Dual-state emission and two-wavelength amplified spontaneous emission behaviors observed from symmetric dyes based on functionalized fluorene and benzotriazole units

Structurally symmetric dyes using functionalized fluorenes and benzotriazole as the main building moieties have been synthesized and found to exhibit efficient dual-state emission (DSE) and interesting two-wavelength or dual amplified spontaneous emission (dual-ASE) behaviors in the solution phase, which may benefit the development of organic gain materials with dual-wavelength amplification.

Temporal-Focusing Multiphoton Excitation Single-Molecule Localization Microscopy Using Spontaneously Blinking Fluorophores

Single-molecule localization microscopy (SMLM) based on temporal-focusing multiphoton excitation (TFMPE) and single-wavelength excitation is used to visualize the three-dimensional (3D) distribution of spontaneously blinking fluorophore-labeled subcellular structures in a thick specimen with a nanoscale-level spatial resolution. To eliminate the photobleaching effect of unlocalized molecules in out-of-focus regions for improving the utilization rate of the photon budget in 3D SMLM imaging, SMLM with single-wavelength TFMPE achieves wide-field and axially confined two-photon excitation (TPE) of spontaneously blinking fluorophores. TPE spectral measurement of blinking fluorophores is then conducted through TFMPE imaging at a tunable excitation wavelength, yielding the optimal TPE wavelength for increasing the number of detected photons from a single blinking event during SMLM. Subsequently, the TPE fluorescence of blinking fluorophores is recorded to obtain a two-dimensional TFMPE-SMLM image of the microtubules in cancer cells with a localization precision of 18±6 nm and an overall imaging resolution of approximately 51 nm, which is estimated based on the contribution of Nyquist resolution and localization precision. Combined with astigmatic imaging, the system is capable of 3D TFMPE-SMLM imaging of brain tissue section of a 5XFAD transgenic mouse with the pathological features of Alzheimer's disease, revealing the distribution of neurotoxic amyloid-beta peptide deposits.

Designing Patient-Centered Health Education Materials for Radiation Dermatitis in Breast Cancer Patients: A Pilot Study and Single-Center Clinical Trial

PURPOSE/OBJECTIVE(S)

For breast cancer patients receiving radiotherapy (RT), radiation dermatitis is the most commonly experienced discomfort. However, patients usually do not participate in the design of health education materials regarding radiation dermatitis. We designed a pilot study to investigate the unmet need of breast cancer patients who would be receiving RT at our department and created a patient-centered educational video. We initiated a single-arm clinical trial to evaluate the effectiveness of the video in improving patient and their family's knowledge of radiation dermatitis, alleviating their anxiety, and helping patients improve self-care skills during RT course.

MATERIALS/METHODS

The pilot study was executed in a radiation oncology department of a tertiary medical center in Taiwan. We designed a questionnaire to explore new breast cancer patients' idea of a comprehensive pre-RT health education. Enrolled patients would fill out an electronic questionnaire during their first visit at our outpatient clinic. They were asked to select at most two of the following items they considered most important for pre-RT health education: (1) The mechanism behind RT; (2) Self-care skills for irradiated skin; (3) Activities to be avoided during RT course; (4) The toxicity grading of radiation dermatitis. Given the above information, we created a 4-minute video set in a clinical scenario of a patient receiving pre-RT health education from a nurse. A single-arm clinical trial (IRB approval number: CMUH111-REC2-121) is currently recruiting. The video was launched on YouTube (Link: https://youtu.be/O1uTXpS_ed0) to give patients easy access to the video. Enrolled patients would complete Skindex-16 survey (translated into Chinese) at 3 timepoints: during their first visit at our clinic, in the middle of RT course, and at the first post-RT follow-up visit. Cronbach's alpha test was applied to determine the internal consistency of the questionnaires.

