Separation of spring viraemia of carp virus from large-volume samples using immunomagnetic beads.

A method for separation of spring viraemia of carp virus (SVCV) from large-volume samples using immunomagnetic beads (IMBs) coated with a polyclonal antibody against SVCV was developed. The optimum amount of IMBs was 2 mg in 100 mL. After IMB treatment, the detection limit of SVCV in reverse transcription quantitative PCR (RT-qPCR) was 103 times the 50% tissue culture infectious dose per mL in 100-mL samples. The concentration of viral RNA extracted from SVCV that had been separated using IMBs was 5.18 × 103-fold higher than that of the unseparated SVCV. When fish samples were tested, the concordance rates of the IMBs/RT-qPCR and RT-qPCR were 100% and 67.5%, respectively.

A rapid quantitative determination method of Luteinizing hormone with gold immunochromatographic strip.

Measurement of Luteinizing hormone (LH) levels is of great importance in guidance for pregnancy, diagnosis of ovarian diseases and evaluation of clinical effect. Gold immunochromatographic strip(GICS) assay is a rapid, simple, low-costs, and on-site technology. Quantitative detection of GICS has advantage over the traditional qualitative or semi-quantitative strip assay. In this paper, we developed a novel quantitative detection method for GICS based on smart-phone. First, smart-phone was used to acquire GICS image. Then, we applied the canny edge detection operator to extract the reading window from GICS image, and the fuzzy c-means (FCM) clustering algorithm to locate the test and control lines in the reading window. In order to reduce environmental interference, luminance compensation based on color constancy algorithms was applied. Finally, the property of the developed quantitative method is demonstrated by the detection of LH sample and clinical serum sample. Experimental results revealed that this method could achieve a low detection limit of 1.0 mIU/mL in a linear range from 1.0 to 125.0 mIU/mL. Furthermore, the proposed method could be used for the determination of clinical serum samples and its corresponding correlation coefficients were 0.964. Results showed that this novel method could be an effective tool for the rapid quantitative determination of LH.

Research on the synchronous detection of neuronal signals under a nerve stimulation system control.

Deep brain stimulation (DBS) provides a recognized research intervention for neurological disease currently. However, there is a lack of traditional electrical stimulator to observe neuronal firing activity synchronously. The aim of the present study was to realize concurrent detection of neuronal signals better under a nerve stimulation system control. Herein, we designed an integrated software, which could control not only neuro-stimulator but also detection instrument at the same time. Moreover, the actual stimulation signals applied to the experiment object could be collected back to data acquisition card and in consistent with the electrophysiological signals. As to basic performance of self-building stimulator, the accuracy of output square signal was verified to be greater than 99.05 % with the change of voltage amplitude. Practicably, combined with homemade microelectrode array (MEA) detecting device, medial forebrain bundle (MFB) DBS effects were observed significantly through the changes of electrophysiological signals in caudate putamen (CPu) of Sprague-Dawley (SD) rat, and the signal-to-noise ratio (SNR) was 5:1 after stimulation. Therefore, the comprehensive nerve stimulation system, which consists of neuro-stimulator and integrated software, could be widely used in the field of neuroscience research with high precision and synchronization.

Monitoring of Subthalamic Nucleus Stimulation-induced DopamineFlux and Spike Firing Change of Striatum Neuronswith a Micro-Nano Electrode Array / 分析化学

Subthalamic nucleus (STN) deep brain stimulation (DBS) has become an important surgical treatment of Parkinson disease, but its exact mechanism is still unclear.In this study, a 16-channel implantable microelectrode array (MEA) was prepared by micro-electromechanical system (MEMS) technique and later modified with platinum black/reduced Graphene Oxide/Nafion (Pt/RGO/Nafion) nanocomposites.Extracellular dopamine (DA) content and spike of dorsal striatum neurons were synchronously recorded before and after STN stimulation.The results showed that the dopamine content began to increase within 20 s after electrical stimulation and dropped to normal level after about 50 s, with the highest rising concentration of 1.72 μmol/L.At the same time, there was an increased spike activity of interneurons in the dopamine ascending phase, and the spike firing rate of medium spiny projection neurons (MSNs) was high when the concentration of DA was higher than the normal level.The MEA sensor can simultaneously record dopamine flux and physiological signals in situ, thus providing an ideal tool for neural information detection.

