Objective To study the influence of the immersed time by hydrogen dioxide on the characteristics of bovine cancellous bone granules in various periods. Methods Ten 24-month-old Qinchuan bovine, male or female, weighing 150-170 g, were selected. Cancellous bone granules from metaphysic of bovine long bone were cut into cubes of 5 mm × 5 mm ×5 mm and immersed by 8.8 mol/L hydrogen dioxide for 0, 12, 24, 36, 48, 60 and 72 hours separately. Determination of ash, scanning electron microscope, X-ray energy spectrum and micro CT were used to investigate the changes of composition, structure and qual ity of bone. Results With the immersed time increasing, the contents of organics in the bone cancellous were reduced gradually, and obviously decreased during the periods of 0 to 24 hours and 60 to 72 hours (P lt; 0.05). The contents of calcium and phosphorus decreased gradually, they could not be detected almost after 60 days (P lt; 0.05). Bone mineral density and bone mineral content were decreased obviously after 60 hours (P lt; 0.05). The bone trabecula became sl immer and trabecular spacing became larger. Conclusion Hydrogen dioxide can be used to remove the antigen in xenogeneic bone; however as the time increasing (more than 60 hours) the composition and structure will be damaged. Thus it is important to control the immersed time for maintaining the biological characteristics of xenogeneic bone substitute as well as el iminating antigen by hydrogen dioxide.
This study aims to explore the differences of event related potential (ERP) between attention deficit hyperactivity disorder (ADHD) and normal children, so that these differences provide scientific basis for the diagnosis of ADHD. Eight children were identified to be ADHD group by the diagnostic criteria of DSM IV (diagnostic and statistical manual of mental disorders IV), and the control group also consisted of 8 normal children. Modified visual continuous performance test (CPT) was used as the experiment paradigm. The experiment included two major conditions, i.e. Go and NoGo. All the 16 subjects participated in the study. A high density EEG acquisition instrument was used to record the EEG signal and processed these EEG data by means of ERP and spectrum analysis. P2 N2 peak peak value and spectral peak around 11 Hz were analyzed between ADHD subjects and those in the control group, and then statistical tests were applied to these two groups. Results showed that: ① Under the condition of Go, ADHD group had a significant lower P2 N2 peak peak value than the values in the control group ( P< 0.05); but under the condition of NoGo there was no significant difference in between. ② Compared with the control group, the ADHD group had significant lower spectral amplitude around 11 Hz under the condition of NoGo ( P< 0.05). However, under the condition of Go the difference was insignificant. In conclusion, there is certain cognitive dysfunction in ADHD children. P2-N2 peak-peak value and spectral peak around 11 Hz could be considered as clinical evaluation indexes of ADHD children′s cognitive function. These two objective indexes provide an early diagnosis and effective treatment of ADHD .
Seizures during sleep increase the probability of complication and sudden death. Effective prediction of seizures in sleep allows doctors and patients to take timely treatments to reduce the aforementioned probability. Most of the existing methods make use of electroencephalogram (EEG) to predict seizures, which are not specific developed for the sleep. However, EEG during sleep has its characteristics compared with EEG during other states. Therefore, in order to improve the sensitivity and reduce the false alarm rate, this paper utilized the characteristics of EEG to predict seizures during sleep. We firstly constructed the feature vector including the absolute power spectrum, the relative power spectrum and the power spectrum ratio in different frequencies. Secondly, the separation criterion and branch-and-bound method were applied to select features. Finally, support vector machine classifier were trained, which is then employed for online prediction. Compared with the existing method that do not consider the characteristics of sleeping EEG (sensitivity 91.67%, false alarm rate 9.19%), the proposed method was superior in terms of sensitivity (100%) and false alarm rate (2.11%). This method can improve the existing epilepsy prediction methods and has important clinical value.
Objective To summarize the basic principle of electrical impedance spectrum technology and the latest progress in the diagnosis of thyroid carcinoma. Methods By the domestic and overseas literatures review， medical application and diagnostic prospect in thyroid carcinoma of electrical impedance spectrum were summarized. Results Electrical impedance spectrum was a kind of somatic function imaging， whose measurement results was objective， and it could diagnose thyroid carcinoma in early stage effectively. In addition， it could be used as a complementary form of fine needle aspiration biopsy， improving the diagnostic accuracy rate of thyroid carcinoma， thereby reducing the unessential thyroid operations. Conclusion Electrical impedance spectrum technology is a potentially useful imaging modality for diagnosing thyroid carcinoma in early stage， and functions as a auxiliary clinical diagnosis method for fine needle aspiration biopsy.
