Effect of the number of positive lymph nodes and lymph node ratio on prognosis of patients after resection of pancreatic adenocarcinoma

BACKGROUND： The prognostic factors related to lymph node involvement [lymph node status, the number of positive lymph nodes, lymph node ratio （LNR）] and the number of nodes evaluated in patients with pancreatic adenocarcinoma after pancreatectomy are poorly defined. METHODS： A total of 167 patients who had undergone resection of pancreatic adenocarcinoma from February 2010 to August 2011 were included in this study. Histological examination was performed to evaluate the tumor differentiation and lymph node involvement. Univariate and multivariate analyses were made to determine the relationship between the variables related to nodal involvement and the number of nodes and survival. RESULTS： The median number of total nodes examined was 10 （range 0-44） for the entire cohort. The median number of total nodes examined in node-negative （pN0） patients was similar to that in node-positive （pN1） patients. Patients with pN1 diseases had significantly worse survival than those with pN0 ones （P=0.000）. Patients with three or more positive nodes had a poorer prognosis compared with those with the negative nodes （P=0.000）. The prognosis of the patients with negative nodes was similar to that of those with one to two positive nodes （P=0.114）. The median survival of patients with an LNR ≥0.4 was shorter than that of patients with an LNR 〈0.4 in the pN1 cohort （P=0.014）. No significance was found between the number of total nodes examined and the prognosis, regardless of the cutoff of 10 or 12 and in the entire cohort or the pN0 and pN1 groups. Based on the multivariate analysis of the entire cohort and the pN1 group, the nodal status, the number of positive nodes and the LNR were all associated with survival. CONCLUSIONS： In addition to the nodal status, the number of positive nodes and the LNR can serve as comprehensive factors for the evaluation of nodal involvement. This approach may be more effective for predicting the survival of patients with pancreatic adenocarcinoma after pancreatectomy.

Design and Blade Number Ratio Analysis of Organic Rankine Cycle Radial-Inflow Turbine on Vehicle

The organic Rankine cycle is widely used in industrial waste heat, engine waste heat and other waste heat recovery applications, and as a key component of the system, it affects the efficiency and output power of the system. In this paper, a centripetal turbine is designed for the organic Rankine cycle, using vehicle exhaust gas as the heat source. Numerical simulations are performed to analyze the effect of the ratio of the number of guide vane blades to the number of impeller blades (vane number ratio) on the turbine performance and flow field. The results show that the effect of the number of impeller blades on the turbine entropy efficiency, the average exit velocity and the temperature of the guiding grate becomes less and less as the ratio of the number of blades increases. The optimum turbine performance is obtained when the number of impeller blades and the ratio of the number of blades are 17 and 1.5882, respectively, and the expansion performance of the guide impeller is improved and the isentropic efficiency of the turbine is improved by 3.84% compared with the preliminary number of blades.

Optimization of process parameters of the activated tungsten inert gas welding for aspect ratio of UNS S32205 duplex stainless steel welds

The activated TIG(ATIG) welding process mainly focuses on increasing the depth of penetration and the reduction in the width of weld bead has not been paid much attention.The shape of a weld in terms of its width-to-depth ratio known as aspect ratio has a marked influence on its solidification cracking tendency.The major influencing ATIG welding parameters,such as electrode gap,travel speed,current and voltage,that aid in controlling the aspect ratio of DSS joints,must be optimized to obtain desirable aspect ratio for DSS joints.Hence in this study,the above parameters of ATIG welding for aspect ratio of ASTM/UNS S32205 DSS welds are optimized by using Taguchi orthogonal array(OA)experimental design and other statistical tools such as Analysis of Variance(ANOVA) and Pooled ANOVA techniques.The optimum process parameters are found to be 1 mm electrode gap,130 mm/min travel speed,140 A current and 12 V voltage.The aspect ratio and the ferrite content for the DSS joints fabricated using the optimized ATIG parameters are found to be well within the acceptable range and there is no macroscopically evident solidification cracking.

Augmentation of Heat Transfer in Pipe Flow Using Plain Twisted Tape Inserts for Different Twist Ratios

The heat transfer augmentation of plain twisted tape inserts for different twist ratios has been studied in this study. The data are conducted using the plain twisted tape insert with five different twist ratios respectively. The range of Reynolds number is considered under a uniform heat flux condition. In the case of simulation, the tapes are made from a stainless steel strip with a thickness of 2 mm. A tubular pipe with 850mm U-loop length and twist length of 800 mm each is considered in our study for simulation. Water is used as working fluids inside the tube for our simulation. The simulation results demonstrate that the important heat transfer parameters including Nusselt number (Nu), friction factor (f) and thermal performance index (η) are gradually increased with the increment of the twist ratio and reached at the saturated level while twist ratio is 3.5,?afterward the thermal properties are decreased.

