Mutation of the rice AN1-type zinc-finger protein gene ASL4 causes chloroplast development defects and seedling lethality.

Plant zinc-finger proteins play a crucial role in biosynthesis and plant development. However, it is not known whether certain zinc-finger proteins play a role in rice chloroplast development. In this study, a novel rice zinc-finger protein mutant asl4 (albino seedling lethality4), which exhibits an albino lethal phenotype at the seedling stage, was used. Chlorophyll fluorescence analysis and TEM were used to investigate features of the asl4 mutant. The genetic behaviour and function of ASL4 gene were then analysed thorough map-based cloning, transgenic complement and subcellular localization. The albino lethal phenotype was caused by a single nucleotide (G*) deletion mutation on the exon of the ASL4 (LOC_Os09g21710) gene. The ASL4 gene encoded a novel zinc-finger protein containing two ZnF-AN1 domains, which was localized to the nucleocytoplasm. The ASL4 transcripts were highly expressed in all leaves but relatively less in other tissues, suggesting its tissue-specific expression. The transcript levels of associated genes for Chl biosynthesis, photosynthesis and chloroplast development were severely suppressed in asl4 mutants. In conclusion, the absence of ASL4 function caused a defect in chloroplast development and seedling lethality. This is the first published report on the importance of the ZnF-AN1 type zinc-finger protein gene in chloroplast development in rice.

[The investigation and prognosis in patients with non-alcoholic fatty liver disease and coronary vulnerable plaque].

Objective: To investigate the prevalence and prognosis of non-alcoholic fatty liver disease (NAFLD) complicated with coronary vulnerable plaque (VP). Method: Consecutive patients were included who had undergone coronary artery CT angiography (CCTA) from January 1, 2011 to January 30, 2015 at the First People's Hospital of Neijiang. NAFLD was diagnosed according to the liver imaging findings (liver/spleen CT ratio≤1.0) and clinical data. Baseline data, diagnosis, vulnerable plaque were recorded and followed up. The end points included all-cause death rate, cardiac death rate, non-fatal myocardial infarction rate, and elective coronary revascularization rate. Result: A total of 1 069 patients were eventually recruited in this study, including 316 (29.6%) cases diagnosed as NAFLD. In patients with NAFLD, 130 (41.1%) cases had vulnerable plaque, which was significantly higher than 217 of 753 non-NAFLD patients (28.8%) (P<0.01). The percentages of spotty calcification, low attenuation plaque, positive remodeling and napkin ring sign in NAFLD cohort were 36.5%, 14.2%, 17.6% and 6.8% respectively, while those corresponding in non-NAFLD cohort were 18.4%, 6.3%, 5.8% and 3.2% respectively. The proportion of each vulnerable feature in NAFLD cohort was significantly higher than that in the non-NAFLD cohort, with P values of 0.016, 0.028, 0.019 and 0.042, respectively. The cardiac mortality rate in NAFLD group was significantly higher than and that of non-NAFLD group (7.0% vs. 3.6%, P=0.044). Multivariate Cox analysis suggested that NAFLD was not an independent risk factor for cardiac death. NAFLD subgroup (n=316) was divided into VP positive group (NAFLD+VP+, n=130) and VP negative group (NAFLD+VP-, n=186). The mean follow-up time was 4.6±1.3 years. All-cause mortality rate, cardiac death rate, elective coronary artery reconstruction rate, non-fatal myocardial infarction rate in NAFLD+VP+group were 20.8%, 12.3%, 25.4%, 13.8% respectively, which were significantly higher than those corresponding rates in NAFLD+VP-group (5.9%, 3.2%, 8.6%, 6.5%) (P<0.01, 0.002,<0.01, and 0.032 respectively). Conclusion: The incidences of cardiac mortality, elective coronary revascularization, and non-fatal myocardial infarction are significantly higher in patients with NAFLD than those without. NAFLD combined with vulnerable plaque of coronary arteries predicts worse prognosis.

