2013—2020年重庆市北碚区胃癌疾病负担变化趋势及预测

目的 了解2013—2020年重庆市北碚区胃癌疾病负担变化趋势,预测2021—2023年胃癌死亡率,为开展胃癌防治工作提供建议。方法 2013—2020年重庆市北碚区胃癌死亡资料来源于“中国疾病预防控制系统人口死亡信息登记管理系统”,计算死亡率、标化死亡率、早逝生命损失年(YLL)、早逝生命损失年(YLL)率、平均减寿年数(AYLL)和期望寿命损失年数(YLEL)等指标,采用指数平滑的非季节性模型预测死亡率。率的标化采用2010年全国普查人口结构。率的比较采用卡方检验。率的趋势分析采用年度变化百分比(APC),并对APC进行t检验。结果 2013—2020年重庆市北碚区胃癌的死亡率和标化死亡率分别由2013年的15.26/10万和11.81/10万下降到2020年的10.66/10万和6.75/10万,APC分别为-6.29%和-8.79%,变化趋势有统计学意义(t值分别为-3.098和-4.690,P＜0.05)。胃癌死亡率随年龄的增加而上升,50岁以下年龄组最低(0.74/10万~2.13/10万),80岁以上年龄组最高(76.21/10万~169.81/10万)。YLL率、AYLL和YLEL分别由2013年的3.63‰、23.77年和0.25年下降到2020年的2.31‰、21.66年和0.16年,APC分别为-7.60%、-1.39%和-7.32%,变化趋势有统计学意义(t值分别为-3.211、-2.308和-4.930,P＜0.05)。指数平滑的简单非季节性模型为最优预测模型,预测2021—2023年胃癌死亡率均为10.66/10万。结论 北碚区胃癌死亡率呈下降趋势,胃癌早死造成的疾病负担较过去有所下降,但疾病负担仍较重,宜继续巩固胃癌的综合防控。     

A boosting approach to flexible semiparametric mixed models

In linear mixed models the influence of covariates is restricted to a strictly parametric form. With the rise of semi- and non-parametric regression also the mixed model has been expanded to allow for additive predictors. The common approach uses the representation of additive models as mixed models. An alternative approach that is proposed in the present paper is likelihood based boosting. Boosting originates in the machine learning community where it has been proposed as a technique to improve classification procedures by combining estimates with reweighted observations. Likelihood based boosting is a general method which may be seen as an extension of L2 boost. In additive mixed models the advantage of boosting techniques in the form of componentwise boosting is that it is suitable for high dimensional settings where many explanatory variables are present. It allows to fit additive models for many covariates with implicit selection of relevant variables and automatic selection of smoothing parameters. Moreover, boosting techniques may be used to incorporate the subject-specific variation of smooth influence functions by specifying 'random slopes' on smooth effects. This results in flexible semiparametric mixed models which are appropriate in cases where a simple random intercept is unable to capture the variation of effects across subjects.     

Consanguinity and Late Fertility: Spatial Analysis Reveals Positive Association Patterns

The role of consanguinity on human complex traits is an important and controversial issue. In this work we focused on the Sardinian population and examined the effect of consanguineous unions on late female fertility. During the last century the island has been characterized by a high incidence of marriages between relatives, favoured by socio economic conditions and geographical isolation, and by high fertility despite a widespread tendency to delay reproduction. Through spatial analysis techniques, we explored the geographical heterogeneity of consanguinity and late fertility, and identified in Central–Eastern Sardinia a common area with an excess of both traits, where the traits are positively associated. We found that their association did not significantly affect women's fertility in the area, despite the expected negative role of both traits. Intriguingly, this critical zone corresponds well to areas reported by previous studies as being peculiar for a high frequency of centenarians and for lower risk in pregnancy outcome. The proposed approach can be generally exploited to identify target populations on which socioeconomic, biodemographic and genetic data can be collected at the individual level, and deeper analyses carried out to disentangle the determinants of complex biological traits and to investigate their association.     

化工数据预处理及其在建模中的应用

对化工数据预处理问题进行了研究,阐述了化工数据智能建模中辅助变量选择、数据采集、数据校正、输入数据降维等各种数据预处理的思路与方法。仿真实验表明:对数据进行有效的预处理,可以改善模型的精确度。     

Comparison between the more recent techniques for smoothing and derivative assessment in biomechanics

When analysising and evaluating human motion, two strictly interconnected problems arise: the data smoothing and the determination of velocities and accelerations from displacement data. Differentiating procedures magnify the noise superimposed on the useful kinematic data. A smoothing procedure is thus required to reduce the measurement noise before the differentiation can be carried out. In the paper two techniques for derivative assessment are presented, tested and compared. One of these is the procedure known as one of the best automatic smoothing and differentiating techniques: generalised cross validatory spline smoothing and differentiation (GCVC). The other, which has recently been presented, features an automatic model-based bandwidth-selection procedure (LAMBDA). The procedures have been tested with signals presented by other authors and available in the literature, by test signals acquired using the ELITE motion analyser and by synthetic data. The results show better or similar performance of LAMBDA compared with GCVC. In the cases in which the natural conditions at the signal boundaries are not met GCVC gives bad results (especially on the third derivative) whereas LAMBDA is not affected at all. Moreover, analysis time is dramatically lower for LAMBDA.     

