Miniaturized substrate-integrated coaxial line bandpass filter with improved upper stopband

A miniaturized substrate-integrated coaxial line (SICL) bandpass filter with improved upper stopband using asymmetrical spiral stub-loaded resonators is presented in this paper. Owing to the space-filling feature of the spiral structure, the size of the proposed filter is significantly reduced. A theoretical analysis is carried out to examine the resonance property of the proposed resonator. It is found that the frequency ratios of the second and third harmonics to the fundamental frequency can be extended to 2.86 and 4.4. Benefiting from the circuit structure and SICL technology, the designed filter has a small size, wide stopband, low crosstalk, and high-density integration ability. The measured results show that the proposed filter, with dimensions of 0.051λ0 × 0.044λ0, operates at 1.056 GHz and the 20-dB rejection band is extended to 3.94f0

Dual-band filtering power divider with capacitor-loaded centrally coupled-line resonators

In this paper, a dual-band filtering power divider (DB-FPD) with capacitor-loaded centrally coupled-line resonators (CLCCLRs) is presented. The proposed design utilizes four CLCCLRs, two resistors and one inductor to achieve the dual functions of dual-band filtering and power division. By altering the values of the capacitors loaded at the ends of the coupled-lines, the center frequencies of the two passbands can be adjusted independently. It is noted that changing one passband will not affect the other. For demonstration, a microstrip filtering power divider is designed, fabricated and measured. Under different values of the loaded capacitors, experimental results show that the lower band center frequency varies from 0.7 GHz to 1.0 GHz with the upper band fixed at 1.75 GHz, whereas the upper band center frequency varies from 1.65 GHz to 1.95 GHz when the lower band is fixed at 1.0 GHz. The measured results show good agreement with the simulations

Circularly polarized integrated filtering antenna with polarization reconfigurability

A new design of circularly polarized (CP) integrated filtering antennas with reconfigurable polarization is proposed in this paper. Two phase-reconfigurable coupled λ/2-resonator pairs have been used to feed the antenna and generate the 2nd-order filtering response and the circular polarization simultaneously. By switching the PIN diodes inserted in the feeding network, a phase difference of +90° or - 90° can be realized at the outputs of the feeding network. This renders the antenna’s capability of switching its polarization from right hand circular polarization (RHCP) to left hand circular polarization (LHCP) or vice versa. The use of the coupled-resonator pairs significantly improves the frequency selectivity and out-of-band rejection of the CP antenna. To the best of the authors’ knowledge, this is the first report of a multifunctional antenna which has integrated filtering performance, circular polarization and polarization reconfigurability. To verify the design concept, a reconfigurable CP antenna operating at 2.45 GHz is implemented. The simulated and measured results agree well with each other and show that the antenna has an impedance bandwidth of 4.5 %, an average in-band gain of 6.0 dBic (LHCP)/6.1 dBic (RHCP), out-of-band rejections of greater than 10.8 dB, and 3-dB AR bandwidth of 9.4 %/10.5 %

Evaluation of pharmacological and pharmacokinetic herb-drug interaction between irinotecan hydrochloride injection and Kangai injection in colorectal tumor-bearing mice and healthy rats

Introduction: Kangai (KA) injection, a Chinese herbal injection, is often used in combination with irinotecan (CPT-11) to enhance the effectiveness of anti-colorectal cancer treatment and alleviate side effects. However, the combined administration of this herb-drug pair remains controversial due to limited pre-clinical evidence and safety concerns. This study aimed to determine the pre-clinical herb-drug interactions between CPT-11 and KA injection to provide a reference for their clinical co-administration.Methods: In the pharmacological study, BALB/c mice with CT26 colorectal tumors were divided into four groups and treated with vehicle alone (0.9% saline), CPT-11 injection (100 mg/kg), KA injection (10 mL/kg), or a combination of CPT-11 and KA injection, respectively. The tumor volume of mice was monitored daily to evaluate the therapeutic effect. Daily body weight, survival rate, hematopoietic toxicity, immune organ indices, and gut toxicity were analyzed to study the adverse effects. Healthy Sprague-Dawley rats in the pharmacokinetic study were administered KA injection only (4 mL/kg), or a combination of CPT-11 injection (20 mg/kg) and KA injection, respectively. Six key components of KA injection (oxymatrine, matrine, ginsenoside Rb1, Rg1, Re, and astragaloside IV) in rat plasma samples collected within 24 h after administration were determined by LC-MS/MS.Results: The pharmacological study indicated that KA injection has the potential to enhance the anti-colorectal cancer efficacy of CPT-11 injection and alleviate the severe weight loss induced by CPT-11 injection in tumor-bearing mice. The pharmacokinetic study revealed that co-administration resulted in inhibition of oxymatrine metabolism in rats, evidenced by the significantly reduced Cmax and AUC0-t of its metabolite, matrine (p < 0.05), from 2.23 ± 0.24 to 1.38 ± 0.12 μg/mL and 8.29 ± 1.34 to 5.30 ± 0.79 μg h/mL, respectively. However, due to the similar efficacy of oxymatrine and matrine, this may not compromise the anti-cancer effect of this herb-drug pair.Discussion: This study clarified the pre-clinical pharmacology and pharmacokinetic benefits and risks of the CPT-11-KA combination and provided a reference for their clinical co-administration

