In order to solve imperfection of heart rate extraction by method of traditional ballistocardiogram (BCG), this paper proposes an improved method for detecting heart rate by BCG. First, weak cardiac activity signals are acquired in real time by embedded sensors. Local BCG beats are obtained by signal filtering and signal conversion. Second, the heart rate is estimated directly from the BCG beat without the use of a heartbeat template. Compared with other methods, the proposed method has strong advantages in heart rate data accuracy and anti-interference, and it also realizes non-contact online detection. Finally, by analyzing the data of more than 20,000 heart rates of 13 subjects, the average beat error was 0.86% and the coverage was 96.71%. It provides a new way to estimate heart rate for hospital clinical and home care.
ObjectiveTo analyze the diagnostic efficacy of colloidal gold immunochromatography assay (GICA) in detection of SARS-CoV-2.MethodsUsing GICA detection kits from three different manufacturers, 33 serum samples were collected from 12 patients with SARS-CoV-2 infection at different time and 45 serum samples from 45 patients without SARS-CoV-2 infection were collected from West China Hospital of Sichuan University from January to February, 2020.ResultsThe sensitivity, specificity, positive predictive value and negative predictive value of the three GICA reagents were 66.7% - 90.9%, 73.3% - 100.0%, 71.4% - 100.0% and 80.4% - 91.7% respectively. The rates of missed diagnosis and misdiagnosis were 9.1% - 33.3% and 0 - 26.7%, respectively. The positive rate decreased with titer increasing. The interference factors mainly included human immunodeficiency virus infection, high rheumatoid factor blood samples, and hemolysis.ConclusionClinical laboratories should pay attention to the differences in the detection ability and potential cross-reaction of different reagents, or use a combination of multiple antibodies.
Objective To observe the effect of BMSCs on the cardiac function in diabetes mellitus (DM) rats through injecting BMSCs into the ventricular wall of the diabetic rats and investigate its mechanism. Methods BMSCs isolated from male SD rats (3-4 months old) were cultured in vitro, and the cells at passage 5 underwent DAPI label ing. Thirty clean grade SD inbred strain male rats weighing about 250 g were randomized into the normal control group (group A), the DM group (group B), and the cell transplantation group (group C). The rats in groups B and C received high fat forage for 4 weeks and the intraperitoneal injection of 30 mg/kg streptozotocin to made the experimental model of type II DM. PBS and DAPI-labeledpassage 5 BMSCs (1 × 105/μL, 160 μL) were injected into the ventricular wall of the rats in groups B and C, respectively. After feeding those rats with high fat forage for another 8 weeks, the apoptosis of myocardial cells was detected by TUNEL, the cardiac function was evaluated with multi-channel physiology recorder, the myocardium APPL1 protein expression was detected by Western blot and immunohistochemistry test, and the NO content was detected by nitrate reductase method. Group C underwent all those tests 16 weeks after taking basic forage. Results In group A, the apoptosis rate was 6.14% ± 0.02%, the AAPL1 level was 2.79 ± 0.32, left ventricular -dP/dt (LV-dP/dt) was (613.27 ± 125.36) mm Hg/s (1 mm Hg=0.133 kPa), the left ventricular end-diastol ic pressure (LVEDP) was (10.06 ± 3.24) mm Hg, and the NO content was (91.54 ± 6.15) nmol/mL. In group B, the apoptosis rate was 45.71% ± 0.04%, the AAPL1 level 1.08 ± 0.24 decreased significantly when compared with group A, the LVdP/ dt was (437.58 ± 117.58) mm Hg/s, the LVEDP was (17.89 ± 2.35) mm Hg, and the NO content was (38.91±8.67) nmol/mL. In group C, the apoptosis rate was 27.43% ± 0.03%, the APPL1 expression level was 2.03 ± 0.22, the LV -dP/dt was (559.38 ± 97.37) mm Hg/ s, the LVEDP was (12.55 ± 2.87) mm Hg, and the NO content was (138.79 ± 7.23) nmol/ mL. For the above mentioned parameters, there was significant difference between group A and group B (P lt; 0.05), and between group B and group C (P lt; 0.05). Conclusion BMSCs transplantation can improve the cardiac function of diabetic rats. Its possible mechanismmay be related to the activation of APPL1 signaling pathway and the increase of NO content.