RESULTS

The pilot study included 19 patients with an average age of 46.6 (range: 34 to 69) years old. All patients' primary language was Chinese Mandarin. Most patients (84%) received at least secondary education. We found by surprise that RTOG skin toxicity grading was considered very important for most patients (79%), while less than half (42%) found the mechanism behind RT important. The internal validity of the Chinese version of Skindex-16 was good (Cronbach's alpha score = 0.87). For the recruiting trial, we have enrolled 10 patients and planned to close the trial upon enrolling 50 participants. The study result should be available before August 2023.

CONCLUSION

We suggest to actively involve patients in designing health education materials for patient-centered care. Toxicity grading of radiation dermatitis should be included in pre-RT health education for breast cancer patients. Whether the educational video helps reduce patients' anxiety and the incidence of severe radiation dermatitis will soon be answered by our ongoing clinical trial.

A Fluorescent Vector of Carbon Dot to Deliver Rab13 and Rab14 Plasmids for Promoting Neurite Outgrowth

The complex processes of neuron differentiation and neuron repair are critical for treating nervous system injuries and neurodegenerative diseases. Neurite outgrowth plays a crucial role in these processes by enabling the formation of connections between neurons and the generation of neuroplasticity to restore the function of the nervous system. In this study, we fabricated functionalized carbon dots (CDs) with distinctive photoluminescence and low cytotoxicity for use as fluorescence imaging probes and nanocarriers to deliver plasmid DNAs to neurons effectively for inducing neurite outgrowth. CDs were prepared through a reflux process in nitric acid solution, and their surface was then modified using polyethylenimine (PEI) to obtain positively charged CDs for increasing the absorption of plasmid DNAs and the efficiency of cell uptake. Experimental results indicated that the fabricated CDs maintained a low cytotoxicity and exhibited a high neuron uptake of up to 97%. An improvement in the plasmid DNA ingestion of neurons resulted in enhanced expression of Rab13-Q67L and Rab14 proteins, which considerably promoted neurite sprouting and elongation. After the fabricated PEI-modified CDs were used to deliver the Rab13-Q67L and Rab14 plasmids, more than 56% of the neurons had a neurite length that was greater than twice the size of their soma. Thus, DNA delivery through functionalized CDs has a high potential for use in gene therapy for neuronal injuries and diseases.

Tris(4'-Nitrobiphenyl)amine─An Octupolar Chromophore with High Two-Photon Absorption Cross-Section and Its Application for Uncaging of Calcium Ions in the Near-Infrared Region

Compounds with high two-photon absorption (2PA) performance in the near-infrared region have attracted great attention because of their application in the material and biological science. In this study, we have developed a simple and novel octupolar chromophore, tris(4'-nitrobiphenyl)amine 1, with three nitro peripheral groups attached to a triphenylamine core via biphenyl linkers. A mono-branched analogue 2 has also been prepared to investigate the effects of octupolar and dipolar systems on photophysical and 2PA behaviors. Compound 1, despite having a much simpler structure than the previous three-branched scaffolds, exhibits comparable σ₂ values, reaching 1330 GM at 730 nm and 900 GM at 820 nm in toluene. Combined with an outstanding σ₂/MW ratio (2.2 GM g^-1 mol) and a high fluorescence quantum yield (0.51), 1 displays potential as a promising two-photon (2P) probe for bioimaging. Subsequently, the ethylene glycol tetraacetic acid-substituted derivatives featuring octupolar (3 and 5) or dipolar (4 and 6) character have been synthesized and their one-photon (1P) and 2P photochemical reactions have been examined. Finally, 1P- and 2P-triggered uncaging of Ca²⁺ from these calcium chelators has been confirmed.

A two-photon fluorescence probe for cell membrane imaging under temporal-focusing multiphoton excitation microscopy (TFMPEM)

A small-sized chromophore, BTTA-2OH, manifesting favorable solubility, large two-photon excitation efficiency, and good fluorescence photostability was synthesized to label the membrane of living cells for visualizing the dynamic movement of membrane-related vesicles via a two-photon fluorescence imaging technique based on wavelength-tunable temporal-focusing multiphoton excitation microscopy.

