Symbol-level fiber-longitudinal power profile estimation.

Symbol-level fiber-longitudinal power profile estimation (PPE) greatly reduces the implementation complexity compared with the waveform-level PPE using oversampled data. However, symbol-rate data cannot account for the inter-sample interaction, which leads to inaccuracy of the absolute power estimation. To realize an accurate symbol-level PPE, we provide an in-depth analysis of the differences between symbol-level and waveform-level perturbation matrices and propose a power calibration method based on the trace of the inverse matrix. Evaluated in the probabilistic constellation shaping (PCS) 64QAM 130 Gbaud 5 × 50 km optical links, the root mean squared error (RMSE) of the symbol-level PPE decreases by 0.98 and 0.62 dB at erbium-doped fiber amplifier (EDFA) positions and all estimated positions with the aid of matrix calibration.

Prediction of Dexterous Finger Forces With Forearm Rotation Using Motoneuron Discharges.

Motor unit (MU) discharge information obtained via electromyogram (EMG) decomposition can be used to decode dexterous multi-finger movement intention for neural-machine interfaces (NMI). However, the variation of the motor unit action potential (MUAP) shape resulted from forearm rotation leads to the decreased performance of EMG decomposition, especially under the real-time condition and then the degradation of motion decoding accuracy. The object of this study was to develop a method to realize the accurate extraction of MU discharge information across forearm pronated/supinated positions in the real-time condition for dexterous multi-finger force prediction. The FastICA-based EMG decomposition technique was used and the proposed method obtained multiple separation vectors for each MU at different forearm positions in the initialization phase. Under the real-time condition, the MU discharge information was extracted adaptively using the separation vector extracted at the nearest forearm position. As comparison, the previous method that utilized a single constant separation vector to extract MU discharges across forearm positions and the conventional method that utilized the EMG amplitude information were also performed. The results showed that the proposed method obtained a significantly better performance compared with the other two methods, manifested in a larger coefficient of determination ( [Formula: see text] and a smaller root mean squared error (RMSE) between the predicted and recorded force. Our results demonstrated the feasibility and the effectiveness of the proposed method to extract MU discharge information during forearm rotation for dexterous force prediction under the real-time conditions. Further development of the proposed method could potentially promote the application of the EMG decomposition technique for continuous dexterous motion decoding in a realistic NMI application scenario.

Multi-style spatial attention module for cortical cataract classification in AS-OCT image with supervised contrastive learning.

BACKGROUND AND OBJECTIVE: Precise cortical cataract (CC) classification plays a significant role in early cataract intervention and surgery. Anterior segment optical coherence tomography (AS-OCT) images have shown excellent potential in cataract diagnosis. However, due to the complex opacity distributions of CC, automatic AS-OCT-based CC classification has been rarely studied. In this paper, we aim to explore the opacity distribution characteristics of CC as clinical priori to enhance the representational capability of deep convolutional neural networks (CNNs) in CC classification tasks. METHODS: We propose a novel architectural unit, Multi-style Spatial Attention module (MSSA), which recalibrates intermediate feature maps by exploiting diverse clinical contexts. MSSA first extracts the clinical style context features with Group-wise Style Pooling (GSP), then refines the clinical style context features with Local Transform (LT), and finally executes group-wise feature map recalibration via Style Feature Recalibration (SFR). MSSA can be easily integrated into modern CNNs with negligible overhead. RESULTS: The extensive experiments on a CASIA2 AS-OCT dataset and two public ophthalmic datasets demonstrate the superiority of MSSA over state-of-the-art attention methods. The visualization analysis and ablation study are conducted to improve the explainability of MSSA in the decision-making process. CONCLUSIONS: Our proposed MSSANet utilized the opacity distribution characteristics of CC to enhance the representational power and explainability of deep convolutional neural network (CNN) and improve the CC classification performance. Our proposed method has the potential in the early clinical CC diagnosis.

High-Frequency Repetitive Magnetic Stimulation at the Sacrum Alleviates Chronic Constipation in Parkinson's Patients.