In order to improve the accuracy and efficiency of automatic seizure detection, the paper proposes a method based on improved genetic algorithm optimization back propagation (IGA-BP) neural network for epilepsy diagnosis, and uses the method to achieve detection of clinical epilepsy rapidly and effectively. Firstly, the method extracted the linear and nonlinear features of the epileptic electroencephalogram (EEG) signals and used a Gaussian mixture model (GMM) to perform cluster analysis on EEG features. Next, expectation maximization (EM) algorithm was used to estimate GMM parameters to calculate the optimal parameters for the selection operator of genetic algorithm (GA). The initial weights and thresholds of the BP neural network were obtained through using the improved genetic algorithm. Finally, the optimized BP neural network is used for the classification of the epileptic EEG signals to detect the epileptic seizure automatically. Compared with the traditional genetic algorithm optimization back propagation (GA-BP), the IGA-BP neural network can improve the population convergence rate and reduce the classification error. In the process of automatic detection of epilepsy, the method improves the detection accuracy in the automatic detection of epilepsy disorders and reduced inspection time. It has important application value in the clinical diagnosis and treatment of epilepsy.
目的 建立测定胎盘灌流液中格列苯脲浓度的高效液相色谱（HPLC）检测方法。方法 采用的色谱柱为Symmetry Shield RP C18（150 mm×4.6 mm，5 μm），柱温40℃，流动相为NaH2PO4缓冲盐（25 mmol/L，pH值5.2）︰乙腈=1︰1；内标为格列齐特，流速1.0 mL/min，检测波长228 nm，采用液-液萃取预处理方法测定胎盘灌流液中格列苯脲的浓度。 结果 格列苯脲浓度线性范围为2.0～25.0 μg/mL，线性方程为：y=0.226x+0.002，r=0.999 9 （n=6），日内相对标准偏差（RSD）＜3.1%，日间RSD＜9.5%，方法学回收率为95.32%～103.35%。 结论 HPLC检测方法灵敏、简便，可用于胎盘灌流液中格列苯脲浓度的检测。
Antimicrobial resistance is a rigorous health issue around the world. Because of the short turn-around-time and broad pathogen spectrum, culture-independent metagenomic next-generation sequencing (mNGS) is a powerful and highly efficient tool for clinical pathogen detection. The increasing question is whether mNGS is practical in the prediction of antimicrobial susceptibility. This review summarizes the current mNGS-based antimicrobial susceptibility testing technologies. The critical determinants of mNGS-based antibacterial resistance prediction have been comprehensively analyzed, including antimicrobial resistance databases, sequence alignment tools, detection tools for genomic antimicrobial resistance determinants, as well as resistance prediction models. The clinical challenges for mNGS-based antibacterial resistance prediction have also been reviewed and discussed.
