflammation are an urgent issue in oral implant surgery that must be solved.Regulating the various phenotypes of macrophages to enhance the inflammatory environment can significantly affect the progression of diseases and tissue engineering repair process.AIM To assess the influence of interleukin-10(IL-10)on the osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs)following their interaction with macrophages in an inflammatory environment.METHODS IL-10 modulates the differentiation of peritoneal macrophages in Wistar rats in an inflammatory environment.In this study,we investigated its impact on the proliferation,migration,and osteogenesis of BMSCs.The expression levels of signal transducer and activator of transcription 3(STAT3)and its activated form,phos-phorylated-STAT3,were examined in IL-10-stimulated macrophages.Subsequently,a specific STAT3 signaling inhibitor was used to impede STAT3 signal activation to further investigate the role of STAT3 signaling.RESULTS IL-10-stimulated macrophages underwent polarization to the M2 type through substitution,and these M2 macrophages actively facilitated the osteogenic differentiation of BMSCs.Mechanistically,STAT3 signaling plays a crucial role in the process by which IL-10 influences macrophages.Specifically,IL-10 stimulated the activation of the STAT3 signaling pathway and reduced the macrophage inflammatory response,as evidenced by its diminished impact on the osteogenic differentiation of BMSCs.CONCLUSION Stimulating macrophages with IL-10 proved effective in improving the inflammatory environment and promoting the osteogenic differentiation of BMSCs.The IL-10/STAT3 signaling pathway has emerged as a key regulator in the macrophage-mediated control of BMSCs’osteogenic differentiation.

Analysis of the Role of D-Dimer,Interleukin-6,and Interleukin-18 in Differential Diagnosis of Pediatric Refractory Mycoplasma pneumoniae Pneumonia

Objective:To analyze the value of D-dimer(D-D),interleukin-6(IL-6),and IL-18 in the differential diagnosis of children with refractory Mycoplasma pneumoniae pneumonia(RMPP).Methods:The medical records of 92 children with Mycoplasma pneumoniae pneumonia(MPP)treated in the hospital were selected for retrospective analysis from January 2023 to January 2024.After comprehensive examinations such as computed tomography examination of the chest,48 children with general Mycoplasma pneumoniae pneumonia(GMPP)were put in the GMPP group and 44 children with RMPP were grouped in the RMPP group.The IL-6,IL-18,and D-D levels were compared between the two groups,and the receiver operating characteristic(ROC)curves were plotted to analyze their value for differential diagnosis of RMPP.Results:The levels of IL-6,IL-18,and D-D in the RMPP group were higher than those in the GMPP group(P<0.05);the ROC curves showed that the specificity of the differential diagnosis of IL-6,IL-18,and D-D was higher,and their diagnostic value was significant.Conclusion:Determination of IL-6,IL-18,and D-D levels in children with MPP can further diagnose the children’s condition,which can help physicians formulate targeted treatment plans,and is of great significance to the improvement of the children’s condition,which is worthy of attention.

Effect of flurbiprofen combined with prednisolone on interleukin-6 in elderly surgery patients

Objective: To determine the effect of flurbiprofen combined with prednisolone on interleukin-6 in elderly surgery patients. Methods: In this double-blind randomized controlled study, patients aged 65 to 80 who were undergoing spinal fusion surgery for disc herniation were administered flurbiprofen 100 mg (P group, flurbiprofen group), prednisolone 0.6 mg/kg (D group, prednisolone group), prednisolone 0.6 mg/kg plus flurbiprofen 100 mg (P + D group, flurbiprofen + prednisolone group) or normal saline (S group, saline group) 15 minutes before the induction of anesthesia. Plasma samples were collected before surgery (T0) and on day 1 (T1), day 2 (T2) and day 3 (T3) following surgery. At the same time, systemic inflammatory response syndrome (SIRS) was assessed by SIRS criteria. The levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP) for collected samples were measured. Results: Other groups had significantly lower levels of IL-6, CRP and occurrence of SIRS than S group (p < 0.05). Compared to groups P and D, the levels of IL-6 and CRP in P + D group were significantly lower on T1 (p < 0.05). Peak levels of IL-6 in all groups were presented on T1 (p 0.05). The levels of CRP within three days were significantly different but did not show peak levels (p > 0.05). Conclusion: Compared to prednisolone or flurbiprofen, combining flurbiprofen with prednisolone in elderly surgery patients led to an increased suppression of IL-6.

