Compressibility of lime-treated dredged slurry with high water content.

Lime is widely used for soft ground treatment, rendering the compressibility of lime-treated soil a crucial factor in deformation analysis in engineering applications. This study investigated the compressibility of three remoulded lime-treated slurries with high water content in Southeast China. Sixty groups of oedometer tests were conducted on lime-treated soils with an initial water content of 1 to 3 times the liquid limit and lime contents between 1 and 3%. The oedometer test results were discussed to examine the remoulded yield stress σ y ' of lime-treated slurry. Considering the relationships between σ y ' , the void ratio, lime content, and initial water content were preliminarily discussed and quantitatively established. Research on the normalised compression curve of lime-treated soil revealed that for soil samples containing a lime content of 0-%, the normalised compression curve at σ p ' > σ y ' can be represented by a unique line. Furthermore, the log(1 + e) - log σ v ' compression curve of lime-treated slurry at pre-yield state is analysed, and a prediction method for the modified compression index is proposed.

A Modified Suture Technique to Improve Scar Appearance in Wounds Under High Tension.

ABSTRACT: The purpose of this study was to introduce a modified suture technique and to compare its effects on skin scar formation with 2 traditional suture methods: simple interrupted suture (SIS) and vertical mattress suture (VMS). Three groups of healthy adult female Sprague-Dawley rats were selected (6 replicates in each group), and the full-thickness skin of 5 cm × 0.2 cm was cut off on the back of the rats after anesthesia. The wounds were then sutured using 1 of the 3 methods for each group: SIS, VMS, and a newly introduced modified vertical mattress suture (M-VMS) technique with the needle reinsertion at the exit point. A traction device was installed on the back of the rats to achieve high tension wounds. The tensile distance was increased by 1 mm every day for 20 days. After 20 days of healing, the hematoxylin-eosin staining method was used for observation of scar morphology. The collagen production rate was measured by Masson staining, and the type I collagen and type III collagen were detected by the immunofluorescence method. Immunohistochemical staining was used to detect the expression of myofibroblast marker α-smooth muscle actin, and real-time quantitative polymerase chain reaction and Western blot techniques were used to detect the expressions of transforming growth factors TGFß1, TGFß2, and TGFß3 to understand the mechanisms of scar formation. Results showed that the quantity and density of collagen fibers were both lower in the M-VMS group than in the other 2 groups. Immunofluorescence results showed that type I collagen was significantly lower, whereas type III collagen was significantly higher in the M-VMS group than in the other 2 groups. The expressions of α-smooth muscle actin and TGFß1 both were lower in the M-VMS group than in the other 2 groups. The expression of TGFß2 and TGFß3 had no obvious difference among the 3 groups. For wounds under high tension, compared with SIS and VMS methods, the M-VMS technique we proposed can reduce scar formation due to the reduction of collagen formation, myofibroblast expression, and TGFß1 expression.

[Vascular anatomy and clinical application of type â ¢ perforator flap based on the oblique branch of lateral circumflex femoral artery].

OBJECTIVE: To investigate the vascular anatomy and the clinical application of type Ⅲ perforator flap based on the oblique branch of lateral circumflex femoral artery on skin soft tissue defect at the limbs. METHODS: Vascular anatomy of anterolateral thigh flap was performed on a 43-year-old male cadaver perfused with red latex, and the travel and perforating distribution of the oblique branches of lateral circumflex femoral artery were observed. A retrospective case series study was used to analyze the clinical data of 12 patients with skin soft tissue defects of the extremities admitted between January 2018 and September 2019, including 9 males and 3 females; aged from 18 to 65 years, with a median age of 32 years. The injury site included 7 cases of foot and ankle, 3 cases of calf, and 2 cases of hand. The wound size was ranged from 9 cm×7 cm to 28 cm×10 cm. The time from injury to operation was 1-2 weeks, with an average of 10 days. All patients were repaired with type Ⅲ perforator flap based on the oblique branch of lateral circumflex femoral artery, including 3 cases of single-leaf flap, 6 cases of double-leaf flaps, and 3 cases of tri-leaf flaps. The flap ranged from 15 cm×5 cm to 28 cm×10 cm. The donor site was directly sutured or repaired with local flap. The flap survival and complications were observed after operation. RESULTS: The results of vascular anatomy showed that the lateral femoral circumflex artery sent out transverse branches, oblique branches, and descending branches. The oblique branches sent out multiple muscle perforating branches along the way, the perforating branches passed through the anterolateral femoral muscle, and the blood supply scope was the skin of the anterolateral femoral region. The clinical results showed that all flaps survived completely and the incisions healed by first intension. There was no complication such as vascular crisis. All 12 patients were followed up 3-12 months, with an average of 7 months. The appearance and texture of the flap were good. At last follow-up, according to the British Medical Research Council (BMRC) Society for neurological trauma standard, the sensory of the flap reached S 2 in 9 cases and S 3 in 3 cases. Linear scar remained in the donor area, without pain, pruritus, tactile allergy, and other discomfort. The patients and their families were satisfied. CONCLUSION: Type Ⅲ perforator flap based on the oblique branch of lateral circumflex femoral artery is a reliable method for repairing the soft tissue defect of the limbs, with reliable blood supply, large cutting area, various types of perforator flaps.