Effects of aspect ratio on unsteady solutions through curved duct flow

The effects of the aspect ratio on unsteady solutions through the curved duct flow are studied numerically by a spectral based computational procedure with a temperature gradient between the vertical sidewalls for the Grashof number 100 ≤ Gr ≤ 2 000. The outer wall of the duct is heated while the inner wall is cooled and the top and bottom walls are adiabatic. In this paper, unsteady solutions are calculated by the time history analysis of the Nusselt number for the Dean numbers Dn = 100 and Dn = 500 and the aspect ratios 1≤γ≤ 3. Water is taken as a working fluid （Pr =7.0）. It is found that at Dn = 100, there appears a steady-state solution for small or large Gr. For moderate Gr, however, the steady-state solution turns into the periodic solution if γ is increased. For Dn = 500, on the other hand, it is analyzed that the steady-state solution turns into the chaotic solution for small and large Gr for any γ lying in the range. For moderate Gr at Dn = 500, however, the steady-state flow turns into the chaotic flow through the periodic oscillating flow if the aspect ratio is increased.

Fuzzy distances based FMAGDM compromise ratio method and application

An extended compromise ratio method（CRM） based on fuzzy distances is developed to solve fuzzy multi-attribute group decision making problems in which weights of attributes and ratings of alternatives on attributes are expressed with values of linguistic variables parameterized using triangular fuzzy numbers.A compromise solution is determined by introducing the ranking index based on the concept that the chosen alternative should be as close as possible to the positive ideal solution and as far away from the negative ideal solution as possible simultaneously.This proposed method is compared with other existing methods to show its feasibility and effectiveness and illustrated with an example of the military route selection problem as one of the possible applications.

中危肺栓塞患者30天内不良预后的预测因素分析

目的:探讨中危肺栓塞早期不良结局的危险因素及可能的预测因素。方法:连续性纳入2016年1月至2021年12月,在我院住院的209例中危肺栓塞患者,按照30d是否存在不良预后分为短期不良结局组和存活组,应用多因素Logistic分析中危肺栓塞早期不良结局的危险因素;应用ROC曲线分析危险因素联合简化版肺栓塞严重程度评分(simplified pulmonary embolism severity index,sPESI)对中危肺栓塞患者早期不良结局的预测价值。结果:多因素Logistic回归分析得出sPESI评分、NLR为预测中危肺栓塞早期不良结局的危险因素(P<0.05)。将NLR≥3.79作为新的指标,计为1分,纳入NLR的sPESI评分预测中危肺栓塞早期不良结局预测价值的ROC曲线下面积为0.968(95%CI:0.932~0.988),当评分≥2分时,灵敏度为100%,特异度为80.61%。结论:纳入NLR的s PESI评分对中危肺栓塞患者早期不良结局具有一定的预测价值。

The Relation between the Coefficient of Friction and Pressure Drop by Using the Different Reynolds Number in a Circular Tube

This study explains the relationship between friction coefficient and pressure change at a range of Reynolds (21,056 - 28,574) and (0 - 1.4) solid loading ratio of two-phase flow (gas-solid) inside a circular copper pipe by using laboratory apparatus and solving the equations mathematically. An experimentally relationship of friction coefficient and pressure change with Reynolds number and flow velocity obtained also the relationship between the Solid loading ratio with friction coefficient and pressure change has been done for a Limit range of Reynolds number. It was noticed that the increase in friction coefficient and pressure change for two-phase flow was occurred when solid loading ratio increased. Also the relationship between pressure change and Reynolds number was direct proportion while the relationship between friction coefficient and Reynolds Number was inversely related.

