ObjectiveTo investigate the role of 4-week high-intensity interval training (HIIT) in modulating the metabolic homeostasis of the pyruvate-lactate axis in the hippocampus of rats with chronic unpredictable mild stress (CUMS) to improve their depressive-like behavior. MethodsForty-eight SPF-grade 8-week-old male SD rats were randomly divided into 4 groups: the normal quiet group (C), the CUMS quiet group (M), the normal exercise group (HC), and the CUMS exercise group (HM). The M and HM groups received 8 weeks of CUMS modeling, while the HC and HM groups were exposed to 4 weeks of HIIT starting from the 5th week (3 min (85%-90%) S_max+1 min (50%-55%) S_max, 3-5 cycles, S_max is the maximum movement speed). A lactate analyzer was used to detect the blood lactate concentration in the quiet state of rats in the HC and HM groups at week 4 and in the 0, 2, 4, 8, 12, and 24 h after exercise, as well as in the quiet state of rats in each group at week 8. Behavioral indexes such as sucrose preference rate, number of times of uprightness and number of traversing frames in the absenteeism experiment, and other behavioral indexes were used to assess the depressive-like behavior of the rats at week 4 and week 8. The rats were anesthetized on the next day after the behavioral test in week 8, and hippocampal tissues were taken for assay. LC-MS non-targeted metabolomics, target quantification, ELISA and Western blot were used to detect the changes in metabolite content, lactate and pyruvate concentration, the content of key metabolic enzymes in the pyruvate-lactate axis, and the protein expression levels of monocarboxylate transporters (MCTs). Results4-week HIIT intervention significantly increased the sucrose preference rate, the number of uprights and the number of traversed frames in the absent field experiment in CUMS rats; non-targeted metabolomics assay found that 21 metabolites were significantly changed in group M compared to group C, and 14 and 11 differential metabolites were significantly dialed back in the HC and HM groups, respectively, after the 4-week HIIT intervention; the quantitative results of the targeting showed that, compared to group C, lactate concentration in the hippocampal tissues of M group, compared with group C, lactate concentration in hippocampal tissue was significantly reduced and pyruvate concentration was significantly increased, and 4-week HIIT intervention significantly increased the concentration of lactate and pyruvate in hippocampal tissue of HM group; the trend of changes in blood lactate concentration was consistent with the change in lactate concentration in hippocampal tissue; compared with group C, the LDHB content of group M was significantly increased, the content of PKM2 and PDH, as well as the protein expression level of MCT2 and MCT4 were significantly reduced. The 4-week HIIT intervention upregulated the PKM2 and PDH content as well as the protein expression levels of MCT2 and MCT4 in the HM group. ConclusionThe 4-week HIIT intervention upregulated blood lactate concentration and PKM2 and PDH metabolizing enzymes in hippocampal tissues of CUMS rats, and upregulated the expression of MCT2 and MCT4 transport carrier proteins to promote central lactate uptake and utilization, which regulated metabolic homeostasis of the pyruvate-lactate axis and improved depressive-like behaviors.

ObjectiveThis study aimed to investigate the effects of 4-week high-intensity interval training (HIIT) on synaptic plasticity in the prefrontal cortex (PFC) of rats exposed to chronic unpredictable mild stress (CUMS), and to explore its potential mechanisms. MethodsA total of 48 male Sprague-Dawley rats were randomly divided into 4 groups: control (C), model (M), control plus HIIT (HC), and model plus HIIT (HM). Rats in groups M and HM underwent 8 weeks of CUMS to establish depression-like behaviors, while groups HC and HM received HIIT intervention beginning from the 5th week for 4 consecutive weeks. The HIIT protocol consisted of repeated intervals of 3 min at high speed (85%-90% maximal training speed, S_max) alternated with one minute at low speed (50%-55% S_max), with 3 to 5 sets per session, conducted 5 d per week. Behavioral assessments and tail-vein blood lactate levels were measured at the end of the 4th and 8th weeks. After the intervention, rat PFC tissues were collected for Golgi staining to analyze synaptic morphology. Enzyme-linked immunosorbent assays (ELISA) were employed to detect brain-derived neurotrophic factor (BDNF), monocarboxylate transporter 1 (MCT1), lactate, and glutamate levels in the PFC, as well as serotonin (5-HT) levels in serum. Additionally, Western blot analysis was conducted to quantify the expression of synaptic plasticity-related proteins, including c-Fos, activity-regulated cytoskeleton-associated protein (Arc), and N-methyl-D-aspartate receptor 1 (NMDAR1). ResultsCompared to the control group (C), the CUMS-exposed rats (group M) exhibited significant reductions in sucrose preference rates, number of grid crossings, frequency of upright postures, and entries into and duration spent in open arms of the elevated plus maze, indicating marked depressive-like behaviors. Additionally, the group M showed significantly reduced dendritic spine density in the PFC, along with elevated levels of c-Fos, Arc, NMDAR1 protein expression, and increased concentrations of lactate and glutamate. Conversely, BDNF and MCT1 contents in the PFC and 5-HT levels in serum were significantly decreased. Following HIIT intervention, rats in the group HM displayed considerable improvement in behavioral indicators compared with the group M, accompanied by significant elevations in PFC MCT1 and lactate concentrations. Furthermore, HIIT notably normalized the expression levels of c-Fos, Arc, NMDAR1, as well as glutamate and BDNF contents in the PFC. Synaptic spine density also exhibited significant recovery. ConclusionFour weeks of HIIT intervention may alleviate depressive-like behaviors in CUMS rats by increasing lactate levels and reducing glutamate concentration in the PFC, thereby downregulating the overexpression of NMDAR, attenuating excitotoxicity, and enhancing synaptic plasticity.

