慢阻肺急性加重期患者延迟就医与家庭动力学的相关性研究

目的研究慢阻肺急性加重期患者延迟就医与家庭动力学的相关性,希望能够为慢阻肺急性加重期患者拟定护理措施提供科学依据。方法选取2017年1月-2019年12月我院240例诊断为慢阻肺急性加重期的患者为研究对象。根据患者入院就医的时间进行分组,时间≥24h的延迟就医的患者为观察组,时间<24h的及时就医患者为对照组。结果两组患者在文化水平、家庭年收入、在职状态、医疗保险和婚姻状况和APACHEⅡ评分比较(P<0.05)。观察组患者疾病观念、个性化、系统逻辑和家庭氛围得分比对照组高(P<0.05)。Pearman的相关性分析结果显示:慢阻肺急性加重期患者延迟就医时间与各个层面分数以及家庭动力总分呈现负相关性(P<0.05)。应变量为延迟就医为应变量,患者的一般资料为自变量,经Logistic回归分析结果表明:延迟就医的影响因素为文化水平、家庭动力评分、职业状态、家庭收入、婚姻状况和APACHEⅡ评分。结论慢阻肺急性加重期患者家庭动力总分与疾病观念、个性化、系统逻辑和家庭氛围得分与延迟就医时间呈现负相关性,患者延迟就医的影响因素是家庭动力学评分。

全捷联图像导引头隔离度辨识及其抑制技术应用

针对全捷联图像导引头中传感器刻度尺误差与动力学偏差引起的隔离度问题,阐述了隔离度寄生回路产生的机理,并提出在线辨识探测器及角速率陀螺刻度尺系数与补偿导引头动力学延迟的隔离度抑制方案。建立导引头"数字平台"的等效模型,基于无迹卡尔曼滤波算法(UKF),对传感器刻度尺系数以及真实弹目视线角速率进行辨识;运用匹配滤波器补偿导引头探测器动力学滞后。最后进行数学仿真,从稳定弹体飞行姿态与提升制导精度两个方面,对各方案的可行性进行了论证。结果表明:UKF滤波算法与匹配滤波器可以有效地对隔离度进行抑制并提升制导系统性能。

Characterization of a Chinese KCNQ1 mutation （R259H） that shortens repolarization and causes short QT syndrome 2

Objectives To evaluate the association between a KCNQ 1 mutation, R259H, and short QT syndrome （SQTS） and to explore the elec- trophysiological mechanisms underlying their association. Methods We performed genetic screening of SQTS genes in 25 probands and their family members （63 patients）. We used direct sequencing to screen the exons and intron-exon boundaries of candidate genes that en- code ion channels which contribute to the repolarization of the ventricular action potential, including KCNQI, KCNH2, KCNE1, KCNE2, KCNJ2, CACNAlc, CACNB2b and CACNA2D1. In one of the 25 SQTS probands screened, we discovered a KCNQ1 mutation, R259H. We cloned R259H and transiently expressed it in HEK-293 cells; then, currents were recorded using whole cell patch clamp techniques. Results R259H-KCNQ 1 showed significantly increased current density, which was approximately 3-fold larger than that of wild type （WT） after a depolarizing pulse at 1 s. The steady state voltage dependence of the activation and inactivation did not show significant differences between the WT and R259H mutation （P 〉 0.05）, whereas the time constant of deactivation was markedly prolonged in the mutant compared with the WT in terms of the test potentials, which indicated that the deactivation of R259H was markedly slower than that of the WT. These results suggested that the R259H mutation can effectively increase the slowly activated delayed rectifier potassium current （Irs） in phase 3 of the cardiac action potential, which may be an infrequent cause of QT interval shortening. Conclusions R259H is a gain-of-function muta- tion of the KCNQ1 channel that is responsible for SQTS2. This is the first time that the R259H mutation was detected in Chinese people.

Effect of Phosphate on Zinc Transport in Lou Soil

A study on the transport characteristics of zinc in lou soil with phosphate at different concentrations was carried out by the method of step input. The effects of phosphate and temperature on zinc transport were studied through analysing the diffusion-dispersion coefficients (D) and the retardation factor (R) obtained by the program CXTFIT. The results showed that D decreased and R increased with increasing concentration of phosphate so that it was difficult for zinc to break through the soil column, and zinc stopped to break through the column at high temperature. One order equation, double constant equation and the Elovich equation were all suitable for the description of zinc dynamica. Effects of phosphate and temperature on zinc transport were further confirmed by the analysis on pseudo-thermodynamic parameters of zinc transport.