Multi-photon properties of branched chromophores derived from indenoquinoxaline and oxadiazole heterocyclic units

Two chromophoric congeners derived from indenoquinoxaline and oxadiazole are designed, synthesized and characterized for their multi-photon properties in the femtosecond time domain. These two model structures are experimentally found to exhibit strong and widely distributed two- and three-photon activities within the spectral range of 680-1500 nm and the larger congener manifests maximum two- and three-photon absorption cross-section values of 2120 GM (at 750 nm) and ∼85 × 10^-80 cm⁶ s² (at 1280 nm), respectively. Both two- and three-photon absorption-based optical power-limiting performance of a representative model compound are also evaluated and demonstrated.

High-Performance Organic Dyes with Electron-Deficient Quinoxalinoid Heterocycles for Dye-Sensitized Solar Cells under One Sun and Indoor Light

A series of Y-shaped sensitizers incorporating quinoxaline or quinoxalinoid moieties were prepared and applied in dye-sensitized solar cells (DSSCs). By the introduction of quinoxalinoid functionalities, the absorption extinction coefficients could be enhanced. The molecular structures were modified by introducing an extra acceptor group (A) between a donor (D) and a π-bridge (D-A-π-A) and also by incorporating electron-donating substituents at various positions of the quinoxalinoid moiety. Some of the dyes and mixtures thereof were found to exhibit good light-harvesting efficiencies under both sunlight and indoor light, with efficiencies up to 7.92 % under one sun (AM 1.5G). When operated under indoor light, the efficiency could be boosted to 27.76, 28.74, and 30.45 % under 600, 1000, 2500 lux illumination, respectively. The best performance could be ascribed partly to an improved dye coverage on the TiO₂ surface.

High-free androgen index is associated with increased risk of non-alcoholic fatty liver disease in women with polycystic ovary syndrome, independent of obesity and insulin resistance

BACKGROUND/OBJECTIVE

Central obesity and insulin resistance (IR) are common conditions in women with polycystic ovary syndrome (PCOS) and in subjects with non-alcoholic fatty liver disease (NAFLD). However, few studies have addressed the association between hyperandrogenism (HA) and NAFLD. We aimed to determine whether variations in the free androgen index (FAI) might be associated with NAFLD prevalence.

SUBJECTS/METHODS

A cross-sectional study was performed including 400 Chinese women with PCOS and 100 age, and body mass index (BMI)-matched women. The anthropometric and serum biochemical parameters related to sex steroids, glucose and lipid profiles were examined. Liver fat content (LFC) was measured by quantitative ultrasound.

RESULTS

The prevalence of NAFLD was 56.23% in PCOS patients and 38% in controls (P=0.001), and this prevalence increased with FAI quartile independently of obesity and homeostasis model assessment of insulin resistance (HOMA-IR). The FAI level increased from non-NAFLD group to NAFLD group. The FAI was positively associated with the metabolic parameters LFC, BMI, waist circumference, alanine aminotransferases, aspartate, triglyceride, total cholesterol and low-density lipoprotein cholesterol, and was negatively associated with high-density lipoprotein. Moreover, in multivariate logistic regression analysis BMI, high-sensitivity C-reactive protein (hsCRP), FAI, LFC and HOMA-IR were significantly associated with NAFLD. The cut-off values of FAI, LFC, BMI and hsCRP to predict NAFLD were 9.86%, 17.19%, 24.38% and 0.72%, respectively. The area under the curve for predicting NAFLD in PCOS patients showed comparable sensitivity and specificity between BMI and a new index combining FAI with hsCRP.

CONCLUSIONS

A higher FAI level is associated with increased LFC and NAFLD prevalence independent of obesity and IR.

A Novel Hybrid Viabahn-assisted Bypass Technique: Extra-arterial Flossing Wiring for Chronic Total Occlusion in Superficial Femoral Artery

Introduction

A hybrid Viabahn-assisted bypass (VAB) technique is introduced for revascularizing chronic total occlusion (CTO) in superficial femoral artery (SFA) when bypass surgery is difficult or endovascular intervention fails.