Heart rate variability (HRV) is an important point to judge a person’s state in modern medicine. This paper is aimed to research a person’s fatigue level connected with vagal nerve based on the HRV using the improved Welch method. The process of this method is that it firstly uses a time window function on the signal to be processed, then sets the length of time according to the requirement, and finally makes frequency domain analysis. Compared with classical periodogram method, the variance and consistency of the present method have been improved. We can set time span freely using this method (at present, the time of international standard to measure HRV is 5 minutes). This paper analyses the HRV’s characteristics of fatigue crowd based on the database provided by PhysioNet. We therefore draw the conclusion that the accuracy of Welch analyzing HRV combining with appropriate window function has been improved enormously, and when the person changes to fatigue, the vagal activity is diminished and sympathetic activity is raised.
ObjectiveTo systematically review the association between maternal folate supplementation during pregnancy and the risk of autism spectrum disorder (ASD) in the offspring.MethodsPubMed, EMbase, Web of Science, The Cochrane Library, Scopus, CNKI, WanFang Data, VIP and CBM databases were electronically searched to collect case-control and cohort studies on the association between maternal folate supplementation during pregnancy and the risk of ASD in the offspring from inception to December 2020. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was then performed using RevMan 5.3 and Stata 14.0 software.ResultsA total of 17 studies involving 10 812 cases and 876 241 controls were included. The results of meta-analysis showed that there was no significant association between maternal folate supplementation during pregnancy and the risk of ASD in the offspring in the total population. The subgroup analysis revealed that maternal folate supplementation during pregnancy was statistically associated with a reduced risk of ASD in the offspring in the Asian population (OR=0.71, 95%CI 0.53 to 0.96, P=0.03). However, there were no statistical correlations in European and American populations.ConclusionsCurrent evidence shows that maternal folate supplementation during pregnancy may reduce the risk of ASD in the offspring in the Asian population. Due to limited quality and quantity of the included studies, more high-quality studies are required to verify the above conclusions.
Neuromyelitis optica spectrum disorder (NMOSD) is a immune-mediated demyelinating disease of the central nervous system, characterized by high recurrence and disability rates. Preventing relapses is crucial in the treatment of this condition. Monoclonal antibodies have emerged as a novel and rapidly evolving clinical therapeutic strategy targeting NMOSD in recent years. An increasing number of studies and clinical trials have also confirmed the effectiveness and safety of monoclonal antibodies. Rituximab, a monoclonal antibody targeting the B-cell surface antigen CD20, has been widely used in the treatment of NMOSD. Currently, in China, the only approved monoclonal antibody for treating NMOSD is Inebilizumab, which targets the B-cell surface antigen CD19. Additionally, various monoclonal antibodies, such as interleukin-6 receptor inhibitors and complement C5 inhibitors, have been used in the treatment of NMOSD. With the deepening of the research on the pathogenesis of NMOSD, the molecular mechanism of disease-related immune network is further clarified, and multi-center clinical trials are widely carried out. More accurate monoclonal antibody treatment strategies for NMOSD will be applied to clinical practice, benefiting more patients.
ObjectiveTo investigate the feasibility of electroencephalography (EEG) power spectrum analysis monitoring noninvasive intracranial pressure (ICP). MethodsBetween September 2008 and May 2009, the EEG signals were recorded in 62 patients (70 cases/times) with central nervous system (CNS). By using self-designed software, EEG power spectrum analysis was conducted and pressure index (PI) was calculated automatically. ICP was measured by lumbar puncture (LP). ResultsThe mean ICP was (239.74±116.25) mm H2O (70-500 mm H2O, 1 mm H2O=0.009 8 kPa), and 52.9% of patients had increased ICP. The mean PI was 0.29±0.20 (0.02-0.85). The Spearman rank test showed that there was a significant negative correlation between PI and ICP (rs=-0.849, P<0.01). The data from the patients with diffuse lesions of CNS and focal lesions were analyzed separately; the results showed there were significant negative correlations between PI and ICP in both groups (rs=-0.815, -0.912; P<0.01). ConclusionThe PI obtained from EEG analysis is correlated with ICP. Analysis of specific parameters from EEG power spectrum might reflect the ICP. Further research should be carried out.
