Observation of Surface Plasmon-coupled Directional Fluorescence Using Thin Iron Films

【中文摘要】表面等离子体耦合定向荧光 (Surface plasmon coupled directional fluorescence, SPCDF)是新近发展起来的一种表面增强荧光检测技术,其原理可理解为表面等离子体共振吸收的逆过程.目前,应用于SPCDF检测的表面金属层多集中于金和银两种金属 .将研究基底扩展到其它金属 , 探讨新基底下的检测特性已成为研究热点. 本文报道了以纳米铁膜为基底的 SPCDF检测方法.以荧光素和卟啉为例 , 探讨了 SPCDF信号的特性, 在固定角度下检测了荧光素 -卟啉双荧光团体系的 SPCDF信号 , 并应用于全血样品的分析 .【Abstract】The observation of surface plasmon-coupled directional fluorescence(SPCDF) on thin iron films was presented. SPCDF from thin iron films was p-polarized with a directional emission angle of 70°. Fluorescein and meso-tetra(4-sulfonatophenyl)porphine(TPPS) were used as a model system of dual fluorophores. Using 25 nm thin iron films,the SPCDF signals of the two fluorophores were observed at a fixed angle just by one scan. The SPCDF signals of Fluorescein and TPPS added to whole blood were identified clearly,eliminating the background interference of blood effectively. Thin iron films have been proven to be new materials for SPCDF detection,promoting a new mode to observe the enhanced fluorescence signals of different fluorophores by one scan. They should be useful for tracking the labled systems of multi-fluorophores in biological applications

Variable-Angle Nanoplasmonic Fluorescence Microscopy: An Axially Resolved Method for Tracking the Endocytic Pathway.

The study of endocytosis, which encompasses diverse mechanisms in biology, requires the utilization of high axial resolution to monitor molecular behavior on both the cell surface and interior of the cell. We have designed a novel axially resolved fluorescence microscopic technique, termed variable-angle nanoplasmonic fluorescence microscopy. The proof-of-principle of this approach is achieved by selectively following the events in the vicinity of a cell membrane or in a cell. We use a 30 nm Au-coated semitransparent coverslip as the nanoplasmonic chip to achieve both surface plasmon resonance excitation and critical angle excitation by tuning the incident angles. This approach leads to improved axial resolution compared to total internal reflection fluorescence microscopy, which is a common imaging technique in cell biology. It offers a unique opportunity to semiquantitatively determine fluorophore axial distributions in the cell. Observing the epidermal growth factor receptor-mediated endocytosis in Caski cells clearly demonstrates the potential application of this new method for cell biology studies

Turning on fluorescence by plasmonic assembly with large tunable spacing: a new observation and its biosensing application

NSFC [21127005]; 973 Program [2013CB933703]; Doctoral Fund of MOE [20110121110011]; MOEAssembling nanoparticle-film metallic junctions with a spacing of up to tens of nanometers efficiently turned on fluorophores attached to the film from the quenching status to an intense surface plasmon-coupled emission. Benefiting from this new finding, a fluorescence biosensor was created based on the use of a biomolecule-linked plasmonic assembly as the trigger

Molecular and Functional Characterization of a c-type lysozyme from the Asian Corn Borer, Ostrinia furnacalis

Some lepidopteran lysozymes have been reported to display activity against Gram-positive and Gram-negative bacteria, in contrast to most lysozymes that are active only against Gram-positive bacteria. OstrinLysC, a c-type lysozyme, was purified from the Asian corn borer, Ostrinia furnacalis Guenée (Lepidoptera: Pyralidae), and shows activity against Gram-positive and Gram-negative bacteria. The NH2-terminal amino acid sequence was determined by Edman degradation and used in a homology cloning strategy. The gene coding for OstrinLysC contains three exons and two introns. The expression profile of the OstrinlysC gene was examined by quantitative real-time PCR. Following injection of the larvae with bacteria, the OstrinlysC gene is strongly up-regulated in immune tissues. Transcripts were also detected in gut tissue. After feeding the larvae with bacteria, OstrinlysC transcripts increased in immune tissues. A very low level of transcript abundance was also detected in gut tissue. These results suggested that the OstrinlysC gene is involved in immune responses. The three dimensional structure of OstrinLysC was predicted. Based on comparison of the 3-D structure of OstrinLysC with that of silkworm lysozyme and chicken lysozyme, we hypothesize that the positive charge-rich surface and the short loop-2, which is close to the cluster of hydrophobic residues, may play important roles in the interaction with the outer membrane of Gram-negative bacterial cell walls

A simulation study on the measurement of D0-D0bar mixing parameter y at BES-III

We established a method on measuring the \dzdzb mixing parameter $y$ for BESIII experiment at the BEPCII $e^+e^-$ collider. In this method, the doubly tagged $\psi(3770) \to D^0 \overline{D^0}$ events, with one $D$ decays to CP-eigenstates and the other $D$ decays semileptonically, are used to reconstruct the signals. Since this analysis requires good $e/\pi$ separation, a likelihood approach, which combines the $dE/dx$, time of flight and the electromagnetic shower detectors information, is used for particle identification. We estimate the sensitivity of the measurement of $y$ to be 0.007 based on a $20fb^{-1}$ fully simulated MC sample.Comment: 6 pages, 7 figure

The complete reference genome for grapevine (Vitis vinifera L.) genetics and breeding

Grapevine is one of the most economically important crops worldwide. However, the previous versions of the grapevine reference genome consisted of thousands of fragments with missing centromeres and telomeres, which limited the accessibility of the repetitive sequences, the centromeric and telomeric regions, and the inheritance of important agronomic traits in these regions. Here, we assembled a telomere-to-telomere (T2T) gap-free reference genome for the pinot noir cultivar (PN40024) using the PacBio HiFi long reads. The T2T reference genome (PN_T2T) was 69 Mb longer with 9026 more genes identified than the 12X.v2 version (Canaguier et al., 2017). We annotated 67% repetitive sequences, 19 centromeres and 36 telomeres, and incorporated gene annotations of previous versions into the PN_T2T. We detected a total of 377 gene clusters, which showed associations with complex traits, such as aroma and disease resistance. Even though the PN40024 sample had been selfed for nine generations, we still found nine genomic hotspots of heterozygous sites associated with biological processes, such as the oxidation-reduction process and protein phosphorylation. The fully annotated complete reference genome, therefore, provides important resources for grapevine genetics and breeding.This work was supported by the National Natural Science Fund for Excellent Young Scientists Fund Program (Overseas) to Yongfeng Zhou, the National Key Research and Development Program of China(grant2019YFA0906200), the Agricultural Science and Technology Innovation Program (CAAS-ZDRW202101), the Shenzhen Science and Technology Program (grant KQTD2016113010482651), the BMBF funded de.NBI Cloud within the German Network for Bioinformatics Infrastructure (de.NBI). We thank Bianca Frommer, Marie Lahaye, David Navarro-Payá, Marcela K. Tello-Ruiz and Kapeel Chougule for their help in analyzing the RNA-Seq data and in running the gene annotation pipeline. This study is also based upon work from COST Action CA17111 INTEGRAPE and form COST Innovators Grant IG17111 GRAPEDIA, supported by COST (European Cooperation in Science and Technology).ViticultureT2Tgap-fregene clustercentromeretelomerePublishe

Non-Standard Errors

In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake