1.Voltage-dependent calcium channel(VDCC)LTP and N-methyl-D-aspartate(NMDA)receptor channel LTP
International Journal of Biomedical Engineering 2008;31(2):74-77
Long-term potentiation(LTP)is a typical model of synaptic plasticity which has great relationship with learning and memory mechanisms:The induction of LTP depends on the activation of the calcium channels and LTPs generated by calcium ions influx through different channels play different roles in memory.This paper reviews the progress of the research on LTPs induced by activations of N-methyl-D-aspanate receptor(NMDAR)channels and voltage-dependent calcium channels(VDCC).Finally,it gives an example of new forms of low frequency stimulation for induction of LTP.
2.Analysis of clinical characteristics and related factors of type 2 diabetic patients with different ankle brachial index
Clinical Medicine of China 2016;32(6):527-529
Objective To study the clinical characteristics and related factors of type 2 diabetes with different ankle brachial index (ABI).Methods Two hundred and sixty-two patients with type 2 diabetes in Tieying Hospital of Fengtai District of Beijing outpatient and inpatient from January 2012 to April 2015 were selected.General information,blood biochemical parameters and ABI of patients were tested and collected.The patients were classified into three groups according to the different ABI.A group was ABI<0.9 with 40 cases,B group was ABI 0.9-1.3 with 191 cases,C group was ABI>1.3 with 31 cases.The clinical characteristics of three groups were analyzed.Results The age of the patients in group B was younger than that in group A and C((62±15) years old vs.(72±10) years old vs.(71±9) years old,P=0.048).The duration of disease in group B was shorter than that in group A and C((6±6) years vs.(10±2) years vs.(11±3) years,P=0.037).The Blood uric acid of patient in group B were lower than those of patient in group A and C((320±111) μmol/L vs.(350±110) μmol/L vs.(338±109) μmol/L,P=0.039).The glycosylated hemoglobin levels of patient in group Bwere higher than those of patient in group A and C((9.5±1.8)% vs.(7.2±2.3)% vs.(8.8±2.0) %,P=0.041).Compared with group A,the level of UA,HbA1c in group B were more higher(P<0.05).The incidence rate of diabetic foot was 23% (9/40) in group A,6% (11/191) in group B,23% (7/31) in group C,and the difference was significant(P=0.042).Compared with group A and C,the the incidence rate of diabetic foot in group B was the lower(P<0.05).Correlation analysis showed that ABI was negatively correlated with age,course of disease,HbA1c(r=-0.65,-0.70,-0.79,-0.61,P<0.05).Conclusion Different ABI of patients with type 2 diabetes have different clinical features.With increasing age,disease duration,glycosylated hemoglobin and blood uric acid level,it is likely to cause patients with abnormal ABI and increase the probability of occurrence of diabetic foot.
3.The expression and clinical significance of serum 1, 25-dihydroxyvitamin D3 in different stages of diabetic nephropathy patients
Clinical Medicine of China 2016;32(4):293-295
Objective To study the expression and clinical significance of serum 1,25-dihydroxyvitamin D3 in different stages of diabetic nephropathy patients.Methods Ninety-eight cases of diabetics were selected as our subjects in observation group,who were hospitalized in Tieying Hospital of Fengtai District of Beijing from January 2010 to December 2014.They were divided into diabetics group(36 cases,UAER <30 mg/24 h),microalbuminuria group(32 cases,UAER was 30-300 mg/24 h),massive proteinuria group (30cases,UAER>300 mg/24 h).One hundred healthy persons were selected as a normal control group over the same period.The changes of fasting blood glucose,course of disease,blood lipid,serum creatinine and serum 1,25-dihydroxyvitamin D3 in all groups were recorded.Results Fasting blood glucose,serum creatinine and serum 