几何参数对轮缘推进器水动力性能影响的研究

轮缘推进器是近年来发展起来的一种无轴组合式特种推进器。与传统推进器相比,轮缘推进器在水动力设计和性能分析方面存在诸多挑战,水动力性能的研究对轮缘推力器的设计和应用具有重要意义。为了研究几何参数对轮缘推力器水动力性能的影响,本文以7叶轮缘驱动推力器为基本模型,基于面元法原理,利用编译的面元法代码对轮缘推力器在开阔水域的工作状态进行了数值模拟。通过求解每个面元的速度场,计算了水动力性能和叶片表面压力分布。此外,本文选择了几个典型的几何特征,如螺距比和叶片数,通过进行变参数分析,比较了不同几何参数下轮缘推力器的敞水性能。结果表明:本文的相关研究对轮缘推力器的设计和开发具有参考价值。

Dynamic response of chlorsulfuron herbicide to nitrogen mineralization and the ratio of microbial biomass nitrogen to nitrogen mineralization in the soil

A laboratory incubation experiment was conducted to elucidate the effect of chlorsulfuron herbicide on nitrogen mineralization and the ratio of microbial biomass nitrogen to nitrogen mineralization (N mic /N min ratio) in loamy sand soil.The herbicide was applied at four levels that were control, field rate 0\^01 (FR), 10 times of field rate 0\^1(10FR),and 100 times of field rate 1\^0 (100FR) μg/g soil. Determinations of N\|mineralization and microbial biomass\|N content were carried out 1,3,5,7,10,15,25 and 45 days after herbicide application. In comparison to untreated soil, the N\|mineralization decreased significantly in soil treated with herbicide at levels 10FR and 100FR within the first 5 days incubation. A more considerable reduction in the N mic /N min ratio was observed in the herbicide treated soil than the non\|treated control.Among the different treatment of chlorsulfuron, 100FR displayed the greatest biocidal effect followed by 10FR and FR,showing their relative toxicity in the order of 100FR>100FR>FR.The results indicated that the side effect of this herbicide on N\|mineralization is probably of little ecological significance.

The “3 Genomic Numbers” Discovery: How Our Genome Single-Stranded DNA Sequence Is “Self-Designed” as a Numerical Whole

This article proves the existence of a hyper-precise global numerical meta-architecture unifying, structuring, binding and controlling the billion triplet codons constituting the sequence of single-stranded DNA of the entire human genome. Beyond the evolution and erratic mutations like transposons within the genome, it’s as if the memory of a fossil genome with multiple symmetries persists. This recalls the “intermingling” of information characterizing the fractal universe of chaos theory. The result leads to a balanced and perfect tuning between the masses of the two strands of the huge DNA molecule that constitute our genome. We show here how codon populations forming the single-stranded DNA sequences can constitute a critical approach to the understanding of junk DNA function. Then, we suggest revisiting certain methods published in our 2009 book “Codex Biogenesis”. In fact, we demonstrate here how the universal genetic code table is a powerful analytical filter to characterize single-stranded DNA sequences constituting chromosomes and genomes. We can then show that any genomic DNA sequence is featured by three numbers, which characterize it and its 64 codon populations with correlations greater than 99%. The number “1” is common to all sequences, expressing the second law of Chargaff. The other 2 numbers are related to each specific DNA sequence case characterizing life species. For example, the entire human genome is characterized by three remarkable numbers 1, 2, and Phi = 1.618 the golden ratio. Associated with each of these three numbers, we can match three axes of symmetry, then “imagine” a kind of hyperspace formed by these codon populations. Then we revisit the value (3-Phi)/2 which is probably universal and common to both the scale of quarks and atomic levels, balancing and tuning the whole human genome codon population. Finally, we demonstrate a new kind of duality between “form and substance” overlapping the whole human genome: we will show that—simultaneously with the duality between genes and junk DNA—there is a second layer of embedded hidden structure overlapping all the DNA of the whole human genome, dividing it into a second type of duality information/redundancy involving golden ratio proportions.

Global Analysis of an SEIR Epidemic Model with a Ratio-Dependent Nonlinear Incidence Rate

In this paper, a SEIR model with ratio-dependent transmission rate in the form ?is studied and the basic reproduction number which determines the disease’s extinction or continued existence is obtained. By constructing the proper Lyapunov function, we prove that if R0 ≤ 1, the disease-free equilibrium point of the model is globally asymptotically stable and the disease always dies out;if R0 > 1, the endemic equilibrium point is globally asymptotically stable and the disease persists.

