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To satisfy the daily demand of skin condition maintenance, make non-invasive real-time detection, and get proper quantitative evaluation of skin viscoelasticity parameters at the same time, a portable non-invasive detection system to acquire real-time skin tissue viscoelasticity is developed. The system relies mainly on a single-degree-of-freedom forced vibration model, with spring-damp-mass, and on dynamic micro indentation method. The experiment is conducted on two kinds of springs, and on pigskin tissues as well, the system's suitability, accuracy and stability are confirmed. The skin viscoelasticity detection in vivo is also carried out on 20 subjects with different ages, the differences of skin viscoelasticity in various parts of the body are investigated, and the correlations between age and skin viscoelasticity are clarified.
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Humans , Elasticity , Skin , Skin Physiological Phenomena , Time , ViscosityABSTRACT
An unconstrained cardiac output detection system based on thoracic electrical impedance method and embedded technology is developed in this study. PWM function of PIC embedded MCU, PIC18F4520, and filter circuit are used to generate a constant current sinusoidal signal with a frequency of 50 kHz and a current RMS of 2 mA, which is applied as an exciting signal to the exciting electrodes located on the positions behind ears and on right lower abdomen. The thoracic electrical impedance is measured by the detecting electrodes pasted along the medial line on the front of the thorax, and is used to calculate cardiac output. A comparative experiment with the thoracic impedance method and the dye dilution method is carried out and the results are investigated. The experimental results show that the two methods have good consistency.
Subject(s)
Cardiac Output , Electric Impedance , Electricity , Electrodes , Monitoring, Physiologic , ThoraxABSTRACT
Objective To investigate the distribution characteristics of the gut microbiome in infants with different delivery mode and feeding pattern at six weeks of life.Methods A total of 60 infants delivered between June and September in 2017 at Peking University First Hospital were recruited.According to delivery modes and feeding patterns,they were respectively divided into two groups,which were vaginal delivery (n=42)and cesarean delivery (n=18) groups,and exclusively breastfeeding (n=40) and mixed-feeding (n=20) groups.Stool samples of all subjects were collected at six weeks after birth.The V3-V4 region of 16s rRNA gene was sequenced on Illumina Hiseq 2500 platform,and the results were analyzed with SILVA database and QIIME software.Independent samples t-test or Mann-Whitney U test was used for statistical analysis.Results (1)Eight bacterial phyla and 146 genera were identified in the 60 stool samples.Firmicutes,Proteobacteria,Actinobacteria and Bacteroidetes were four dominant phyla,and Bifidobacterium,Clostridium,Klebsiella,Bacteroides,Streptococcus,Escherichia-Shigella,Veillonella and Faecalibacterium were the top eight most abundant genera.(2) At the phyla level,the vaginal delivery group was characterized with reduced Firmicutes (0.56 ± 0.1 0 vs 0.42± 0.20,t=2.94,P＜0.05) and increased Actinobacteria and Bacteroidetes [0.04 (0.01-0.11)vs 0.20 (0.05-0.36),U=223,P＜0.05;0.05 (0.01-0.23) vs 0.09 (0.02-0.29),U=315,P＜0.05] as compared with the cesarean delivery group.However,there was no significant difference in the four dominant phyla between exclusively breastfeeding and mixed-feeding groups (all P＞0.05).At the genus level,the relative abundance of Bifidobacterium was higher in the vaginal delivery group than in the cesarean delivery group [0.19 (0.02-0.36) vs 0.01 (0.00-0.07),U=210,P＜0.01].Similarly,there was no significant difference in the eight dominant genus between exclusively breastfeeding and mixed-feeding groups(all P＞0.05).(3) The vaginal delivery group showed significantly lower Shannon and Simpson indexes than the cesarean delivery group [4.26 (3.61-5.52) vs 5.48± 1.19,U=227,P＜0.05;0.86±0.08 vs 0.94 (0.92-0.97),U=194,P＜0.05],while no significance was found in operational taxonomic unit (OTU) number and Chaol index (all P＞0.05).However,there was no significant difference in OTU number,Chaol,Shannon or Simpson index between the exclusively breastfeeding and the mixed-feeding groups (all P＞0.05).Conclusion The early infancy is a critical period for the establishment of gut microbiome.Significant differences in the composition and diversity of gut microbiota are found between infants born vaginally and abdominally,but not in infants with different feeding patterns.
