In order to enhance the position accuracy of ablation catheter in heart electrophysiology operation, signals of respiration and heartbeat must be removed for subsequent data processing. Based on locating principle of electrical field with low frequency, synchronous detector with MC1496 has been developed in this study. In the present research, several methods are utilized to optimize the circuit performance, such as coupling and stopping direct current, low-pass filtering, as well as limiting ripple voltage etc. Through simulation results, it showed that the demodulation performance of the circuit was fine. Through simulation platform of thorax electric field and animal experiment, the circuit feasibility were further proved good for extracting signals of respiration and heartbeat.
Atrial Fibrillation ; surgery ; Catheter Ablation ; methods ; Computer Simulation ; Electromagnetic Fields ; Heart ; anatomy & histology ; physiology ; Humans ; Models, Biological ; Signal Processing, Computer-Assisted ; Thorax

Objective: To establish a scoring system to predict the risk of anastomotic leakage in patients with rectal cancer older than 60 years. Methods: The study included 995 patients (≥ 60 years) with rectal cancer locating 3-12 cm from the anal verge who underwent anterior resection or intersphincteric resection at the Department of General Surgery, Henan Cancer Hospital from January 2012 to December 2016. Potential risk factors for leakage were subjected to univariate analysis. Multivariate logistic regression analysis was used to identify the independent risk factors for anastomotic leakage. The scoring system was developed based on regression coefficient for each significant risk factor. One point was allocated to the risk factor with a regression coefficient β < 1, and two points were allocated to the risk factor with β > 1. The proposed scoring system was tested by the area under curve (AUC) of the receiver operating characteristic curve (ROC) . Results: Surgery was successfully performed in all 995 patients. The incidence of anastomotic fistula was 4.6% (46/995) . Among these 46 patients, 31 recovered after conventional treatment, and 13 patients underwent transverse colostomy, and 2 died of multiple organ failure. Independent risk factors included age (β = 0.643, OR = 1.902, 95%CI: 1.020 - 3.614, P = 0.048) , body mass index (BMI) (β = 1.218, OR = 3.379, 95%CI: 1.607 - 7.105, P = 0.001) , albumin levels (β = 0.986, OR = 2.681, 95%CI: 1.432-5.021, P = 0.002) , and level of anastomosis from the anal verge (β = 1.395, OR = 4.034, 95%CI: 2.086-7.801, P = 0.000) . The scoring system was created base on coefficient β of the independent risk factors (age≥70 years for 1, BMI≥25 kg/m² for 2, albumin levels < 35 g/L for 1, level of anastomosis from anal verge < 4.0 cm for 2) . All the scores were added up, and all patients were divided into the high-risk group (4-6 points, n=71) and intermediate-low-risk group (0-3 points, n=924) based on the scoring system. The incidence of anastomotic leakage in the two groups was 23.9% (17/71) and 3.1% (29/924) , respectively (χ² = 60.092, P = 0.000) . The AUC of age, BMI, albumin levels, and level of anastomosis from the anal verge were 0.598, 0.591, 0.622, and 0.635 respectively. The AUC of the scoring system was 0.656, which was higher than above parameters with a sensitivety of 0.37 and specificity of 0.94. Conclusions The scoring system is effective and accurate for identifying a subgroup at high risk for postoperative anastomotic leakage in rectal cancer patients over 60 years old.

Objective To explore the clinical effects of pedicled ligamentum teres hepatis in preventing duodenum stump fistula after resection of gastric cancer.Methods The clinicopathological data of 563 patients with gastic cancer who underwent resection from Jan.2013 to Dec.2016 were analyzed.Results Fourteen patients in the control group developed duodenum stump fistula.Four patients in the experimental group developed duodenum stump fistula.The incidence of duodenum stump fistula in the control group was 4.6％,while that in the experimental group was 1.5％ (x2 =4.356,P =0.037).All the 14 patients in the control group had high fever and 2 died of multiple organ failure,8 were cured with conservative treatment,and 4 received reoperation.For patients in the experimental group,moderate fever was observed in 2 patients and all were cured by conservative treatment.Conclusion Pedicled ligamentum teres hepatis was safe and effective to prevent duodenum stump fistula after resection of gastric cancer.