基于冲刷指数的雨水管渠冲刷淤积分析

流速、雷诺数、充满度等单因素指标虽然与雨水管渠的冲刷和淤积量有一定的关联,但是通过单因素指标不足以全面地判断雨水管道的冲刷和淤积。在起动流速和止动流速的基础上,提出了冲刷指数的概念。结合连续非恒定流不同工况下冲刷和淤积量模拟,计算了流速、雷诺数、充满度、冲刷指数4个因素与冲刷量的灰色关联度,其关联度大小依次为:冲刷指数>雷诺数>充满度>流速。根据不同工况的恒定流模型实验的结果,其关联度大小依次为:冲刷指数>>流速>雷诺数>充满度。可以认为,在恒定流与非恒定流工况下,冲刷量和冲刷指数有显著的强相关性,冲刷指数能代替具体的冲刷量计算实现对冲刷程度和趋势的合理判断。

平头孔板的初生空化特性定量分析

随着现代水利水电工程的日益优化创新,高坝设计中需要解决的重大技术瓶颈是消杀高坝泄放洪流所携带的超大能量。利用水流的突扩、突缩消能的孔板制造简便,并且消能效率高。孔板的抗空化特性跟它的最小壁面压强系数大小紧密相关,其作为孔板设计制造的一个关键性指标。通过数值模拟和物理模型试验的方法,研究了平头孔板初生空化数与相关体型要素和水力要素之间的关系,并得到了经验表达式。研究结果表明,平头孔板初生空化数的经验表达式与实际吻合较好,为孔板的工程应用提供了参考。

循环小数化为分数教学中等比数列的应用

纯循环小数与混循环小数是初等数论中常讲解的内容,但怎样把此两类小数化为分数却没有讲解,通过利用中学的等比数列把纯循环小数和混循环小数化为分数,并给出了纯循环小数和混循环小数化为分数的计算公式。为中小学数学教师教学中,把循环小数化为分数提供了一个有力的计算公式。

高雷诺数下质量比对圆柱涡致振动影响分析

涡致振动分析可为柔性结构抗风研究与工程应用提供重要理论依据。采用基于非平稳雷诺均值Navier-Stokes方程(Unsteady Reynolds-Averaged Navier-Stokes equations,URANS)的数值方法模拟了高雷诺数、高质量比条件下单向自由度圆柱的涡激振动。在改进的剪切应力输运k-ω(Shear Stress Transport,SST k-ω)模型基础上,运用动网格技术实现流固耦合,并结合Newmark-β方法求解结构运动方程。在雷诺数为1.39×104~1.04×105、折算速度为2~12的条件下,模拟分析了圆柱在不同折算速度时的涡激振动响应,得到了不同质量比时圆柱涡激振动的振幅比、振动频率比、升力系数等的变化特点,讨论了圆柱振动响应和旋涡脱落特性,分析总结了高雷诺数下不同质量比的圆柱涡激振动特性规律。结果表明:数值结果与已有试验的吻合程度较好;雷诺数和质量比对圆柱的涡激振动影响效果明显,对进一步分析圆柱涡致振动具有参考意义。

Effects of Different Breeds,Number of Squabs and Temperature on Production Performance of Pigeons

To explore the effects of breeds,number of nurturing squabs,and temperature on nest feed conversion ratio and analyze the effects of number of nurturing squabs on parent pigeon body mass,fertility rate,and laying intervals,5 widely used breeds of pigeon were nurtured under the condition of natural laying and hatching in this research.In each breed,24 pair pigeons nurturing 1,2,3,and 4 squabs were chosen to measure the production performance,respectively.The results indicated that different numbers of nurturing squabs had a significant effect on parent pigeon body mass changes and survival rate of 28-d old squabs(P<0.05);the nest feed conversion ratio of breeds nurturing 1 squab(7.58)was extremely significantly higher than those of nurturing 2,3,and 4 squabs(P<0.01);the nest feed conversion ratio of breeds nurturing 2 squabs(4.75)was extremely significantly higher than those of nurturing 3(3.95)and 4 squabs(3.75)(P<0.01);there was no significant difference between breeds nurturing 3 and 4 squabs(P>0.05).Laying intervals of breeds nurturing 4 squabs(43.8 d)were significantly higher than those of nurturing 3(37.4 d),2(35.4 d),and 1(33.8 d)squabs(P<0.05).Nest feed conversion ratio significantly increased with the decrease of environment temperature(P<0.05).The breed showed no effect on the nest feed conversion ratio.In production,nurturing 3 squabs of parent pigeons is appropriate.In some cold areas in winter,cold protection measures should be taken.