Efficacy of Laparoscopic Cholecystectomy in Treating Patients with Gallstones and Its Effect on Interleukin-6 and Tumor Necrosis Factor-α Levels

Objective:To investigate the efficacy of laparoscopic cholecystectomy in the treatment of patients with gallstones and its effect on the levels of interleukin-6(IL-6)and tumor necrosis factor-α(TNF-a).Methods:A total of 82 patients with gallstones admitted from July 2020 to July 2023 were recruited and allocated into control and observation groups using the random number table method,with 41 cases in each group.The patients were treated with laparoscopic cholecystectomy,with the anterior triangle anatomical approach to the gallbladder in the control group and the posterior triangle anatomical approach to the gallbladder in the observation group.The treatment effect and inflammatory factor levels of both groups were observed and compared.Results:When comparing the clinical outcomes of both patient groups,the key parameters evaluated included time to mobilization,duration of surgery,extubation time,and intraoperative bleeding.The observation group exhibited a significant advantage in these parameters compared to the control group(P<0.05).Regarding the levels of inflammatory factors between the two groups before and after treatment,there was no significant difference in values before treatment.However,following treatment,patients in the observation group showed significantly lower levels of IL-6,TNF-α,and C-reactive protein(CRP)compared to the control group(P<0.05).Conclusion:Patients undergoing laparoscopic cholecystectomy for gallstones can benefit from the implementation of the posterior triangular anatomical approach to the gallbladder,which not only enhances therapeutic efficacy but also offers significant advantages in reducing levels of IL-6,TNF-α,and CRP.Therefore,it is recommended for the widespread adoption of this treatment approach in clinical practice.

苦瓜皂苷L调控PI3K/AKT通路促进内皮祖细胞增殖能力和内皮功能的实验研究

目的:探讨苦瓜皂苷L对内皮祖细胞(EPC)增殖能力和内皮功能的作用及机制。方法:体外分离、培养、鉴定外周血EPC。使用不同浓度苦瓜皂苷L处理EPC 24 h后,应用细胞计数试剂盒(CCK-8)法检测各组细胞活力。使用AutoDock Tools 5.6软件,分别以磷脂酰肌醇3-激酶(PI3K)和蛋白激酶B(AKT)为受体,以药物分子苦瓜皂苷L为配体采用盲对接法进行分子对接。使用PI3K/AKT抑制剂LY294002和最佳使用浓度的苦瓜皂苷L单独或同时处理EPC 24 h后检测各组细胞活力和磷酸化PI3K(p-PI3K)、磷酸化AKT(p-AKT)及磷酸化内皮型一氧化氮合酶(p-eNOS)表达水平。结果:与对照组比较,苦瓜皂苷L呈剂量依赖性地促进EPC增殖,且40μmol/L的苦瓜皂苷L是最佳药物浓度。与对照组比较,LY294002可下调EPC细胞活力,苦瓜皂苷L可上调细胞活力。与苦瓜皂苷L组比较,共同使用苦瓜皂苷L和LY294002可降低细胞活力。分子对接结果显示,苦瓜皂苷L与PI3K和AKT均存在直接作用,形成稳定的锁钥结构。与对照组比较,LY294002可显著下调p-PI3K、p-AKT和p-eNOS蛋白水平;苦瓜皂苷L可上调p-PI3K、p-AKT和p-eNOS蛋白水平。与苦瓜皂苷L组比较,使用苦瓜皂苷L和LY294002可降低p-PI3K、p-AKT和p-eNOS蛋白水平。结论:苦瓜皂苷L通过PI3K/AKT信号通路靶向调节EPC的增殖能力,进而上调内皮型一氧化氮合酶(eNOS)活化水平以促进EPC内皮功能。

