Objective To carry out rigid-body inverse dynamics modelling and analysis of a self-designed 6RSS parallel bio-inspired masticatory robot.Methods Firstly,the functions of kinematic variables including translational/rotational velocities and accelerations were derived for rigid-body inverse dynamics modelling.Secondly,the rigid-body inverse dynamics model was established with the Newton-Euler's law.Finally,the chewing motion trajectories of the oral health volunteers were tracked and numerical calculations were carried out in the case where the robot was subjected to a chewing reaction force.Results Numerical calculations showed that the driving torque and the constraint force of the robot peaked when the chewing reaction force was at its maximum.Conclusion The external force has a large impact on the inverse dynamics of the robot,and theoretical references are provided for the motion control and optimal design of the robot.[Chinese Medical Equipment Journal,2024,45(3):16-22]

Objective: To identify the risk factors in mortality of pediatric acute respiratory distress syndrome (PARDS) in pediatric intensive care unit (PICU). Methods: Second analysis of the data collected in the "efficacy of pulmonary surfactant (PS) in the treatment of children with moderate to severe PARDS" program. Retrospective case summary of the risk factors of mortality of children with moderate to severe PARDS who admitted in 14 participating tertiary PICU between December 2016 to December 2021. Differences in general condition, underlying diseases, oxygenation index, and mechanical ventilation were compared after the group was divided by survival at PICU discharge. When comparing between groups, the Mann-Whitney U test was used for measurement data, and the chi-square test was used for counting data. Receiver Operating Characteristic (ROC) curves were used to assess the accuracy of oxygen index (OI) in predicting mortality. Multivariate Logistic regression analysis was used to identify the risk factors for mortality. Results: Among 101 children with moderate to severe PARDS, 63 (62.4%) were males, 38 (37.6%) were females, aged (12±8) months. There were 23 cases in the non-survival group and 78 cases in the survival group. The combined rates of underlying diseases (52.2% (12/23) vs. 29.5% (23/78), χ²=4.04, P=0.045) and immune deficiency (30.4% (7/23) vs. 11.5% (9/78), χ²=4.76, P=0.029) in non-survival patients were significantly higher than those in survival patients, while the use of pulmonary surfactant (PS) was significantly lower (8.7% (2/23) vs. 41.0% (32/78), χ²=8.31, P=0.004). No significant differences existed in age, sex, pediatric critical illness score, etiology of PARDS, mechanical ventilation mode and fluid balance within 72 h (all P>0.05). OI on the first day (11.9(8.3, 17.1) vs.15.5(11.7, 23.0)), the second day (10.1(7.6, 16.6) vs.14.8(9.3, 26.2)) and the third day (9.2(6.6, 16.6) vs. 16.7(11.2, 31.4)) after PARDS identified were all higher in non-survival group compared to survival group (Z=-2.70, -2.52, -3.79 respectively, all P<0.05), and the improvement of OI in non-survival group was worse (0.03(-0.32, 0.31) vs. 0.32(-0.02, 0.56), Z=-2.49, P=0.013). ROC curve analysis showed that the OI on the thind day was more appropriate in predicting in-hospital mortality (area under the curve= 0.76, standard error 0.05,95%CI 0.65-0.87,P<0.001). When OI was set at 11.1, the sensitivity was 78.3% (95%CI 58.1%-90.3%), and the specificity was 60.3% (95%CI 49.2%-70.4%). Multivariate Logistic regression analysis showed that after adjusting for age, sex, pediatric critical illness score and fluid load within 72 h, no use of PS (OR=11.26, 95%CI 2.19-57.95, P=0.004), OI value on the third day (OR=7.93, 95%CI 1.51-41.69, P=0.014), and companied with immunodeficiency (OR=4.72, 95%CI 1.17-19.02, P=0.029) were independent risk factors for mortality in children with PARDS. Conclusions: The mortality of patients with moderate to severe PARDS is high, and immunodeficiency, no use of PS and OI on the third day after PARDS identified are the independent risk factors related to mortality. The OI on the third day after PARDS identified could be used to predict mortality.
Female ; Male ; Humans ; Child, Preschool ; Infant ; Child ; Critical Illness ; Pulmonary Surfactants/therapeutic use* ; Retrospective Studies ; Risk Factors ; Respiratory Distress Syndrome/therapy*

