Retrograde intrarenal surgery for lower pole stones utilizing stone displacement technique yields excellent results

Objective:To evaluate the long-term stone-free rate(SFR)of retrograde intrarenal surgery(RIRS)in the treatment of lower pole renal calculi using only basket relocation and identify independent predictors of stone-free status.Methods:All consecutive patients undergoing RIRS lower pole renal calculi at a single highvolume tertiary center were analyzed retrospectively.Lower pole stones were relocated to the upper pole,where laser lithotripsy was performed.All patients were followed up in the clinic following the surgery and yearly thereafter.The stone-free status was assessed with a combination of an abdominal ultrasound and abdominal X-ray,or an abdominal non-contrast computed tomography if the stones were known to be radiolucent.Results:A total of 480 consecutive patients who underwent RIRS for treatment of lower pole renal calculi,between January 2012 and December 2018,were analyzed from a prospectively maintained database of 3000 ureteroscopies.With a median follow-up time of 18.6 months,the mean SFR was 94.8%.The procedures were unsuccessful in 26(5.4%)patients due to unreachable stones.The median stone size of the unreachable stones was 12 mm(range 10e30 mm).Multivariable logistic regression analysis revealed two predictors of SFR for lower pole stones:a small cumulative stone burden(odds ratio[OR]:0.903,95%confidence interval[CI]:0.867e0.941,p<0.0001)and preoperative ureteral stent insertion(OR:0.515,95%CI:0.318e0.835,pZ0.007).Conclusion:The long-term SFR of RIRS for the treatment of lower pole stones with basket displacement with appropriate patient selection is high.

Design Optimization of a Novel Axial-radial Flux Permanent Magnet Claw Pole Machine with SMC Cores and Ferrite Magnets

Soft magnetic composite(SMC)material is an ideal soft magnetic material employed for developing 3D magnetic flux electromagnetic equipment,due to its advantages of 3D magnetic isotropy characteristic,low eddy current loss,and simple manufacturing process.The permanent magnet claw pole machine(PMCPM)with SMC cores is a good case that the SMC to be adopted for developing 3D flux electrical machines.In this paper,a novel axial-radial flux permanent magnet claw pole machine(ARPMCPM)with SMC cores and ferrite magnets is proposed.Compared with the traditional PMCPM,the proposed ARPMCPM is designed with only one spoke PM rotor and its whole structure is quite compact.For the performance prediction,the 3D finite element method(FEM)is used.Meanwhile,for the performance evaluation,a previously developed axial flux claw pole permanent magnet machine(AFCPM)is employed as the benchmark machine and all these machines are optimized by using the combined multilevel robust Taguchi method.It can be seen that the proposed ARPMCPM is with higher torque/weight density and operation efficiency.

Design and Performance Analysis of Permanent Magnet Claw Pole Machine with Hybrid Cores

Permanent magnet claw pole machine(PMCPM) is a special kind of transverse flux permanent magnet machine. Compared with other electrical machines, it has the advantages of high torque density and high efficiency for high speed operation. However, because of its complex irregular structure, the manufacturing process using silicon sheets is complicated. Soft magnetic composite material(SMC) is manufactured by powder metallurgy technology, which can produce various shapes of stator core structures, so it is easier to produce various irregular shapes of the stator core. However, the raw SMC material is relatively expensive, and the mechanical strength of SMC is weak. In this paper, a PMCPM with hybrid cores is proposed. With the adoption of hybrid silicon sheet-SMC cores and amorphous alloy-SMC cores, the torque ability of PMCPM can be improved greatly and it can have higher efficiency for more wide operation frequency. Meanwhile, its mechanical strength has been improved and it can be designed for high torque direct drive applications as it is a modular machine. Furthermore, three methods are proposed to reduce the additional eddy current loss which resulted from the employment of hybrid cores in PMCPM.

We Live on a Small Space Comet: The Third Extraordinary Motion of Earth towards the North Pole and Its Various Effects

The idea of research started with a crazy imaginary theory in the field of astrogeography, saying: We often taught ourselves and then convinced the students that the planet Earth moves despite not feeling the vibrations of traffic, and we listed successive scientific confirmations to indicate the rotation of the planet in a regular movement around its axis once every 24 hours, and it is running in another second movement around the sun once every 365¼ days, so are they only two movements, no more?! Is it possible for him to run at a regular speed in an additional direction?

