Amblyopia is a visual development deficit caused by abnormal visual experience in early life, mainly manifesting as defected visual acuity and binocular visual impairment, which is considered to reflect abnormal development of the brain rather than organic lesions of the eye. Previous studies have reported abnormal spontaneous brain activity in patients with amblyopia. However, the location of abnormal spontaneous activity in patients with amblyopia and the association between abnormal brain function activity and clinical deficits remain unclear. The purpose of this study is to analyze spontaneous brain functional activity abnormalities in patients with amblyopia and their associations with clinical defects using resting-state functional magnetic resonance imaging (fMRI) data. In this study, 31 patients with amblyopia and 31 healthy controls were enrolled for resting-state fMRI scanning. The results showed that spontaneous activity in the right angular gyrus, left posterior cerebellum, and left cingulate gyrus were significantly lower in patients with amblyopia than in controls, and spontaneous activity in the right middle temporal gyrus was significantly higher in patients with amblyopia. In addition, the spontaneous activity of the left cerebellum in patients with amblyopia was negatively associated with the best-corrected visual acuity of the amblyopic eye, and the spontaneous activity of the right middle temporal gyrus was positively associated with the stereoacuity. This study found that adult patients with amblyopia showed abnormal spontaneous activity in the angular gyrus, cerebellum, middle temporal gyrus, and cingulate gyrus. Furthermore, the functional abnormalities in the cerebellum and middle temporal gyrus may be associated with visual acuity defects and stereopsis deficiency in patients with amblyopia. These findings help explain the neural mechanism of amblyopia, thus promoting the improvement of the treatment strategy for amblyopia.
The forced oscillation technique (FOT) is an active pulmonary function measurement technique that was applied to identify the mechanical properties of the respiratory system using external excitation signals. FOT commonly includes single frequency sine, pseudorandom and periodic impulse excitation signals. Aiming at preventing the time-domain amplitude overshoot that might exist in the acquisition of combined multi sinusoidal pseudorandom signals, this paper studied the phase optimization of pseudorandom signals. We tried two methods including the random phase combination and time-frequency domain swapping algorithm to solve this problem, and used the crest factor to estimate the effect of optimization. Furthermore, in order to make the pseudorandom signals met the requirement of the respiratory system identification in 4–40 Hz, we compensated the input signals’ amplitudes at the low frequency band (4–18 Hz) according to the frequency-response curve of the oscillation unit. Resuts showed that time-frequency domain swapping algorithm could effectively optimize the phase combination of pseudorandom signals. Moreover, when the amplitudes at low frequencies were compensated, the expected stimulus signals which met the performance requirements were obtained eventually.
ObjectiveTo explore the predictive value of the maximum amplitude (MA) in the thromboelastogram (TEG) in the occurrence of venous thromboembolism (VTE) in patients with lung cancer after surgery.MethodsForty-one lung cancer patients with postoperative VTE in our hospital from September 2018 to August 2020 were enrolled into a thrombosis group, including 25 males and 16 females, aged 72.17±10.08 years. The 87 lung cancer patients who underwent surgery during the same period but did not suffer postoperative VTE were enrolled into a control group, including 51 males and 36 females, aged 71.06±9.49 years. The MA of thrombus in the TEG before and after the operation was compared between the two groups, and logistic regression analysis was used to test the value of the MA of thrombus at each time point in the TEG to predict the occurrence of VTE in patients with lung cancer surgery. The receiver operating characteristic curve was drawn to test the effectiveness of the MA of thrombus at each time point in the TEG to predict the occurrence of VTE in patients with lung cancer.ResultsThe MA of thrombus in the two groups after operation was greater than that before operation, and the MA of thrombus in the TEG on the day 3 after operation in the two groups> day 1> day 5 (P<0.05). The logistic regression analysis showed that the MA of thrombus in the TEG increased, which had predictive value for the occurrence of VTE in patients with lung cancer after surgery; the MA of thrombus in the TEG at each postoperative point was used as the test variable. Taking the occurrence of VTE as a state variable, the area under the curve (AUC) of MA of thrombus in the TEG on the 1st postoperative day was 0.82, and its optimal threshold was 75.15 mm; on the 3rd postoperative day, AUC was 0.88, and its optimal threshold was 80.05 mm; on the 5th day afterwards, AUC was 0.78, and its optimal threshold was 66.30 mm.ConclusionThe MA of TEG has a high predictive power for the occurrence of VTE in lung cancer patients after surgery, which suggests that TEG dynamic monitoring should be performed before surgery for lung cancer patients, and a reasonable anticoagulation plan should be formulated accordingly to reduce the occurrence of VTE.
