The ulnar palmar perforator flap: anatomical study and clinical application.

BACKGROUND: Defects sustained at the little finger and the ulnar aspect of the hand are common and pedicled perforator flaps have unique advantages in resurfacing it. The purpose of this study is to reappraise the anatomy of the septocutaneous perforator in the postero-medial aspect of the hand and present our clinical experience in using perforator flaps based on it. METHODS: This study was divided into anatomical study and clinical application. In the anatomical study, 30 preserved upper limbs were used. Clinically, 16 patients with defects at the little finger or the ulnar aspect of the hand underwent reconstruction with flaps based on the perforator from the ulnar palmar artery of little finger. The defects ranged from 2.3 × 1.3 cm(2) to 5.7 × 3.0 cm(2). RESULTS: The septocutaneous perforator was constantly located 1.3 ± 0.3 cm superior to the fifth metacarpophalangeal joint with a diameter of 0.8 ± 0.2 mm. It travelled through the space between the superficial layer and the deep layer of hypothenar muscles, and ramified into three branches before entry into the skin. The ascending branch of the perforator has two patterns of anastomoses with the descending dorsal carpal branch of the ulnar artery: true anastomoses and choked anastomoses. Clinically, flaps in all 16 cases survived uneventfully, and donor sites healed without deformity. CONCLUSION: The location of the perforator at the postero-medial aspect of the hand is consistent; the ulnar palmar perforator flap is particularly suitable to cover defects in the little finger or the ulnar aspect of hand.

Effect of biochar amendment on the bioavailability of pesticide chlorantraniliprole in soil to earthworm.

To evaluate the effect of biochar amendment on the bioavailability of chlorantraniliprole (CAP) in soils with different physico-chemical properties, the uptake of CAP from various soils by earthworms was studied. It was observed that the biochar amendment of the soils affected the sorption of CAP, but the magnitude of the sorption enhancement by biochar amendment among the soils was varied, presumably due to the attenuation of the sorptivity of the biochar when amended in the soil. The amendment with biochars leads to a decrease in the bioavailability of CAP in the soils to earthworms, and more prominent for biochar BC850 amendment. In the soil with a CAP concentration of 10 mg kg(-1), the residue of CAP in the earthworm tissues was found to be 9.65 mg kg(-1), in comparison with that the CAP residue was 4.05 mg kg(-1) in BC450 amended soil and 0.59 mg kg(-1) in BC850, respectively. The degree of bioavailability reduction by same level of biochar amendment was different among soils with different properties. The results demonstrate that the properties of soils are important to performance of biochar in soil.

[Impact of biochar amendment on the sorption and dissipation of chlorantraniliprole in soils].

The effects of biochar amendment on sorption and dissipation of chlorantraniliprole (CAP) in 5 different agricultural soils were studied. Red gum wood (Eucalyptus spp.) derived biochar was amended into a black soil, a yellow soil, a red soil, a purplish soil, and a fluvo-aquic soil at the rate of 0.5% (by weight). The sorption and dissipation behaviors of CAP in soils with and without biochar amendment were measured by batch equilibration technique and dissipation kinetic experiment, respectively. The objective was to investigate the impact of biochar application on the environmental fate of pesticides in agricultural soils with different physical-chemical properties, and evaluate the potential ecological impacts of field application of biochar materials. The results showed that biochar application in soils could enhance the sorption of CAP, but the magnitudes were varied among soils with different properties. Amendment of 0.5% (by weight) biochar in the black soil, which have high content of organic matter (4.59%), resulted in an increase of sorption coefficient (K(d)) by 2.17%; while for the fluvo-aquic soil with organic matter content of 1.16%, amendment of biochar at the same level led to an increase of 139.13%. The sorption capacity of biochar was partially suppressed when biochar was mixed with soils. The calculated K(Fbiochar) of biochar after mixed in the black soil, yellow soil, red soil, purplish soil, and fluvo-aquic soil were decreased by 96.94%, 90.6%, 91.31%, 68.26%, and 34.59%, respectively, compared to that of the original biochar. The half-lives of CAP in black soil, yellow soil, red soil, purplish soil, and fluvo-aquic soil were 115.52, 133.30, 154.03, 144.41 and 169.06 d, respectively. In soils amended with biochar, the corresponding half-lives of CAP were extended by 20.39, 35.76, 38.51, 79.19, and 119.75 d, respectively. Similar to the effects of biochar on CAP sorption, in soil with higher content of organic matter, the retardation of CAP dissipation by amending biochar was smaller than that in soil with lower content of organic matter. Our results suggested that application of biochar in soils could enhance the sorption and sequestration of CAP, and retard its soil dissipation, but the magnitudes depended on the organic matter content of the soils.