The infra-acetabular channel is a channel parallel to the quadrilateral body of the pelvis that passes through the anterior and posterior columns at the medial side of the hip joint. With the widespread use of infra-acetabular channel screws, the acetabular frame screw fixation technique has been proposed to provide stronger fixation for acetabular fractures. There are gender differences in the anatomical parameters of the infra-acetabular channel screws (the length and diameter of the infra-acetabular channel in males are larger than those in females, and the angle between the long axis of the channel and the sagittal plane is smaller). Due to the narrow infra-acetabular channel, it may increase the risks of screw insertion into the hip joint and iatrogenic injury. 3D navigation system-guided placement of infra-acetabular channel screws improves the precision of nail placement. The application of infra-acetabular screws in the fixation of anterior and posterior column fractures has been proved by biomechanical experiments, however, in bicolumnar fractures and T-shaped fractures is still controversial. In order to standardize the placement of infra-acetabular channel screws and to clarify their indications, many studies have been conducted to observe the anatomical parameters of the infra-acetabular channel screws, the surgical technique of placement, biomechanics, and clinical efficacy. This article reviews these studies in order to provide theoretical basis and guidance for the application of infra-acetabular channel screws in acetabular fractures.

OBJECTIVE:To establish the quality standard of Corydalis tomentella. METHODS:The medicinal material was identified in respects of property,microscopic characteristics and TLC. The contents of moisture,total ash and water soluble ex-tract were determined. The content of dehydrocavidine was determined by HPLC. The determination was performed on Agilent C18 column with mobile phase consisted of acetonitrile-phosphate buffer solution(containing 20 mmol/L monopotassium phosphate,10 mmol/L diethylamine,0.1% phosphoric acid)(28:72,V/V)at the flow rate of 1.0 mL/min. The detection wavelength was set at 347 nm,and the column temperature was 35 ℃. The sample size was 10 μL. RESULTS:The original plant is perennial herbs. The me-dicinal material often shrank into a ball. The main root was in conical shape;the rhizomes and roots were distinctly chapped;leaves curled and broken,and flowers were yellowish-white. The pollen grains were round-like in shape;square and columnar crys-tals were found;there were a large number of nonglandular hairs. The bordered pit,threaded and reticulate catheter were found;wood fiber was also found. TLC spots were clear and well-separated. The content of moisture were 7.5%-18.5%,total ash were 20.5%-26.2%,and extract were 29.9%-46.4%. The linear range of dehydrocavidine were 0.04008-2.4048 μg(r=0.9999);RSDs of precision,stability and reproducibility tests were lower than 2.0%. The recoveries were 95.6%-102.5%(RSD=2.3%,n=9). CONCLUSIONS:The established standard can be used for quality evaluation of C. tomentella.

Objective To construct the eukaryotic expression vector coding HCV gene E2 fused with His-Tag, and to express fused protein in CHO cells for investigating the function of HCV envelope protein E2. Methods The gene encoding HCV envelope protein E2 was amplified from pBRTM/HCV1-3011, a plasmid containing the cDNA of HCV's ORF, by polymerase chain reaction (PCR) method and cloned into the vector pET28(a) containing His-Tag to obtain the fused HCV envelope protein E2 gene fused with His-Tag. The fused gene was cloned into pcDNA3.1 to construct the recombinant plasmid pcDNA3.1-His-E2, which will express the E2 protein, fused with His tag. This recombinant plasmid was transfected into CHO cells by Lipofactamine 2000 reagent. The fused protein was identified by indirect immunofluorescence (IIF) and Western-blot (WB) methods. Result The positive results were obtained when the fused protein of HCV E2 with His-Tag were identified by IIF and WB methods. Conclusion The eukaryotic expression vector pcDNA3.1-His-E2 was constructed successfully and the fused proteins were expressed in cells.