Report

This technique combines extra-arterial flossing wiring with antegrade-retrograde intervention via traditional open exposure of middle SFA and deploying a Viabahn from the proximal true lumen through the subintimal lumen and extra-arterial space, and back into distal true lumen to restore flow. It only needs a 3–5 cm incision to expose the mid-SFA without clamping or endarterectomy of the SFA.

Discussion

This hybrid procedure is an alternative technique to improve SFA revascularization in some difficult CTOs.

Synthesis and characterization of novel symmetrical two-photon chromophores derived from bis(triphenylaminotetrathienoacenyl) and fused-thiophene units

Four new donor–π–donor (D–π₁–π₂–π₁–D) fused-thiophene-based chromophores, end-functionalized with electron-donating triphenylamine (TPA) groups, were developed and characterized for a two-photon absorption study.

A sulfhydryl-reactive ruthenium (II) complex and its conjugation to protein G as a universal reagent for fluorescent immunoassays

To develop a fluorescent ruthenium complex for biosensing, we synthesized a novel sulfhydryl-reactive compound, 4-bromophenanthroline bis-2,2′-dipyridine Ruthenium bis (hexafluorophosphate). The synthesized Ru(II) complex was crosslinked with thiol-modified protein G to form a universal reagent for fluorescent immunoassays. The resulting Ru(II)-protein G conjugates were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The emission peak wavelength of the Ru(II)-protein G conjugate was 602 nm at the excitation of 452 nm which is similar to the spectra of the Ru(II) complex, indicating that Ru(II)-protein G conjugates still remain the same fluorescence after conjugation. To test the usefulness of the conjugate for biosensing, immunoglobulin G (IgG) binding assay was conducted. The result showed that Ru(II)-protein G conjugates were capable of binding IgG and the more cross-linkers to modify protein G, the higher conjugation efficiency. To demonstrate the feasibility of Ru(II)-protein G conjugates for fluorescent immunoassays, the detection of recombinant histidine-tagged protein using the conjugates and anti-histidine antibody was developed. The results showed that the histidine-tagged protein was successfully detected with dose-response, indicating that Ru(II)-protein G conjugate is a useful universal fluorescent reagent for quantitative immunoassays.

Simplified 2-D cubic spline interpolation scheme using direct computation algorithm

It has been shown that the 2-D cubic spline interpolation (CSI) proposed by Truong et al. is one of the best algorithms for image resampling or compression. Such a CSI algorithm together with the image coding standard, e.g., JPEG, can be used to obtain a modified image codec while still maintaining a good quality of the reconstructed image for higher compression ratios. In this paper, a fast direct computation algorithm is developed to improve the computational efficiency of the original FFT-based 2-D CSI methods. In fact, this algorithm computes the 2-D CSI directly without explicitly calculating the complex division usually needed in the FFT or Winograd discrete Fourier transform (WDFT) algorithm. In addition, this paper describes a novel way to derivate the 2-D CSI from the 1-D CSI by using the row-column method. This new fast 2-D CSI provides a regular and simple structure based upon linear correlations. Therefore, it can be implemented by the use of a modification of Kung’s pipeline structure and is naturally suitable for VLSI implementations. Experimental results show that the proposed new fast 2-D CSI algorithm can achieve almost the same CSI performance with much fewer arithmetic operations in comparison with existing efficient algorithms.

Novel fluorophore based on a multi-substituted olefin skeleton with enhanced three-photon absorption in the femtosecond regime

A new multipolar fluorophore based on a multi-substituted olefin skeleton that possesses strong three-photon absorption and optical-limiting properties in the femtosecond regime has been designed and synthesized; this archetype suggests a new strategy to further optimize molecular structures toward enhanced nonlinear absorptivities based on known materials.