Objective:To compare the effectiveness of cylindrical-shaped and conical-shaped cuff catheters for airway closure using different pressure measurement methods at the lowest safe pressure and to guide the clinical application.Methods:Twenty-four patients with endotracheal intubation admitted to the intensive care unit (ICU) of Guangxi Medical University Cancer Hospital from December 2021 to January 2022 were enrolled. Leakage test in vitro was performed on the secretion on the patients' cuff. The needle and plunger from 20 mL syringe was separated, the syringe was sealed with adhesive, and the syringe nozzle was filled thoroughly to create a tracheal model. Consecutively, both cylindrical-shaped and conical-shaped cuff catheters were inserted into the simulated trachea, and the cuff pressure was calibrated to 20 cmH 2O (1 cmH 2O≈0.098 kPa) before commencing the experiment. The viscosity of the secretion on the patients' cuff was classified (grade Ⅰ was watery subglottic secretion, grade Ⅱ was thick subglottic secretion, grade Ⅲ was gel-like subglottic secretion), and the same viscosity secretion was injected into the catheter cuff. Utilizing a self-control approach, intermittent pressure measurement was initially conducted on both the cylindrical-shaped and conical-shaped cuff by improved pressure measurement method (intermittent pressure measurement group), followed by continuous pressure measurement experiment (continuous pressure measurement group). The leakage volume of the three viscosity subglottic secretions and the values of cuff pressure measurement of different shaped cuff catheters at 4, 6, 8 hours of inflation were recorded. Results:A total of 180 retention samples were extracted from 24 patients with tracheal intubation during ventilation, with 90 samples in each of the two groups using different pressure measurement methods, and 30 samples of retention materials with different viscosities in each group. In the intermittent pressure measurement group, at 4 hours of inflation, all samples of secretion with grade Ⅰ and grade Ⅱ on cylindrical-shaped cuff leaked, while 3 samples of secretion with grade Ⅲ also leaked. For conical-shaped cuff, 28 samples of secretion with grade Ⅰ leaked, only 2 samples of secretion with grade Ⅱ leaked, and there was no leak for secretion with grade Ⅲ. At 6 hours of inflation, all samples of the three viscosity secretions on different shaped cuffs leaked. The leakage was gradually increased with the prolongation of inflation time. In the continuous pressure measurement group, at 4 hours of inflation, all samples of secretion with grade Ⅰ on cylindrical-shaped cuff leaked, while 29 samples of secretion with grade Ⅱ leaked, and there was no leak for secretion with grade Ⅲ. For the conical-shaped cuff, 26 samples of secretion with grade Ⅰ leaked, and there was no leak for secretion with grade Ⅱ and grade Ⅲ. At 6 hours of inflation, the conical-shaped cuff still had no leak for secretion with grade Ⅲ. As the inflation time prolonged, the leakage of subglottic secretion on different shaped cuffs in both groups was gradually increased. At 8 hours of inflation, all samples experienced leakage, but the leakage of subglottic secretion on different shaped cuffs in the continuous pressure measurement group was significantly reduced as compared with the intermittent pressure measurement group [leakage for secretion with grade Ⅲ (mL): 1.00 (0.00, 1.25) vs. 2.00 (1.00, 2.00) on the cylindrical-shaped cuff, 1.00 (0.00, 1.00) vs. 2.00 (2.00, 2.00) on the conical-shaped cuff, both P < 0.01]. The values of pressure measurement of cuffs with different shapes at different time points of inflation in the continuous pressure measurement group were within the set range (20-21 cmH 2O). The cuff pressure at 4 hours of inflation in the intermittent pressure measurement group was significantly lower than the initial value (cmH 2O: 18.3±0.6 vs. 20.0±0.0 in the cylindrical-shaped cuff, 18.4±0.6 vs. 20.0±0.0 in the conical-shaped cuff, both P < 0.01), and the cuff pressure in both shaped cuffs showed a significant decrease tendency as inflation time prolonged. However, there was no statistically significant difference in values of pressure measurement between the different shaped cuff catheters. Conclusions:Continuous pressure monitoring devices can maintain the effective sealing of conical-shaped cuff catheters at the lowest safe pressure. When using an improved pressure measurement method for intermittent pressure measurement and/or using a cylindrical cuff catheter, the target pressure should be set at 25-30 cmH 2O, and the cuff pressure should be adjusted regularly.

