Electroencephalogram (EEG) is a non-invasive, high temporal-resolution technique for monitoring brain activity. However, affected by the volume conduction effect, EEG has a low spatial resolution and is difficult to locate brain neuronal activity precisely. The surface Laplacian (SL) technique obtains the Laplacian EEG (LEEG) by estimating the second-order spatial derivative of the scalp potential. LEEG can reflect the radial current activity under the scalp, with positive values indicating current flow from the brain to the scalp (“source”) and negative values indicating current flow from the scalp to the brain (“sink”). It attenuates signals from volume conduction, effectively improving the spatial resolution of EEG, and is expected to contribute to breakthroughs in neural engineering. This paper provides a systematic overview of the principles and development of SL technology. Currently, there are two implementation paths for SL technology: current source density algorithms (CSD) and concentric ring electrodes (CRE). CSD performs the Laplace transform of the EEG signals acquired by conventional disc electrodes to indirectly estimate the LEEG. It can be mainly classified into local methods, global methods, and realistic Laplacian methods. The global method is the most commonly used approach in CSD, which can achieve more accurate estimation compared with the local method, and it does not require additional imaging equipment compared with the realistic Laplacian method. CRE employs new concentric ring electrodes instead of the traditional disc electrodes, and measures the LEEG directly by differential acquisition of the multi-ring signals. Depending on the structure, it can be divided into bipolar CRE, quasi-bipolar CRE, tripolar CRE, and multi-pole CRE. The tripolar CRE is widely used due to its optimal detection performance. While ensuring the quality of signal acquisition, the complexity of its preamplifier is relatively acceptable. Here, this paper introduces the study of the SL technique in resting rhythms, visual-related potentials, movement-related potentials, and sensorimotor rhythms. These studies demonstrate that SL technology can improve signal quality and enhance signal characteristics, confirming its potential applications in neuroscientific research, disease diagnosis, visual pathway detection, and brain-computer interfaces. CSD is frequently utilized in applications such as neuroscientific research and disease detection, where high-precision estimation of LEEG is required. And CRE tends to be used in brain-computer interfaces, that have stringent requirements for real-time data processing. Finally, this paper summarizes the strengths and weaknesses of SL technology and envisages its future development. SL technology boasts advantages such as reference independence, high spatial resolution, high temporal resolution, enhanced source connectivity analysis, and noise suppression. However, it also has shortcomings that can be further improved. Theoretically, simulation experiments should be conducted to investigate the theoretical characteristics of SL technology. For CSD methods, the algorithm needs to be optimized to improve the precision of LEEG estimation, reduce dependence on the number of channels, and decrease computational complexity and time consumption. For CRE methods, the electrodes need to be designed with appropriate structures and sizes, and the low-noise, high common-mode rejection ratio preamplifier should be developed. We hope that this paper can promote the in-depth research and wide application of SL technology.

Objective To explore the protective mechanism of icariin on neuronal oxidative damage,providing a basic pharmacological basis for the treatment of cognitive impairment.Methods Glutamate was used to induce oxidative stress injury in HT22 cells.HT22 cells were divided into control group(normal cultured cells),model group(glutamate injury model)and experimental-L,-M,-H groups(5,10 and 20 μmol·L-1 icariin pretreatment for modeling,respectively).Cell proliferation was detected by cell counting kit-8(CCK-8)method;cytotoxicity was detected by lactate dehydrogenase(LDH)method;reactive oxygen species(ROS)levels were detected by flow cytometry;superoxide dismutase(SOD)levels were detected by biochemical kits;the expression levels of Kelch-like epichlorohydrin-related protein-1(Keap1),nuclear factor E2-related factor 2(Nrf2)were detected by Western blotting;the corresponding mRNA expression was detected by real-time fluorescence quantification polymerose chain reaction.Results The cell viability of control group,model group and experimental-L,-M,-H groups were(100.00±1.31)％,(66.38±2.44)％,(72.07±4.95)％,(82.41±3.57)％and(87.97±4.98)％;LDH release were(0.48±0.52)％,(18.82±2.09)％,(15.32±1.17)％,(10.37±1.39)％and(6.51±0.87)％;ROS level were(14.23±1.13)％,(41.74±1.60)％,(35.69±1.08)％,(33.28±1.69)％and(30.32±2.03)％;SOD levels were(54.84±1.17),(37.95±1.13),(48.02±1.28),(50.56±1.34)and(52.55±1.04)U·mg-1;Keap1 protein levels were 0.36±0.01,0.52±0.03,0.46±0.04,0.39±0.09 and 0.35±0.12;Nrf2 protein levels were 0.29±0.02,0.13±0.08,0.18±0.03,0.21±0.11 and 0.26±0.04;catalase(CAT)mRNA levels were 1.01±0.08,0.81±0.06,0.90±0.04,1.05±0.15 and 1.33±0.26;SOD mRNA levels were 1.09±0.12,0.83±0.03,0.86±0.08,0.94±0.08 and 1.09±0.16.Among the above indicators,the differences between the model group and the control group were statistically significant(all P＜0.01);the differences between the experimental-M,-H groups and the model group were statistically significant(P＜0.01,P＜0.05).Conclusion Icariin may activate the Keap1/Nrf2/antioxidant response element(ARE)signaling pathway,regulate the expression of related proteins,and reduce the level of ROS to effectively alleviate oxidative stress injury in neuronal cells.