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Subthalamic nucleus (STN) deep brain stimulation (DBS) has become an important surgical treatment of Parkinson disease, but its exact mechanism is still unclear.In this study, a 16-channel implantable microelectrode array (MEA) was prepared by micro-electromechanical system (MEMS) technique and later modified with platinum black/reduced Graphene Oxide/Nafion (Pt/RGO/Nafion) nanocomposites.Extracellular dopamine (DA) content and spike of dorsal striatum neurons were synchronously recorded before and after STN stimulation.The results showed that the dopamine content began to increase within 20 s after electrical stimulation and dropped to normal level after about 50 s, with the highest rising concentration of 1.72 μmol/L.At the same time, there was an increased spike activity of interneurons in the dopamine ascending phase, and the spike firing rate of medium spiny projection neurons (MSNs) was high when the concentration of DA was higher than the normal level.The MEA sensor can simultaneously record dopamine flux and physiological signals in situ, thus providing an ideal tool for neural information detection.
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Objective To observe the clinical effect of Shumu-Yuntu-Zhike decoction with conventional treatment for the Gastroesophageal Reflux Cough (GERC).Methods A total of 64 patients with GERC were randomly divided into the conventional treatment group and the combined treatment group, 32 in each. The conventional treatment group took the Rabeprazole capsule and Mosapride Citrate Tablets, and the combined treatment group received the traditional prescription of Shumu-Yuntu-Zhike decoction on the basis of the conventional therapy. Two groups were treated for 8 weeks and evaluated the effect with the Visual analogue scale (VAS), Reflux diagnostic questionnaire (RDQ) and Chronic cough impact questionnaire (CCIQ) before and after 4 and 8 weeks' treatment.Results After 4 week treatment, the VAS (4.47 ± 1.32vs. 6.22 ± 1.34;t=-5.859,P<0.01), CCIQ (32.60 ± 5.83vs. 47.32 ± 5.56,t=-11.548,P<0.01) in the combined treatment group decreased significantly than the conventional group, but the RDQ (13.62 ± 2.89vs. 13.67 ± 2.77;t=-0.079, P=0.937) showed no significant difference between the two groups. After 8 weeks' treatment. After 8 week treatment, the VAS (2.57 ± 1.69vs. 4.55 ± 2.06;t=-4.676,P<0.01), CCIQ (12.47 ± 3.41vs. 23.47 ± 3.55;t=-14.126,P<0.01) in the combined treatment group decreased significantly, but the RDQ (9.18 ± 2.77vs. 9.3 ± 2.43,t=-0.202,P=0.841) showed no significant difference between the two groups. After the treatment, the total effective rate of combined treatment group was 90.6% (29/32), while the control group was 68.7% (22/32). There was significant difference between the two groups (χ2=4.730,P=0.030).Conclusions The therapy of Shumu-Yuntu-Zhike decoction combined with conventional therapy can relieve the symptom of gastroesophageal reflux cough.
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Chymotrypsin C (CTRC) is a trypsinogen synthesized by pancreatic acinar cells and secreted by pancreatic duct cells and belongs to the family of serine chymotrypsin. The main function of CTRC is to regulate the balance between activation and degradation of trypsin and maintain the structural and functional integrity of the pancreas. CTRC gene mutations can cause abnormal activation of trypsinogen and abnormal degradation of trypsin and then lead to the development of pancreatitis. The downregulation or absence of CTRC expression may be associated with the development and metastasis of pancreatic cancer. This article introduces the structure and biological function of CTRC and its mechanism of action in the development and progression of pancreatitis and pancreatic cancer.
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As one of the important indexes for the diagnosis and treatment of cardiovascular diseases, cardiac output can reflect the state of cardiovascular system timely, and can play a guiding role in the treatment of related diseases. In recent years detection technology of cardiac output has caused great attention, especially minimally invasive and non-invasive methods. In this paper, the principle of non-invasive detection methods and their recent developments are described, and various detection methods are also analyzed.
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Humans , Cardiac Output , Cardiovascular Diseases , Diagnosis , Cardiovascular Physiological PhenomenaABSTRACT
High extracellular potassium can induce spreading depression-like depolarizations, elevations of extracellular glutamate and even neuronal death in normal brain. To investigate the contribution of high potassium in vivo, a microelectrode arrays ( MEAs ) probe integrated with recording sites for glutamate concentration (50í150 μm) and local field potential ( LFP) ( diameter=15 μm) was fabricated by Micro-electro-mechanical-systems ( MEMS) technologies. We implanted the MEA probe acutely in the rat brain and exposed the brain to a high potassium solution. During these multi-modal recordings, it was observed that high potassium elevated extracellular glutamate while suppressing the LFP irreversibly. This is one of the first studies in which a dual mode MEA probes is applied in vivo for neuronal death, and it is concluded that our MEA probes are capable of examining specific spatiotemporal relationships between electrical and chemical signaling in the brain.
