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 %

Spurious-Free Dynamic Range Augmentation for Digital-to-Analog Converters using PSO-PID Adaptive Algorithms

In this paper, we propose a new method for enhancing the spurious-free dynamic range (SFDR) of digital-to-analog converters (DACs) by implementing a digital predistorter to suppress harmonic distortion. First, the particle swarm optimization (PSO) algorithm is used to optimize the proportional-integral-derivative (PID) parameters, after which the PSO-PID algorithm is implemented to identify the best signal featuring the least harmonic distortion. Next, the Hilbert transform-based memory polynomial (HTBMP) model is employed to accurately represent the harmonic predistorter for the DAC. Finally, using a single-tone sine signal in shortwave frequency bands, it is demonstrated that the proposed HTBMP predistortion model can enhance the SFDR of a DAC by at least 9 dB

A nomogram based on inflammation and nutritional biomarkers for predicting the survival of breast cancer patients

BackgroundWe aim to develop a new prognostic model that incorporates inflammation, nutritional parameters and clinical-pathological features to predict overall survival (OS) and disease free survival (DFS) of breast cancer (BC) patients.MethodsThe study included clinicopathological and follow-up data from a total of 2857 BC patients between 2013 and 2021. Data were randomly divided into two cohorts: training (n=2001) and validation (n=856) cohorts. A nomogram was established based on the results of a multivariate Cox regression analysis from the training cohorts. The predictive accuracy and discriminative ability of the nomogram were evaluated by the concordance index (C-index) and calibration curve. Furthermore, decision curve analysis (DCA) was performed to assess the clinical value of the nomogram.ResultsA nomogram was developed for BC, incorporating lymphocyte, platelet count, hemoglobin levels, albumin-to-globulin ratio, prealbumin level and other key variables: subtype and TNM staging. In the prediction of OS and DFS, the concordance index (C-index) of the nomogram is statistically greater than the C-index values obtained using TNM staging alone. Moreover, the time-dependent AUC, exceeding the threshold of 0.7, demonstrated the nomogram’s satisfactory discriminative performance over different periods. DCA revealed that the nomogram offered a greater overall net benefit than the TNM staging system.ConclusionThe nomogram incorporating inflammation, nutritional and clinicopathological variables exhibited excellent discrimination. This nomogram is a promising instrument for predicting outcomes and defining personalized treatment strategies for patients with BC

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