Nanopore analysis is a powerful technique for single molecule analysis by virtue of its electrochemically confined effects. As a single molecule translocates through the nanopore, the featured ionic current pattern on the time scale contains single molecule characteristics including volume, charge, and conformational properties. Although the characteristics of a single molecule in a nanopore have been written to the featured ionic current, extracting the dynamic information from a complex current trace is still a big challenge. Here, we present an applicable nanopore analysis method employing the Hilbert-Huang Transform (HHT) to study the vibrational features and interactions of a single molecule during the dynamic translocation process through the confined space of a nanopore. The HHT method is specially developed for analyzing nonlinear and non-stationary data that is highly compatible with nanopore data with a high frequency resolution. To provide proof-of-concept, we applied HHT to measure the frequency response for the wild-type (WT) aerolysin and mutant K238E aerolysin nanopores with and without the presence of poly(dA)4, respectively. The energy-frequency-time distribution spectra demonstrate that the biological nanopore contributes greatly to the characteristics of the high frequency component (>2 kHz) in the current recording. Our results suggest that poly(dA)4 undergoes relatively more consistent and confined interactions with K238E than WT, leading to a prolonging of the duration time. Therefore, the characteristics in frequency analysis could be regarded as an "single-molecule ionic spectrum" inside the nanopore, which encodes the detailed behaviours of single-molecule weak interactions.

ObjectivesTo evaluate the efficacy and safety of anti-vascular endothelial growth factor (VEGF) agents and corticosteroids for the treatment of macular oedema (ME) secondary to central retinal vein occlusion (CRVO).DesignSystematic review and network meta-analysis.ParticipantsPatients from previously reported randomised controlled trials (RCTs) comparing anti-VEGF and corticosteroids for the treatment of ME secondary to CRVO.MethodsLiterature searches were conducted using PubMed, Medline, Embase, Cochrane Library and clinicaltrials.gov until March 2017. Therapeutic effects were estimated using the proportions of patients gaining/losing ≥15 letters, best-corrected visual acuity (BCVA) and central retinal thickness (CRT). Treatment safety was estimated using the proportions of adverse events, namely increased intraocular pressure (IOP), cataracts, vitreous haemorrhage (VH) and retinal tear. The software ADDIS (V.1.16.8) was used for analysis. Treatment effect and safety of different drugs could be ranked based on simulation.ResultsEleven RCTs comprising 2060 patients were identified. Regarding patients gaining ≥15 letters, aflibercept and ranibizumab were significantly more effective than sham/placebo at 6 months. Regarding patients losing ≥15 letters at 6 months, ranibizumab showed significant improvement compared with dexamethasone. Aflibercept, bevacizumab or ranibizumab showed greater improvements in BCVA than sham/placebo at 6 months. Intravitreal ranibizumab injection demonstrated greater CRT reduction than both sham and dexamethasone did. Dexamethasone had a higher risk of increased IOP than aflibercept and ranibizumab. Ranibizumab demonstrated a greater risk of cataracts than dexamethasone. Aflibercept and ranibizumab demonstrated low incidence of VH and retinal tear, respectively. Aflibercept had a slight advantage over ranibizumab as assessed by benefit–risk analysis.ConclusionsAnti-VEGF agents have advantages in the treatment of ME secondary to CRVO. Aflibercept and ranibizumab showed marked BCVA improvement and CRT reduction. Aflibercept may have a slight advantage over ranibizumab. The results of this study can serve as a reference for clinicians to provide patient-tailored treatment.PROSPERO registration numberCRD42017064076.

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In the present work, a novel 5-methyl-thiophene-carbaldehyde-functionalized rhodamine 6G Schiff base (RA) was designed and easily prepared as an Al(3+) fluorescent and colorimetric probe, which could selectively and sensitively detect Al(3+) by showing enhanced fluorescence emission. Meanwhile distinct color variation from colorless to pink also provided 'naked eye' detection of Al(3+), due to the ring spirolactam opening of the rhodamine derivative. Other metal ions (including K(+), Mg(2+), Na(+), Ba(2+), Mn(2+), Cd(2+), Fe(2+), Ni(2+), Pb(2+), Zn(2+), Hg(2+), Co(2+), Li(+), Sr(2+) and Cu(2+)) could only induce limited interference. The detection limit of the fluorescent probe was estimated to be 4.17 × 10(-6) M, the binding constant of the RA-Al(3+) complex was 1.4 × 10(6)  M(-1). Moreover, this fluorescent probe RA possessed high reversibility. As aluminum is a ubiquitous metal in nature and plays vital roles in many biological processes, this chemosensor could be explored for biological study applications.

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