Objective To explore the mechanism of thymoquinone (TQ) on NSCLC cytotoxicity.Methods SK-MES-1 was inoculated into 96-well plates and cultured at 20,40,60,80 and 100 μmol/L TQ for 24 h,and the IC50 of TQ was calculated.SK-MES-1 was cultured in close proximity to IC50 concentration TQ,and time-dependent was observed.The ERK inhibitor U0126 and the p38 inhibitor SB203580 were applied to SK-MES-1 and 95-D,respectively,then TQ-activated MAPK-mediated cytotoxicity were observed.The SK-MES-1 expression of p-p38,p38,p-ERK1/2,ERK1/2,pJNK and JNK protein were detected by U0126 pretreatment for 1 h and TQ-cultured for 30 min.Results ① TQ was used to mediate NSCLC cells in a concentration and time-dependent manner,and the viability of NSCLC cells was decreased.② The cell viability of 30 μmol/L TQ and 10 μmol/L U0126 +30 μmol/L TQ showed significant differences (P =0.000),but no significant difference was found when compared with 10 μmol/L SB203580 + 30 μmol/L TQ (P =1.00).10 μmol/L SB203580 + 30 μmol/L TQ was significantly different from 10 μmol/L U0126 + 30 μmol/L TQ (P =0.000).60μmol/LTQ,10μmol/LU0126 + 60μmol/LTQ,10μmol/LSB203580 + 60 μmol/L TQ showed no significant differences between every two groups (P ＞ 0.0 5).With the increase of TQ concentration,the protective effect of SB203580 on 95-D cells gradually decreased,and 10 μmol/L SB203580 +40 μmol/L TQ group was significantly different from 40 μmol/L TQ group (P =0.033).③ Western blot analysis showed that U0126 could significantly inhibit the phosphorylation of ERK1/2,phosphorylated p38 increased with the increasing of TQ concentration.However,ERK1/2 phosphorylation decreased,and JNK phosphorylation did not change significantly.Conclusion TQ can mediate NSCLC cytotoxicity through phosphorylation of p38 pathway,but not ERK1/2 pathway.

Objective To explore the mechanism of thymoquinone (TQ) on NSCLC cytotoxicity.Methods SK-MES-1 was inoculated into 96-well plates and cultured at 20,40,60,80 and 100 μmol/L TQ for 24 h,and the IC50 of TQ was calculated.SK-MES-1 was cultured in close proximity to IC50 concentration TQ,and time-dependent was observed.The ERK inhibitor U0126 and the p38 inhibitor SB203580 were applied to SK-MES-1 and 95-D,respectively,then TQ-activated MAPK-mediated cytotoxicity were observed.The SK-MES-1 expression of p-p38,p38,p-ERK1/2,ERK1/2,pJNK and JNK protein were detected by U0126 pretreatment for 1 h and TQ-cultured for 30 min.Results ① TQ was used to mediate NSCLC cells in a concentration and time-dependent manner,and the viability of NSCLC cells was decreased.② The cell viability of 30 μmol/L TQ and 10 μmol/L U0126 +30 μmol/L TQ showed significant differences (P =0.000),but no significant difference was found when compared with 10 μmol/L SB203580 + 30 μmol/L TQ (P =1.00).10 μmol/L SB203580 + 30 μmol/L TQ was significantly different from 10 μmol/L U0126 + 30 μmol/L TQ (P =0.000).60μmol/LTQ,10μmol/LU0126 + 60μmol/LTQ,10μmol/LSB203580 + 60 μmol/L TQ showed no significant differences between every two groups (P ＞ 0.0 5).With the increase of TQ concentration,the protective effect of SB203580 on 95-D cells gradually decreased,and 10 μmol/L SB203580 +40 μmol/L TQ group was significantly different from 40 μmol/L TQ group (P =0.033).③ Western blot analysis showed that U0126 could significantly inhibit the phosphorylation of ERK1/2,phosphorylated p38 increased with the increasing of TQ concentration.However,ERK1/2 phosphorylation decreased,and JNK phosphorylation did not change significantly.Conclusion TQ can mediate NSCLC cytotoxicity through phosphorylation of p38 pathway,but not ERK1/2 pathway.