The objective of this study is to combine troponin and indicators of cardiac acoustics for synthetically evaluating cardiac fatigue of rabbits, analyzing exercise-induced cardiac fatigue (EICF) and exercise-induced cardiac damage (EICD). New Zealand white rabbits were used to conduct a multi-step swimming experiments with load, reaching an exhaustive state for evaluating if the amplitude ratio of the first to second heart sound (S1/S2) and heart rate (HR) during the exhaustive exercise would decrease or not and if they would be recovered 24-48 h after exhaustive exercise. The experimental end point was to complete 3 times of exhaustions or death from exhaustion. Circulating troponin I (cTnI) were detected from all of the experimental rabbits at rest [(0.02±0.01) ng/mL], which, in general, indicated that there existed a physiological release of troponin. After the first exhaustive swim, cTnI of the rabbits increased. However, with 24-hour rest, S1/S2, HR, and cTnI of the tested rabbits all returned toward baseline levels, which meant that the experimental rabbits experienced a cardiac fatigue process. After repeated exhaustion, overloading phenomena were observed, which led to death in 3 out of 11 rabbits, indicating their cardiac damage; the troponin elevation under this condition could be interpreted by pathological release. Evaluation of myocardial damage can not be based on the troponin levels alone, but can only be based on a comprehensive analysis.
Objective To explore the evaluation value of burden of amplitudes and epileptiform discharges score (BASED) in the efficacy of adrenocorticotropic hormone (ACTH) combined with magnesium sulfate therapy for infantile epileptic spasms syndrome (IESS). Methods Retrospective collection the clinical and EEG data of 124 patients admitted to the Dongguan Maternal and Child Health Care Hospital from 2015 to 2023, who were diagnosed with IESS and treated with ACTH combined with magnesium sulfate. According to whether there were epileptic seizures 14 days after ACTH treatment, the patients were divided into two groups: non seizure group (n=74 cases) and seizure group (n=50 cases). The BASED system was used to evaluate the relationship between changes in EEG before and after ACTH treatment and clinical efficacy in both groups. The analysis of electroencephalogram included: ① abnormally high amplitude background waves, ② >3 spike foci , ③ grouped multifocal spikes, ④ paroxysmal voltage attenuation. ResultThe control rate of ACTH combined with magnesium sulfate in the treatment of IESS was 59.7% (74/124), and there was no statistically significant difference in the control rate among children with different etiologies (P=0.09). The BASED score suggests that the overall response rate of electroencephalogram (EEG) in infants with epileptic spasm syndrome after treatment was 57.2%. The EEG remission rate in the seizure control group was 81% (60/74), while in the uncontrolled group was 22% (11/50). The EEG remission rate in the seizure control group was significantly higher than that in the uncontrolled group after treatment (P<0.001), and the EEG score was closely related to clinical efficacy (Spearman correlation coefficient rp=0.601, P<0.001). ConclusionThe BASED score is related to clinical efficacy, and it can provide a quantitative basis for evaluating the efficacy of ACTH combined with magnesium sulfate in the treatment of IESS.
We investigated the baseline brain activity level in patients with major depressive disorder (MDD) by amplitude of low-frequency fluctuation (ALFF) based on resting-state functional MRI (fMRI). We examined 13 patients in the MDD group and 14 healthy volunteers in the control group by resting-state fMRI on GE Signa 3.0T. We calculated and compared the ALFF values of the two groups. In the MDD group, ALFF values in the right medial prefrontal were higher than those in control group, with statistically significant differences (P<0.001). ALFF values in the left parietal in the MDD group were lower than those in control group with statistically significant differences (P<0.001). This resting-state fMRI study suggested that the alteration brain activity in the right medial prefrontal and left parietal ALFF contributed to the understanding of the pathophysiological mechanism of MDD patients.
In order to quickly and accurately identify the onset and offset of the QRS complex in electrocardiogram (ECG) signal with different forms, a triple local transform method was employed in the present study to detect the suspected onset and offset points of QRS. The accurate onset and offset points of QRS complexes were selected according to the rules drawn by the trial process based on the characteristics of angle and amplitude constituted within these suspected points. The method makes full advantage of the angle and amplitude characteristics of the QRS complex, by which the results can be acquired with some simple arithmetic quickly, accurately and adaptively. The method was investigated with data from the MIT-BIH arrhythmia database and satisfactory results were obtained.
