First Observation of Acceleration of Electrons by a Laser in a Vacuum

Using the BNL Accelerator Test Facility we have shown that a tightly focused laser on a vacuum can accelerate an electron beam in free space. The electron beam had energy of 20 MeV and the CO2 laser had energy of about 3 Joule. In the readout of the experiment we detect a clear effect for the laser beam off and on. The size of the effect is about 20% and is reproducible over many laser and beam shots. This is a proof of principle and the data are fully consistent with the CAS theory. The results of this experiment may have an impact on the LASER fusion method.

Splicing of Receptor-Like Kinase-Encoding SNC4 and CERK1 is Regulated by Two Conserved Splicing Factors that Are Required for Plant Immunity

Plant immune receptors belonging to the receptor-like kinase （RLK） family play important roles in the recog- nition of microbial pathogens and activation of downstream defense responses. The Arabidopsis mutant snc4-1D con- tains a gain-of-function mutation in the RLK SNC4 （SUPPRESSOR OF NPRI-1, CONSTITUTIVE4）, which leads to constitutive activation of defense responses. Analysis of suppressor mutants of snc4-1D identified two conserved splicing factors, SUA （SUPPRESSOR OF ABI3-5） and RSN2 （REQUIRED FOR SNC4-1D 2）, that are required for the constitutive defense responses in snc4-1D. In sua and rsn2 mutants, SNC4 splicing is altered and the amount of 5NC4 transcripts is reduced. Further analysis showed that SUA and RSN2 are also required for the proper splicing of CERK1 （CHITIN ELICITOR RECEPTOR KINASE1）, which encodes another RLK that functions as a receptor for chitin. In sua and rsn2 mutants, induction of reactive oxygen species by chitin is reduced and the non-pathogenic bacteria Pseudomonas syringae pv. tomato DC3OOOhrcC grows to higher titers than in wild-type plants. Our study suggests that pre-mRNA splicing plays important roles in the regulation of plant immunity mediated by the RLKs SNC4 and CERK1.

A bifunctional rhodamine derivative as chemosensor for recognizing Cu^2+ and Hg^2+ ions via different spectra

A new simple bifunctional chemosensor 1 based on rhodamine was synthesized by hydrazide and formylformic acid,which could detect Cu^2+and Hg^2+via dif ferent detecting methods in CH3 CN-HEPES buffer solution(20 mmol/L,pH 7.4)(1:9,v/v)respectively.When sensor 1 bound with Cu^2+,it showed a colorimetric change,while a selective enhancement in fluorescence occurred upon 1 binding with Hg^2+,resulting from the spirolatam-ring opening process.The binding modes of 1 with Cu^2+and Hg^2+were investigated based on UV,fluorescence change,ESI-Mass and Job’s Plot data.Moreover,sensor 1 could selectively detect target ion in a mixed solution of Cu^2+and Hg^2+,and the two metal ions do not inte rfere with each other in the process of detecting Cu^2+or Hg^2+with 1.

Bacteriostatic effect of lipopeptides from Bacillus subtilis N-2 on Pseudomonas putida using soybean meal by solid-state fermentation

Bacillus subtilis N-2 which was isolated from natto,produced lipopeptides using soybean meal as a substrate.This work aimed to purify,identify,and determine the antibacterial mechanism of lipopeptides produced by B.subtilis N-2.The fermented product obtained by solid-state fermentation was subjected to water extraction,acid precipitation,and methanol extraction.Fractions were separated and collected using a two-step ultrafiltration method and then identified by LC-MS/MS.Mass spectrometry characterization revealed the presence of four variants of iturin A that differed according to the p-amino fatty acid chain from C14 to C17 as well as the amino acid positions.A new lipopeptide(m/z 1070.3)was identified and its structure was different from the previously reported lipopeptides.The lipopeptides were shown to inhibit the growth of an isolate of Pseudomonas putida,a common pathogen in decaying fish,by changing membrane permeability.These results suggest that the lipopeptides from B.subtilis N-2 could be used as a biocontrol agent in aquaculture.

Controllability of intense-laser ion acceleration

An ion beam has the unique feature of being able to deposit its main energy inside a human body to kill cancer cells or inside material. However, conventional ion accelerators tend to be huge in size and cost. In this paper, a future intenselaser ion accelerator is discussed to make the laser-based ion accelerator compact and controllable. The issues in the laser ion accelerator include the energy efficiency from the laser to the ions, the ion beam collimation, the ion energy spectrum control, the ion beam bunching, and the ion particle energy control. In the study, each component is designed to control the ion beam quality by particle simulations. The energy efficiency from the laser to ions is improved by using a solid target with a fine sub-wavelength structure or a near-critical-density gas plasma. The ion beam collimation is performed by holes behind the solid target or a multi-layered solid target. The control of the ion energy spectrum and the ion particle energy, and the ion beam bunching are successfully realized by a multi-stage laser–target interaction.

Response of Salmonella enterica serovar Typhimurium to alginate oligosaccharides fermented with fecal inoculum:integrated transcriptomic and metabolomic analyses

Alginate oligosaccharides(AOS),extracted from marine brown algae,are a common functional feed additive;however,it remains unclear whether they modulate the gut microbiota and microbial metabolites.The response of Salmonella enterica serovar Typhimurium,a common poultry pathogen,to AOS fermented with chicken fecal inocula was investigated using metabolomic and transcriptomic analyses.Single-strain cultivation tests showed that AOS did not directly inhibit the growth of S.Typhimurium.However,when AOS were fermented by chicken fecal microbiota,the supernatant of fermented AOS(F-AOS)exhibited remarkable antibacterial activity against S.Typhimurium,decreasing the abundance ratio of S.Typhimurium in the fecal microbiota from 18.94 to 2.94%.Transcriptomic analyses showed that the 855 diferentially expressed genes induced by F-AOS were mainly enriched in porphyrin and chlorophyll metabolism,oxidative phosphorylation,and Salmonella infection-related pathways.RT-qPCR confrmed that F-AOS downregulated key genes involved in fagellar assembly and the type III secretory system of S.Typhimurium,indicating metabolites in F-AOS can infuence the growth and metabolism of S.Typhimurium.Metabolomic analyses showed that 205 microbial metabolites were signifcantly altered in F-AOS.Among them,the increase in indolelactic acid and 3-indolepropionic acid levels were further confrmed using HPLC.This study provides a new perspective for the application of AOS as a feed additive against pathogenic intestinal bacteria.