Co-processing Vacuum Residue with Waste Plastics in a Delayed Coking Process:Kinetics and Modeling

Thermal upgrading of vacuum residue mixed with waste plastics was studied in a laboratory scale delayed coking unit.The model of feed thermal decomposition was set up and the first order reaction kinetics was used to predict products distribution during the coking process.The distillate yield was higher(70%) for the vacuum residue/polystyrene(VR/PS) feed system and the vacuum residue/low density polyethylene(VR/LDPE) feed system.The resulted distillate yield was separated into fractions according to their boiling points,with gasoline and diesel being our fractions of concern.The activation energy was higher for gasoline production(around 60 kcal/mol) varying with the type of feed system,while it was 33 kcal/mol for diesel fraction.The regression coefficient R was 0.990.

Approximate Entropy Analysis of Electroencephalogram

Based on the time-delayed embedding method of phase space reconstruction, a new method to compute the approximate entropy （ApEn） of electroencephalogram （EEG） is proposed. The computational results show that there are signiticant differences between epileptic： EEG and normal EEG in the approximate entropy with the variance of embedding dimension. This conclusion is helpful to analyze the dynamical behavior of difibrent EEGs by entropy.

Crustal structure of northeastern margin of the Tibetan Plateau by receiver function inversion

Using seismic data of about one year recorded by 18 broadband stations of ASCENT project, we obtained 2547 receiver func- tions in the northeastern Tibetan Plateau. The Moho depths under 14 stations were calculated by applying the H-x domain search algorithm. The Moho depths under the stations with lower signal-noise ratio （SNR） were estimated by the time delay of the PS conversion. Results show that the Moho depth varies in a range of -40--60 kin. The Moho near the Haiyuan fault is vague, and its depth is larger than those on its two sides. In the Qinling-Qilian Block, the Moho becomes shallower gradually from west to east. To the east of 105~E, the average depth of the Moho is 45 km, whereas the west is 50 km or even deeper. Combining our results with surface wave research, we suggest a boundary between the Qinling and the Qilian Mountains at around 105~E. S wave velocities beneath 15 stations have been obtained through a linear inversion by using Crust2.0 as an ini- tial model, and the crustal thickness that was derived by H-x domain search algorithm was also taken into account. The results are very similar to the results of previous active source studies. The resulting figure indicates that low velocity layers devel- oped in the middle and lower crust beneath the transition zone of the Tibet Block and western Qinling, which may be related to regional faults and deep earth dynamics. The velocity of the middle and lower crust increases from the Songpan Block to the northeastern margin of Tibetan Plateau. Based on the velocity of the crust, the distribution of the low velocity zone and the composition of the curst （Poisson＇s ratio）, we infer that the crust thickening results from the crust shortening along the direc- tion of compression.

EXPONENTIALLY ADAPTIVE SYNCHRONIZATION OF AN UNCERTAIN DELAYED DYNAMICAL NETWORK

Over the past decades, complex networks have been prosperous greatly in various fields of sciences and engineering. Much attention has been given to investigate the synchronization of complex networks in recent years. However, few work has done for the networks with uncertain parameters and unknown topology. In this paper, to further reveal the dynamical mechanism in complex networks with time delays, an uncertain general complex dynamical network with delayed nodes is studied. By constructing a drive network and a suitable slave network, several novel criteria for the networks consisting of the identical nodes and different nodes have been obtained based on the adaptive feedback method. Particularly, the hypotheses and the proposed adaptive laws for network synchronization are simple and can be readily applied in practical applications. Finally, numerical simulations are provided to illustrate the effectiveness of the proposed synchronization criteria.

A Mathematical Model with Delays for Schistosomiasis Japonicum Transmission

A dynamic model of schistosoma japonicum transmission is presented that incorporates effects of the prepatent periods of the different stages of schistosoma into Baxbour＇s model. The model consists of four delay differential equations. Stability of the disease free equilibrium and the existence of an endemic equilibrium for this model are stated in terms of a key threshold parameter. The study of dynamics for the model shows that the endemic equilibrium is globally stable in an open region if it exists and there is no delays, and for some nonzero delays the endemic equilibrium undergoes Hopf bifurcation and a periodic orbit emerges. Some numerical results are provided to support the theoretic results in this paper. These results suggest that prepatent periods in infection affect the prevalence of schistosomiasis, and it is an effective strategy on schistosomiasis control to lengthen in prepatent period on infected definitive hosts by drug treatment （or lengthen in prepatent period on infected intermediate snails by lower water temperature）.

GLOBAL DYNAMICS OF A DELAYED HIV-1 INFECTION MODEL WITH ABSORPTION AND SATURATION INFECTION

In this paper, an HIV-1 infection model with absorption, saturation infection and an intracellular delay accounting for the time between viral entry into a target cell and the production of new virus particles is investigated. By analyzing the characteristic equations, the local stability of an infection-free equilibrium and a chronic-infection equilibrium of the model is established. By using suitable Lyapunov functionals and LaSalle＇s invariance principle, it is proved that if the basic reproduction ratio is less than unity, the infection-free equilibrium is globally asymptotically stable; and if the basic reproduction ratio is greater than unity, sufficient condition is derived for the global stability of the chronic-infection equilibrium.