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Objective To compare the clinical use of continuous glucose monitoring system (CGMS) and self-monitoring blood glucose (SMBG) when monitoring blood glucose level of patients with gestational diabetes mellitus (GDM) or type 2 diabetes mellitus (DM) complicated with pregnancy.Methods A total of 99 patients with GDM (n=70) and type 2 DM complicated with pregnancy (n=29) that whether hospitalized or in clinical of Peking University First Hospital were recruited from Aug 2012 to Apr 2013.The CGMS was used to monitor their blood glucose level during the 72-hour time period,while the SMBG was also taken seven times daily.The correlation between these blood glucose levels and their glycosylated hemoglobin (HbA1c) levels were analyzed by comparing the average value,the maximum and the minimum value of blood glucose,and the appeared time of these extremum values in these two monitoring methods,and the amount of insulin usage was recorded as well.Results (1) The maximum,minimum and the average blood glucose value in the GDM group were (8.7± 1.2),(4.5 ±0.6) and (6.3 ± 0.6) mmol/L of SMBG vs.(10.1±1.7),(3.1±0.7),(6.0±0.6) mmol/L of CGMS.These values in DM group were (10.1±2.2),(4.5±1.0),(6.9±1.1) mmol/L of SMBG vs.(12.2±2.6),(2.8±0.8),(6.6±1.1) mmol/L of CGMS.By using the two methods,the maximum and the average value of the two groups showed significant differences (P＜0.01) while the minimum value showed no significant differences (P＞0.05).(2) In the GDM group,the average blood glucose values of CGMS and SMBG were significantly correlated (r=0.864,P＜0.01).The maximum values presented the same result (r=0.734,P＜0.01).Correlation was not found in the minimum values of CGMS and SMBG (r=0.138,P＞0.05).In the DM group,the average valves of two methods were significantly correlated (r=0.962,P＜0.01),the maximum values showed the same result (r=0.831,P＜0.01).It can also be observed in the minimum values (r=0.460,P＜0.05).(3) There was significant correlation between the average value of CGMS and HbA1c level (r=0.400,P＜0.01),and the average value of SMBG and HbA1c level were correlated (r=0.031,P＜0.05) in the GDM group; the average values of CGMS (r=0.695,P＜0.01) and SMBG (r=0.673,P＜0.01) were both significantly correlated with the HbA1c level in the DM group.(4) In the GDM group,37％ (26/70) of the minimum values of SMBG appeared 30 minutes before breakfast,while 34％(24/70) of them appeared 30 minutes before lunch; 86％(60/70) of the maximum values of SMBG were evenly distributed 2 hours after each of the three meals.In the DM group,41％(12/29) of the minimum values of SMBG presented 30 minutes before lunch,while 21％(6/29) and 14％(4/29) of them were showed 30 minutes before breakfast and dinner respectively; about 30％ of the maximum values of SMBG appeared 2 hours after each of the three meals.(5) In the GDM group,23％(16/70) of the minimum values of CGMS occurred between 0:00-2:59 am.,and most of the other minimum values of CGMS were evenly distributed in the rest of the day,except for 3％(2/70) of them were found during 18:00-20:59 pm.43％(30/70) of the maximum values of CGMS appeared during 6:00-8:59 am.,only 1％(1/70) and 3％(2/70) of them presented during 0:00-2:59 am.and 21:00-23:59 pm.,and the rest were evenly distributed for the other times of the day.In the DM group,34％(10/29) of the minimum values of CGMS were found during 0:00-2:59 am.,14％(4/29) of them appeared during 9:00-11:59 am.and 15:00-17:59 pm.,45％(13/29) of the maximum values of the CGMS presented during 6:00-8:59 am.,none was found during 21:00-23:59 pm.,0:00-2:59 am.and 3:00-5:59 am.,and the rest were evenly distributed for the other times of the day.(6) 64％(45/70) of the patients in the GDM group did not require for insulin treatment,while 36％(25/70) of them did.For those patients who received insulin treatment,after CGMS,64％(16/25) of them adjusted the insulin dosage according to their blood glucose levels.In the DM group,14％(4/29) of them did not receive insulin treatment,while for the others who did(86％,25/29); 60％ (15/25) of them adjusted the insulin dosage according to their blood glucose levels after CGMS.Conclusions Both CGMS and SMBG could correctly reflect patients' blood glucose levels.It was more difficult to control the blood glucose levels in patients with type 2 DM complicated with pregnancy than the GDM patients.Compared with SMBG,CGMS could detect postprandial hyperglycemia and nocturnal hypoglycemia more effectively.