Reducing Greenhouse Gas Emissions through Improving the Life Span of Wooden Power Electric Poles of Eucalyptus saligna

The present work deals with reducing greenhouse gas emissions through improving the life span of wooden power electric poles of Eucalyptus saligna. Indeed, in Sub-Saharan African countries, Cameroon in particular, most of the power line networks are made of wooden supports and according to the Cameroon energy distribution company, wooden poles represent 32% of the causes of death linked to the state of the network. The company’s 2019 annual report indicates that 40,000 wooden poles were in critical condition and should be replaced. A significant number of mechanical failures affecting these supports have been observed. For example, on the HVA/LV power line “D17 Nko- abang” in Yaoundé in Cameroon, less than three years old, 10 (ten) cases of poles falling and/or breaking, due to their mechanical loading, were observed over a period of fewer than nine months, causing an average service stoppage for more than 11 hours and affecting an average of 3280 customers. These incidents lead to questions about how the supports are dimensioned and what load capacities they are designed to support. The aim of this work is, therefore, to suggest a method of dimensioning wooden poles hence reducing green- house gas emissions due to the deforestation by reducing the number of woo- den poles at risk to be replaced on Cameroon’s electricity distribution network. And more specifically, to reduce the number of mechanical failures affecting the wooden supports observed by analyzing the current wooden supports with their loads and to make proposals for improving the actual dimensioning me- thods. From the study carried out, it appears that 449 out of 845 supports, i.e., 53% needed to be replaced or monitored because they support the nominal forces ranging from 85% to 150% of their admissible limit and proposals have been made to improve their dimensioning.

POLE突变在肿瘤发生发展中的作用

POLE为DNA聚合酶的催化亚基,具有5'3'DNA聚合酶活性和3'→5'核酸外切酶活性,对DNA复制和校正具有重要作用。POLE突变将引起校正功能缺失,可能导致肿瘤发生。近年来,TCGA在多种肿瘤中检出POLE突变,POLE突变的肿瘤以其独特超强突变分子表型及良好的预后成为近期研究热点。本文综述POLE的结构、功能及其突变在肿瘤发生发展中的作用的研究进展。

South Pole温度风速廓线的统计分析

利用2008年South Pole的探空资料,通过大气温度和风速廓线,确定了South Pole地区冬季(6,7,8月)和夏季(12,1,2月)的大气边界层结构、边界层和对流层顶的高度。对近地面的温度、水汽压、风速和风向进行了统计分析。结果表明,South Pole大气边界层大多时候为稳定型,但在夏季也存在不稳定的情况,尤其在1月份较多;夏季夜晚的边界层平均高度为389 m,比白天的304 m大,冬季夜晚的边界层平均高度为591 m,大于夏季夜晚;夏季白天对流层顶平均高度比夜晚略大,分别为6172 m和5770m。South Pole高层大气理查森数的倒数基本都小于4,发生湍流的可能性很小。

Design and field measurement of a dipole magnet for a newly developed superconducting proton cyclotron beamline

The design, field quality optimization, multipole field analysis, and field measurement of a dipole for a newly developed superconducting proton cyclotron(SC200) beamline are presented in this paper. The maximum magnetic field of the dipole is 1.35 T; the bending radius is 1.6 m with a proton beam energy in the range of70–200 Me V. The magnetic field was calculated with 2 D and 3 D simulations, and measured with a Hall mapping system. The pole shim and end chamfer were optimized to improve the field quality. Based on the simulated results,the multipole field components in the good-field region were studied to evaluate the field quality. The results showed that the field quality is better than ± 5 × 10^(-4) at1.35 T with shimming and chamfering. For the transverse field homogeneity, the third-order(B3) and fifth-order(B5)components should be controlled with symmetrical shims.The second-order(B2) component was the main disturbance for the integral field homogeneity; it could be improved with an end chamfer. The magnet manufacturing and field measurement were performed in this project. The measurement results demonstrated that the magnetic design and field quality optimization of the 45° dipole magnet can achieve the desired high field quality and satisfy the physical requirements.

基于South Pole站和McMurdo站的极区电离层闪烁统计特性

利用South Pole和Mc Murdo两站2013年12月至2014年11月期间的电离层相位闪烁数据,统计分析了两站电离层相位闪烁发生率的周日分布和季节分布。统计结果表明,两站的相位闪烁发生率在季节分布上,春秋季明显大于夏冬季;在周日分布上呈双峰结构。在磁中午附近和磁子夜后有较大的闪烁发生率。磁中午附近是因为极隙区的软电子沉降和电离层对流导致的电离层不均匀性,造成较强的无线电波闪烁;磁子夜附近闪烁增强可能是穿越极盖区的等离子体云破碎造成较大密度梯度导致。总体上说,Mc Murdo站的闪烁发生率高于South Pole站,这可能是因为它们所处的磁纬不同所致。

