The stable index of digraphs

The stable index of a digraph $D$ is defined to be the smallest integer $k$ such that $D$ contains two distinct $(k+1)$-walks with the same initial vertex and terminal vertex if such an integer exists; otherwise the stable index of $D$ is defined to be $\infty$. We characterize the set of stable indices of digraphs with a given order

Characterization of Laser-Resistant Port Wine Stain Blood Vessels Using In Vivo Reflectance Confocal Microscopy.

Background and objectivesPort wine stain (PWS) is a congenital vascular malformation of the human skin. Laser is the treatment of choice for PWS. Laser-resistant PWS is one crucial factor accounting for inadequate treatment outcome, which needs to be fully characterized. This study aims to quantitatively characterize the morphology of laser-resistant PWS blood vessels in the upper papillary dermis using in vivo reflectance confocal microscopy (RCM).Study design/materials and methodsA total of 42 PWS subjects receiving laser treatment from August 2016 through July 2018 were enrolled into this study. Thirty-three subjects had facial PWS; nine had extremity PWS. All subject's PWS received multiplex 585/1,064 nm laser treatment. RCM images were taken before and after treatment. The density, diameter, blood flow, and depth of PWS blood vessels were analyzed.ResultsWe found 44.4% PWS on the extremities (four out of nine subjects) were laser-resistant, which was significantly higher (P < 0.001) when compared with those PWS on the face (15.2%, 5 out of 33 subjects). The laser-resistant facial PWS blood vessels had significantly higher blood flow (1.35 ± 0.26 U vs. 0.89 ± 0.22 U, P < 0.001), larger blood vessel diameters (109.60 ± 18.24 µm vs. 84.36 ± 24.04 µm, P = 0.033) and were located deeper in the skin (106.01 ± 13.87 µm vs. 87.82 ± 12.57 µm, P < 0.001) in the skin when compared with laser-responsive PWS on the face. The average PWS blood vessel density (17.01 ± 4.63/mm2 vs. 16.61 ± 4.44/mm2 , P = 0.857) was not correlated to the laser resistance.ConclusionsLaser-resistant PWS blood vessels had significantly higher blood flow, larger diameters, and were located deeper in the skin. RCM can be a valuable tool for a prognostic evaluation on laser-resistant lesions before treatment, thereby providing guidance for tailored laser treatment protocols, which may improve the therapeutic outcome. The limitations for this study include relative small sample size and acquisitions of different blood vessels before and after 2 months of treatment. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc

Engineering microencapsulated PCM slurry with improved performance for cold storage

Cold is essential in many aspects of everyday life ranging from food, drugs and chemicals processing, storage and distribution to control of thermal comfort and superconductors in power electronics. The demand for cooling in all its forms is accelerating with the growing global urban population1. However, existing cooling technologies consume large amounts of energy and can be highly polluting in terms of carbon and other emissions2. One way of reducing the energy required for cooling and increasing cooling technologies efficiency whilst minimising their environmental impact involves the storage of energy efficiently as cold and to deliver cooling whenever needed without worsening peak demand. To this end we have developed a range of microencapsulated low freezing point phase change materials in slurries (MPCMSs) where the PCM core and the carrier fluid are both liquid coolants. Our strategy was to encapsulate LPCM and structured LPCM with thermal conductivity enhancer materials using inorganic-organic composite shell material to achieve improved cold storage performance from -35˚C to -110˚C. Figure 1 shows microencapsulated diethyl benzene based coolant and structured methanol-water dispersed in ethylene glycol-water and silicone based fluid, respectively. Initial results are promising and these MPCMSs now offer new horizon for cold storage and energy management. Please click Additional Files below to see the full abstract

Daisy: Data analysis integrated software system for X-ray experiments

Daisy (Data Analysis Integrated Software System) has been designed for the analysis and visualization of the X-ray experiments. To address an extensive range of Chinese radiation facilities community's requirements from purely algorithmic problems to scientific computing infrastructure, Daisy sets up a cloud-native platform to support on-site data analysis services with fast feedback and interaction. The plugs-in based application is convenient to process the expected high throughput data flow in parallel at next-generation facilities such as the High Energy Photon Source (HEPS). The objectives, functionality and architecture of Daisy are described in this article

N2 fixation rate and diazotroph community structure in the western tropical North Pacific Ocean

Abstract(#br)In the present study, we report N2 fixation rate (15N isotope tracer assay) and the diazotroph community structure (using the molecular method) in the western tropical North Pacific Ocean (WTNP) (13°–20°N, 120°–160°E). Our independent evidence on the basis of both in situ N2 fixation activity and diazotroph community structure showed the dominance of unicellular N2 fixation over majority of the WTNP surface waters during the sampling periods. Moreover, a shift in the diazotrophic composition from unicellular cyanobacteria group B-dominated to Trichodesmium spp.-dominated toward the western boundary current (Kuroshio) was also observed in 2013. We hypothesize that nutrient availability may have played a major role in regulating the biogeography..