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The nano-structure TiN was modified on the laboratory self-made planar microelectrode array pMEA by magnetron sputtering method. The performance of modified pMEA was investigated. Research on neuroelectrical and neurochemical recording was studied in vitro. The impedance of the modified pMEA was decreased almost one order of magnitude, and the background noise level was reduced to ±6 μV. In the same testing environment, the signal-to-noise ratio (SNR) of modified electrodes was 1. 7 times of bare electrodes. The SNR of neuroelectrical recording on the brain slice of SD rats reached 10:1 , and the weak signal such as ±12 μV was separated easily. For neuroelectrical recordings, the detection limit of dopamine ( DA) solution reached 50 nmol/L with the 2:1 (S/N). During the concentration range of 0. 05-100 μmol/L, the linearly correlation coefficient of the DA oxidation currents was 0 . 998 . The modification of nano-structure TiN on pMEA reduced pMEA impedance and background noise level, meanwhile the SNR was increased. The weak signals of neuroelectrical and neurochemical recording were successfully recorded.
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The principle of ambulatory cardiac output (CO) measuring technique is introduced in this paper. Experimental studies about the applicability of the two-compartment coaxial cylindrical model for ambulatory measurement of cardiac output with spot-electrodes have been carried out with using our newly-developed multi-channel impedance mapping system. The key factors using a spot-electrode array instead of a conventional band-electrode array for non-invasive CO) measurement are elaborated. The variations of the electric impedance pulsatile component (deltaZ waveform) and the two kinds of typical modes of deltaZ distributions measured by six electrodes on the midsternal (midian) line from the medial portion at the level of clavicle to the portion above the xiphisternum are discussed. The applicability of the two-compartment coaxial cylindrical model for ambulatory measurement of CO with spot-electrodes is analyzed. Synthesizing the deltaZ distributions and their typical changing models on the midsternal (midian) line during blood inflowing into aorta is the optimal positions of a pair of spot-electrodes for voltage pick-up at the level of clavicle for the upper electrode and the position at the level of nipple for the lower electrode when spot-electrode is being used to measure non-invasive CO.
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Humans , Biomedical Engineering , Cardiac Output , Physiology , Cardiography, Impedance , Methods , Electrocardiography, Ambulatory , Methods , Electrodes , Equipment Design , Heart , Physiology , Models, Cardiovascular , ThoraxABSTRACT
Objective To explore the long term effects of gestational diabetes mellitus (GDM)on offsprings of affected women.Methods One hundred and twenty-four singleton pregnant women with GDM,who delivered in Department of Obstetrics and Gynecology,Peking University First Hospital from June 14,2006 to December 31,2007,were enrolled as the study group.Ninety-eight singleton pregnant women with normal glucose metabolism who delivered at the corresponding period were enrolled as the control group.The follow-up study was performed from November 6,2010 to January 31,2011 on their offsprings.Anthropometry indexes,including height,weight,waist circumference,systolic and diastolic blood pressure (DBP),triceps skin fold (TSF) and sub-scapular skin fold (SSF) were measured.According to the development standard of children less than five years old issued by World Health Organization in 2006,there were six detailed evaluation indicators including length/height for age z-score (HAZ),weight for age z-score (WAZ),weight for length/ height z score (WHZ),body mass index (BMI) for age z-score (BAZ),triceps skin folds for agez-score (TSFZ) and sub-scapular skin folds for age z-score (SSFZ).Chi-square,t-test or variance analysis were applied.Results (1) No statistical difference on age,birth weight,sex,height,weight,BMI,waist circumference,blood pressure,TSF and SSF was found between offsprings of study and control group (P＞0.05).