According to the instruction of the operator, the designed programmable multichannel stimulator will deliver stimuli with an assigned amplitude and a proper width to the electrode-array in various modes. Each stimulation time is controlled by the internal timer of the MCU, while the stimulated electrodes' spatial parameter is controlled by the CPLD. Having abandoned conventional isolation using the transformer, we have adapted optical coupling and stable float ground connection to achieve the safety standard required by physiological measurements.
Electric Stimulation ; instrumentation ; methods ; Electric Stimulation Therapy ; instrumentation ; Electrodes, Implanted ; Electrophysiology ; instrumentation ; methods

The external defibrillator is an emergency instrument used very widely in clinics. It plays an important role in rescuing ventricle fibrillation (VF) patients. We have designed an external defibrillator using the truncated exponential biphasic waveform. The system consists of three parts: the ECG collection module, the control module and the defibrillator module. They are introduced respectively, listing the main problems and the methods to solve them. Some experiments have been done and the corresponding results are given.
Animals ; Defibrillators ; Equipment Design ; Swine ; Ventricular Fibrillation

EMG, This paper introduces a slope variability algorithm which uses the CU Database and the AHA Database. The sensitivity, specificity, positive predictivity and accuracy are calculated and these values are compared with the results from two earlier detection algorithms. The results show this algorithm is more effective and fast than other algorithms.
Algorithms ; Defibrillators ; Electric Countershock ; instrumentation ; Predictive Value of Tests ; Sensitivity and Specificity

This paper proposes a method of automatic ECG analysis and arrhythmia diagnosis for telemonitoring system. A multi-buffer technique is applied to organize dispersive ECG data. Then, according to second order derivatives of ECG signals, peaks of R waves are automatically detected. Finally, real-time heart rhythm is decided by results of R wave detection. Tests prove that the proposed method is precise, efficient and stable to be applied in real-time ECG telemonitoring system.
Algorithms ; Automation ; instrumentation ; methods ; Electrocardiography, Ambulatory ; instrumentation ; methods ; Remote Consultation ; instrumentation ; methods ; Signal Processing, Computer-Assisted

A method based on wavelet transform has been developed for detecting QRS-waves.The MIT-BIH database is used to evaluate this method, and the accuracy is over 99.5%. Then the method is implanted into the embedded system to implement the real-time detection of ECG. This method has good performances in time-delay and computation.
Algorithms ; Electrocardiography ; methods ; Wavelet Analysis

Abstract: Objective　To understand the kdr (knockdown resistance, kdr) gene mutation of the voltage-gated sodium channel (VGSC) of Anopheles sinensis in Yunnan Province. Methods　From 2018 to 2019, mosquitoes were collected in Luoping County, Suijiang County, Tengchong City, Yingjiang County, Yuanjiang County and Mengla County in Yunnan Province. The collected mosquitoes were morphologically identified as Anopheles sinensis and genomic DNA was extracted by kits. The DNA templates were sequenced after PCR amplification and the sequencing results were identify as Anopheles sinensis by homology alignment in NCBI. After the ⅡS5 and ⅡS6 fragments of the sodium channels in Anopheles sinensis were amplified and sequenced, the sequencing results were multiple aligned by DNAMAN software, and the mutations were analyzed one by one with BioEdit software to determine the kdr allele types and genotypes, and the frequencies were calculated. Results This survey amplified 287 sequences, and the sequence maps showed that 1014 loci had three alleles, including wild type TTG/L (89.20%), mutant type TTT/F (9.76%) and TCG/S (1.04%). Five genotypes: homozygous wildtype L/L (85.02%), homozygous mutant F/F (6.27%) and S/S (0.35%), heterozygous mutant L/F (6.97%) and L/S (1.39%). The wild type allele TTG/L was the main allele in six sampling sites except Suijiang County. The frequency of wild type allele in Tengchong City was the highest (100.00%). That is, no mutation was detected, while the rest of counties occurred different degrees of mutation at 1014 loci. The frequency of mutant allele in Suijiang County was the highest, reaching 55.68%. Luoping County, Mengla County and Suijiang County had two mutant types. Yingjiang County and Yuanjiang County had one heterozygous mutant L/F. Conclusion　Wild type L1014 (TTG/L) is still dominant in most areas of Yunnan Province. The kdr mutation type is mainly L1014F, followed by L1014S, and the mutation frequency is lower than that in central provinces of China.

AIMTo establish the methods for determining the activity of sphingosine kinase(SPK) and the content of sphingosine 1-phosphate (S1P) in biological samples.

METHODSThe ECV304 cells were transfected with pcDNA3 vector encoding Flag-labeled SPK gene. The expression of SPK was measured by Western blot assay and the activity of SPK was determined by enzymatic reaction, isotope incorporation and thin-layer chromatography methods. The S1P in biological samples was extracted, digested by alkaline phosphatase and then catalyzed by SPK. The S1P contents were determined according to the amounts of products.

RESULTSSPK gene transfection could enhance the expression and activity of SPK in cells markedly, and the cellular S1P was also increased obviously. HGF stimulation could increase the activity of SPK and cellular S1P in ECV304 cells.

CONCLUSIONMethods for determining the activity of SPK and the content of SPK in biological samples were established.

