Exploration and optimization of mixed acid synergistic catalysis pretreatment for maximum C5 sugars.

The liquid hot water (LHW) pretreatment could be strengthened by acetic and lactic acids produced from the process. The synergistic effect of the mixed acid catalyst of lactic acid and acetic acid was investigated for the purpose of maximization of the overall C5 sugars yield. Individual acids (acetic and lactic acid) and mixed acid were used to strengthen the LHW pretreatment at different conditions. The results showed that the suitable conditions of mixed acid synergistic catalysis was at 180 °C for 60 min and 3 wt% mixed acid where the ratio of 40% (i.e. 0.40 in mass fraction of lactic acid in mixed acid). Response surface methodology (RSM) was applied to further optimize this process. The highest yield of C5 sugars of 93.83% according to theoretical predicted model, was close to the experiment value of 92.53% at 177 °C for 67 min and with the ratio of mixed acid of 40%.

[The clinical application of free anteromedial thigh perforator flap in the reconstruction of tongue and mouth floor defect after tongue carcinoma].

Objective: To investigate the application of free anteromedial thigh (AMT) perforator flap in the reconstruction of tongue defect after radical resection of tongue carcinoma. Methods: From September 2010 to January 2015,57 cases with tongue carcinoma underwent radical resection, leaving tongue and mouth floor defects which were reconstructed by AMT perforator flaps at the same stage. These 57 eases included tongue carcinoma at lingual margin (n =36),at ventral tongue (n =15) and at mouth floor (n=6). . Results: The size of AMT perforator flap ranged from 5.5 cm ×4.0 cm to 7.5 cm × 5.5 cm, the thickness of flap ranged from 1.0-1.7 cm. The length of pedicle from descending branch of lateral circumferential femoral artery is (8.2 ± 0.6) cm, found in 28 cases. The length of pedicle from profunda femoral artery is (8.5 ±0.4) cm, found in 17 cases. The length of pedicle from femoral artery is (8.1 ± 0.7) cm, found in 12 cases. All 57 perforator flaps survived uneventfully, the defects at donor site were closed directly in all cases. All patients were followed up for 12-24 months with satisfactory esthetic and functional results in reconstructed tongue. No local recurrence happened. Only linear scar left in the donor sites, the function of thighs were not affected Conclusions: The free AMT perforator flap is an ideal choice for reconstruction of the tongue and mouth floor defect after radical resection of tongue carcinoma.

[Clinical application of thoracoacromial artery perforator flap for hypopharyngeal reconstruction].

Objective: To explore the clinical effect of thoracoacromial artery perforator (TAAP) flap as a reconstructive option for hypopharyngeal defects. Methods: Between June 2011 and November 2015,TAAP flap was used to restore oncologic hypopharyngeal defects in 13 patients with recurrence of hypopharyngeal carcinoma. The size of hypopharyngeal defects ranged from 7.0 cm× 4.5 cm to 8.5 cm × 5.5 cm. Doppler was used to detect the location of thoracoacromial artery perforator. The flap was designed on the line joining the acromion to the xiphoid process with the size 0.5-1.0 cm larger than the defect,the flap was passed under the clavicular head of the pectoralis major and under the clavicle bone and sternocleidomastoid to the recipient site for insetting. The donor site was closed directly. Results: The size of TAAP flap is from 7.0 cm×5.0 cm to 9.5 cmu×6.0 cm. The length of pedicle is 7.5-9.0 cm. The distance from pivot point of flap to central point of recipient site was 9.0-10.5 cm. All 13 flaps survived completely, the defect at donor site was closed directly in all cases. Good appearance was achieved at 8 months to 42 months' follow up, with no recurrence, fistulas, stenosis/strictures, dehiscence, or swelling, only linear scars were left on the donor sites, pectoralis major muscle function was completely preserved in all patients. Conclusions: TAAP flap is a good choice for reconstruction of hypopharyngeal defects.