Pole基因在子宫内膜癌中的研究进展

2013年美国癌症基因组图谱(TCGA)提出依据分子改变将子宫内膜癌分为Pole突变型,MSI(微卫星不稳定)高突变型,高拷贝数型,低拷贝数型。其中,pole基因突变型具有形态学高度恶性,但具有较好预后,对免疫抑制剂反应良好的临床病理特征,同时pole基因突变可能与合并多个基因突变的子宫内膜癌有关,因此认识和了解pole基因突变与子宫内膜癌的关系非常重要。另外,对于pole突变合并P53,或者错配修复蛋白基因突变以及P53和错配修复蛋白基因同时突变,或者三个基因同时发生突变时,pole基因与其他基因的相互作用本文将复习文献,对pole基因突变的子宫内膜癌中研究进展进行综述。

Improvement of Electrochemical Machining Accuracy by Using Dual Pole Tool

Electrochemical machining (ECM) is one of the best al ternatives for producing complex shapes in advanced materials used in aircraft a nd aerospace industries. However, the reduction of the stray material removal co ntinues to be major challenges for industries in addressing accuracy improvement . This study presents a method of improving machining accuracy in ECM by using a dual pole tool with a metallic bush outside the insulated coating of a cathode tool. The bush is connected with anode and so the electric field at the side gap area is substantially weakened. The modeling and simulation indicate that the p ositive bush brings down the current density at the side gap area of the machine d hole and hence reduces the stray material removal there. It has been experimen tally observed that the machining accuracy and the process stability are signifi cantly improved.

Retrograde intrarenal surgery vs miniaturized percutaneous nephrolithotomy to treat lower pole renal stones 1.5-2.5 cm in diameter

AIM To compare the outcomes of retrograde intrarenal surgery(RIRS) and miniaturized percutaneous nephrolithotomy(mini-PCNL) in treating lower pole(LP) renal stones with a diameter of 1.5-2.5 cm.METHODS A total of 216 patients who underwent mini-PCNL(n = 103) or RIRS n = 113) for LP stones with a diameter of 1.5-2.5 cm were enrolled between December 2015 and April 2017 at the Urology Department of Ningbo Urology and Nephrology Hospital.RESULTS Significant differences were found in the hospital stay(9.39 ± 4.01 vs 14.08 ± 5.26, P < 0.0001) and hospitalization costs(2624.5 ± 513.36 vs 3255.2 ± 976.5, P < 0.0001) between the RIRS and mini-PCNL groups. The mean operation time was not significantly different between the RIRS group(56.48 ± 24.77) and the mini-PCNL group(60.04 ± 30.38, P = 0.345). The stone-free rates at the first postoperative day(RIRS vs mini-PCNL: 90.2% vs 93.2%, P = 0.822) and the second month postoperatively(RIRS vs mini-PCNL: 93.8% vs 95.1%, P = 0.986) were not significantly different.CONCLUSION RIRS and mini-PCNL are both safe and effective methods for treating LP stones with a diameter of 1.5-2.5 cm. RIRS can be considered as an alternative to PCNL for the treatment for LP stones of 1.5-2.5 cm.

Continuous-wave mid-infrared intracavity singly resonant optical parametric oscillator based on periodically poled lithium niobate

This paper reports a continuous-wave （CW） mid-infrared intracavity singly resonant optical parametric oscillator based on periodically poled lithium niobate （PPLN） pumped by a diode-end-pumped CW Nd：YVO4 laser. Considering the thermal lens effects, it adopted an optical ballast lens and the near-concentric cavity for better operation. At the PPLN＇s grating period of 28.5 μm and the temperature of 140℃, the maximum idler output power of 155 mW at 3.86 μm has been achieved when the 808 nm pump power is 8.5 W, leading to an optical-to-optical conversion efficiency of 1.82%.

中国汉族人群DNA聚合酶ε基因POLE1单核苷酸多态性与肺癌易感性的关系

目的:探讨人类DNA聚合酶ε基因POLE1单核苷酸多态性(SNP)与肺癌易感性间的关系。方法:采用病例对照研究方法,选择经组织学确诊的肺癌患者462例,以及相同地区,性别年龄频数匹配的对照466例,针对经筛选的5个SNP进行基因型检测,通过统计分析研究基因频率与肺癌风险的关系,并探讨吸烟在其中的影响。结果:病例组rs5744738基因频率分布高于对照组(P<0.05)。A/A纯合变异携带人群的患肺癌风险显著降低(校正OR=0.47,95%CI:0.25～0.91)。在分层分析中,60岁以上人群患肺癌的风险显著下降(校正OR=0.28,95%CI:0.09～0.91),无患肿瘤家族史人群下降到0.42倍(校正OR=0.42,95%CI:0.19～0.90)。随着吸烟量的增加,G/G或G/A基因型人群肺癌风险显著升高。rs5744962变异位点(T→C)可提高非吸烟人群的患肺癌风险至1.75倍(95%CI:1.02～3.00)。结论:选取的5个人类POLE1基因SNP的多态性可能与中国汉族人群肺癌遗传易感性有关,在携带rs5744738及与之紧密连锁的rs4883545、rs5744873突变纯合基因的人群,患肺癌的风险显著降低,而携带rs5744962、rs5745047突变基因位点的非吸烟人群患肺癌的风险升高。