Primary vs. delayed resection for obstructive left-sided colorectal cancer: impact of surgery on patient outcome

PURPOSE

By comparing surgical outcomes between primary and delayed resection, we addressed whether and how surgical strategies impacted prognosis of patients with left-sided colorectal cancer underwent emergency curative resection.

METHODS

Between January 1980 and December 2002, a total of 143 patients were identified who presented with obstructive left-sided colorectal cancer and received emergency curative resection in Taipei Veterans General Hospital. Patients were stratified according to the timing of tumor resection into two groups: primary resection and delayed resection. Demographic data of the patients, characteristics of the tumors, and short-term and long-term outcomes were analyzed and compared between the two groups.

RESULTS

The demographic data and tumor characteristics did not differ between the two groups except for more rectal cancers in the delayed resection group (P=0.021). Primary resection group had a higher anastomotic leakage rate (P=0.017) and a trend toward a higher mortality rate, which did not reach statistical significance (P=0.063). The median follow-up intervals were similar (60.4 vs. 58.3 months; P=0.79). The median survival tended to be longer in delayed resection group (66 vs. 105 months; P=0.088). Overall five-year and ten-year survival for primary resection were 43.7 and 31.9 percent, respectively, compared with 67.2 and 53.2 percent, respectively, for delayed resection.

CONCLUSIONS

Delayed resection seems to be a safer procedure and provided a better oncologic outcome compared with primary resection in obstructive left-sided colorectal cancer under emergency situations.

Midazolam attenuates adenosine diphosphate-induced P-selectin expression and platelet-leucocyte aggregation

BACKGROUND AND OBJECTIVE

The expression of P-selectin on the surface of platelets and platelet-leucocyte conjugate formation are considered to be an indicator of platelet activation in thrombotic and inflammatory disease. Midazolam is a widely used sedative and anaesthetic induction agent. It may inhibit platelet aggregation and suppress interleukin-6 and -8 response in human leucocytes, but any effect on the adhesion of activated platelets to leucocytes remains obscure. We have examined the influence of midazolam on adenosine diphosphate (ADP)-induced platelet surface P-selectin expression and platelet-leucocyte aggregation in whole blood.

METHODS

Human whole blood was stimulated with 2 x 10(-5)M ADP in the presence of midazolam (3 x 10(-4) to 3 x 10(-6)M). Samples were stained with a fluorochrome-conjugated CD62P and CD41a antibody for detecting human platelet P-selectin antigens. The leucocyte subpopulations were separately gated and platelet-leucocyte aggregates were defined as cells found positive for CD45 and CD62P. All samples were analysed and were electronically separated into specific cell types (platelets, neutrophils, monocytes and lymphocytes) according to their typical forward/side scattering by flow cytometry.

RESULTS

Midazolam significantly inhibited ADP-induced platelet P-selectin expression and attenuated platelet-leucocyte aggregation (mainly in neutrophils and monocytes) in a dose-dependent manner with a maximum inhibitory effect at 3 x 10(-4)M (P < 0.01).

CONCLUSIONS

This study demonstrated that midazolam decreases the ADP-induced expression of platelet surface P-selectin and platelet-leucocyte aggregation.

The antiproliferative activity of prodelphinidin B-2 3′-O-gallate from green tea leaf is through cell cycle arrest and Fas-mediated apoptotic pathway in A549 cells

Prodelphinidin B-2 3'-O-gallate, a proanthocyanidin gallate isolated from green tea leaf, was investigated for its anti-proliferative activity in human non-small cell lung cancer A549 cells. The results showed that prodelphinidin B-2 3'-O-gallate inhibited the proliferation of A549 cells with no detectable toxic effects on normal WI-38 cells as measured by the XTT assay. Flow cytometric analysis showed that prodelphinidin B-2 3'-O-gallate blocked cell cycle progression in the G0/G1 phase. In addition, prodelphinidin B-2 3'-O-gallate effectively induced A549 cell apoptosis as determined by assessing the nucleosome level in cytoplasm. Enzyme-linked immunosorbent assay showed that the G0/G1 phase arrest is due to p53-independent induction of p21/WAF1. An enhancement in Fas/APO-1 and its two form ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), might be responsible for the apoptotic effect induced by prodelphinidin B-2 3'-O-gallate. We suggested that prodelphinidin B-2 3'-O-gallate's activities might be potentially contribute to its overall chemopreventive effects against lung cancer, and can possibly be considered for future therapeutic application.