1,25-dihydroxyvitamin D3 were (8.97±2.3) mmol/L,(76.2±19.5) μmol/L,(28.9±13.6) μg/L in observation group,and (4.7±0.4) mmol/L,(63.1±12.0) μmol/L,(70.1±21.3) μg/L in control group respectively,the difference between the two group was statistically significant (P =0.031,0.046,0.028).Serum 1,25-dihydroxyvitamin D3 was (52.68±20.91) μg/L in patients of diabetics group,(31.40±15.23) μg/L in microabuminuria group,(15.76±7.81) μg/L in massive proteinuria group,the difference among the three group was statistically significant (P =0.036).Serum 1,25-dihydroxyvitamin D3 of microabuminuria group and massive proteinuria group were lower than of diabetics group,of massive proteinuria group was lower than of microabuminuria group(P<0.05).Serum 1,25-dihydroxyvitamin D3 was negatively correlated with the cause of disease(r=-0.301),fasting blood glucose (r =-0.281) and serum creatinine (r =-0.536) in patients with type 2 diabetes,the difference was statistically significant (P < 0.05).Conclusion Serum 1,25-dihydroxyvitamin D3 in patients with diabetic nephropathy decrease in different degree,which reflects the severity of renal damage.The results indicate that reduction of serum 1,25-dihydroxyvitamin D3 may be involved in the occurrence and development of diabetic nephropathy
4.LabVIEW and its application in biomedical engineering
International Journal of Biomedical Engineering 2001;24(2):59-64
This paper describes virtual instrumentation and its most representative developing environment-LabVIEW. The use of LabVIEW to program custom functions ,such as signal acquisition ,processing ,system control ,in biomedical research ,is also introduced.
5.Research advances in the let-7e biological function
International Journal of Biomedical Engineering 2010;33(2):106-108
let-7e is one member of let-7 miRNA family, a class of endogenous noncoding RNA which consists of 22 nucleotides. The recent miRNA profiles investigation and analysis results showed that let-7e could be involved in embryonic stem cells differentiation, tumorigenesis in cancer, temporal lobe epilepsy and sleep loss, lipopolysaccharide induced inflammation by regulating its target mRNA expression. This paper gives a review of the important biological function of let-7e.
6.Targeted migration of glycosylated bone marrow mesenchymal stem cells in bone defect models
Chinese Journal of Orthopaedic Trauma 2015;17(1):75-81
Objective To observe the targeted migration of glycosylated bone marrow mesenchymal stem cells (BMSCs) in rabbit bone defect models.Methods A New Zealand rabbit of 2 months old and 1.5 kg in weight was used to separate,extract and amplify BMSCs.α-1,3 fucosyltransferase Ⅵ (FUT-6) gene was transfected to the BMSCs by liposome method to screen the positive clone cell lines.ELISA was used to detect FUT-6 expression and Sialyl Lewis X (sLeX) of FUT-6/BMSCs and BMSCs.Flow cytometry was used to detect the binding force of FUT-6/BMSCs and BMSCs with E/P selectin.FUT-6/BMSCs and BMSCs were labeled with eGFP in vitro and then intravenously re-infused respectively to 2 equal groups of bone defect models made of 12 New Zealand rabbits.Fluorescence microscopy was used at 6,12 and 24 hours postoperation to observe the number of labeled cells in the medullary cavity tissue at the bone defect sites to evaluate the targeted migration.Results BMSCs were amplified by in vitro culture.Transfected BMSCs expressed a significantly higher level of FUT-6,and increased significantly generation of sLeX (P < 0.05).Compared with BMSCs,FUT-6/BMSCs had an obviously higher binding force with E/P selectin (15.0% and 12.7% versus 68.9% and 59.7%).Fluorescence microscopy at 6,12 and 24 hours showed that there were significantly more FUT-6/BMSCs than BMSCs in the medullary cavity tissue at the bone defect sites (P < 0.05).Conclusion Glycosylated BMSCs possess an obvious ability to migrate to the sites of lesion.