(2) Offsprings in both groups were further divided into macrosomia and non-microsomia subgroups,i.e.GDM macrosomic subgroup (n =15),GDM nonmacrosomic subgroup (n=109),control macrosomia subgroup (n=6) and control non-macrosomia subgroup (n=92).Significant difference was shown amont the four subgroups in weight [(19.8±3.9),(17.0±1.9),(17.7±1.7)and (17.2±1.7) kg,F=6.238,P＜0.001],BMI (17.6±2.6,16.0±1.2,16.6±1.1 and 16.2±1.1,F=5.901,P＜0.001),waist circumference [(53.6±5.3),(49.9±2.7),(50.9±3.3) and (50.4±0.9) cm,F=5.307,P＜0.001],WHZ (1.40±1.44,0.45±0.81,0.88±0.75 and 0,60±0.87,F=5.269,P=0.002),HAZ (1.22±0.78,0.47±0.82,0.98±0.74 and 0.50±1.00,F=3.668,P=0.013),WAZ (1.68±1.23,0.58±0.79,1.15±0.85and 0.71±0.93,F=7.361,P＜0.001) and BAZ (1.41±1.52,0.42±0.84,0.81±0.76 and 0.60±0.90,F=5.210,P =0.002).While comparing between each two subgroups,there was statistical difference between GDM macrosomia subgroup and GDM non macrosomia subgroup,and between GDM marosomia subgroup and control non-macrosomia group.(3) While comparing GDM macrosomia and GDM non-macrosomia subgroup with control group [weight (17.2±2.5) kg,BMI (16.2± 1.4),waist circumference (50.5 ± 3.6) cm,DBP (55.2 ± 6.9)mm Hg,SSF(6.1 ± 1.8) mm,WHZ (0.62±0.87),HAZ (0.53±0.99),WAZ (0.73±0.92),BAZ(0.61±0.89)],the weight (F=9.283,P＜0.001),BMI (F=8.707,P＜0.001),waist circumference (F=7.934,P＜0.001),DBP(F=3.123,P=0.046),SSF (F=3.499,P=0.032),WHZ (F=7.639,P＜0.001),HAZ(F=4.709,P=0.010),WAZ (F=10.302,P＜0.001) and BAZ (F=7.689,P＜0.001) was higher in GDM group than the control group.(4) The proportions of overweight and obesity were higher in GDM macrosomia subgroup than in GDM non-macrosomia and control groups [overweight:9/15 vs24.8％ (27/109) and 24.5％ (24/98),x2 =8.870,P=0.012; obesity:5/15 vs 7.3％(8/109) and 9.2％(9/98),x2=10.083,P=0.006].If all subjects were divided into macrosomia and non-macrosomia group,then the proportion of overweight and obesity was higher in the former group [overweight:52.4％ (11/21) vs24.4％(49/201),x2=7.560,P=0.006; obesity:28.6％ (6/21)vs 7.9％(16/201),x2 =9.047,P=0.003].Conclusions GDM may have long term adverse effect on the development of offsprings at three-four-year-old with higher incidence of obesity or high diastolic blood pressure in macrosomic babies of GDM mothers than in non macrosomic babies of GDM mothers or babies of non GDM mothers.
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A small experimental system is constructed with working principle of continuous blood pressure monitoring based on the volume compensation method. The preliminary experimental results show that the system can collect blood pressure signals at the radial artery effectively. The digital PID algorithm can track the variation of blood pressure. And the accuracy of continuous blood pressure detecting achieve the level of same kind of product.
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Humans , Algorithms , Blood Pressure Determination , Methods , Equipment Design , Signal Processing, Computer-AssistedABSTRACT
Principle of ambulatory cardiac output (CO) measuring technique is introduced in this paper. A lot of experimental studies of the current distribution on the thorax under the condition that the current injection electrodes were adhered to different positions were carried out by using a developed multi-channel impedance mapping system. The static impedance contour maps (Zo-map) and its pulsatile component contour maps (deltaZ-map) under different measuring conditions were analyzed, and the applicability of a two-compartment coaxial cylindrical model using a spot-electrode array instead of the conventional band-electrode array for ambulatory CO measurement, as well as the optimal spot-electrode array, were discussed. Based on the experimental results and the daily use of the ambulatory CO measuring technique, the optimal spot-electrode array meeting the condition of the two-compartment coaxial cylindrical model was determined as that a pair of spot-electrodes for current injection was located on the positions behind the ears and on the right lower abdomen, and a pair of spot-electrodes for voltage pick-up places on the medial portion at the level of clavicle and on the portion above the xiphisternum.