L型隔板弧形双钢板组合墙板抗爆性能试验与数值研究

弧形双钢板混凝土组合墙板结构具有和拱结构相同的传力机理,可以充分发挥混凝土优异的抗压性能,极大地提高了结构的承载力。该文开展了L型隔板弧形双钢板混凝土组合墙板(L-shaped-Curved Double Steel Concrete Composite Wallboard,L-CDSCW)在近场爆炸作用下的试验研究,通过混凝土的损伤分析和结构变形分析探究其抗爆性能。基于ANSYS/LS-DYNA软件进行了L-CDSCW试件爆炸响应的数值分析,参数化分析了不同关键参数对L-CDSCW试件抗爆性能的影响规律。结果表明:近场爆炸作用下,L-CDSCW试件未出现倒塌或崩塌现象,具有较强的抗爆性能;增加钢板厚度可以减小混凝土跨中凹陷深度和混凝土塑性破坏;增加TNT当量和降低爆距会显著增加底部钢板跨中最大挠度,同时也会增加混凝土跨中凹陷深度和混凝土损伤。研究结果可以为弧形双钢板混凝土组合板的应用提供一定的技术参考。

跗骨窦小切口与经外侧“L”形切口术对跟骨骨折患者的疗效

目的 比较跗骨窦小切口与经外侧“L”形切口术治疗跟骨骨折的疗效及对足功能恢复情况的影响。方法 研究对象选取2020年10月至2022年10月收治的跟骨骨折患者88例,按照手术方法分为对照组43例,研究组45例,对照组采用经外侧“L”形切口术,研究组采用跗骨窦小切口手术。检测比较2组手术情况及并发症发生情况、足功能、跟骨解剖结构、骨代谢、炎性因子、应激反应指标水平。结果 与对照组比较,研究组术后引流量、术中出血量较少,手术、住院及骨折愈合时间较短,并发症发生率较低(P<0.05)。与术前比较,术后3个月2组AOFAS评分、Bohler角、Gissane角、跟骨长度、跟骨高度、P1NP、骨特异性碱性磷酸酶(BALP)水平升高,且研究组高于对照组,抗酒石酸酸性磷酸酶(TRAP)、环磷酰胺(CTX)水平降低,且研究组低于对照组(P<0.05)。与术前比较,术后3 d 2组CRP、IL-6、MDA水平升高,但研究组低于对照组,SOD水平降低,但研究组高于对照组(P<0.05)。结论 跗骨窦小切口术治疗跟骨骨折效果理想,可减少手术创伤,减轻炎症及应激反应,且可促进术后足功能、骨代谢恢复,并发症少。

形状系数对20 L球内铝粉分散特性的影响研究

为研究不同形状系数(SF)的铝粉在20 L球型容器中的分散特征,通过建立描述气流携带粉尘形成两相分散系的非稳态数值模型,包括气体流动和粉尘颗粒运动轨迹方程,开展非稳态数值模拟,分析粉尘SF分别为0.2、0.4、0.6、0.8和1.0条件下的粉尘空间分布以及球室中心的湍流动能、速度随时间变化。结果表明:球室内气流携带粉尘分散可以分为进粉、扩散、稳定和沉降4个阶段,其分散均匀性和最大速度值随SF的增加而增强;SF越大,即颗粒形状越接近球形,铝粉尘的分散性越好;SF越小,粉尘容易堆积在壁面附近;标称浓度一定时,SF≤0.4,浓度峰值随SF的增加而增加;SF>0.4,浓度峰值随SF的增加而减小;铝粉-空气混合物的湍流动能最大值随SF值的增加而降低;铝粉颗粒的速度峰值随SF值的增加而升高。

一种L波段300W GaN脉冲功率模块

随着第三代半导体GaN器件技术的不断发展,GaN高电子迁移率晶体管(HEMT)在电子系统中逐步得到了广泛应用。研制了一款小型化L波段300 W GaN脉冲功率模块。研发了满足高压脉冲工作条件的GaN HEMT芯片,采用负载牵引技术进行了器件大信号阻抗参数提取,并以此为基础设计了小型化匹配网络进行阻抗变换。基于高压驱动芯片和开关器件芯片设计了小型化高压脉冲调制电路。测试结果表明,在工作频率990~1130 MHz、工作电压50 V、脉冲宽度100μs、占空比10%下,功率模块脉冲输出功率大于300 W,功率附加效率大于53%,功率增益大于38 dB。功率模块尺寸为30 mm×30 mm×8 mm。