Objective: This study was to investigate the therapeutic effect of high-frequency repetitive magnetic stimulation (HF-rMS) at the sacrum for chronic constipation in Parkinson's patients (PD). Materials and Methods: Eventually 48 PD patients were enrolled from July 2019 to October 2020, and randomly divided into the HF-rMS group (the intervention group, n = 24) and the sham HF-rMS group (the control group, n = 24). The intervention group received HF-rMS at the sacrum, whereas the control group received ineffective magnetic stimulation. We performed clinical evaluation before and after HF-rMS treatment, including constipation score scale (KESS questionnaire), Unified Parkinson's Disease Rating Scale (UPDRS-III exercise examination), Hoehn-Yahr (H-Y) stage of motor function; simple mental status scale (MMSE), anxiety/depression table (HAD-A/HAD-D), the activity of daily living (ADL), and quality of life scale for patients with constipation (PAC-QOL) to evaluate symptoms and satisfaction of PD patients with chronic constipation. Results: There was no significant difference in the clinical characteristics between the two groups. As compared to the control group, the HF-rMS group displayed a larger change (pre and posttreatment) in the KESS scores of PD patients with chronic constipation, suggesting a significant improvement. Moreover, HF-rMS significantly promoted the mood, activity of daily living, and quality of life of PD patients when comparing the alteration of HAD-A/HAD-D scores, ADL scores, and PAC-QOL scores between the two groups. Finally, there was no significant difference in the change of the UPDRS III score and the MMSE score between the two groups. Conclusion: HF-rMS at the sacrum can improve chronic constipation in PD patients.

Transcriptome Sequencing of CeRNA Network Constructing in Status Epilepticus Mice Treated by Low-Frequency Repetitive Transcranial Magnetic Stimulation.

It is shown that great progress was recently made in the treatment of repetitive transcranial magnetic stimulation (rTMS) for neurological and psychiatric diseases. This study aimed to address how rTMS exerted it therapeutic effects by regulating competitive endogenous RNAs (ceRNAs) of lncRNA-miRNA-mRNA. The distinction of lncRNA, miRNA and mRNA expression in male status epilepticus (SE) mice treated by two different ways, low-frequency rTMS (LF-rTMS) vs. sham rTMS, was analyzed by high-throughput sequencing. The Gene Ontology (GO) functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were carried out. Gene-Gene Cross Linkage Network was established; pivotal genes were screened out. qRT-PCR was used to verify gene-gene interactions. Our results showed that there were 1615 lncRNAs, 510 mRNAs, and 17 miRNAs differentially which were expressed between the LF-rTMS group and the sham rTMS group. The expression difference of these lncRNAs, mRNAs, and miRNAs by microarray detection were consistent with the results by qPCR. GO functional enrichment showed that immune-associated molecular mechanisms, biological processes, and GABA-A receptor activity played a role in SE mice treated with LF-rTMS. KEGG pathway enrichment analysis revealed that differentially expressed genes were correlated to T cell receptor signaling pathway, primary immune deficiency and Th17 cell differentiation signaling pathway. Gene-gene cross linkage network was established on the basis of Pearson's correlation coefficient and miRNA. In conclusion, LF-rTMS alleviates SE through regulating the GABA-A receptor activity transmission, improving immune functions, and biological processes, suggesting the underlying ceRNA molecular mechanisms of LF-rTMS treatment for epilepsy.

Effect of High-Frequency Repetitive Peripheral Magnetic Stimulation on Motor Performance in Intracerebral Haemorrhage: A Clinical Trial.

