Diffusion dynamics of laser-ablated noble-metal nanoparticles in liquids

The diffusion dynamics in water of Brownian particles constituted by noble-metal nanoclusters has been treated by a transport model across a limiting surface that separates two layers of the same fluid, having different values of density and temperature. This model, developed by Parrondo and adapted by Streater, has recently been shown to be useful in several situations like ours by the work of Grillo et al. By this approach, which introduces a one-dimensional vertical adiabatic potential produced by density gradients governing the net current of particles across the limiting surface, we are able to explain the mass and thermal energy transport, which rapidly restores the equilibrium conditions when they are perturbed by laser ablation of a noble-metal target vertically submerged in water. Experimentally, the laser ablation of noble-metal targets has been performed by irradiating pure metal sheets submerged in water with a pulsed Nd:YAG laser at 500 mJ cm^?2 fluency for 5 min and pulses of duration on the nanosecond timescale.     

经导管射频消融术发展史及对医学教育的启示

自20世纪未,经导管射频消融术成功用于治疗快速心律失常,取得了瞩目的成就,本文回顾这一技术的发展史,认为它是理工科和医学高度结合的产物,提出医学教育与科研应该有理工医结合的环境。     

关于晚期消化道肿瘤姑息性手术治疗的思考

晚期消化道肿瘤预后差,生存期短,容易合并某种或某些严重影响脏器功能、甚至危及生命的并发症,如果手术无法彻底根治,需要尽快处理,采取姑息性手术治疗能够缓解症状、减轻痛苦、改善生活质量,甚至达到延长生命的目的。在综合治疗过程中,外科手术能够为下一步治疗提供基础,创造条件。多年以来,对于晚期消化道肿瘤的治疗,姑息性手术取得一...     

慢性房颤的导管消融：时机已经成熟

心房解剖及电重构基础上的多发子波折返是慢性房颤的维持机制,支持线性消融策略;导管消融有关的操作逐渐标准化;盐水灌注导管和三维标测系统等新器械不断进展;慢性房颤消融策略的争议逐渐减少,采用肺静脉隔离加线性消融者越来越多;消融终点更多的以肺静脉隔离和线性阻滞为主,以直接终止心动过速为终点者减少。慢性房颤的导管消融时机已经成...     

慢性房颤导管消融策略的原则和个体化治疗

目前,慢性房颤导管消融的成功率及复发率均不尽人意。由于缺乏统一术式,慢性房颤消融采用的是肺静脉隔离、电图靶向消融及线性消融等多术式综合策略。在房颤消融策略上,既要坚持肺静脉电隔离原则,又要体现消融术式选择和实施的个体化,阶梯消融综合术式的推出就是这种思维方法的具体运用。     

无序的心律有序的认知——心房颤动电生理机制认识过程的回顾与治疗决策的选择

心房颤动（房颤）病因谱广,病理基础呈多样性,电生理机制复杂。本文回顾了房颤电生理机制认识过程的百年历史。提出去除或控制病因是治疗房颤的基础和前提。经外科或导管消融治疗应依据房颤的不同临床背蒂和电生理特征而采用不同的治疗策略。     

客观认识心脏介入治疗

心脏介入治疗技术作为当代心血管领域里先进技术的代表,已在我国很多医院广泛应用,取得了良好的疗效。然而,近年来由于医疗卫生体制的不完善,导致某些医务人员对它的认识出现了偏差,甚至滥用心脏介入治疗技术,给国家和患者带来沉重的负担。因此笔者认为有必要客观认识它,规范它在临床上的应用,使其真正做到为患者解除疾苦。     

如何提高慢性房颤导管消融的成功率

慢性心房颤动（房颤）的基本导管消融方法包括环肺静脉消融隔离、复杂碎裂心房电位消融和线性消融,肺静脉外异位兴奋灶的消融和基质改良是提高慢性房颤消融成功率的有效方法,复合式或个体化消融方案是治疗慢性房颤的趋势,但是如何针对不同患者选择个体化的消融策略进一步提高慢性房颤消融的有效性仍是一大挑战。     

环肺静脉消融策略在房颤治疗中地位的思考

房颤是临床上最常见的快速心律失常之一,对患者危害极大。由于对它发病机制的认识不同导致了临床上不同的治疗方法。肺静脉及环肺静脉开口的肺静脉前庭在房颤的发生和维持中的作用已引起人们的共识。本文通过对房颤机制认识的回顾及治疗方法进展,来探讨环肺静脉消融在临床实践中的重要性,为将来的治疗策略提供依据。     

Temperature dependence of the stacking fault energy of glide set-dissociated dislocations in Si

Recently, it was found that the dissociation distance of glide set dislocations introduced in Si just below the melting temperature by laser shock peening (LSP) is unusually wide (Iwata et al. J. Jpn Inst. Met. Materi.,79(2015),308–314). In order to distinguish whether or not this is to be attributed to uncorrelated motions of leading and trailing Shockley partials or the intrinsic temperature dependence of the stacking fault energy (SFE), dislocations introduced by LSP were annealed at 1350 °C, which should be high enough for the uncorrelated partials to assume the equilibrium correlated configuration. It was found that this unusual widening of a dissociated dislocation introduced by LSP is attributed to uncorrelated motions of Shockley partials. Following this conclusion, the temperature dependence of the intrinsic SFE of Si was determined on correlated dissociated dislocations up to near the melting temperature. The intrinsic SFE of Si shows only negligibly small temperature dependence from 400 °C up to near the melting temperature.