Protective Effect of Rivaroxaban Against Amyloid Pathology and Neuroinflammation Through Inhibiting PAR-1 and PAR-2 in Alzheimer’s Disease Mice

Background: Recent studies have revealed that atrial fibrillation (AF) patients have a high risk of developing cognitive impairment, vascular dementia, and Alzheimer’s disease (AD). Some reports suggest that the application of oral anticoagulant with an appropriate dose may have a preventive effect on AD. However, which oral anticoagulant drug is more appropriate for preventing AD and the underlying mechanism(s) is still unknown. Objective: The aim of the present study was to assess the treatment effect of rivaroxaban administration as well as investigate the roles of PAR-1 and PAR-2 in the AD + CAA mice model. Methods: In the present study, we compared a traditional oral anticoagulant, warfarin, and a direct oral anticoagulant (DOAC), rivaroxaban, via long-term administration to an AD with cerebral amyloid angiopathy (CAA) mice model. Results: Rivaroxaban treatment attenuated neuroinflammation, blood-brain barrier dysfunction, memory deficits, and amyloid-β deposition through PAR-1/PAR-2 inhibition in the AD + CAA mice model compared with warfarin and no-treatment groups. Conclusion: The present study demonstrates that rivaroxaban can attenuate AD progress and can be a potential choice to prevent AD

Analysis on contamination of Bacillus cereus in foodstuff in Jilin Province from 2011 to 2019

Objective To understand the contamination of Bacillus cereus in foodstuff of Jilin Province from 2011 to 2019, and to provide theoretical basis for food safety monitoring and prevention of foodborne diseases. Methods Totally 3 173 samples were collected from the catering service and circulation of nine prefecture (city) levels in Jilin Province from 2011 to 2019. Bacillus cereus in food was detected according to the method of GB 4789.14-2014 national food safety standard microbiological examination of food. The detection rate was analyzed by rate, composition ratio and χ2 test. Results Among 3 173 food samples from 2011 to 2019 in Jilin Province, the total detection rate of Bacillus cereus was 23.6% (750/3 173), the highest was in 2015 (38.5%, 62/161), and the lowest was in 2017 (11.8%, 20/170). Baishan City had the highest detection rate (35.8%, 139/388), followed by Yanbian Prefecture (31.4%, 97/309), and Siping City had the lowest detection rate (15.3%, 76/496). The detection rate of egg and egg products was the highest (60.0%, 3/5), followed by milk and dairy products (39.3%, 114/290) and infant food (31.1%, 185/595). Contamination of Bacillus cereus was the highest in department stores (32.4%, 22/68), followed by snack bars and beverage stores (30.9%, 43/139), and fast food stores (29.1%, 25/86). The median (interquartile interval) of the detection result of Bacillus cereus by colony forming units method was 5.8 (2.9, 8.7) CFU/g (mL), and the median (interquartile interval) of that by most probable number method was 6.4 (3.2, 9.6) MPN/g (mL). Conclusion There were different degrees of Bacillus cereus contamination in foodstuff in Jilin Province. Among the different cities, foodstuff samples collected from Baishan City was much more serious. Eggs and egg products, milk and dairy products were the main contaminated food. Safety monitoring and management of the snack bar, beverage shop and places in department store should be strengthen

Dynamic behavior modeling and nonlinearity precompensation for broadband transmitters

De-embedding static nonlinearities and accurately identifying and modeling memory effects in wideband RF transmitters -- Hammerstein predistorter for linearization of broadband wireless transmitters -- Dynamic behavorial modeling of 3G power amplifiers using real-valued time delay natural networks