可用于WLAN的双频MIMO天线设计

设计了一款可用于WLAN的双频MIMO天线。天线的正面为L型单极子,背面为金属接地板。通过在接地板上加载耦合枝节使天线具有双频特性。同时,为了天线的小型化,对耦合枝节进行了弯折处理,减小天线尺寸。在两个天线单元之间加载T型寄生枝节和刻蚀矩形缝隙来提高天线的隔离度。使用电磁仿真软件和矢量网络分析仪对天线进行仿真和实测,结果表明:天线的工作频段为2.4~2.55 GHz和5.1~6.3 GHz,覆盖了WLAN的频段,同时在低频段内隔离度高于19 dB,高频段内隔离度高于25 dB。此外,天线的包络相关系数小于0.01且具有全向辐射特性。天线整体性能较好,可以满足WLAN的需求。

基于高阶幂的单快拍LDACS系统波达方向估计

L波段数字航空通信系统(L band digital aeronautical communication system,LDACS)是未来航空宽带通信重要的基础设施之一,针对LDACS信号容易受到相邻波道大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出了联合正交投影干扰抑制与单快拍稀疏分解的波达方向(direction of arrival,DOA)估计方法。通过子空间投影抑制DME干扰,然后使用单快拍数据构建伪协方差矩阵,对伪协方差矩阵求高阶幂,之后进行奇异值分解,并利用约束条件求解稀疏解得到期望信号来向的估计值。所提方法使用高阶伪协方差矩阵降低了噪声影响,仅用单快拍就可以准确估计LDACS信号的入射方向。仿真结果表明,改进单快拍高级幂(improved single snapshot high order power,ISS-HOP)L1-SVD算法的估计精度优于ISS-HOP-MUSIC算法。该方法可以有效抑制DME干扰,提高OFDM接收机性能。

2020年呼和浩特市和林格尔M_(L)4.5地震破裂方向性测定及发震构造分析

本文基于区域数字地震台网波形数据,在三维空间内利用gCAP反演方法获得2020年3月30日和林格尔M_(L)4.5地震矩心的空间精细位置为40.131°N, 111.922°E,深度为13 km。最佳震源机制解节面Ⅰ为走向279°,倾角41°,滑动角-27°;节面Ⅱ为走向30°,倾角72°,滑动角-127°;矩震级MW3.98。采用双差定位法对主震和余震序列进行重定位,获得19个地震事件的重定位结果。研究表明,主震震源参数为40.136°N, 111.858°E,震源深度为11.718 km;余震序列沿NW—SE方向双向扩展,地下破裂长度约为4.6 km;深度剖面显示,主震位于余震区中部,主破裂同时向上和向下扩展,深度分布范围为4~17 km。利用Hypocenter-Centroid方法对地震发震断层进行快速判断,20组测定结果均显示NW走向的节面Ⅰ为发震断层面。综合震源区地质构造、余震序列分布、区域构造应力场及三维地壳结构等研究结果,推断和林格尔M_(L)4.5地震的发震断层是一条沿NW向延伸的隐伏断裂。本次地震是一次左旋走滑、带正断分量的事件。地震发生于地壳内波速高低转换的过渡区,位于偏高速体一侧。综合分析认为,流体物质的涌入是引发2020年和林格尔M_(L)4.5地震的关键因素,而复杂的断层结构不仅为流体运移提供了通道,且控制着地震的发生及地震序列的空间展布。

L型阵水下目标方位和距离联合最大似然估计

空间目标定位是阵列信号处理领域中的研究热点,广泛应用于雷达、声纳、通信、射电天文、医学诊断、地震遥感等众多领域。传统的水下声源定位仅获取目标声源的深度和距离信息,却无法估计目标的方位信息。针对这一问题,在充分考虑水下声传播模型的基础上,利用L型阵列固有的结构特征,将最大似然估计技术应用到水下目标定位,提出一种基于L型水听器阵列的水下目标方位与距离联合最大似然估计算法。研究表明:最大似然估计法可有效突破传统波束形成分辨力“瑞利限”的限制,提高水下目标定位的分辨能力和精度。计算机仿真分析显示,在单目标和相干双目标的场景中,文中所提出的方法均具有更为尖锐的谱峰及更低的旁瓣水平,可对水下目标进行有效的方位角和距离联合估计。