Optimizing electromagnetic enhancement of flexible nano-imprinted hexagonally patterned surface-enhanced Raman scattering substrates.

The production of inexpensive, large-scale, uniform substrates for surface-enhanced Raman scattering (SERS) is a key to popularize its usage in chemical and biological detection. We demonstrate a flexible nano-imprinted hexagonally patterned SERS-active substrate. Its electromagnetic enhancement factor was optimized by the thickness adjustment of its silver over-coated film. The experimental data show a good correspondence with the theoretical prediction. Such substrate was shown to exhibit high uniformity and reproducibility with a variation of less than 2%, offering a potential of greatly exploiting such substrate in infield biocide monitoring.

Enhancing intensity of emitted light from a ring by incorporating a circular groove.

We fabricated a ring containing a single circular groove (RCG) on silver film and which was supported on a glass substrate. We found that by changing the mean radius of the circular groove, the light intensity emitted from the RCG can be modulated by using the scattering light from the circular groove. In addition, we also fabricated circular grooves with the same depth but of different widths so that we could examine the scattering light behavior of the grooves. Herein, we propose a theoretical model which takes into account the amplitude modulation of the cylindrical waves. Our results showed that our proposed model agreed well with the experimental results.

Similarities and differences for light-induced surface plasmons in one- and two-dimensional symmetrical metallic nanostructures.

Two types of double-sided nanostructure, one possessing a slit aperture with parallel grooves and the other possessing a circular aperture with concentric grooves, were fabricated to examine the similarities and differences of their diffraction behavior in one-dimensional (1-D) and two-dimensional (2-D) nanostructures. Based on the projection-slice theory, we conjecture that the surface plasmons in these two different nano-scale grooves possess similar modes. A localized surface plasmon (LSP) was used to examine the transmission characteristics induced by the apertures. The transmission characteristics of the slitted nanostructure and the circular nanostructure aperture were then measured. We coupled the transmission spectra measured from these two apertures with a 1-D parallel groove transmission curve simulated by a 1-D rigorous coupled wave analysis. Measured spectra results show reasonable agreement with the simulated data. We propose that the apparent blueshift observed in the peak frequency of a 2-D nanostructure is due to the difference in the shape of the aperture and the spot transmission characteristics of 1-D and 2-D systems as induced by a LSP.

Beaming light from a subwavelength metal slit surrounded by dielectric surface gratings.

In this article, we demonstrate that a subwavelength metal slit surrounded by dielectric surface gratings possesses a directional beaming effect. We propose a surface plasmon diffraction scheme to explain the three kinds of beaming conditions. The numerical simulations of the illustrative structures undertaken used a Finite Difference Time Domain (FDTD) Method and a Rigorous Coupled Wave Analysis (RCWA) Method. Our simulations were found to be consistent and in agreement with the experimental results. In comparison with other metal structures, we find that dielectric metal structures offer better performance as well as the advantage of being able to be efficiently mass produced for large volume industrial applications.

Simulation and fabrication of subwavelength structures for a nanometer feature enabling lens-less laser writers.

A set-up was proposed to propagate submicrometer light beams without resorting to the conventional approach of using a lens. The main target was to develop a method of either by passing or circumventing the diffraction limit to develop a new optical head for a laser writer system with submicrometer resolution. Starting from using surface plasma theory to explain the mechanism of extraordinary transmission phenomenon, we move to discuss the fabrication processes for free-standing metal films and the corresponding transmission light beam images in the far field. A finite difference time domain (FDTD) method was adopted to simulate the electromagnetic field distribution of transmission light beams from the near field to the far field. The experimental results confirm that surface structures on the incident side of incoming light beams can excite surface plasma and enhance the throughput energy of transmission light beams. In addition, we also established that surface structures on the exit side can suppress the diffraction effect and make transmission light beams directional. The experimental and simulation results were found to agree well with each other, which validates the effectiveness of the FDTD simulation approach. As a free-standing film was too fragile to be of practical use, a proposition to develop a substrate-based nanostructured film to ease the construction of an optical head for a laser writer was developed.