Objective To study the feature extraction methods for the event related potential (ERP) evoked by mental arithmetical tasks through the sample entropy, in order to enhance the features of electroencephalograph (EEG) signals for brain computer interface (BCI).Methods Three types of mental arithmetic tasks including a simple counting, a random number and a stroke of Chinese character counting were proposed and 16 channel EEG signals were recorded from eight healthy subjects.The sample entropy method was then applied in characteristic signal complexity analysis.The characteristic and difference of signal complexity of ERP evoked by three types of mental arithmetical tasks were explored.Results The entropy value for EEG signal evoked by non-target stimulus was higher than that by the target stimulus with the significant difference (P＜0.01).The entropy of the mental arithmetic based on the Chinese characters counting task was significandy higher than that of the other two tasks (P＜0.05).EEG signals evoked by target/non-target were fundamentally signals under the state of attention or non-attention.Conclusions For the Chinese characters counting task, more complex information have been processed by the brain and the non-linear connection between nerve cells are much more complicated and a higher entropy value is achieved.In summary, the mental arithmetic task can effectively activate the relevant brain regions and the sample entropy can distinguish signals evoked by target or non-target stimuli.

Objective To propose A brain computer interface paradigm based on the combination of the motion-onset visual evoked potential(mVEP) and the steady state visual evoked potential(SSVEP).Methods By designing a 3 ×3 character spelling matrix,a vertical white bar in the column of matrix which flicks at a pre-set frequency induced the corresponding SSVEP.The vertical white bar also randomly moved horizontally so as to induce mVEP.Then the two types of features were extracted by time frequency analysis.Finally the support vector machine was applied to compare the target character identification rate between the proposed paradigm and the single mVEP paradigm.Results The target character identification accuracy of subject S1 and S6 was improved by about 2％ comparing the proposed paradigm to the single paradigm.Other subjects achieved the improvement of 6％ for the same performance comparison.The averaged identification accuracy of the proposed paradigm could reach 91.4％ if the same stimulus repeated for more than 3 times,while the accuracy of single paradigm achieved 85.6％.Conclusions The proposed brain computer interface paradigm could effectively induce many kinds of brain feature signals.The identification accuracy by the proposed paradigm is higher than that by the single paradigm for various numbers of repeated trials.The proposed paradigm of combined visual stimulus merges the motion induction and the flash frequency modulation together and hence reduces the stimulation time and increases the efficiency of the feature extraction.

In the traditional P300 brain-computer interface (BCI) system, the electroencephalogram (EEG) signals can only provide limited information with a low signal-to-noise ratio. A BCI paradigm under visual stimulus was proposed in our study aiming to effectively activate the related brain areas and response signal while dealing with specific cognitive task (mental arithmetic task), so as to enhance the EEG signals. The result was compared with the traditional P300 counting task paradigm. Then the collected EEG data were preprocessed including extracting signal features with coherent averaging method, and analyzing the influences of different experimental paradigms on main components of event related potential (ERP). In the improved paradigm experiments the average increasing rate of P300 amplitude was 6. 83MV (73. 94%). The brain activity from 400ms was more active and lasted longer. Besides, unlike traditional counting task, mental arithmetic task appeared to have apparent activation at 650ms. The results showed that the improved paradigm could activate the related brain areas better and enhance the characteristics of signal. This provides a new system paradigm for BCI.
Brain-Computer Interfaces ; Electroencephalography ; Event-Related Potentials, P300 ; physiology ; Humans ; Mathematical Concepts ; Mental Processes ; physiology ; Task Performance and Analysis

Objective Retrospectively analyze of urate crystal deposition using dual-source CT in asymptomatic hyperuricaemia and symptomatic gout patients.Methods Sixty patients with asymptomatic hyperuricemia (uric acid ≥540 μmol/L) and 48 patients with gout (without any change in the appearance of the limbs and obvious gout nodules) were selected.All patients underwent dual-energy CT imaging.The location number and size were analyzed using CT gout software.Results Eighteen patients with asymptomatic hyperuricemia with urate crystal deposition in limb joints (13 in foot and ankle, 7 in the hand and wrist, 2 in knee), the average size of crystal was (0.12±0.04) cm3.Forty-eight gout patients (28 cases of early gout and 20 cases of late gout and 20 gout cases) had urate crystal deposition (48 in foot and ankle, 39 in hand and wrist, 27 in knee), the average size of crystal was (1.7±0.7) cm3.The number and size of urate crystals deposited in the joints, tendons and ligaments was higher in patients with gout than asymptomatic hyperuricemia (x2=52.076, P＜0.001;t=44.834, P＜0.001).There was no difference between the early gout and late gout in the size of urate crystals (t=0.163, P＞0.05).Conclusion Urate crystals can deposite in asymptomatic hyperuricemia.However, more and larger urate crystals appear in gout patients, there is no difference in size and number of urate crystals between the course duration of gout.