High efficiency continuous-wave tunable signal output of an intracavity singly resonant optical parametric oscillator based on periodically poled lithium niobate

In this paper we report on a continuous-wave （CW） intracavity singly resonant optical parametric oscillator （ICSRO） based on periodically poled LiNbO3 （PPLN） pumped by a diode-end-pumped CW Nd：YVO4 laser. Considering the thermal lens effects and diffraction loss, an optical ballast lens and a near-concentric cavity are adopted for better operation. Through varying the grating period and the temperature, the tunable signal output from 1406 nm to 1513 nm is obtained. At a PPLN grating period of 29 pm and a temperature of 413 K, a maximum signal output power of 820 mW at 1500 nm is achieved when the 808 nm pump power is 10.9 W, leading to an optical-to-optical conversion efficiency of 7.51%.

Research on the Casting-forging Precision Forming Process of Alternator Poles

The casting-forging combined technique and the closed die forging without flash-less are both new developed material working methods. The former can not only decrease forming operations of forgings, but also increase the material utilization ratio. Therefore, it is applied to produce more complex forgings. The latter is required for forging precise parts without burrs. The alternator pole is a complex forging, which was usually produced by hot forging, upsetting-extrusion or upsetting-extrusion and bending processes. During these processes, not only the forming force is higher, but the material of burrs accounts for 30 percent or so of total required material. And burrs are difficult to remove in the sequential machining process. In accordance with defects exiting in current manufacturing of alternator poles by upsetting-extruding process, such as more material demand, higher forming force and difficulty of next machining, a casting-forging precision process of alternator poles was developed and investigated in this paper. In the process, the pole was formed by two operations. One is the pre-forming operation by casting. The other is the final forming operation by the closed precision forging process. This can not only shorten processes, decrease material and power demand, but also increase precision of forgings. First, the casting blocker was designed considering the casting process and the forging ratio and the mode of deformation. Then the die structure for closed precision forging was designed, and the closing device for forging dies with spring assemblies in order to provide the necessary closing force was also designed. Finally the forming processes was investigated by test and numerical simulation method to optimum process parameters and die structure design parameters. The result can provide basis for applying the process to manufacture poles in practice.

Non-destructive Measurement of Magnetic Properties of Claw Pole

The magnetic properties of the claw pole have a direct effect on the output power of a generator Many methods can be used to measure these magnetic properties,each with its own advantages,but an important shortcoming is that all are destructive.In this study,a new non-destructive method to measure the magnetic properties of claw pole was proposed and a corresponding testing set-up was designed.A finite-element model was constructed to simulate the measurement process.Results proved that the measured magnetization-like curves had good agreement with the trend of the input magnetic curves and the effect of the positioning error in the measuring process could be neglected.To further validate the new method,seven types of claw poles of different materials subjected to different heat-treatment processes were forged and tested by both the new method and the conventional ring-sample method.Compared with the latter,the new method showed better consistency,relatively higher accuracy,and much stronger stability of measurement results;however,its sensitivity needs to be improved.The effects of material compositions and heat-treatment parameters on the magnetic properties of the claw pole were briefly analyzed.

Three-wavelength generation from cascaded wavelength conversion in monolithic periodically poled lithium niobate

Tunable coherent emission is generated in a single-pass, cascaded wavelength conversion process from mode-locked laser-pumped monolithic periodically poled lithium niobate（PPLN）. Three ranges of wavelength, including visible output from 628 nm to 639 nm, near-infrared output from 797 nm to 816 nm, and mid-infrared output from 3167 nm to 3459 nm,were obtained from the monolithic PPLN, which consists of a 10-mm section for 532-nm-pumped optical parametric generation（OPG） and a 7-mm section for 1064-nm-pumped sum frequency generation（SFG）. A pump-to-signal conversion efficiency of 23.4% for OPG at 50°C and a quantum efficiency of 26.2% for SFG at 200°C were obtained.

Pole placement method of controlling chaos in DC-DC buck converters

Based on the mechanism for the generation of chaos in a buck converter, a pole placement method is proposed and applied to controlling the chaos in a circuit. The control circuit is designed and tested. Numerical calculation and circuit implementation demonstrate the validity of this chaos control method.