The "Smart" Escape Interval: An Innovative Approach to Cardiac Pacing

This study attempts to improve cardiac pacing by utilizing a new strategy based on integrative rather than substitutive stimulation. This type of cardiac stimulation does not compete with the sinoatrial oscillator and can position the stimulated beat at the expected time. This can be achieved by locking the pacemaker's escape interval to the sinus cycle, making it a variable parameter continuously updated on the preceding cycle. When the rate and rhythm are regular, the pacemaker's activity is completely "concealed," although the escape interval continues to be updated. When a sudden conduction block occurs, the pacemaker positions the stimulated beat where we would expect the natural beat to be. When the natural heart rate goes outside the locking field by being too low, the pacemaker loses the lock and returns to its free-running frequency. However, an alternative choice is to pass to "overdrive" stimulation: this occurs when the escape interval is locked in phase to the sinoatrial oscillator, but is set to have a period equal to one-half or one-third of the sinus cycle. When applied to sinus bradycardia, this can multiply the natural heart rate by 2 or 1.5, but the rate responsiveness is maintained because it is locked to a natural "sensor." When applied to bicameral pacing, the phase-locked pacemaker marks a jump from atrial triggered stimulation to a "true" atrial synchronous stimulation. In this novel situation, the ventricular stimulator remains relatively independent with respect to the atrial rhythm while the tracking of the sinusal drive is ensured. This feature could prove useful in reducing both the incidence of pacemaker mediated tachycardias and effects such as myopotential interference.     

Construction of the World Health Organization child growth standards: selection of methods for attained growth curves

The World Health Organization (WHO), in collaboration with a number of research institutions worldwide, is developing new child growth standards. As part of a broad consultative process for selecting the best statistical methods, WHO convened a group of statisticians and child growth experts to review available methods, develop a strategy for assessing their strengths and weaknesses, and discuss methodological issues likely to be faced in the process of constructing the new growth curves. To select the method(s) to be used, the group proposed a two-stage decision-making process. First, to select a few relevant methods based on a list of set criteria and, second, to compare the methods using available tests or other established procedures. The group reviewed 30 methods for attained growth curves. Using the pre-defined criteria, a few were selected combining five distributions and two smoothing techniques. Because the number of selected methods was considered too large to be fully tested, a preliminary study was recommended to evaluate goodness of fit of the five distributions. Methods based on distributions with poor performance will be eliminated and the remaining methods fully tested and compared.     

卡尔曼滤波滴定分析法:苯扎溴铵的测定

研究了卡尔曼滤波及平滑在滴定分析中的应用,该法对热力学平衡及非平衡(动力学)体系均能适应;特别是对非平衡滴定,当许多其它方法误差较大或无法使用时,卡尔曼滤波法仍可获得正确的结果。已用于苯扎溴铵的硝酸银电位滴定分析与快速测定。     

不同通络中药对糖尿病大鼠坐骨神经中NF-κB活性的影响

目的:以蛋白印记技术观察糖尿病大鼠坐骨神经中转录因子NF-κB的蛋白表达。方法:148只雄性Wistar大鼠,以STZ诱导糖尿病模型,随机分为正常组、模型组、辛味通络组、藤类通络组、虫类通络组。于治疗后2周、4周、8周处死大鼠取坐骨神经备蛋白印记观察用。结果:造模组NF-κB水平明显高于同期正常组(P<0.01),与同期模型组比较,通络中药组均能降低NF-κB的表达(P<0.01),同期治疗组之间无显著性差异。结论:不同通络中药随着疗程延长均具有延缓神经病变进程的作用,可能与调节NF-κB信号系统有关。     

逍遥散处方来源探讨

逍遥散其方名出自《太平惠民和剂局方》,其后衍化方众多,如丹栀逍遥散、黑逍遥散、柴胡清肝饮等。溯及逍遥散来源,观点则有源自仲景四逆散及当归芍药散合方或单独一方之说,或源自柴胡方(小柴胡汤、柴胡汤)之说,或源自孙思邈《千金要方》调中汤之说等。梳理文献,归纳思考,以"逍遥散取四逆散与当归芍药散之和"的观点最为妥切。