Objective To investigate the efficacy of fine needle aspiration-thyroglobulin (FNA-Tg) with colloidal gold immunochromatographic assay (CGICA) on the assessment of lymph node metastasis during surgery in papillary thyroid carcinoma (PTC) patients. Methods Seventy-eight patients with PTC who underwent surgery in the Department of Thyroid Surgery of West China Hospital of Sichuan University from August to December 2019 were selected as the research objects, 289 neck lymph node specimens cleaned during the operation were prepared into eluent after lymph node FNA within 10 minutes in vitro, and then the FNA-Tg level was detected rapidly and quantitatively by CGICA. The specimen of washout fluid was labeled and sent to the laboratory for FNA-Tg detection by Roche electrochemiluminescence immunoassay. The lymph nodes in the whole group were divided into central region group and lateral cervical region group according to their location. According to the long diameter of lymph nodes, they were divided into <5 mm group, 5–10 mm group and >10 mm group. With postoperative pathological report as the gold standard, the receiver operating characteristic (ROC) curve of the whole group of data subjects was drawn, and the area under curve (AUC) was compared to calculate the best cut-off value of FNA-Tg in diagnosing PTC lymph node metastasis. The sensitivity, specificity, diagnostic accuracy, positive predictive value and negative predictive value of FNA-Tg CGICA method and Roche method in the whole group and different subgroups were compared. The data of 55 lymph nodes detected by FNA-Tg CGICA method and rapid frozen pathology were collected, and the diagnostic efficacy indexes of CGICA method and rapid frozen pathology in the diagnosis of lymph node metastasis were compared. Results The ROC curves AUC of FNA-Tg detected by CGICA method and Roche method was 0.850 and 0.883, respectively, the difference was not statistically significant (Z=1.011, P>0.05). The sensitivity was 77.7% and 79.6% respectively (χ2=0.05, P>0.05), specificity was 84.9% and 93.5% respectively (χ2=7.50, P<0.05). Using McNemar test, there was no significant difference in the diagnostic results between the CGICA method and Roche method of FNA-Tg in the whole group (P>0.05). The diagnostic efficacy of FNA-Tg CGICA method was better in the lateral cervical region group than that in the central region group, and the diagnostic efficacy of the group with the long diameter of lymph nodes >10 mm was better than those of the groups with the long diameter of lymph nodes <5 mm and 5–10 mm. There was no significant difference in diagnostic results between FNA-Tg CGICA method and rapid frozen pathology (P>0.05). Conclusions The FNA-Tg CGICA method has high value in diagnosing PTC cervical lymph node metastasis, and has the characteristics of rapidity and convenience. The diagnostic efficiency is similar to that of Roche method.
Surface electromyography (sEMG) has been widely used in the study of clinical medicine, rehabilitation medicine, sports, etc., and its endpoints should be detected accurately before analyzing. However, endpoint detection is vulnerable to electrocardiogram (ECG) interference when the sEMG recorders are placed near the heart. In this paper, an endpoint-detection algorithm which is insensitive to ECG interference is proposed. In the algorithm, endpoints of sEMG are detected based on the short-time energy and short-time zero-crossing rates of sEMG. The thresholds of short-time energy and short-time zero-crossing rate are set according to the statistical difference of short-time zero-crossing rate between sEMG and ECG, and the statistical difference of short-time energy between sEMG and the background noise. Experiment results on the sEMG of rectus abdominis muscle demonstrate that the algorithm detects the endpoints of the sEMG with a high accuracy rate of 95.6%.
目的:研究O型RhD阳性孕妇(其丈夫为非O型)血清IgG抗-A(抗-B)抗体效价与新生儿溶血病(HDN)的关系。方法:应用微柱凝胶技术对382例O型RhD阳性孕妇进行了免疫性IgG抗A(B)抗体效价检测及对其新生儿进行HDN(①新生儿ABO、Rh系统定型;②新生儿直抗实验;③游离IgG测定;④放散实验)的检测。结果:382例O型RhD阳性孕妇中IgG抗-A(B)效价lt;64者330例(占总数86.39%),抗体效价≥64者13.61%。其中发生HDN 5例,抗-A 3例,抗-B12例,总发生率1.31%.结论:夫妇血型不合应及时检测孕妇IgG抗体,随着孕妇体内IgG抗体效价的增高,新生儿ABO溶血病的发病率也随之升高。孕妇产前应定时进行IgG抗体检测,了解效价与新生儿溶血病发病率之问的关系,对于预防新生儿溶血病极为有效。
This article summarizes the development of lateral flow immunoassay for SARS-CoV-2 antigen detection. Lateral flow immunoassay is a rapid, low cost, and ease of use detection tool that has been widely applied in clinical and public health sectors. Since the outbreak of COVID-19, the technique has been adopted for rapid antigen diagnostic test of SARS-CoV-2, including commonly used colloidal gold nanoparticle-based lateral flow immunoassays as well as various fluorescence-based lateral flow immunoassays. With innovations in labelling methods, this detection technique has been in continuous development and is shifting from qualitative toward quantitative as well as gaining sensitivity.