Alzheimer’s disease (AD) is a neurodegenerative disease characterized by cognitive impairment, with the predominant clinical diagnosis of spatial working memory (SWM) deficiency, which seriously affects the physical and mental health of patients. However, the current pharmacological therapies have unsatisfactory cure rates and other problems, so non-pharmacological physical therapies have gradually received widespread attention. Recently, a novel treatment using 40 Hz light flicker stimulation (40 Hz-LFS) to rescue the cognitive function of model animals with AD has made initial progress, but the neurophysiological mechanism remains unclear. Therefore, this paper will explore the potential neural mechanisms underlying the modulation of SWM by 40 Hz-LFS based on cross-frequency coupling (CFC). Ten adult Wistar rats were first subjected to acute LFS at frequencies of 20, 40, and 60 Hz. The entrainment effect of LFS with different frequency on neural oscillations in the hippocampus (HPC) and medial prefrontal cortex (mPFC) was analyzed. The results showed that acute 40 Hz-LFS was able to develop strong entrainment and significantly modulate the oscillation power of the low-frequency gamma (lγ) rhythms. The rats were then randomly divided into experimental and control groups of 5 rats each for a long-term 40 Hz-LFS (7 d). Their SWM function was assessed by a T-maze task, and the CFC changes in the HPC-mPFC circuit were analyzed by phase-amplitude coupling (PAC). The results showed that the behavioral performance of the experimental group was improved and the PAC of θ-lγ rhythm was enhanced, and the difference was statistically significant. The results of this paper suggested that the long-term 40 Hz-LFS effectively improved SWM function in rats, which may be attributed to its enhanced communication of different rhythmic oscillations in the relevant neural circuits. It is expected that the study in this paper will build a foundation for further research on the mechanism of 40 Hz-LFS to improve cognitive function and promote its clinical application in the future.
Denoising methods based on wavelet analysis and empirical mode decomposition cannot essentially track and eliminate noise, which usually cause distortion of heart sounds. Based on this problem, a heart sound denoising method based on improved minimum control recursive average and optimally modified log-spectral amplitude is proposed in this paper. The proposed method uses a short-time window to smoothly and dynamically track and estimate the minimum noise value. The noise estimation results are used to obtain the optimal spectrum gain function, and to minimize the noise by minimizing the difference between the clean heart sound and the estimated clean heart sound. In addition, combined with the subjective analysis of spectrum and the objective analysis of contribution to normal and abnormal heart sound classification system, we propose a more rigorous evaluation mechanism. The experimental results show that the proposed method effectively improves the time-frequency features, and obtains higher scores in the normal and abnormal heart sound classification systems. The proposed method can help medical workers to improve the accuracy of their diagnosis, and also has great reference value for the construction and application of computer-aided diagnosis system.
With the widespread use of electrical equipment, cognitive functions such as working memory (WM) could be severely affected when people are exposed to 50 Hz electromagnetic fields (EMF) for long term. However, the effects of EMF exposure on WM and its neural mechanism remain unclear. In the present paper, 15 rats were randomly assigned to three groups, and exposed to an EMF environment at 50 Hz and 2 mT for a different duration: 0 days (control group), 24 days (experimental group I), and 48 days (experimental group II). Then, their WM function was assessed by the T-maze task. Besides, their local field potential (LFP) in the media prefrontal cortex (mPFC) was recorded by the in vivo multichannel electrophysiological recording system to study the power spectral density (PSD) of θ and γ oscillations and the phase-amplitude coupling (PAC) intensity of θ-γ oscillations during the T-maze task. The results showed that the PSD of θ and γ oscillations decreased in experimental groups I and II, and the PAC intensity between θ and high-frequency γ (hγ) decreased significantly compared to the control group. The number of days needed to meet the task criterion was more in experimental groups I and II than that of control group. The results indicate that long-term exposure to EMF could impair WM function. The possible reason may be the impaired communication between different rhythmic oscillations caused by a decrease in θ-hγ PAC intensity. This paper demonstrates the negative effects of EMF on WM and reveals the potential neural mechanisms from the changes of PAC intensity, which provides important support for further investigation of the biological effects of EMF and its mechanisms.