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【Objective】The non-linear characteristics of Light Emitting Diodes (LEDs) contribute to the degradation of Bit Error Rate (BER) performance in Visible Light Communication (VLC) systems, particularly in Optical Orthogonal Frequency Division Multiplexing (O-OFDM) systems with high Peak-to-Average Power Ratio (PAPR). A single-stage equalizer based on the Volterra series can handle the high-order non-linear distortions of LEDs with low latency. However, solving the traditional Volterra series necessitates multiple integration operations, resulting in the high implementation complexity of the Volterra-based equalizer. Additionally, the single-stage equalizer accumulates errors with limited performance improvements.【Methods】Firstly, to address the issue of high computational complexity in the traditional calculations of the Volterra series, a proposition is made to retain only the high-order power series terms of the various nonlinear terms and kernel coefficients within the Volterra series. This approach, known as the Memory Polynomial-based Volterra Series (MPVS), not only reduces the computational complexity compared to the traditional Volterra series but also enhances the accuracy of nonlinear system modeling by considering all input signals at the current moment. Subsequently, the design of channel equalizer considers the Memory Polynomial-based Volterra (MPV) equalizer and the Memory Polynomial-based Volterra Decision Feedback Equalizer (MPV-DFE). For a single-stage MPV-DFE, if an error occurs in the decision part leading to an incorrect symbol decoding, this error tends to manifest as a consecutive series of errors, thereby impacting the entire symbol sequence. To mitigate this, a proposal is made to cascade the two non-linear equalizers, MPV and MPV-DFE, forming a hybrid equalizer called MPV+MPV-DFE. The MPV equalizer performs a primary equalization on the LED's nonlinear distortion signal, effectively suppressing a portion of the non-linear distortions and thereby reducing symbol decoding errors in the MPV-DFE. Subsequently, a secondary equalization is carried out by the MPV-DFE, leading to improved suppression of residual nonlinear distortions.【Results】Finally, the effectiveness of the system design was validated using Monte Carlo simulation to analyze the BER. The results demonstrate that compared to the single-stage MPV equalizer and the linear-cascade nonlinear hybrid equalizer (LMS+MPV-DFE), the proposed hybrid equalizer achieves approximately 7 dB and 2 dB Signal-to-Noise Ratio (SNR) gains, respectively, in a 4 Quadrature Amplitude Modulation (QAM) -modulated Asymmetrically Clipped Optical OFDM (ACO-OFDM) system at a BER of 10-4.【Conclusion】In conclusion, the implementation of the MPV equalizer is straightforward, and the cascaded design of the two-stage nonlinear equalizers as a hybrid equalizer enables better mitigation of the LED’s nonlinearity.

Abstract Sarcopenia has been associated with higher toxicity induced by anti-cancer treatments and shorter survival in patients with squamous cell lung carcinoma (SqCLC). Over the past few decades, immune checkpoint inhibitors (ICIs) significantly improves the prognosis. However, few clinical studies explored the effectiveness of immunotherapy in the elderly population. Here, we performed a retrospective analysis to determine the prognostic role of sarcopenia in older patients with SqCLC receiving ICIs. We retrospectively assessed SqCLC patients who were treated with PD-1 inhibitors and all patients were at least 70 years old. Pre-treatment sarcopenic status was determined by analyzing L3 skeletal muscle index (SMI) with chest CT. Progression-free survival (PFS), disease-specific survival (DSS) and overall survival (OS) were estimated using the Kaplan–Meier method, and the differences in survival were compared using the log-rank test. Among 130 male SqCLC patients, 93 had sarcopenia. Patients with sarcopenia were older and had a lower body mass index (BMI). Over an average follow-up of 20.8 months, 92 patients died. For all 130 patients, the mean OS was 13.3 months. Patients with sarcopenia had a significantly shorter OS and PFS than those without sarcopenia (OS, 12.4 ± 5.2 months vs. 15.5 ± 10.5 months, P = 0.028; PFS, 6.4 ± 2.9 months vs. 7.7 ± 4.2 months; P = 0.035). Multivariable analysis showed that sarcopenia was an independent prognostic factor for shorter OS and PFS. CT-determined sarcopenia is an independent prognostic factor for older patients with SqCLC receiving ICIs.

Objective: Hashimoto’s thyroiditis is an inflammatory disease, and research suggests that a low-carbohydrate diet may have potential anti-inflammatory effects. This study aims to utilize Dixon-T2-weighted imaging (WI) sequence for a semi-quantitative assessment of the impact of a low-carbohydrate diet on the degree of thyroid inflammation in patients with Hashimoto’s thyroiditis. Methods: Forty patients with Hashimoto’s thyroiditis were recruited for this study and randomly divided into two groups: one with a normal diet and the other with a low-carbohydrate diet. Antibodies against thyroid peroxidase (TPOAb) and thyroglobulin (TgAb) were measured for all participants. Additionally, thyroid water content was semi-quantitatively measured using Dixon-T2WI. The same tests and measurements were repeated for all participants after 6 months. Results: After 6 months of a low-carbohydrate diet, patients with Hashimoto’s thyroiditis showed a significant reduction in thyroid water content (94.84 ± 1.57% vs 93.07 ± 2.05%, P < 0.05). Concurrently, a decrease was observed in levels of TPOAb and TgAb (TPOAb: 211.30 (92.63–614.62) vs 89.45 (15.9–215.67); TgAb: 17.05 (1.47–81.64) vs 4.1 (0.51–19.42), P < 0.05). In contrast, there were no significant differences in thyroid water content or TPOAb and TgAb levels for patients with Hashimoto’s thyroiditis following a normal diet after 6 months (P < 0.05). Conclusion: Dixon-T2WI can quantitatively assess the degree of thyroid inflammation in patients with Hashimoto’s thyroiditis. Following a low-carbohydrate diet intervention, there is a significant reduction in thyroid water content and a decrease in levels of TPOAb and TgAb. These results suggest that a low-carbohydrate diet may help alleviate inflammation in patients with Hashimoto’s thyroiditis.

Students are commonly in a high cognitive load state when they encounter sophisticated knowledge. Whether the novel augmented reality (AR) technology can be utilized in an online learning course to explain complicated scientific concepts in a more understandable manner to students during the COVID-19 period is an unaddressed issue. This study aims to investigate the influences of reducing the physical touch or face-to-face teaching/learning practices via using mobile augmented reality learning systems (MARLS) on students' perceived learning effectiveness. The information feedback viewpoint, flow theory, and cognitive load theory are integrated to examine the effects of the information feedback of MARLS on students' learning effectiveness. This study recruited 204 participants from ten universities to complete a learning task via a MARLS and fill out a questionnaire to collect data for the proposed research model. The empirical results revealed information feedback positively and significantly affected flow experience, perceived learning effectiveness, and continued intention. The improved learning performance of learners was positively related to their continued intention. Also, the extraneous cognitive load negatively and significantly moderated the relationship between information feedback and perceived learning effectiveness. This study proposes meaningful implications and suggestions for future research based on the findings of this experiment.