7.Spatial distributions of multi-channel electroencephalographs power in different frequency band during visual working memory
International Journal of Biomedical Engineering 2015;38(2):77-80
Objective Working memory (WM) is one of important cognitive functions.The aim of this study was to investigate spatial distributions of electroencephalographs (EEGs) power during visual WM task,which may provide support for studying the principal frequency band and critical region related to WM.Methods 32-channel EEGs were recorded from 16 healthy subjects while they perform visual WM task.The data came from 240 trials and the original EEGs were preprocessed.Fourier transform was applied to calculate spatial distributions of EEGs power in the δ,θ,α,β,γfrequency bands and the percentage of each band in the total power.Results The percentages of δ,θ,α,β,γbands in the total power were (22.44±0.86)%,(31.88±0.55)%,(24.66±1.43)%,(13.54±0.64)%,(7.47±0.48)%,respectively.The power in the θ band was significantly higher than those in the other bands (paired t-test,P<0.001).The θ power was focused in the frontal midline region.Conclusions The principal frequency band related to WM was the θ band and the critical region was the frontal region.
8.Causal flow distribution of multi-channel electroencephalographs during visual working memory
International Journal of Biomedical Engineering 2015;38(2):69-72,110
Objective The ability of working memory (WM) is to temporarily hold and manipulate information for cognitive tasks.The aim of this study was to investigate the causal flow distribution of multi-channel electroencephalographs (EEGs) during Sternberg visual WM task to help understand WM mechanism from the view of neural information transform.Methods Sixteen-channel EEGs were recorded from 8 healthy subjects during Sternberg task,total EEG data for 80 trials were recorded and preprocessed.The EEG powers for each channel were calculated via Fast Fourier transform (FFT).The feature channel was extracted based on the maximum power,and the feature frequency band for WM was determined by time-frequency analysis.The directed transfer function (DTF) and the value of causal flow in EEG feature frequency band were calculated.Results The EEG power focused on θ band (4-8 Hz) and at Fz channel.The maximum value of causal flow was located at Fz,and the first 4 maximum negative values of causal flow were at C3,C4,C5,C6.Conclusions The feature frequency band for WM is the θ band.The causal source (responsible region) is at Fz (frontal region) and the causal sinks are at C3,C4,C5,C6.
9.Collaborative coding rats working memory via mutual information on multi-channel θ band LFPs-Spikes
International Journal of Biomedical Engineering 2015;38(2):-
Objective This paper aimed to investigate the collaborative coding of two different modes of neural signals including local field potentials and spiking activity (multi-unit activity) which recorded in medial prefrontal cortex of sprague-dawley (SD) rats in Y maze working memory (WM) task,to provide computing support for neural coding mechanism of WM.Methods 1.Experiment data was multi-channel neural signals (local field potentials (LFPs)-Spikes) recorded from prefrontal cortex of 4 SD rats during WM process and resting state,provided by the lab of Neuro-engineering,Tianjin Medical University.2.LFPs preprocessing included baseline drift removing and power-line noise eliminating.3.Physiology window width 500 ms,step 125 ms were selected and average rate per channel was calculated to turn the discrete point signal spikes to continuous signal.4.LFPs characteristic frequency band was obtained by using short time Fourier transform and signals of the characteristic frequency band were extracted by band pass filter.5.Mutual information (MI) of LFPs-spikes was computed to get the distribution of multi-channel MI values.Results 1.LFPs distribution demonstrated that the power focused at θ band (4-12 Hz)during the WM tasks.2.The average MI value of θ band LFPs and spikes (4 rats,over 10 trials) were 0.49±0.04,0.39±0.03,0.41±0.03,0.48±0.02,respectively,which were significantly larger than those in the resting state (t test,P<0.05).Conclusions These findings indicate that θ band LFPs represents behavior correlated to WM and its synergy with spiking activity plays an important role in encoding WM task.
10.Automatic Registration between Portal Images and Reference Images in Radiotherapy
Chinese Journal of Medical Physics 2009;26(6):1481-1484
Objective: To correct the set-up error of patients during radiotherapy is very important for increasing treatment effective. Methods: This paper proposes a registration method based on portal images and reference images. Canny Operator was used to extract edge features. The extracted edge features were set as datum mark to calculate the maximal mutual information between the portal images and reference images. Parameters were optimized with simplex-simulated annealing optimization strategy. Results: The portal images and reference images of 29 patients with the cervix cancer and prostatic carcinoma were registrated in this paper. The results showed that the registration was precise, and the registration speed was increased remarkably. Conclusion: So this registration method can be applied for online estimation for set-up errors in clinical radiation.