Research on neural information detecting system measuring neuroelectricity in hippocampus in vivo and dopamine in vitro based on microelectrode array.

Concurrently detecting the electrical activity of neurons and neurotransmitter release signals, will have a great significance in understanding the working mechanism of the brain. This paper describes a neural information detecting system based on microelectrode array(MEA) measuring neuroelectricity in hippocampus in vivo and dopamine(DA) in vitro. The detecting system contains of electrophysiological headstage, electrochemical headstage, microprocessor, electrophysiological signal amplifier, data acquisition module and neural signal analysis software. In electrophysiological test, the neural information detecting system was applied to detect neuroelectricity in hippocampus of SD rat with 16-channel microelectrode array in vivo. Active potentials were captured. The amplitude of the recorded neural spikes reached 182.90 µV, and signal to noise ratio was 7:1. For measure dopamine as neurotransmitter, there was a good linear relationship between response current and concentration of dopamine from 10nM to 18.88µ with correlation coefficient of 0.9974. Electrophysiological experiment and electrochemical experiment demonstrate the capability of the neural information detecting system to capture dual mode neural signal, which provides a convenient way to study dual mode operating mechanism of neural system.

Application value of percutaneous puncture biopsy technique under CT guide in clinical ;pathological changes of breast / 中国医学装备

Objective: To evaluate the diagnosis value of percutaneous puncture biopsy technique under CT guiding in clinical pathological changes of breast. Methods:46 patients with breast lumps or nodules, including six cases of pleural disease, were carried out percutaneous puncture biopsy under CT guide, where a coaxial Angiotech 17G trocar together with BiopincelSG were used in the puncture process. Results: 44 cases of pathological findings were acquired and the diagnosis ratio was 93.4%, including 9 cases of squamous cell carcinoma, 24 cases of adenocarcinoma, 3 cases of small cell carcinoma, 1 case of metastatic tumor, 1 case of tuberculosis cases, 5 cases of inflammation and 1 case of normal reflexed pleura. 2 cases have no clear diagnosis. Conclusion: The percutaneous lung biopsy technique under CT guide has the merits of less diagnosis trauma, high diagnosis accuracy and high clinical application value.

Synchronous Detection of Rat Neural Spike Firing and Neurochemical Signals Based on Dual-mode Recording Instrument / 分析化学

A dual-mode recording system used for synchronous detection of neuroeletrical and neurochemical signals was developed, and a dual-mode synchronous detection experiment was carried out using the instrument. The device comprised 64-channel neuroelectricity recording module with voltage resolution of 0. 3 μV and 4-channel neurochemistry recording module with current resolution of 1 pA. The software had many basic features, including Spike separation and sort, chronoamperometry, cyclic voltammetry, etc. In particular, the software could observe and analyze the dual-mode neural signals synchronously. The performance of the system was demonstrated in the single mode detection experiments. In neuroeletrical experiments, 64-channel simulate neural signals were detected and the signal to noise ratio ( S/N) of Spike recorded from cortex of Sprague-Dawley ( SD ) rat was 6. In the K3 [ Fe ( CN )6 ] and ascorbic acid measurement experiments, the current response of K3 [ Fe ( CN)6 ] in the range of 0. 1-10 mmol/L was obtained by cyclic voltammetry, with a correlation coefficient of 0. 9889, and the current response of ascorbic acid ( concentration:10-800 μmol/L) by chronoamperometry increased linearly with a correlation coefficient of 0. 9841. Based on the rat model of global cerebral ischemia, a dual-mode detection experiment was carried out. In the experiment, the neuroelectrical and neurochemical signals were synchronously recorded in the SD rat primary visual cortex. According to the experimental results, we got the conclusion that the concentration of ascorbic acid negatively related to the Spike firing in the SD rat primary visual cortex.