Stimulated Rayleigh-Bragg scattering enhanced by two-photon excitation

A frequency-unshifted and backward stimulated Rayleigh scattering can be produced in a linearly transparent but two-photon absorbing medium. Using a novel two-photon active dye solution as the nonlinear medium pumped by 532-nm and ~10-ns laser pulses, a highly directional backward stimulated scattering at the pump wavelength can be readily observed. The experimental results on spectral structure, spatial and temporal behaviors, and output/input relationship of this new type of stimulated scattering are presented. To explain the observed phenomenon and its experimental behaviors, a physical model of feedback mechanism provided by a two-photon-excitation enhanced Bragg grating inside the scattering medium is proposed. Comparing to other types of stimulated scattering, the stimulated Rayleigh-Bragg scattering exhibits the advantages of no-frequency shift, low threshold, and low requirement for pump spectral line-width.

Causes and consequences of high osmotic potentials in epiphytic higher plants

Past reports of the water relations of epiphytes, particularly bromeliads, indicate that tissue osmotic potentials in these tropical and subtropical plants are very high (close to zero) and are similar to values for aquatic plants. This is puzzling because several ecophysiological studies have revealed a high degree of drought stress tolerance in some of these epiphytes. The goal of this study was two-fold: (1) to increase the number of epiphytic taxa sampled for tissue osmotic potentials; and (2) to explain the apparent discrepancy in the significance of the tissue water relations and tolerance of drought stress in epiphytes. Tissue osmotic potentials of 30 species of epiphytic ferns, lycophytes, and orchids were measured in a subtropical rain forest in northeastern Taiwan. Nearly all values were less negative than -1.0 MPa, in line with all previous data for epiphytes. It is argued that such high osmotic potentials, indicative of low solute concentrations, are the result of environmental constraints of the epiphytic habitat on productivity of these plants, and that low rates of photosynthesis and transpiration delay the onset of turgor loss in the tissues of epiphytes such that they appear to be very drought-stress tolerant. Maintenance of photosynthetic activity long into drought periods is ascribed to low rates of transpiration and, hence, delayed tissue desiccation, and hydration of the photosynthetic tissue at the expense of water from the water-storage parenchyma.

Degenerate two-photon-absorption spectral studies of highly two-photon active organic chromophores

Degenerate two-photon absorption (TPA) spectral properties of five AFX chromophore solutions have been studied using a single and spectrally dispersed sub-picosecond white-light continuum beam. In a specially designed optical configuration, optical pathways inside the sample solution for different spectral components of the focused continuum beam were spatially separated from each other. Thus, the nondegenerate TPA processes coming from different spectral components can be eliminated, and the direct nonlinear absorption spectrum attributed to degenerate TPA processes can be readily obtained. Using this new technique, the complete TPA spectra for these five highly two-photon-active compounds (AF-380, AF-350, AF-295, AF-270, and AF-50) were obtained in the spectral range from 600 to 950 nm on an absolute scale of TPA cross section. The relationship between the molecular structures and their TPA spectral behaviors are discussed. In general the measured TPA spectra are not identical with the linear absorption spectra on the scale of absorbed photon(s) energy. Moreover, for some sample (such as AF-380), the TPA spectrum is totally different from the linear spectrum, which implies the difference of molecular transition pathways and selection rules for one- and two-photon excitation processes. At high excitation intensity levels (>or=15 GW/cm(2)), the saturation behavior of TPA transition can be observed obviously in AF-350 and AF-380 solutions that exhibit much higher nonlinear absorptivity than the other chromophores investigated.