Flow-Induced Stream-Wise Vibration of Circular Cylinders

Results from a series of studies on the stream-wise vibration of a circular cylinder verifying Japan Society of Mechanical Engineers Standard S012-1998, Guideline for Evaluation of Flow-induced Vibration of a Cylindrical Structure in a Pipe, are summarized and discussed in this paper. Experiments were carried out in a water tunnel and in a wind tunnel using a two-dimensional cylinder model elastically supported at both ends of the cylinder and a cantilevered cylinder model with a finite span length that was elastically supported at one end. These cylinder models were allowed to vibrate with one degree of freedom in the stream-wise direction. In addition, we adopted a cantilevered cylinder model that vibrated with two degrees of freedom in both the stream-wise and cross-flow directions under the same vibration conditions as an actual thermocouple well. The value of the Scruton number (structural damping parameter) was changed over a wide range, so as to evaluate the value of the critical Scruton number that suppressed vibration of the cylinder. For the two-dimensional cylinder, two different types of stream-wise excitations appeared in the reduced velocity range of approximately half of the resonance-reduced velocity. For the stream-wise vibration in the first excitation region, due to a symmetric vortex flow, the response amplitudes were sensitive to the Scruton number, while the shedding frequency of alternating vortex flow was locked-in to half of the Strouhal number of vibrating frequency of a cylinder in the second excitation region. In addition, the effects of the aspect ratio of a cantilevered cylinder on the flow-induced vibration characteristics were clarified and compared with the results of a two-dimensional cylinder. When a cantilevered circular cylinder with a finite length vibrates with one degree of freedom in the stream-wise di-rection, it is found that acylinder with a small aspect ratio has a single excitation region, whereas a cylinder with a large aspect ratio has two excitation regions. Furthermore, the vibration mechanism of a symmetric vortex flow was investigated by installing a splitter plate in the wake to prevent shedding of alternating vortices. The vibration amplitude of acylinder with a splitter plate increased surprisingly more than the amplitude of a cylinder without a splitter plate. For a cantilevered cylinder vibrating with two degrees of freedom, the Lissajous figure of vibration of the first excitation region shows the trajectories of elongated elliptical shapes, and in the second excitation region, the Lissajous trajectories draw a figure “8”. The results and information from these experimental studies proved that Standard S012-1998 provides sufficient design methods for suppressing hazardous vibrations of cylinders in liquid flows.

沙土比对混凝土试件空蚀影响的试验研究

在小型循环式水洞中试验研究了沙土比对混凝土试件空蚀影响的机理。首先,在循环式水洞内筒中配制11种沙土比(0%,10%,20%,30%,40%,50%,60%,70%,80%,90%,100%)试样,用红外测沙仪测定相同沙土比的3种不同含沙量(2,12,30 kg/m 3)的挟沙水样,用压力传感器和压力数据采集系统实时采集水洞文丘里工作段空化区和空蚀区的压力;然后,制作了水灰比为0.4、灰砂比为1.5,7 d龄期强度f cu,k=17.8 MPa的混凝土试件,将其安放在水洞文丘里工作段混凝土试件盒中进行4 h的空蚀试验。试验结果表明:沙土比的增大对空化和空蚀破坏均具有促进作用;消失空化数随沙土比的增加而增加,对空化发生具有抑制作用;相同沙土比时,混凝土试件的空蚀量随着含沙量的增加而增加。

二元超声速混压式进气道亚临界稳定裕度研究

为了研究内收缩比和来流马赫数对二元超声速混压式进气道亚临界稳定裕度的影响规律及失稳机制,采用二维非定常仿真方法研究了内收缩比(ICR)为1.04~1.25的进气道在来流马赫数Ma0为2.4的条件下,以及内收缩比为1.08的进气道在来流马赫数为2.2~2.8条件下,其由稳态向失稳状态转变的过程。研究结果表明:(1)当Ma0=2.4时,在1.04≤ICR≤1.12内,随着ICR增加,亚临界稳定裕度ζ减小;1.16≤ICR≤1.25内,随着ICR增加,亚临界稳定裕度增大。(2)在内收缩比为1.08的条件下,马赫数变化引起的分离激波角和分离包再附压升两个关键因素变化共同主宰着进气道亚临界稳定裕度的变化趋势。(3)总体上,根据稳定亚临界初始状态的三相点无量纲高度?b是否大于1可将进气道的亚临界稳定裕度变化情形分为两类,当?b<1时,ζ随着?b的增加而减小;当?b> 1时,ζ随着?b的增加而增加。