Objective To explore the relationship between the types of bicuspid aortic valves(BAV)and the outcome of functional mitral regurgitation(FMR)and the affecting factors of FMR.Methods From Jun 2018 to Sep 2022,patients with severe BAV aortic valve stenosis(AS)complicated with FMR underwent post transcatheter aortic valve replacement(TAVR)in Zhongshan Hospital,Fudan University were retrospectively analyzed.The baseline information and imaging data of different BAV patients were collected.Logistic regression was used to analyze the factors affecting the outcome of FMR(improvement and non-improvement).Result A total of 100 patients with TAVR were included,including 49 patients with type 0 of BAV and 51 patients with type 1 of BAV.Compared with patients of type 1,patients of type 0 had younger age[(72.78±6.09)y vs.(77.00±8.35)y,P=0.050],lower male ratio(47%vs.73%,P= 0.009)higher BMI[(23.19±2.62)kg/m2 vs.(21.99±3.13)kg/m2,P=0.041],and lower incidence of aortic regurgitation(69%vs.92%,P=0.040).Compared with the non-improvement group,the improvement group had a lower incidence of coronary heart disease(5%vs.18%,P=0.042),higher incidence of pulmonary hypertension(20%vs.2%,P=0.007),larger left ventricular diastolic diameter[(51.98±6.74)mm vs.(48.04±7.72)mm,P=0.009]and higher maximum flow velocity[(4.86±0.95)cm/s vs.(4.47±0.75)cm/s,P= 0.023]of the aortic valve.The results of Logistic regression analysis showed that preoperative pulmonary hypertension,left ventricular end-diastolic diameter and maximum valvular flow velocity of BAV patients were the potential affecting factors of FMR improvement after TAVR.Conclusion No significant difference was found in FMR improvement between BAV patients of type 0 and type 1 after TAVR.For BAV patients with AS,preoperative pulmonary hypertension,larger left ventricular end-diastolic diameter,and faster aortic valve flow velocity were associated with higher FMR improvement rate.

ObjectiveThe purpose of this study was to investigate the effects of transcutaneous electrical acupoint stimulation (TEAS) on cognitive function of vascular dementia (VD) rats and its mechanism. MethodsVD rat model was established by modified two-vessel occlusion (2-VO). After modeling, TEAS and electroacupuncture (EA) were used to stimulate Baihui and Zusanli points of rats respectively for 14 d. After treatment, novel object recognition test, Morris water maze test, and Y maze test were used to evaluate the spatial memory and learning ability of rats. Hematoxylin and eosin staining was used to observe the morphology of hippocampal neurons. Transmission electron microscopy was used to observe the ultrastructure of hippocampal mitochondria. Enzyme-linked immunosorbent assay kits were used to detected the levels of SOD, CAT, GSH-Px, MDA and ROS in serum of rats. Western blot was used to detect the expression of PGC-1α, TFAM, HO-1, NQO1 proteins in the hippocampus, Keap1 protein in the cytoplasm and Nrf2, NRF1 proteins in the nucleus. ResultsAfter treatment for 14 d, compared to the model group, the escape latency of VD rats decreased, while the discrimination index, the times of rats crossing the original platform area, the residence time in the original platform quadrant, and the percentage of alternation increased. TEAS can improve the structure of hippocampal neurons and mitochondria of VD rats, showing that neurons were arranged more regularly and distributed more evenly, nuclear membrane and nucleoli were clearer, and mitochondrial swelling were reduced, mitochondrial matrix density were increased, and mitochondrial cristae were more obvious. The levels of SOD, GSH-Px and CAT in serum increased significantly, while the concentration of MDA and ROS decreased. TEAS also up-regulated the expression levels of PGC-1α TFAM, NQO1 and HO-1 proteins in the hippocampus and Nrf2, NRF1 proteins in the nucleus, but down-regulated the Keap1 protein in the cytoplasm. ConclusionTEAS can improve cognition, hippocampal neurons and mitochondrial structure of VD rats, and the effect is better than EA. The mechanism may be the activation of PGC-1α mediated mitochondrial biogenesis and antioxidant stress, which also provides a potential therapeutic technology and experimental basis for the treatment of VD.