Objective:To investigate the relationship between the dose of preoperative neoadjuvant radiotherapy and the pathologic complete response (pCR) rate in patients with locally advanced squamous cell esophageal cancer (ESCC).Methods:Clinical data of 116 patients with ESCC who received neoadjuvant chemoradiotherapy followed by esophagectomy in our cancer center from July 2017 to December 2019 were retrospectively analyzed. The radiation doses were divided into 2 ranges based on Grays (Gy) received: 40-45 Gy and 45 Gy or more.Results:The overall pCR rate was 38. 8%(45/116). pCR was observed in 35 out of 80(44%) patients treated with 40-45 Gy and 10 of 36(28%) patients treated with 45 Gy or more. The pCR rate did not significantly differ between two groups [(40-45 Gy) vs.( ≥ 45 Gy), P=0.105)]. Conclusions:Preoperative neoadjuvant radiotherapy with a higher dose (≥ 45 Gy) fails to increase the pCR rate in patients with locally advanced ESCC. Prospective randomized trials are required to determine the optimal dose of preoperative adjuvant radiotherapy.

Objective: To investigate the feasibility of echocardiography-guided closed-chest repeated intraventricular blood sampling in mice, and to clarify the maximum blood volume that can be collected by this method, and whether the method can be used for long-term repeated blood collection in mice. Methods: Twenty-four male C57BL/6J mice (10-14 weeks old) were divided into the terminal experiment group (n=4, for investigating the maximum blood amount that could be sampled at one time), the repeated 0.5 ml blood collection group (n=10, sampling 0.5 ml whole blood each time, once every two days for consecutive 4 weeks), and the repeated 0.75 ml blood collection group (n=10, sampling 0.75 ml whole blood each time, once every two days for consecutive 4 weeks). High-frequency echocardiography was used to display the largest section of the left ventricle, guiding the insulin syringe needle through the thorax into the left ventricle for blood collection. In the repeated 0.5 ml blood collection group, echocardiography was used to detect the cardiac structure and function before blood collection, three minutes after blood collection, and one week after the last (the 14th) blood collection. Results: We successfully performed echocardiography-guided closed-chest intraventricular blood sampling, with an average operating time (88±19)s per mouse, and a maximum blood volume (1.43±0.11)ml per mouse. In the repeated 0.5 ml blood collection group, heart rate, left ventricular ejection fraction, left ventricular fractional shortening, left ventricular end-diastolic dimension and left ventricular posterior wall end-diastolic thickness remained uncganged before the first blood collection and after 4 weeks of repeated blood collection (all P>0.05). No death in the repeated 0.5 ml blood collection group. However, in the 0.75 ml blood collection group, two mice died before the end point. Conclusions: The echocardiography-guided closed-chest intraventricular blood sampling is a safe, minimally invasive, convenient and efficient method, and can be used repeatedly for long-term blood collection in mice.
Animals ; Echocardiography ; Feasibility Studies ; Heart Ventricles ; Male ; Mice ; Mice, Inbred C57BL ; Ventricular Function, Left

Trauma is the leading cause of death for people under 40 years old in the world. At present, the rescue and treatment system of trauma patients in China is not yet well established, and the mortality of trauma patients is higher than those in the developed countries. Improving the treatment system is the key to reducing the trauma mortality. In order to innovate the service mode of trauma first aid, further promote the establishment of regional trauma first aid system, improve the ability of trauma treatment, reduce the mortality and disability rate of trauma patients in Jiangxi Province, recently Health Commission of Jiangxi Province and the First Affiliated Hospital of Nanchang University have reached a consensus on the establishment of Jiangxi trauma first aid center. In order to provide reference for the construction of trauma treatment system, the author analyzes the following aspects including functional positioning, basic requirements, organization management, and evaluation of core indicators.

Purpose To explore whether potassium perchlorate shall be taken orally to occlude gastric mucosa before taking 99Tcm-3PRGD2 SPECT/CT gastric image,and to provide theoretical evidence for clinical application.Material and Methods Eighteen adult male Wistar rats were divided into three groups randomly:low dose group of potassium perchlorate (36 mg/kg),high dose group (72 mg/kg) and normal saline control group,with six rats in each group.All rats were conducted with gavage of 1 ml/100 g respectively and,one hour later,injected with 99Tcm-3PRGD2 intravenously to rat tail.Then 99Tcm-3PRGD2 gastric image was taken two hours later.The same film reader carried out audio analysis of the image and then gastric and radioactivity ratio (T/N) on the lung of the same side were analyzed.Results Preparation of 99Tcm-3PRGD2 was simple and radiochemical purity of final products was (98.90±0.70)％.Rat weights in high dose group of potassium perchlorate,low dose group and control group were (479.7t21.5) g,(481.0± 17.6) g and (478.5± 16.5) g,respectively.The differences were of no statistical significance (F=0.027,P＞0.05).T/N values in rat stomach area were 1.2219±0.0165,1.2204±0.0167 and 1.2186±0.0175,respectively.The differences were of no statistical significance (F=0.055,P＞0.05).Conclusion Preparation of 99Tcm-3PRGD2 is simple and radiochemical purity is high.There is great possibility of no need to take potassium perchlorate orally to occlude gastric mucosa when taking 99Tcm-3PRGD2 SPECT/CT image (especially when the radiochemical purity of final products is over 98％),making it convenient in clinical promotion and utilization.