Methamphetamine (METH) is a powerful stimulant drug that can cause addiction and serious health problems. It is one of the most widely abused drugs in the world. However, the mechanisms of how METH affects the brain and leads to addiction are still unclear, and there are no effective treatments for METH addiction in clinical practice. Therefore, it is important to explore the new addiction mechanisms and treatment strategies of METH. METH addiction is a complex and chronic brain disorder that involves multiple brain regions and neurotransmitter systems. Neurotransmitters are chemical messengers that transmit signals between neurons (nerve cells) in the brain. Some of the main neurotransmitters involved in METH addiction are dopamine (DA), glutamate (Glu), norepinephrine (NE), and serotonin (SNRIS). These neurotransmitters regulate various aspects of brain function, such as reward, reinforcement, motivation, cognition, emotion, and behavior. When a person takes METH, it causes a surge of these neurotransmitters in the brain, especially in the prefrontal cortex (mPFC), ventral tegmental area (VTA), and nucleus accumbens (NAc). These brain regions form a circuit called the mesocorticolimbic system, which is responsible for mediating the rewarding and reinforcing effects of drugs and natural stimuli. The increased levels of neurotransmitters in this circuit make the person feel euphoric, alert, confident, and energetic. However, repeated or chronic use of METH can also cause negative effects, such as anxiety, paranoia, psychosis, depression, and cognitive impairment. The effects of METH on the brain are not only due to the changes in neurotransmitter levels, but also to the changes in gene expression. Gene expression is the process by which genes are turned on or off to produce proteins that perform various functions in the cells. Gene expression can be influenced by environmental factors, such as drugs, stress, diet, etc. One way that environmental factors can affect gene expression is through epigenetic mechanisms. Epigenetics is a branch of genetics that studies the heritable changes in gene expression that are not caused by changes in DNA sequence. Epigenetic mechanisms include histone modifications, DNA methylation, and non-coding RNA regulation. These mechanisms can modulate the chromatin structure and accessibility, thereby affecting the transcriptional activity of genes. Chromatin is a complex of DNA and proteins that forms the chromosomes in the nucleus of the cell. The chromatin structure can be altered by adding or removing chemical groups to histones (proteins that wrap around DNA) or DNA itself. These chemical groups can either activate or repress gene expression by changing the affinity of transcription factors (proteins that bind to DNA and initiate transcription) or other regulatory molecules. Non-coding RNAs are RNA molecules that do not code for proteins but can regulate gene expression by interacting with DNA, RNA, or proteins. Epigenetic mechanisms provide a link between environmental stimuli and gene expression, and play an important role in various physiological and pathological processes, including drug addiction. Recent studies have shown that epigenetic mechanisms are involved in the regulation of neurotransmitter systems and neural plasticity in response to METH exposure. Neural plasticity is the ability of neurons to change their structure and function in response to experience or injury. Neural plasticity is essential for learning, memory, adaptation, and recovery. The expression of some genes related to METH addiction is altered by epigenetic modifications, such as histone acetylation, methylation, ubiquitination, and non-coding RNA regulation. These epigenetic changes may affect the synaptic function and morphology, neuronal connectivity, and circuitry formation in the brain regions implicated in METH addiction. Moreover, some epigenetic modifications may persist for a long time after METH withdrawal, suggesting that they may contribute to the development and maintenance of METH addiction. In this article, we review the current literature on the epigenetic mechanisms of METH addiction. We will first introduce METH and its pharmacological effects, and then discuss the epigenetic regulation of neurotransmitter systems and neural plasticity by METH. We will focus on the changes of histone, DNA, and RNA during METH addiction, and the possible causes and consequences of their relationship with METH addiction. We will also provide some perspectives on the potential applications of epigenetic interventions for METH addiction treatment.

