Triphenylamine pyridine acetonitrile fluorogens with green emission for pH sensing and application in cells

In this work,triphenylamine pyridine acetonitrile compounds Py A1,Py A2 and Py A3 are designed and synthesized.They show green fluorescence in water and bright emission in solid state.They have large Strokes shift（about 100 nm）.The excitation and emission spectra are investigated in ethyl acetate,chloroform,cyclohexane,ethanol,water,acetonitrile,THF,DMF and DMSO.It is interesting to find that these compounds are able to sense increasing pH values ranging from pH 2 to 7 by showing different color and emission intensities：almost no emission at pH 2 and strong green emission at pH 7.The acid–base switched color and fluorescence changes can be observed under UV irradiation,in water solution and 1% agarose gel.These changes can be repeated for several cycles.We are able to employ these compounds for cell pH environment imaging.

Reconstruction of Allen's type IV fingertip amputation via bilateral unequal-sized hallux osteo-onychocutaneous free flaps:A retrospective study with 5-year follow-up

Purpose:The reconstruction of Allen''s type IV fingertip amputation is a clinical challenge.Our team designed bilateral unequal-sized hallux osteo-onychocutaneous free flaps for the long-term reconstruction of Allen''s type IV fingertip amputation and conducted a retrospective study with a 5-year follow-up aims to evaluate the effects of this technique.Methods:A retrospective analysis with a 5-year follow-up including 13 patients with Allen''s type IV fingertip amputation who were admitted to our hospital from January 2010 to January 2017 was conducted.The patients were treated with bilateral unequal-sized hallux osteo-onychocutaneous free flaps.The operation time,intraoperative blood loss,and complications were recorded,and the survival rate of the transplanted flaps was calculated.During the 5-year follow-up after operation,the nail growth time was recorded and the finger appearance was observed.At the last follow-up appointment,the length,width,and girth of the reconstructed fingertip and contralateral normal fingertip,range of motion of the reconstructed fingertip and contralateral normal fingertip,Semmes-Weinstein test(for the evaluation of tactile sensation),and two-point discrimination testing results were recorded.SPSS 22.0 software was used for the statistical analysis and the data are presented as mean±SD.Results:The mean operation time was(5.62±0.51)h,the mean intraoperative blood loss was(34.15±3.13)mL,and the survival rate of the transplanted flaps was 100%.During the 5-year follow-up,the average nail growth time was(10.14±1.98)months and the average bone union time was(3.78±0.91)months.The length,width,and girth of the reconstructed fingertip were(31.52±3.73)mm,(17.82±1.74)mm,and(59.75±3.04)mm,respectively,which did not differ from those of the contralateral normal fingertip.The range of motion of the reconstructed fingertip was(12.15±2.79)degrees which is different from that of the contralateral normal fingertip.The average tactile sensation evaluated via the Semmes-Weinstein test and the average two-point discrimination test of the reconstructed fingertip were(0.39±0.17)g and(7.46±1.14)mm,respectively,which were not different from those of the contralateral normal fingertip.The average Maryland score of feet in the donor area was 87.66±7.39,which was satisfactory.Conclusion:Bilateral unequal-sized hallux osteo-onychocutaneous free flaps are an effective method to reconstruct Allen''s type IV fingertip amputations with a satisfactory appearance and good sensory function.