Objective To compare the hypnotic effects of propofol administered by target-controlled infusion (TCI in daytime and nighttime,in order to explore the effect of circadian rhythm on the sedative effect of propofol.Methods Sixty-five male ASA Ⅰ or Ⅱ patients,aged 18-55 years,with the body mass index (BMI) of 18.5-24.9 kg/m2,undergoing emergency minor hand surgery were divided into two groups according to the time of the day when they received TCI of propofol:daytime group (from 07:01 to 19:00) and nighttime group (from 19:01 to 07:00).The pharmacokinetic parameters proposed by Schnider et al.which suggested the effect-site concentration (Ce) was used.Four Ces of propofol were set at 0.8,1.2,2.0 and 4.0 μg/ml,respectively.Ce was increased step by step and each Ce was maintained for 5 minutes.The level of sedation at each Ce was assessed by bispectral index (BIS) and observer's assessment of alertness/sedation (OAA/S) scores.BIS values and Ces of propofol were recorded and compared between the two groups when the patients lost consciousness (OAA/S score =2).Results There were 28 and 30 patients in daytime and nighttime groups,respectively.When Ces were 1.2 and 2.0 μg/ml,the BIS values were significantly lower in the nighttime group than in the daytime group.There was no significant difference in BIS values between the two groups when Ces were 0.8 and 4.0 μg/ml.When the patients lost consciousness (OAA/S =2),the BIS value was comparable between the two groups,but Ce was significantly lower in the nighttime group than in the daytime group.Conclusion The hypnotic effect of propofol is greater during night time than during day time.

OBJECTIVEThe purpose of this study was to investigate the value of postoperative chemotherapy for locally advanced rectal cancer patients who reached pathological ypT1-4N0 after neo-adjuvant chemoradiotherapy.

METHODSWe performed a retrospective study of 104 patients treated with preoperative chemoradiotherapy followed by radical resection, who achieved pathological ypT1-4N0, between Mar 2003 and Dec 2010. There were 73 patients who received postoperative adjuvant chemotherapy, and the other 31 patients did not. The distribution of final pathologic stages for these patients was ypT1-2N0 in 39 cases and ypT3-4N0 in 65 cases.

RESULTSThe median follow-up was 41 months. The 3-year overall survival rate (OS) and recurrence-free survival rate (RFS) for the whole group (ypT1-4N0) were 93.4% and 85.3%, respectively. The 3-year OS and RFS in the adjuvant chemotherapy group and non-adjuvant chemotherapy group were 95.5%, 88.6% and 88.6%, 77.2%, respectively. There were no significant differences in 3-year RFS (P = 0.108) and OS (P = 0.106) between the two groups. The 3-year local recurrence and distant metastasis rates in the adjuvant chemotherapy group were 4.1% (3/73) and 5.5% (4/73), while for the non-adjuvant chemotherapy group, the 3-year local recurrence rate and distant metastasis rate were 3.2% (1/31) and 16.1% (5/31), respectively. Significant difference was found in distant metastasis rates (P = 0.030) between the two groups, but not in local recurrence rates (P = 0.676).Further subgroup analysis indicated that for the ypT1-2N0 patients, there were no significant differences in 3-year OS (P = 0.296) and RFS (P = 0.939) between the adjuvant and non-adjuvant chemotherapy groups, while negative results displayed in 3-year local recurrence rates (P = 0.676) and distant metastasis rates (P = 0.414). However, for patients with ypT3-4N0, significant differences were showed in both the 3-year OS (P = 0.034) and RFS (P = 0.025), and further analysis revealed that the 3-year distant metastasis rate was significantly higher in the non-adjuvant chemotherapy group than in the adjuvant chemotherapy group (P = 0.010) , but with non-significant difference in the 3-year local recurrence (P = 0.548).