Based on the genomic information of Emericella sp. 1454, in conjunction with literature analysis of its secondary metabolite emestrin, this study identified the biosynthetic precursors of emestrin and enhanced its production by supplementing the culture medium with these precursors. In this study, it was found for the first time that the addition of biosynthetic precursor, reduced glutathione, to the culture medium significantly increased emestrin yield. By incorporating 1.5 g of reduced glutathione into 50 g of rice culture medium and fermenting for 15 days, a yield of 30.82 mg of emestrin was obtained, which marked an 11.71-fold increase compared to the original fermentation approach. The method is both simple and cost-effective, establishing a solid foundation for the efficient synthesis of emestrin and similar compounds. Additionally, it serves as an important reference for enhancing the production of other epipolythiodioxopiperazine compounds.

Separation and determination of chiral and achiral impurities in glimepiride tablets by supercritical fluid chromatography. Chiral and achiral impurities were separated on a ACQUITY UPC² Trefoil^TM CEL1 column (150 mm × 3.0 mm, 2.5 μm) maintained at 30 ℃ with the mobile phase containing a mixture of CO₂ and methanol-isopropanol (1∶1) at 1 mL·min^-1, and the detection wavelength was set at 228 nm. The back pressure was set at 13.8 MPa. The injection volume was 5 μL. In the chromatogram of the system suitability solution, the peaks elute in the following order: impurity Ⅳ, impurity Ⅴ, glimepiride, impurity Ⅲ, impurity Ⅰ and impurity Ⅱ. The six substances were separated successfully in 6 min using the proposed method with a resolution factor of 2.9, 1.6, 3.0, 2.0, 6.4. The impurity Ⅰ-Ⅴ detection limit (S/N = 3) was 0.17, 0.10, 0.06, 0.15, 0.10 μg·mL^-1, respectively. Good linear relationship was established between the peak response and the concentration in the range of 0.48-51.30 μg·mL^-1 for all impurities. The spiked recovery of impurity Ⅰ-Ⅴ was found to be acceptable for 99.9%, 98.9%, 102.1%, 100.1%, 96.3% (n = 9), respectively. The related substance and assay results of 11 sample batches are consistent with the results obtained using the HPLC method in the Chinese Pharmacopoeia. Compared to the two HPLC methods in the Chinese Pharmacopoeia, the established supercritical fluid chromatography method can simultaneously separate glimepiride and its 5 impurities in a single run, and it has the following advantages: simplified sample preparation, greatly reducing the volumes of organic solvents, environmentally friendly, high accuracy and good reproducibility. It can be employed for the quality control of the chiral and achiral impurities in glimepiride tablets.

Objective To propose a deep learning-based method for removing Gaussian and pepper noises of the surgical instrument visual images so as to recover the detailed features of the images.Methods A lightweight multi-task progressive network was constructed involving in a multi-feature fusion encoder-decoder network,an attention-guided network and a detail-recovery progressive network,which used the multi-feature fusion encoder-decoder network to predict and eliminate the noise information in the visual images,the attention-guided network to remove the residual noise and the detail-recovery progressive network to restore the underlying detail features of the denoised images.Some of the regular convolutions in the detail recovery progressive network were replaced with depth separable convolutions to realize lightweight design of the network constructed.Denoising experiments were conducted on the publicly available CBSD68 and Kodak24 datasets and the self-constructed surgical instrument noise dataset so as to compare the denoising effects of the network constructed and the traditional methods and the classification accuracies of ResNet-18 model and ResNet-34 model for the denosied images by the network and to analyze computing power and memory usage before and after the lightweight design.Results The network constructed gained better denoising effect than the classical methods for publicly available datasets,and ResNet-18 model and ResNet-34 model had higher accuracies when used to classify the images denoised by the network for the self-constructed surgical instrument noise dataset.Lightweight design had the parameter number and floating point operations(FLOPs)decreased by approximately 27.27％and 29.81％,respectively.Conclusion The proposed lightweight multi-task progressive network behaves well in denoising surgical instrument visual images with reduced computating power consump-tion and memory usage.[Chinese Medical Equipment Journal,2024,45(2):1-7]

Objective To propose a multi-cascade deep learning processor-based surgical instrument detection and pose estimation algorithm to facilitate the robotic scurb nurse to recognize and delivery surgical instruments.Methods The proposed multi-cascade deep leaning processor-based CYSP algorithm was hibernated with several functional modules such as YOLOX with coordinate attention block(CA-YOLOX),segment anything model(SAM)and principal component analysis(PCA).Firstly,CA-YOLOX was applied to identifying the types of the surgical instruments and completing the coarse positioning of x and y coordinates;secondly,the SAM segmenter was used to clarify the positions of the instruments in the RGB image,and the depth information and internal parameters of the camera were introduced to obtain the point cloud of the surgical instruments;finally,the center of mass,principal direction and normal direction of the surgical instrument point cloud were determined through the PCA algorithm,with which the rotation and translation(RT)matrix between the target coordinate system(surgical instrument center of mass coordinate system)and the base coordinate system of the robotic arm was solved,and the matrix was converted into a quaternion and then transmitted to the robotic arm control unit so as to drive the robotic arm to arrive at the corresponding position and pick up the instrument to complete the instrument delivery task.Migration training was accomplished on a self-constructed surgical instrument image dataset and the effectiveness of the proposed algorithm was evaluated,and instrument delivery experiments were performed on a seven-degree-of-freedom robotic arm and the success rate of the algorithm was assessed.Results The multi-cascade deep leaning processor-based CYSP algorithm had a recognition accuracy of 98.52％on the surgical instrument dataset,a success rate of 94％for the in-strument delivery experiment and average time for recognition of 0.28 s.Conclusion The multi-cascade deep leaning proces-sor-based CYSP algorithm with high reliability and practicability behaves well in facilitating the robotic scurb nurse to recog-nize and deliver surgical instruments.[Chinese Medical Equipment Journal,2024,45(6):1-8]

