The relief of hypoxic microenvironment using an O2 self-sufficient fluorinated nanoplatform for enhanced photodynamic eradication of bacterial biofilms

Hypoxia,an important characteristic of bacterial biofilms,can hinder the generation of reactive oxygen species(ROS)in photodynamic therapy(PDT),leading to reduced therapeutic efficacy of PDT.In order to address this issue,fluorinated liposome was fabricated as an oxygen-sufficient nanoplatform for enhanced photodynamic eradication of bacterial biofilms.The liposomes(denoted as Lip-Ce6-PFH@O₂)were prepared by co-encapsulation of O₂ carrier perfluorohexane(PFH)and photosensitizer chlorin e6(Ce₆).Lip-Ce6-PFH@O₂ could achieve efficient biofilm penetration due to the positively charged surface.The hypoxic microenvironment of biofilms would then be relieved,leading to the generation of more ROS under laser irradiation.Therefore,the bactericidal capability of PDT could be significantly improved because of the co-delivered O₂ carrier PFH.Lip-Ce6-PFH@O₂ exhibited much better antibiofilm ability than that of Lip-Ce6 both in vitro and in vivo.Meanwhile,Lip-Ce6-PFH@O₂ also effectively alleviated inflammation symptoms and accelerated wound healing in the mice model.In general,this study provides a new paradigm to enhance the therapeutic efficacy of PDT for efficient biofilm eradication.     

Few-layer graphene direct deposition on Ni and Cu foil by cold-wall chemical vapor deposition

We report an alternative synthesis process, cold-wall thermal chemical vapor deposition (CVD), is replied to directly deposit single-layer and few-layer graphene films on Ar plasma treated Ni and Cu foils using CH4 as carbon source. Through optimizing the process parameters, large scale single-layer graphene grown on Ni foil is comparable to that grown on Cu foil. The graphene films were able to be transferred to other substrates such as SiO2/Si, flexible transparent PET and verified by optical microscopy, Raman microscopy and scanning electron microscopy. The sheet resistance and transmission of the transferred graphene films on PET substrate were also discussed.     

Ohmic contact effect of Ag-nanodots on quantum efficiency of Si solar cell

The authors investigated Si solar cell with the inclusion of nano-Ag dots using the ink-jet printer. These nano-Ag dots were used for the Ohmic contact layer on phospho-silicate glass layer, which was not removed after the formation of Si emitter layer by phosphorus diffusion process. The SiNx layer deposited on the nano-Ag dots shows the catalyst selective growth and so the layer formed beneath of nano-Ag dots. The photoreflectances show that the long wavelength from 360 nm to 1200 nm tends to be increased as the density of the nano-Ag is increased. In case of short wavelength from 294 nm to 367 nm, it shows the opposite trend, indicating the plasmon effect of the nano-Ag. As embedding the nano-Ag dots on the phospho-silicate glass layer, the blocked Ohmic contact was opened and the quantum efficiency of 14.4% was achieved, which is higher than the reference sample of 12.72% without the glass layer. The nano-Ag dots form the good Ohmic contact and also enhance the light conversion efficiency with the formation of surface plasmon.     

Highly conductive and porous activated reduced graphene oxide films for high-power supercapacitors

We present a novel method to prepare highly conductive, free-standing, and flexible porous carbon thin films by chemical activation of reduced graphene oxide paper. These flexible carbon thin films possess a very high specific surface area of 2400 m(2) g(-1) with a high in-plane electrical conductivity of 5880 S m(-1). This is the highest specific surface area for a free-standing carbon film reported to date. A two-electrode supercapacitor using these carbon films as electrodes demonstrated an excellent high-frequency response, an extremely low equivalent series resistance on the order of 0.1 ohm, and a high-power delivery of about 500 kW kg(-1). While higher frequency and power values for graphene materials have been reported, these are the highest values achieved while simultaneously maintaining excellent specific capacitances and energy densities of 120 F g(-1) and 26 W h kg(-1), respectively. In addition, these free-standing thin films provide a route to simplify the electrode-manufacturing process by eliminating conducting additives and binders. The synthetic process is also compatible with existing industrial level KOH activation processes and roll-to-roll thin-film fabrication technologies.     

Removal of ammonium from wastewater using calcium form clinoptilolite

The paper concerns the removal of ammonium ions from aqueous solution using a modified clinoptilolite-Ca(2+)-formed clinoptilolite (CaY) prepared from natural clinoptilolite. The batch study results show that the pH has an effect on ammonium adsorption capacity as it can influence both the character of the exchanging ions and the clinoptilolite itself; the CaY has a high selectivity to NH(4)(+) and the exchange decreases with increasing temperature; ammonium ion uptake onto CaY was suitably described by the Langmuir model. The column results indicated that the effluent of simulated wastewater treated with CaY could meet the integrated wastewater discharge standard of China, and CaY can be circulated through regenerating by Ca(OH)(2).     

Distinguishing between cis/trans isomers of monounsaturated fatty acids by FAB MS

Fast-atom bombardment (FAB) mass spectrometry in the negative ion mode can be used to unambiguously distinguish between cis and trans isomers of monounsaturated fatty acids by the relative signal strengths of an intense pair of ion signals. Under normal FAB ionization/desorption conditions, the deprotonated molecules (i.e., [M - H]-) of six fatty acids underwent charge remote fragmentation. A characteristic fragmentation pattern of two intense peak clusters of peaks with three weak intervening clusters of peaks are used in each case to identify the position of the double bond. The possibility of resonance electron capture occurring during the FAB process is discussed.     

Influence of atmospheric turbulence on the spatial correlation properties of partially coherent flat-topped beams

The analytical expression for the spectral degree of coherence of partially coherent flat-topped beams propagating through the turbulent atmosphere is derived, and the spatial correlation properties are studied in detail. In particular, we find that the oscillatory behavior and phase singularities of the spectral degree of coherence may appear when partially coherent flat-topped beams propagate through the turbulent atmosphere; this behavior is very different from the behavior of Gaussian Schell-model beams. But the oscillatory behavior becomes weaker with increasing turbulence and even disappears when the turbulence is strong enough. The width of the spectral degree of coherence is always smaller than that of the spectral density in the far field when the turbulence is strong enough, whereas the width of the spectral degree of coherence in free space can be either larger or smaller than that of the spectral density in the far field.     

Composing Cardinal Direction Relations Based on Interval Algebra

Direction relations between extended spatial objects are important commonsense knowledge. Skiadopoulos proposed a formal model for representing direction relationsbetween compound regions (the finite union of simple regions), known as SK-model. Itperhaps is currently one of most cognitive plausible models for qualitative direction information, and has attracted interests from artificial intelligence and geographic informationsystem. Originating from Allen first using composition table to process time interval constraints; composing has become the key technique in qualitative spatial reasoning to checkthe consistency. Due to the massive number of basic directions in SK-model, its compositionbecomes extraordinary complex. This paper proposed a novel algorithm for the composition.Basing the concepts of smallest rectangular directions and its original directions, it transforms the composition of basic cardinal direction relations into the composition of intervalrelations corresponding to Allen''s interval algebra. Comparing with existing methods, thisalgorithm has quite good dimensional extendibility, that is, it can be easily transferred tothe tridimensional space with a few modifications.