CONCLUSIONSAdjuvant chemotherapy may not improve survival for ypT1-2N0 patients. However, it may be clinically meaningful for ypT3-4N0 patients by decreasing distant metastasis rate. Further randomized controlled clinical trials are needed to confirm our results.

Adenocarcinoma ; drug therapy ; pathology ; radiotherapy ; surgery ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Chemoradiotherapy, Adjuvant ; Chemotherapy, Adjuvant ; Deoxycytidine ; analogs & derivatives ; therapeutic use ; Female ; Fluorouracil ; analogs & derivatives ; therapeutic use ; Follow-Up Studies ; Humans ; Leucovorin ; therapeutic use ; Male ; Middle Aged ; Neoadjuvant Therapy ; Neoplasm Metastasis ; Neoplasm Recurrence, Local ; Neoplasm Staging ; Organoplatinum Compounds ; therapeutic use ; Postoperative Period ; Radiotherapy, Conformal ; Rectal Neoplasms ; drug therapy ; pathology ; radiotherapy ; surgery ; Retrospective Studies ; Survival Rate ; Young Adult

Objective To compare the hypnotic effect of propofol administered by target-controlled infusion (TCI) during day-time and night-time,in order to explore the effect of circadian rhythms on the sedative effect of propofol.Methods Sixty-five male ASA Ⅰ or Ⅱ patients aged 18-55 yr undergoing emergency minor hand surgery were divided into 2 gorups according to the time of the day when they received propofol TCI:day-time group (from 7:01 to 19:00) and night-time group (from 19:01 to 7:00).The pharmacokinetic parameters proposed by Schnider which predict effect-site concentration (Ce) were used.Four effect-site concentrations of propofol were set:0.8,1.2,2.0 and 4.0 μg/ml.Ce was increased step by step and each Ce was maintained for 5 min.The level of sedation at each Ce was assessed by BIS and OAA/S scores.BIS value and Ce of propofol were recorded and compared between the 2 groups when the patients lost consciousness (OAA/S score =2).Results There was 28 and 30 patients in day-time and nighet-time groups respectively.When Ce =1.2 and 2.0 μg/ml,the BIS values were significantly lower in night-time group than in day-time group.There was no significant difference in BIS value between the 2 groups when Ce =0.8 and 4.0 μg/ml.When the patients lost consciousness (OAA/S =2),the BIS value was comparable between the 2 groups,but Ce was significantly lower in night-time group than that in daytime group.Conclusion The hypnotic effect of propofol is greater during night-time than during day-time.

OBJECTIVETo assess the characteristics and daily treatment compliance of non-alcoholic fatty liver disease (NAFLD) patients in China.

METHODSNAFLD adult patients from 21 clinics of 12 cities in China were enrolled in this registry. Physical examination such as demographic characteristics (height, weight, waist circumference measurement), blood pressure and clinical laboratory and ultrasonographic examination of liver were undertaken. Daily practice including life style and medication were recorded and assessed in accordance with 2006 Chinese NAFLD treatment guidelines.

RESULTSA total of 1656 patients were enrolled (1146 male and 510 female), mean of 45.8 ± 12.6 years old, mean duration of NAFLD history was (47.2 ± 47.7) months. 44.9% of NAFLD were suffering from metabolic syndromes. Patients with central obesity have higher incidence of hypertension and lower level of high-density lipoprotein cholesterol (HDL-C) than those without central obesity, P < 0.05. Body mass index (BMI), waist circumference, triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) in ALT abnormal group were higher than those in ALT normal group (P < 0.05), HDL-C was lower in ALT abnormal group (P < 0.05). Significant differences existed between the BMI, female waist circumference, TG, fast insulin, HOMA index, ALT, AST and HDL-C among subgroups with mild, moderate and severe steatosis. Majority of the patients did not follow recommendations of NAFLD treatment guidelines. Among targeted population only 15.3% of patients used insulin sensitizers and 23.8% took lipid lowering medicine according to the guideline.

CONCLUSIONData indicated that nearly half of NAFLD patients co-morbid with metabolic disorders. Therapy compliance was unsatisfactory and the gap between current practice and Chinese NAFLD treatment guidelines was not optimal.

Adult ; Asian Continental Ancestry Group ; China ; epidemiology ; Fatty Liver ; diagnosis ; epidemiology ; therapy ; Female ; Humans ; Male ; Metabolic Syndrome ; epidemiology ; Middle Aged ; Non-alcoholic Fatty Liver Disease ; Risk Factors ; Waist Circumference