Non-thermal ablation of expanded polytetrafluoroethylene with an intense femtosecond-pulse laser

Ablation of expanded polytetrafluoroethylene without disruption of the fine porous structure is demonstrated using an intense femtosecond-pulse laser. As a result of laser-matter interactions near ablation threshold fluence, high-energy ions are emitted, which cannot be produced by thermal dissociation of the molecules. The ion energy is produced by Coulomb explosion of the elements of (-CF_{2}-CF_{2-})n and the energy spectra of the ions show contributions from the Coulomb explosions of the ions rather than those of thermal expansion to generate high-energy ions. The dependence of ion energy on the laser fluence of a 180-fs pulse, compared with that of a 400-ps pulse, also suggests that the high-energy ions are accelerated by Coulomb explosio

Anatomic characterisation of the parietal branches arising from the internal iliac artery in the foetal pig (Sus scrofa domestica)

Background: It is critical for surgeons to have a full understanding of the complex courses and ramifications of the human internal iliac artery and its parietal branches. Although numerous anatomical studies have been performed, not all variations at this site are currently understood. Therefore, we characterised these blood vessels in foetal pigs to provide additional insight from a comparative anatomical perspective. Materials and methods: Eighteen half-pelvis specimens from foetal pigs were dissected and examined on macroscopic scale. Results: Among our findings, we identified the internal iliac artery as a descending branch of the abdominal aorta. A very thick umbilical artery arose from the internal iliac artery. The superior gluteal, inferior gluteal, and internal pudendal arteries formed the common arterial trunk. Although the superior gluteal artery emerged from the common trunk from inside the pelvis, the inferior gluteal and internal pudendal arteries bifurcated at deep layer within the gluteus muscles after leaving pelvic cavity. We were unable to detect an typical obturator artery emerging from the internal iliac artery. A branch supplying the hip adductors was identified as arising from the inferior epigastric artery which itself was derived from the distal end of the external iliac artery. Conclusions: We identified the anatomic characteristics of the internal iliac artery and its parietal branches in the foetal pig. Our findings provide new insight into the comparative anatomy of the internal iliac artery and will promote understanding of related morphogenetic processes

Concomitant diagnosis of immune deficiency and Pseudomonas sepsis in a 19 month old with ecthyma gangrenosum by host whole-genome sequencing.

X-linked agammaglobulinemia (XLA, OMIM#300300) is a rare monogenic primary immunodeficiency caused by mutations in the Bruton tyrosine kinase (BTK) gene. XLA is characterized by insufficient immunoglobulin levels and susceptibility to life-threatening bacterial infections. We report on a patient that presented with ecthyma gangrenosum and septicemia. Rapid trio whole-genome sequencing (rWGS) revealed an apparently de novo hemizygous pathogenic variant (c.726dupT; p.Ile243TyrfsTer15) in the BTK gene. Metagenomic analysis of rWGS sequences that did not align to the human genome revealed 770 aligned to the Pseudomonas aeruginosa PAO1 genome. The patient was diagnosed with XLA and pseudomonal sepsis

Mechanism of femtosecond laser nano-ablation for metals

Metals have three ablation threshold fluences (high,middle and low-threshold fluence, here called) forfemtosecond laser pulses. In order to investigatethe physics of metal ablation under an intenseoptical field, the ions emitted from a laserirradiatedcopper surface were studied by time-offlightenergy spectroscopy. The low laser fluenceat which ions are emitted, Fth,L is 0.028 J/cm2, andtwo higher emission thresholds were identified atfluences of Fth,M =0.195 J/cm2 and Fth,H =0.470J/cm2. The relation between the number of emittedions per pulse Ni and laser fluence F was in goodagreement with Ni ∝F4 for Fth,L - Fth,M, Ni ∝F3 forFth,M - Fth,H, and Ni ∝F2 for ≥ Fth,H. Thedependence of ion production on laser energyfluence is explained well by multiphotonabsorption and optical field ionization.For fluence levels near the middle to high ablationthreshold, the formation of grating structures onmetal surfaces has been observed. The interspacesof grating structures were shorter than the laserwavelength, and the interspaces depend on fluencefor Mo and W with a 160 fs laser pulse. Thisphenomenon is well explained by the parametricdecay model proposed by Sakabe et al

Two-population replicator dynamics and number of Nash equilibria in random matrix games

We study the connection between the evolutionary replicator dynamics and the number of Nash equilibria in large random bi-matrix games. Using techniques of disordered systems theory we compute the statistical properties of both, the fixed points of the dynamics and the Nash equilibria. Except for the special case of zero-sum games one finds a transition as a function of the so-called co-operation pressure between a phase in which there is a unique stable fixed point of the dynamics coinciding with a unique Nash equilibrium, and an unstable phase in which there are exponentially many Nash equilibria with statistical properties different from the stationary state of the replicator equations. Our analytical results are confirmed by numerical simulations of the replicator dynamics, and by explicit enumeration of Nash equilibria.Comment: 9 pages, 2x2 figure

Species Abundance Patterns in Complex Evolutionary Dynamics

An analytic theory of species abundance patterns (SAPs) in biological networks is presented. The theory is based on multispecies replicator dynamics equivalent to the Lotka-Volterra equation, with diverse interspecies interactions. Various SAPs observed in nature are derived from a single parameter. The abundance distribution is formed like a widely observed left-skewed lognormal distribution. As the model has a general form, the result can be applied to similar patterns in other complex biological networks, e.g. gene expression.Comment: 4 pages, 3 figures. Physical Review Letters, in pres