Objective To investigate clinicopathologic characteristics,individualized immunotherapy and prognosis of antibody-mediated rejection (AMR)after renal transplantation.Methods Clinical data of 32 patients,who were confirmed as AMR after renal transplantation by pathology and admitted in the Department of Urology and Renal Transplantation of the First Affiliated Hospital of Henan Traditional Medical College from January 2010 to December 2013,were retrospectively studied.The corresponding immunological intervention was adopted according to the clinicopathologic characteristics of different patients.The indicators including renal function,panel reactive antibody (PRA)and serum immunoglobulin (Ig)G,IgA and IgM level before and after treatment were determined,and adverse reactions were observed.Results Of all 32 patients, 18 developed acute antibody-mediated rejection (AAMR ) and 14 developed chronic antibody-mediated rejection (CAMR).Of 13 PRA-positive patients,8 (62%,8 /13)cases were with donor specific antibody and 5 (38%,5 /13)cases were with non-donor specific antibody.The primary pathological manifestations of early AAMR were changes of acute tubular necrosis (ATN ),peritubular capillary inflammation,glomerulitis, fibrinoid necrosis of small arteries,linear C4d deposition in peritubular capillaries (PTC)and immunoglobulin or C3 deposition in arterial wall.The pathological manifestations of CAMR were changes of glomerulopathy, splitting of PTC basement membrane,fibrous intimal thickening and diffuse C4d deposition in PTC.After treatment,the renal function of 20 (63%,20 /32)patients returned to normal,the renal function of 7 (22%, 7 /32)patients were stable,the serum creatinine (Scr)of 5 (16%,5 /32)patients increased slowly.Of such 5 patients,2 (2 /5 )patients continued hemodialysis,3 (3 /5 )patients did not need hemodialysis and no patient died.The indicators including blood urea nitrogen (BUN),Scr,PRA and serum IgG,IgA and IgM after treatment decreased significantly when compared with those before treatment (all in P <0.01).No serious adverse reaction was noted during the treatment.Conclusions AMR may manifest as AAMR or CAMR after renal transplantation.The gold standard for diagnosing AMR is pathologic biopsy of transplant kidney.To adopt effective individualized immunotherapy in time is the critical measure for treatment of AMR.

【Objective】 To analyze the association between copper death-related genes and prognosis of prostate cancer and immune cell infiltration based on the cancer genome atlas (TCGA). 【Methods】 The mRNA transcriptome data of all prostate cancer patients were downloaded from TCGA, including 501 prostate cancer tissues and 52 normal tissues.The expression matrix of copper death-related genes was extracted with R software.Differential analysis and multivariate regression analysis were conducted to screen out the prognostic genes, which were then analyzed to explore the correlation between prognosis-related genes and immune cells. 【Results】 GCSH gene was significantly correlated with the prognosis of prostate cancer, and significantly correlated with dendritic cells, CD8⁺ T cells and plasma cells (P<0.05). 【Conclusion】 GCSH gene plays an important role in the occurrence and development of prostate cancer, and may become a prognostic marker of the disease.

Pyroptosis is a programmed cell death mediated by cysteine proteases and is characterized by mitochondrial participation,inflammasome assembly,plasma membrane perforation,and inflammatory release.As an important mechanism mediating the body's inflammatory responses,pyroptosis plays a key role in renal ischemia-reperfusion injury(RIRI).This article reviews the molecular mechanisms of pyroptosis,pyroptotic mechanisms in RIRI,and the progress of research into therapeutic drugs in recent years,with the aim of providing a theoretical reference for the development of early treatments for RIRI.