OBJECTIVES: The aim of the randomized, double-blind, sham-controlled trial was to explore the efficacy and safety of HF-rPMS synchronosly applied to the axilla (stimulating the brachial plexus) and the popliteal fossa (stimulating the tibial nerve and common peroneal nerve) in patients with intracerebral hemorrhage on rehabilitation of motor functions. MATERIALS AND METHODS: Patients with intracerebral haemorrhage in the early period were recruited and randomly assigned to the HF-rPMS group or the sham rPMS group. The two synchrous coils of magnetic stimulation in the two groups were respectively applied to the axilla and the popliteal fossa of the affected limb. But the sham group received the ineffective rPMS and only heard the sound as occured in the HF-rPMS group. Clinical outcomes included the change of Fugl-Meyer Assessment (FMA) scale and Medical Research Council (MRC) scale before and after HF-rPMS. RESULTS: Of 76 eligible patients, 30 were included and only 26 patients completed this study. The diferences on the improvement of the upper extremity FMA (P=0.012), the lower extremity FMA (P=0.001), the proximal MRC of upper extremity (p = 0.043), the proximal MRC of lower extremity (p= 0.004) and the distal MRC scores of lower extremity (p= 0.008) between the the HF-rPMS group and sham rPMS group were statistically signifcant. CONCLUSIONS: Synchrous HF-rPMS intervention at the axilla and the popliteal fossa significantly improved motor function and proximal muscle strength of upper and lower limb of patients in acute or early subacute phase of intracerebral hemorrhage.

Kramers-Kronig detection with the Brillouin-amplified virtual carrier.

We proposed a novel scheme for realizing Kramers-Kronig detection by utilizing the narrow-band and high-gain characteristic of stimulated Brillouin scattering. At the receiver, the weak virtual carrier located at the edge of the signal spectrum is Brillouin amplified by the output of a slave laser, which is injection locked by a weak pump seed provided by the transmitter. More than a 2.7-dB optical signal-to-noise ratio sensitivity improvement is experimentally obtained compared with the traditional virtual carrier assisted scheme after an 80-km transmission. The effective number of bits requirement and the performance gain in the nonlinear transmission are both analyzed by the simulation.

Enhanced performance in serial-to-parallel data conversion via Raman-assisted time lens processing.

We have demonstrated a new approach to enhance the uniformity of conversion efficiency in serial-to-parallel data conversion via time lens processing. In our approach, Raman amplification is applied to enhance four-wave mixing in a highly nonlinear fiber. By carefully selecting the pump wavelength, the Raman gain profile can be exploited to compensate the roll-off in conversion efficiency resulted from the varying phase mismatch between the linearly chirped pump and the signal. With Raman amplification, improvement of sensitivity up to 6.8 dB has been experimentally obtained. The variation of sensitivity across the output channels has been reduced from 8.4 to 2.0 dB.

Goose Toll-like receptor 7 (TLR7), myeloid differentiation factor 88 (MyD88) and antiviral molecules involved in anti-H5N1 highly pathogenic avian influenza virus response.

In mammals, Toll-like receptor 7 (TLR7) is an important membrane-bound receptor triggered by antiviral compounds and single-stranded RNA. It is implicated in the immune response to viruses such as influenza virus. It was not known whether geese, a natural host for avian influenza viruses, possess a homologue of mammalian TLR7 for recognizing avian influenza virus. In this study, we cloned the full-length of goose TLR7 and partial sequences of its adaptor protein, myeloid differentiation factor 88 (MyD88), some antiviral molecules such as RNA-dependent protein kinase (PKR) and 2',5'-oligoadenylate synthetase (OAS). Goose TLR7 has a protein secondary structure identical to that of mammals, consisting of several leucine-rich domains, a transmembrane domain, and Toll/interleukin-1 receptor domain. To further understand whether the MyD88-dependent pathway of TLR7 is involved in the antiviral innate immune response against highly pathogenic avian influenza virus (HPAIV) infection in geese, we inoculated geese with an H5N1 HPAIV isolated from ducks in 2004. The virus, A/Duck/Guangdong/212/2004, replicated in various tissues resulting in 40% mortality. Quantitative real-time PCR analysis showed upregulation of mRNA transcripts for TLR7, MyD88, PKR and OAS in the lungs of geese at 1, 2 and 3 days post-inoculation. Therefore, the MyD88-dependent pathway of TLR7 was involved in the early stage of antiviral innate immune response in geese during H5N1 HPAIV infection.