Objective To evaluate the clinical efficacy of oral administration of Guizhi Decoction combined with acupoint application of Banxia Fuling Decoction in the treatment of hyperemesis gravidarum(nausea and vomiting during pregnancy)of taiyin syndrome.Methods Sixty patients with hyperemesis gravidarum of taiyin syndrome were randomly divided into the treatment group and thecontrol group at the ratio of 1∶1,with 30 cases in each group.The control group was given acupoint application of Banxia Fuling Decoction on the acupoints of Zhongwan(CV12),bilateral Neiguan(PC6),bilateral Zusanli(ST36),and bilateral Yinlingquan(SP9).The treatment group was treated with Guizhi Decoction orally on the basis of treatment for the control group.Both groups were treated for 2 weeks.The changes of Pregnancy-Unique Quantification of Emesis(PUQE)score,Nausea and Vomiting of Pregnancy Specific Quality of Life Questionnaire(NVPPQOL)score and traditional Chinese medicine(TCM)syndrome score in the two groups were observed before and after treatment.Multiple linear regression analysis was performed for the exploration of the influencing factors of PUQE score in the two groups before treatment.After treatment,the cured and markedly effective rate,negative conversion rate of pregnancy anxiety and negative conversion rate of urinary ketone bodies were compared between the two groups.Results(1)After 2 weeks of treatment,the cured and markedly effective rate of the treatment group was 86.67%(26/30),and that of the control group was 56.67%(17/30).The intergroup comparison showed that the cured and markedly effective rate of the treatment group was significantly superior to that of the control group(P＜0.05).(2)After treatment,the PUQE score,NVPPQOL score and TCM syndrome score of the two groups were significantly decreased compared with those before treatment(P＜0.05),and the decrease of PUQE score,NVPPQOL score and TCM syndrome score in the treatment group was significantly superior to that in the control group(P＜0.05).(3)Pearson correlation analysis showed that PUQE score was negatively correlated with gestational age(P＜0.05),but had no correlation with gestational weeks and anxiety score(P＞0.05).(4)After treatment,the negative conversion rate of pregnancy anxiety in the treatment group was 16.67%(5/30),and that in the control group was 6.67%(2/30).There was no significant difference between the two groups(P＞0.05).(5)After treatment,the negative conversion rate of urinary ketone bodies in the treatment group was 53.33%(16/30),and that in the control group was 13.33%(4/30).The intergroup comparison showed that the negative conversion rate of urinary ketone bodies in the treatment group was significantly higher than that in the control group(P＜0.01).(6)There were no obvious adverse reactions or adverse events in the two groups during the treatment,and there were no abnormal changes in the blood and urine routine test,liver and kidney function indicators and other safety indexes of the patients,with high safety.Conclusion Oral administration of Guizhi Decoction combined with acupoint application of Banxia Fuling Decoction can effectively alleviate the symptoms of nausea and vomiting,improve the quality of life of patients,and increase the negative conversion rate of urinary ketone bodies in the patients with hyperemesis gravidarum of taiyin syndrome.Moreover,there is a certain correlation of the nausea and vomiting PUQE score with the age of the patients.

Objective To design a novel oxygenator to solve the existing problems of extracorporeal membrane oxygenation(ECMO)machine in high transmembrane pressure difference,low efficiency of blood oxygen exchange and susceptibility to thrombosis.Methods The main body of the oxygenator vascular access flow field was gifted with a flat cylindrical shape.The topology of the vascular access was modeled in three dimensions,and the whole flow field was cut into a blood inlet section,an inlet buffer,a heat exchange zone,a blood oxygen exchange zone,an outlet buffer and a blood outlet section.The oxygenator was compared with Quadrox oxygenator by means of ANSYS FLUENT-based simulation and prototype experiments.Results Simulation calculations showed the oxygenator designed was comparable to the clinically used ones in general,and gained advantages in transmembrane pressure difference,blood oxygen exchange and flow uniformity.Experimental results indicated that the oxygenator behaved better than Quadrox oxygenator in transmembrane pressure difference and blood oxygen exchange.Conclusion The oxygenator has advantages in transmem-brane pressure difference,temperature change,blood oxygen ex-change and low probability of thrombosis.[Chinese Medical Equipment Journal,2024,45(3):23-28]