Auto-ignition of biomass synthesis gas in shock tube at elevated temperature and pressure

Ignition delay times of multi-component biomass synthesis gas （bio-syngas） diluted in argon were measured in a shock tube at elevated pressure （5, 10and 15 bar, 1 bar = 105 Pa）, wide temperature ranges （1,100-1,700 K） and various equivalence ratios （0.5, 1.0, 2.0）. Additionally, the effects of the variations of main constituents （H2：CO = 0.125-8） on ignition delays were investigated. The experimental results indicated that the ignition delay decreases as the pressure increases above certain temperature （around 1,200 K） and vice versa. The ignition delays were also found to rise as CO concentration increases, which is in good agreement with the literature. In addition, the ignition delays of bio-syngas were found increasing as the equivalence ratio rises. This behavior was primarily discussed in present work. Experimental results were also compared with numerical predictions of multiple chemical kinetic mechanisms and Li＇s mechanism was found having the best accuracy. The logarithmic ignition delays were found nonlinearly decrease with the H2 concentration under various conditions, and the effects of temperature, equivalence ratio and H2 concentration on the ignition delays are all remarkable. However, the effect of pressure is rela- tively smaller under current conditions. Sensitivity analysis and reaction pathway analysis of methane showed that R1 （H ＋O2= O -9 OH） is the most sensitive reaction promot- ing ignition and R13 （H ＋O2 （＋M） = HO2 （＋M））, R53（CH3＋H （＋M）= CH4 （＋M））, R54 （CH4＋H= CH3 ＋ H2） as well as R56 （CH4 ＋ OH = CH3 ＋ H2O） are key reactions prohibiting ignition under current experimental conditions. Among them, R53 （CH3 ＋ H （＋M） = CH4 （＋M））, R54 （CH4 ＋ H = CH3 ＋ H2） have the largest posi- tive sensitivities and the high contribution rate in rich mixture. The rate of production （ROP） of OH of R1 showed that OH ROP of R1 decreases sharply as the mixture turns rich. Therefore, the ignition delays become longer as the equiva- lence ratio increases.

Dynamics of an infection model with two delays

In this paper, a HTLV-I infection model with two delays is considered. It is found that the dynamics of this model are determined by two threshold parameters R0 and R1, basic reproduction numbers for viral infection and for CTL response, respectively. If R0 〈 1, the infection-free equilibrium P0 is globally asymptotically stable. If R1 〈 1 〈 R0, the asymptomatic-carrier equilibrium P1 is globally asymptotically stable. If R1 〉 1, there exists a unique HAM/TSP equilibrium P2. The stability of P2 is changed when the second delay T2 varies, that is there exist stability switches for P2.

EFFECT OF KAIROMONE ON PREDATOR-PREY DYNAMICS -- A DELAY MODEL

In most of the predator-prey systems, prey individuals make transitions between vulnerable and invulnerable states or locations. This transition is regulated by various inducible defense mechanisms. Diel vertical migration （DVM） in zooplankton is the most effective and instantaneous defense observed in zooplankton population. Zooplankton shows downward vertical migration in the daytime in the presence of predators （or predator kairomones） to avoid predation （i.e. refuge use）, and it enters into the surface water again at night to graze phytoplankton. The dynamics of the planktonic ecosystem under DVM of zooplankton along with fish kairomone and the multiple delays due to migration for vulnerable and invulnerable prey and reproduction in the predator population is of considerable interest both in theoretical and experimental ecologists. By developing mathematical model, we analyze such a system. The conditions for which the system enters into Hopf-bifurcation are obtained. Moreover, the conditions for which the bifurcating branches are supercritical are also derived. Our results indicate that DVM along with the effect of kairomone and multiple delays with a certain range are responsible to enhance the stability of the system around the positive interior equilibrium point.

Distinguish on the viability of human umbilical cord mesenchymal stem cells using delayed luminescence

In this paper, we report the discrimination of the viability of human umbilical cord mesenchymal stem cells(hUC-MSCs) with photo-induced delayed luminescence(DL). We measure the DL decay kinetics of hUC-MSCs using an ultraweak luminescence detection system, and find the significant difference in the weight distributions of the decay rate for hUC-MSCs with high and low viabilities. Spectral discrimination of hUC-MSCs with high and low viabilities is thus carried out by comparing the DL kinetics parameters, including the initial intensity, the peak decay rate and the peak weight value. Our results show that the novel optical method for the viability diagnosis of hUC-MSCs has a promising prospect.