Objective:To construct an evaluation index system of internal control medical equipment based on the internal control theory of The Committee of Sponsoring Organizations of the Treadway Commission(COSO)and combined with the current situation of medical equipment internal management in public hospitals,so as to provide reference and suggestions for the evaluation of internal control of medical equipment in public hospitals.Methods:Through literature research and expert consultation,the evaluation index system of internal control of medical equipment was preliminarily determined.Using the Delphi method,15 experts from 1 medical college and 3 tertiary hospitals in Beijing who were engaged in the use and management of medical equipment were selected to conduct two rounds of consultation on the evaluation index system of internal control of medical equipment,and the evaluation indicators were scored and screened.The analytic hierarchy process(AHP)was used to determine the index weights,and the internal control evaluation index system of medical equipment in public hospitals based on COSO was constructed.Results:The coefficient of the two rounds of expert consultation was 100%.The authority degree of consulting experts was 0.867.Finally,the evaluation index system of internal control of medical equipment in tertiary public hospitals was formed,which included 5 first-level indicators,17 second-level indicators and 50 third-level indicators.Conclusion:The evaluation index of internal control of medical equipment in public hospitals based on COSO has high expert enthusiasm,authority and coordination.The evaluation index system includes the unit level and the business level of internal control,with a wide coverage,which makes up for the limitations of traditional internal evaluation of medical equipment,which can make up for the limitations of the internal evaluation of traditional medical equipment,improve the internal control system of medical equipment in public hospitals,and optimize the medical equipment management system.

Objective:To explore the potential causal relationship between gut microbiota and teratozoospermia.Methods:We searched the database of Genome-Wide Association Study(GWAS)for gut microbiota-and teratozoospermia-related data.We used gut microbiota as an exposure factor,determined the instrumental variables according to the GWAS data on 18 340 participants released by the MiBioGen Alliance,and derived the outcome variables from the European data on teratozoospermia,with a sample size of 85 716,including 915 cases and 209 006 controls.Using inverse-variance weighting(IVW),MR-Egger regression and the weighted median estimator(WME),we performed two-sample Mendelian randomization(MR)analysis on the retrieved data,and estimated the causal relationship between gut microbiota and teratozoospermia based on the β value.Results:Two-sample MR analysis indicated that the class Erysipelotrichia,family Erysipelotrichaceae,family Streptococcaceae,genus Coprococcusl,genus Ruminococcaceae UCG009,genus Streptococcus,order Clostridialesm and order Erysipelotrichales were causally related with the increased risk,while the family Porphyromonadaceae with the decreased risk of teratozoospermia.Conclusion:The class Erysipelotrichia,family Erysipe-lotrichaceae,family Streptococcaceae,genus Coprococcusl,genus Ruminococcaceae UCG009,genus Streptococcus,order Clostridia-lesm and order Erysipelotrichales are one of the causes of teratozoospermia,related to the increased risk of the condition,while the family Porphyromonadaceae has a protective effect on sperm morphology,reducing the risk of teratozoospermia.

AIM To establish a UPLC-MS/MS method for the simultaneous content determination of pseudoginsenoside F11 and ginsenosides Rf,Rg1,Re,Rb1,Rb2,Rb3,Rg2,Rg3,Rc,Rd.METHODS The analysis was performed on a 40℃ thermostatic Phenomenex Kinetex F5 column(2.1 mm×100 mm,1.7 μm),with the mobile phase comprising of acetonitrile-2 mmol/L ammonium formate flowing at 0.3 mL/min in a gradient elution manner,and electron spray ionization source was adopted in negative ion scanning with multiple reaction monitoring mode.RESULTS Eleven ginsenosides showed good linear relationships within their own ranges(r>0.9900),whose average recoveries were 97.40％-103.74％with the RSDs of 1.76％-3.48％.CONCLUSION This sensitive,practical and reproducible method can be used for the quality control of Ginseng Radix et Rhizoma in Fukang Tablets.