Cell Line ; Cytophotometry ; Humans ; Isotope Labeling ; Lysophospholipids ; metabolism ; Phosphotransferases (Alcohol Group Acceptor) ; metabolism ; Sphingosine ; analogs & derivatives ; metabolism

PURPOSE: The aim of the study was to evaluate the efficacy and safety of combining sorafenib with chemotherapy in patients with human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. METHODS: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, American Society for Clinical Oncology abstracts, and European Society for Medical Oncology abstracts were searched. Randomized clinical trials that compared the efficacy and safety of sorafenib plus chemotherapy in patients with HER2-negative advanced breast cancer with placebo plus chemotherapy were eligible. The endpoints were progression-free survival (PFS), overall survival (OS), time to progression (TTP), duration of response (DOR), overall response rate (ORR), clinical benefits, and adverse effects. The meta-analysis was performed using Review Manager 5.2.6 (The Nordic Cochrane Centre), and the fixed-effect model weighted by the Mantel-Haenszel method was used. When considerable heterogeneity was found (p<0.1), further analysis (subgroup analysis, sensitivity analysis, or random-effect model) was performed to identify the potential cause. The results are expressed as hazard ratios or risk ratios, with their corresponding 95% confidence intervals. RESULTS: The final analysis included four trials comprising 844 patients. The results revealed longer PFS and TTP, and higher ORR and clinical benefit rates in patients receiving sorafenib combined with chemotherapy compared to those receiving chemotherapy and placebo. OS and DOR were similar in the two groups. Meanwhile, the incidence of some adverse effects, including hand-foot skin reaction/hand-foot syndrome, diarrhea, rash, and hypertension, were significantly higher in the sorafenib arm. CONCLUSION: Sorafenib combined with chemotherapy may prolong PFS and TTP. This treatment was associated with manageable toxicities, but frequent dose interruptions and reductions were required.
Arm ; Breast Neoplasms* ; Breast* ; Diarrhea ; Disease-Free Survival ; Drug Therapy* ; Exanthema ; Humans ; Hypertension ; Incidence ; Medical Oncology ; Odds Ratio ; Population Characteristics ; Receptor, Epidermal Growth Factor ; Skin ; Treatment Outcome

OBJECTIVESTo detect the expression of Cathepsin B (CatB) in the intracranial aneurysm wall and its effect to the apoptosis of vascular smooth muscle cells, aimed at clarifying the pathological formation mechanism of intracranial aneurysm.

METHODSFrom November 2006 to February 2009, 20 intracranial aneurysm samples were collected as the experimental group, and 6 cases of normal pallium artery samples were collected as the control group. Immunohistochemical technique was used to evaluate the expressions of CatB, alpha-smooth muscle actin (alpha-SMA) and Caspase-3. The expression of CatB mRNA was evaluated by real-time PCR. The ultrastructure of intracranial aneurysms were observed by using the transmission electronic microscope.

RESULTSCompared with the normal pallium artery specimens, the expression of CatB and Caspase-3 both significantly increased in the intracranial aneurysm walls where alpha-SMA decreased (P < 0.05). The mean expression of CatB mRNA in intracranial aneurysm samples was about 3.8-folds than that in control group (P < 0.01). There were excessive apoptotic vascular smooth muscle cells (VSMCs) in the tunica median, and typical apoptotic body were observed in some aneurysm walls.

CONCLUSIONCathepsin B may be involved in the formation and the progression of intracranial aneurysm.

Adolescent ; Adult ; Aged ; Apoptosis ; Case-Control Studies ; Cathepsin B ; metabolism ; Female ; Humans ; Intracranial Aneurysm ; enzymology ; pathology ; Male ; Middle Aged ; Muscle, Smooth, Vascular ; pathology ; Young Adult

Objective To evaluate the protective effect of Yersinia pestis capsular antigen F1 and recombinant rV270 on mice after immunization with them.Methods According to body weight,40 female Balb/c mice aged 6 to 8 weeks were randomly divided into four experimental groups(Fl-10 μg + aluminum adjuvant,F1-20 μg + aluminum adjuvant,rV-10 μg + aluminum adjuvant,and rV-20 μg + aluminum adjuvant) and a control group,8 in each group.Mice in experimental groups were immunized with the natural antigen F1 and recombinant antigen rV270 adsorbed to 25％ aluminum adjuvant and the control group was immunized with the same amount of aluminum adjuvant.Each mouse was immunized at the hind leg muscle with 100 ml immunizing agent,then a booster immunization was done once on the 21st day after the first immunization.The blood of all mice was collected on the 8th week after the first immunization,serum antibody titers were detected by ELISA and the data of antibody titers were analyzed by t test for comparison between groups.At the same time the mice were injected subcutaneously with 2000-fold LD50 of Yersinia pestis virulent strain 141,after 14 days,the protective effect of immunization was analyzed.Results The control group did not produce antibody.Antibody geometric mean titers (GMT) of the F1-10 mg + aluminum adjuvant and F1-20 mg + aluminum adjuvant groups were 1 ∶ 30443.9,and 1 ∶21527.8,respectively,and compared between the two groups,the difference was not statistically significant (t =1.1282,P ＞ 0.05).The GMTs of the rV-10 μg + aluminum adjuvant and rV-20 μg + aluminum adjuvant groups were 1 ∶ 13957.3 and 1 ∶18100.9,respectively,and compared between the two groups,the difference was not statistically significant(t =0.9408,P ＞ 0.05 ).After subcutaneous injection with Yersinia pestis virulent strain 141,all mice died in the control group but all survived in the experimental group.Conclusion The immune activity of natural antigen F1 and recombinant rV270 is high,which can be used as the main component of subunit vaccine in the plague subunit vaccine study.