Study of Microelectrode Array Probe for Simultaneous Detection of Glutamate and Local Field Potential during Brain Death / 分析化学

High extracellular potassium can induce spreading depression-like depolarizations, elevations of extracellular glutamate and even neuronal death in normal brain. To investigate the contribution of high potassium in vivo, a microelectrode arrays ( MEAs ) probe integrated with recording sites for glutamate concentration (50í150 μm) and local field potential ( LFP) ( diameter=15 μm) was fabricated by Micro-electro-mechanical-systems ( MEMS) technologies. We implanted the MEA probe acutely in the rat brain and exposed the brain to a high potassium solution. During these multi-modal recordings, it was observed that high potassium elevated extracellular glutamate while suppressing the LFP irreversibly. This is one of the first studies in which a dual mode MEA probes is applied in vivo for neuronal death, and it is concluded that our MEA probes are capable of examining specific spatiotemporal relationships between electrical and chemical signaling in the brain.

A Wearable Wireless Electrochemical Instrument Used for In_vivo Neurotransmitter Detection / 分析化学

A wireless electrochemical recording device was designed for in_vivo neurotransmitters real_time detection. Low_power microcontroller MSP430 was chosen as main control unit in hardware system. Other modules were current detection module, waveform generator module and data transceiver module. This device had the merits of small size (2. 3 cm×1. 8 cm×0. 6 cm) and low power consumption. Firmware program design was based on uC/OS operating system. Combined with the PC software, the device could achieve online display and analysis of the recording data. For neurotransmitter detecting needs, the device implemented fast_scan cyclic voltammetry ( FSCV) and fixed_potential amperometry. By using fast_scan cyclic voltammetry method, a linear relationship ( R=0. 99 ) between the concentration of dopamine and response current was acquired in the range of 5. 0×10-7-7. 0×10-5 mol/L. In the in_vivo experiments, the electrically evoked dopamine was recorded in the caudate_putamen area of brain in rats. Experimental results showed that the system had high detection accuracy, which could realize qualitative and quantitative analysis of the brain neurotransmitter. This work would have a broad application prospect in the field of neuroscience research.

Application of Planar Microelectrode Array Modified by Nano-structure Titanium Nitride on Dual Mode Neural Information Recording / 分析化学

The nano-structure TiN was modified on the laboratory self-made planar microelectrode array pMEA by magnetron sputtering method. The performance of modified pMEA was investigated. Research on neuroelectrical and neurochemical recording was studied in vitro. The impedance of the modified pMEA was decreased almost one order of magnitude, and the background noise level was reduced to ±6 μV. In the same testing environment, the signal-to-noise ratio (SNR) of modified electrodes was 1. 7 times of bare electrodes. The SNR of neuroelectrical recording on the brain slice of SD rats reached 10:1 , and the weak signal such as ±12 μV was separated easily. For neuroelectrical recordings, the detection limit of dopamine ( DA) solution reached 50 nmol/L with the 2:1 (S/N). During the concentration range of 0. 05-100 μmol/L, the linearly correlation coefficient of the DA oxidation currents was 0 . 998 . The modification of nano-structure TiN on pMEA reduced pMEA impedance and background noise level, meanwhile the SNR was increased. The weak signals of neuroelectrical and neurochemical recording were successfully recorded.

A design of simple ventilator control system based on LabVIEW / 中国医疗器械杂志

This paper designed a ventilator control system to control proportional valves and motors. It used LabVIEW to control the object mentioned above and design ,validate, evaluate arithmetic, and establish hardware in loop platform. There are two system' s hierarchies. The high layer was used to run non-real time program and the low layer was used to run real time program. The two layers communicated through TCP/IP net. The program can be divided into several modules, which can be expanded and maintained easily. And the harvest in the prototype designing can be seamlessly used to embedded products. From all above, this system was useful in employing OEM products.