ObjectiveTo observe and analyze the subtype-specific prognostic factors for visual recovery in patients with demyelinating optic neuritis (DON) after glucocorticoid pulse therapy. MethodsA retrospective cohort study. A total of 195 patients (249 eyes) with DON diagnosed by ophthalmology examination at Department of Ophthalmology, Xi'an People's Hospital (Xi'an Fourth Hospital) from January 2021 to December 2024 were included in the study. According to the results of serum antibody detection and clinical diagnostic criteria, the patients were divided into the neuromyelitis optica spectrum disorder (NMOSD)-associated optic neuritis (ON) (NMOSD-ON) group, the myelin oligodendrocyte glycoprotein antitide-associated ON (MOG-ON) group, and the double antibody negative ON group. They were 51 cases (58 eyes), 72 cases (103 eyes), and 72 cases (88 eyes) respectively. Baseline clinical data, imaging characteristics, and treatment protocols were collected. The primary endpoints were complete visual recovery [best-corrected visual acuity (BCVA) ≥1.0] and moderate recovery (BCVA ≥0.5) at 3 months post-onset. Multivariate logistic regression was used to identify independent prognostic factors for visual outcomes within each subtype. ResultsAt 3 months post-onset, complete recovery rates were 9 (15.5%, 9/58) in the NMOSD-ON group, 64 (62.1%, 64/103) in the MOG-ON group, and 31 (35.2%, 31/88) in the double-seronegative ON group. The results of multivariate regression analysis showed that age [odds ratio (OR) =0.901, 95% confidence interval (CI) 0.854-0.950, P＜0.001] and peak visual acuity (OR=0.311, 95%CI 0.147-0.660, P=0.002) and the involvement of optic nerve length ≥1/2 (OR=3.849, 95%CI 1.083-13.682, P=0.037) were the influencing factors for the complete recovery of visual acuity in the affected eyes of the double antibody negative ON group. Age (OR=0.958, 95%CI 0.933-0.983, P=0.001) was the only influencing factor for the complete recovery of visual acuity in the affected eyes of the MOG-ON group. Peak visual acuity (OR=0.288, 95%CI 0.090-0.927, P=0.037) and optic nerve involvement length ≥1/2 (OR=19.974, 95%CI 1.905-209.559, P=0.013) were the influencing factors for the complete recovery of visual acuity in the affected eyes of the NMOSD-ON group. Age (OR=0.936, 95%CI 0.890-0.983, P=0.009), time from onset to intravenous infusion of methylprednisolone sodium succinate intervention (OR=0.854, 95%CI 0.759-0.961, P=0.009), optic disc edema (OR=4.405, 95%CI 1.108-17.512, P=0.035) and peak visual acuity (OR=0.13, 95%CI 0.046-0.365, P＜0.001) were the influencing factors for the moderate recovery of visual acuity in the affected eyes of the double antibody negative ON group. Peak visual acuity was the only influencing factor for the moderate recovery of visual acuity in the MOG-ON group (OR=0.060, 95%CI 0.010-0.352, P=0.002) and the NMOSD-ON group (OR=0.163, 95%CI 0.053-0.500, P=0.001). ConclusionsThe prognostic factors for visual recovery in patients with DON after glucocorticoid pulse therapy are subtype-specific. Peak visual acuity is a common predictor for all subtypes. For NMOSD-ON and double antibody-negative ON, attention should be paid to the length of optic nerve lesions. MOG-ON is age-related. Early intravenous infusion of methylprednisolone sodium succinate for double antiantibody negative ON is more likely to achieve moderate vision recovery.
Transcranial direct current stimulation (tDCS) is a non-invasive low-current brain stimulation technique, which is mainly based on the different polarity of electrode stimulation to make the activation threshold of neurons different, thereby regulating the excitability of the cerebral cortex. In this paper, healthy subjects were randomly divided into three groups: anodal stimulation group, cathodal stimulation group and sham stimulation group, with 5 subjects in each group. Then, the performance data of the three groups of subjects were recorded before and after stimulation to test their mental rotation ability, and resting state and task state electroencephalogram (EEG) data were collected. Finally, through comparative analysis of the behavioral data and EEG data of the three groups of subjects, the effect of electrical stimulation of different polarities on the three-dimensional mental rotation ability was explored. The results of the study found that the correct response time/accuracy rate and the accuracy rate performance of the anodal stimulation group were higher than those of the cathodal stimulation and sham stimulation groups, and there was a significant difference (P < 0.05). The alpha wave power analysis found that the mental rotation mainly activates the frontal lobe, central area, parietal lobe and occipital lobe. In the anodal stimulation group, the alpha wave power changed significantly in the frontal lobe and occipital lobe (P < 0.05). The results of this paper show that anodal stimulation group can improve the mental rotation ability of the subjects to a certain extent. The results of this paper can provide important theoretical support for further research on the mechanism of tDCS on mental rotation ability.