两种腹腔镜手术方案在乙状结肠癌患者中的疗效对比

目的对比传统腹腔镜乙状结肠癌根治术与腹部无切口经直肠取出标本腹腔镜手术的近期疗效。方法以2015年1月-2016年12月于该院拟实施腹腔镜辅助乙状结肠癌根治手术的患者中选出34例实施腹部无切口经直肠取出标本腹腔镜乙状结肠癌根治术的患者作为腹部无切口组。以1∶2的配对方式选择同期内年龄、性别一致,体质指数(BMI)相近的实施腹腔镜辅助乙状结肠癌根治手术的患者68例作为对照组。对比两种腹腔镜手术方案的手术时间、手术出血量、术后排气时间、术后疼痛评分、手术并发症、术后住院时间、附加镇痛处理情况、肠管切除长度、近远端切缘、肿瘤大小、淋巴结清扫数目和p TNM分期。结果腹部无切口组乙状结肠癌患者的手术时间、手术出血量明显高于对照组,腹部无切口组乙状结肠癌患者的术后排气时间、术后清醒时疼痛评分、术后第1天的疼痛评分明显低于对照组,差异有统计学意义(P<0.05);两组乙状结肠癌患者的肠管切除长度、远近端切缘、肿瘤大小、淋巴结清扫数目和p TNM分期差异无统计学意义(P>0.05)。腹部无切口组随访5~8个月,平均6个月;对照组随访6~9个月,平均7个月,均未发现肿瘤局部复发及远处转移。结论相比于传统腹腔镜手术,腹部无切口经直肠取出标本腹腔镜乙状结肠癌根治术可以明显降低患者的疼痛程度,缩短术后排气时间,肿瘤根治效果相近。

Synthesis of Bi_2S_3 microsphere and its efficient photocatalytic activity under visible-light irradiation

A novel Bi2S3 microsphere was fabricated through one-pot urea-assisted solvothermal method.The synthesized Bi2S3 microsphere was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transformed infrared spectroscopy(FT-IR)and thermal gravimetric analysis and differential thermal analysis(DTA-TG).Subsequently,the photocatalytic performances of Bi2S3 microsphere were evaluated by photocatalytic degradation of methyl orange(MO)simulation solution under visible-light irradiation.The results show that,Bi2S3 microsphere could be used as a potential cost-efficient catalysis for eliminating of methyl orange from aqueous solutions,whose degradation rate could reach 91.07%within 180 min.Besides,a tentative photocatalytic reaction mechanism was discussed according to the energy band position.Therefore,this work indicated a simplistic approach for the fabrication of visible-light responsive Bi2S3 microsphere photocatalyst,which can be used as a valuable candidate in solar energy conversion and environment pollution treatment.

Near-resonance tidal evolution of the Earth-Moon system influenced by orbital-scale climate change

We build a conceptual coupled model of the climate and tidal evolution of the Earth-Moon system to find the influence of the former on the latter. An energy balance model is applied to calculate steady-state temperature field from the mean annual insolation as a function of varying astronomical parameters. A harmonic oscillator model is applied to integrate the lunar orbit and Earth’s rotation with the tidal torque dependent on the dominant natural frequency of ocean. An ocean geometry acts as a bridge between temperature and oceanic frequency. On assumptions of a fixed hemispherical continent and an equatorial circular lunar orbit, considering only the 41 kyr periodicity of Earth’s obliquity ε and the M2 tide, simulations are performed near tidal resonance for 106 yr. It is verified that the climate can influence the tidal evolution via ocean. Compared with the tidal evolution with constant ε, that with varying ε is slowed down;the EarthMoon distance oscillates in phase with ε before the resonance maximum but exactly out of phase after that;the displacement of the oscillation is in positive correlation with the difference between oceanic frequency and tidal frequency.

Next-to-leading-order relativistic and QCD corrections to prompt J/ψpair photoproduction at future e^(+)e^(−)colliders

Within the framework of nonrelativistic-QCD factorization,we calculate both the next-to-leading-order relativistic and QCD corrections to prompt J/ψpair production,with feed-down fromψ(2S)mesons,via photon-photon collisions at future e^(+)e^(−)colliders,including the Future Circular Lepton Collider(FCC-ee),the Circular Electron Positron Collider(CEPC),and the Compact Linear Collider(CLIC).We present total cross sections and distributions in single J/ψtransverse momentum and rapidity,as well as in J/ψpair invariant mass.The relativistic and QCD corrections both turn out to be large and negative.However,the production rates are large enough for useful experimental studies.

Modeling pollutant transport in overland flow over non-planar and non-homogenous infiltrating surfaces

Pollutant transport in overland flow over surfaces with spatially varying microtopography,roughness,and infiltration was investigated using the diffusion wave equation and transport rate-based equation.The finite volume method in space and an implicit backward difference scheme in time were employed in the numerical solution of the 2D governing equations.The developed model was first tested against an analytical solution and an experimental study involving overland flow and the associated pollutant transport,subsequently a series of numerical tests were carried out.Non-point source pollution was investigated under spatially varying microtopography,roughness,and infiltration.The simulation results showed that microtopography and roughness were the dominant factors causing significant spatial variations in solute concentration.When the spatially varying microtopography was replaced by a smooth surface,the result was an overestimation of the solute rate at the outlet of the upland.On the other hand,when the spatially varying roughness was replaced by the average roughness and spatially varying infiltration rate by the average infiltration rate,the pollutant discharge at the outlet of the upland was not significantly affected.The numerical results further showed that one cannot ignore the spatial variations of slope and roughness when investigating the local pollutant concentration distribution.

高速冲击作用下压力管道力学行为的数值研究（英文）

目的:压力管道是海洋石油化工等领域的常用构件,但经常受到泄漏、爆炸和冲击等事件的威胁。本文旨在探讨压力管道在高速冲击作用下的力学响应及失效机理。创新点:1.开发考虑金属大变形和高应变率的非线性模型,通过基于表面的流体腔模型来模拟管道气体和管道的耦合作用,简化计算模型,提高计算效率;2.通过非线性有限元模型,对管道高速冲击响应的影响因素进行研究分析。方法:1.采用Johnson-Cook模型模拟金属的大应变及大应变率;2.采用基于表面的流体腔模拟管道与内部气体的耦合作用;3.与实验结果对比验证模型的准确性;4.分析影响管道抗冲击性能的参数。结论:1.管道壁厚显著影响管道的抗冲击性能;2.在相同冲量下,冲击头与管道的接触面积越小,管道越容易被穿透;3.在管道受到冲击时,管道内压越大,管道抗穿透能力越小;4.在管道未被破坏时,管道内压能够增加管道的弹性,减小管道受冲击后的凹陷深度。