Objective To design a Bluetooth auscultation system to solve the problems of the traditional stethoscope in determining the starting position of heart sound signals due to long distance,high noises or serious diseases.Methods The Bluetooth auscultation system was mainly composed of a handheld terminal(lower unit)and a personal computer or Bluetooth headset(upper unit).The handheld terminal had a STM32F103C8 Micro Control Unit as its core unit and consisted of a heart sound signal acquisition unit,an ECG signal acquisition unit and a Bluetooth transmission unit,which had all the task threads arranged with a uC/OS Ⅱ embedded system;the upper unit used MATLAB and C# platform to realize signal storage and display and basic analysis of digital signals.Results Among the heart sound signals acquired with the system,the signals from health volunteers had clear components and the signals from patient volunteers were almost obliterated by heart murmurs.Conclusion The Bluetooth auscultation system realizes acquisition,processing and analysis of heart sound signals,which can be applied in the fields of daily medical treatment,military medical service support,public health care and heart sound auscultation teaching after further optimization.[Chinese Medical Equipment Journal,2024,45(5):22-27]

Objective To investigate the performance of brands and types of high-flow nasal cnnula oxygen therapy(HFNC)devices at different altitudes.Methods Four different models of HFNC devices,including R-80S bi-level non-invasive ventilator integrated with HFNC device,HF-60A HFNC device,HFT-300 HFNC device and H-80A HFNC device,were connected with the gas flow meter,simularted head and QuickLung and then put into a low-pressure chamber.The flow rates of the HFNC devices were set to 10,15,20,25,30,35,40,45,50,55 and 60 L/min,and the simulated altitudes of the low-pressure chamber were set to 6 000,5 000,4 000,3 000,2 000,1 000 and 0 m.The actual output airway flow rates,airway pressure changes and trends of the four HFNC devices were recorded at different setting altitudes and flow rates.SPSS 25.0 software was used for statistical analysis.Results The actual output airway flow rates of the four HFNC devices showed an increasing trend as the altitude rose with the simulated altitude of 6 000 m and the setting flow rate kept constant,which increased slowly and even went to decrease when the altitude and flow rate exceeded some limits.The degree of changes in the flow rate with the increasing altitude varied,and there was no uniform pattern.With the rising of altitude,the actual output airway pressure of the four HFNC devices with the flow rate raning from 10 to 35 L/min also increased gradually,which showed a decreasing trend(turning point)after going up to some certain value when the flow rate exceeded 35 L/min,and the altitude where the turning point appeared was lowered as the flow rate increased.Conclusion The actual output airway flow rates and airway pressure during HFNC rise at a high-altitude environment,and generally considerations have to be taken on required airway pressure,patient comfort and the altitude of the patient's usual place of residence when setting the flow rates of the HFNC device.[Chinese Medical Equipment Journal,2024,45(6):49-58]

Objective To develop a portable collection device of human exhaled breath condensate(EBC)based on natural breathing to meet the needs for rapid screening of human respiratory tract(especially lower respiratory tract)infections.Methods The device consisted of a refrigeration unit,a heat dissipation unit and a condensation unit.The refrigeration unit adopted a TES1-7102 thermoelectric Peltier cooler semiconductor as the refrigeration element;the heat dissipation unit was composed of a high thermal conductivity aluminum heat sink and a high-speed brushless cooling fan;the condensation unit was made up of a cold guide plate and a condenser,in which the cold guide plate was made of thin sheet of aluminum alloy,and the condenser was prepared by 3D printing technology and made of hydrophobic polylactic acid,with primary and secondary 2-stage guide grooves and an ultra-thin condensing surface.The performance of the device was verified in terms of cooling,thermal conductivity,condensation and human EBC collection and content analysis.Results Performance analysis showed that after refrigeration began the temperature difference between the condenser surface and the exhaled gas met the requirements of the condenser,and no obvious thermal resistance was found on the condensing surface so that large droplets could be formed rapidly and then be collected after the gas-liquid phase change of the exhaled gas on the condensing surface.Human EBC collection and content analysis indicated the device realized home self-collection of EBCs from people of all ages,and the concentrations of interleukins,C-reactive protein and other inflammation-related indexes and the pH value of the collected EBC samples were all correlated with respiratory infections in the subjects.Conclusion The device developed with easy operation avoids the discomfort of blowing collection and the risk of saliva contamination,and is worthy promoting for rapid diagnosis and dynamic monitoring of respiratory tract infection and other related diseases.[Chinese Medical Equipment Journal,2024,45(8):32-37]