Novel two-photon absorption compounds with different organic cations: facile synthesis, photophysical properties, detection of viscosity, and selective imaging of the endoplasmic reticulum in living cells.

Three novel imidazole-based two-photon absorption compounds bearing different organic cations (1PIPy, 2PIQu, and 3PIIm) were facilely synthesized and fully characterized by 1H NMR, 13C NMR, FT-IR, and HRMS. The linear and nonlinear photophysical properties of the target compounds were systematically investigated in various solvents, supplemented with the density functional theory calculations to shed light on their structure-property relationships. The maximum two-photon action cross-sections (Φ × Î´max) were determined to be 22.4-98.2 (CH2Cl2), 9.6-41.3 (DMF), and 3.9-11.8 (H2O) GM. It is found that 3PIIm shows significant viscosity sensitivity with a sharp 27-fold increase in fluorescence intensity. Its fluorescence intensity also exhibits a linear relationship with the viscosity of the media in a logarithmic plot. The Φ × Î´max value of 3PIIm in highly viscous glycerol was found to be 107.5 GM. Cytotoxicity tests indicate that these compounds have relatively low cytotoxicity. All the target compounds were successfully characterized by one- and two-photon fluorescence imaging in living cells. The colocalization experiments reveal that 1PIPy and 3PIIm are specially located in the endoplasmic reticulum (ER) with the Pearson's coefficients above 0.90. 3PIIm can also monitor the fluctuation of ER viscosity during etoposide-induced apoptosis.

Novel red light-emitting two-photon absorption compounds with large Stokes shifts for living cell imaging.

Three novel donor-π-acceptor two-photon absorption compounds (1PZPy, 2PZIm, 3CZPy) bearing the 10-butyl-10H-phenothiazine (9-butyl-9H-carbazole) donor, the pyridinium (benzimidazolium) acceptor, and the 2,5-divinylthiophene π-bridge were synthesized and fully characterized by 1H NMR, 13C NMR, FT-IR, and HRMS. The linear and nonlinear photophysical properties were systematically investigated. Their absorption properties show a strong solvent dependence, while the emission properties are nearly independent of solvent polarity. All of them possess large Stokes shifts (Δλ=149-190 nm in H2O). 1PZPy and 3CZPy exhibit red fluorescence emission centered at about 635 and 660 nm, respectively. The two-photon absorption cross-sections measured by the open aperture Z-scan technique are determined to be 486 (1PZPy), 601 (2PZIm), and 753 GM (3CZPy) in DMF. The density functional theory calculations were further carried out to reveal their electronic structures. All the target compounds are verified to have low cytotoxicity in the working solution and good capability for one- and two-photon excitation fluorescence imaging, suggesting their potential application in bioimaging. Moreover, they show the organelle targeting ability in living cells with the high Pearson's coefficients above 0.94 for the endoplasmic reticulum.

Impact of Surgical Modalities on Long-term Survival Outcomes of Patients with Duodenal Gastrointestinal Stromal Tumor.

BACKGROUND: The optimal surgical modality for duodenal gastrointestinal stromal tumor (GIST) remains undefined. The purpose of this study was to evaluate long-term survival outcomes of patients who underwent radical resection (RR) or limited resection (LR) of duodenal GIST. METHODS: A total of 325 patients identified from the Surveillance, Epidemiology and End Results (SEER) database who underwent surgery for duodenal GIST between 1986 and 2016 were classified into a LR group and a RR group based on the type of surgery received. Propensity score matching (PSM) was performed to minimize the selection bias in comparisons. Disease-specific survival (DSS) and overall survival (OS) were observed, and factors affecting the survival outcome were analyzed. RESULTS: In the entire cohort, 105 patients (32.3%) underwent RR and 220 (67.7%) received LR. Both the 5-year OS and DSS in RR group were significantly better than those in LR group (71.0% vs. 54.1%, P = 0.014; 66.6% vs. 49.1%, P = 0.025). PSM resulted in 95 pairs of patients, with long-term outcomes being comparable between the two groups. After adjusting covariates in the propensity matched cohort, the type of surgery still showed no significant impact on OS (hazard ratio [HR] 1.160; 95% confidence interval [CI] 0.662-2.033) and DSS (HR 1.208; 95% CI 0.686-2.128). CONCLUSIONS: Surgical modalities do not seem to have a significant impact on long-term survival outcomes of patients with duodenal GIST and should mainly depend on the tumor size and location.

Survival after repeat hepatectomy for recurrent colorectal liver metastasis: A review and meta-analysis of prognostic factors.

BACKGROUND: Frequent recurrent hepatic metastasis after hepatic metastasectomy is a major obstacle in the treatment of colorectal liver metastasis (CRLM). We performed the present systematic review to evaluate the short- and long-term outcomes after repeat hepatectomy for recurrent CRLM and determine factors associated with survival in these patients. DATA SOURCES: An electronic search of PubMed database was undertaken to identify all relevant peer-reviewed papers published in English between January 2000 and July 2018. Hazard ratios (HR) with 95% confidence interval (95% CI) were calculated for prognostic factors of overall survival (OS). RESULTS: The search yielded 34 studies comprising 3039 patients, with a median overall morbidity of 23% (range 8%-71%), mortality of 0 (range 0-6%), and 5-year OS of 42% (range 17%-73%). Pooled analysis showed that primary T3/T4 stage tumor (HR = 1.94; 95% CI: 1.04-3.63), multiple tumors (HR = 1.49; 95% CI: 1.10-2.01), largest liver lesion ≥5 cm (HR = 1.89; 95% CI: 1.11-3.23) and positive surgical margin (HR = 1.80; 95% CI: 1.09-2.97) at initial hepatectomy, and high serum level of carcinoembryonic antigen (HR = 1.87; 95% CI: 1.27-2.74), disease-free interval ≤12 months (HR = 1.34; 95% CI: 1.10-1.62), multiple tumors (HR = 1.64; 95% CI: 1.32-2.02), largest liver lesion ≥5 cm (HR = 1.85; 95% CI: 1.34-2.56), positive surgical margin (HR = 2.25; 95% CI: 1.39-3.65), presence of bilobar disease (HR = 1.62; 95% CI: 1.19-2.20), and extrahepatic metastases (HR = 1.60; 95% CI: 1.23-2.09) at repeat hepatectomy were significantly associated with poor OS. CONCLUSIONS: Repeat hepatectomy is a safe and effective therapy for recurrent CRLM. Long-term outcome is predicted mainly by factors related to repeat hepatectomy.

A new series of two-photon blue/violet fluorescent trans-alkenes: Green synthesis and optical properties.

A new series of trans-alkenes (3a-3e) containing different electron-donating groups were synthesized by the solvent-free Horner-Wadsworth-Emmons reaction, and characterized by infrared, hydrogen nuclear magnetic resonance, mass spectrometry and elemental analysis. Their UV-visible absorption, one-photon excited fluorescence, two-photon absorption, and two-photon excited fluorescence were systematically investigated in different solvents. Experimental results show different trends in linear and nonlinear optical properties with different donor units. 3a with triphenylamine donor exhibits the best optical properties. It emits strong blue up-converted fluorescence, and the two-photon absorption cross-section can be as large as 218 GM in DCM.