Note: Optimization and calibration for auto-cumulative flowmeter in horizontal oil-water two-phase flow

This note presented the optimization and calibration for a novel auto-cumulative flowmeter (ACF) to measure the oil flow rate in horizontal oil-water two-phase segregated flow. By using the finite element method, the electrode geometry of the probe in the ACF was designed, optimized, and simulated for oil accumulation measurement. Considering the practical application of ACF, a novel circuit for ACF with the optimized geometry of the probe was designed, simulated, and analyzed. The experiment for oil-water two-phase segregated flow with the novel circuit was carried out to calibrate the ACF. The calibration results can provide a theoretical basis and technical reference for the practical application of ACF.

Evaluation of bone matrix gelatin/fibrin glue and chitosan/gelatin composite scaffolds for cartilage tissue engineering

This study was designed to evaluate bone matrix gelatin (BMG)/fibrin glue and chitosan/gelatin composite scaffolds for cartilage tissue engineering. Chondrocytes were isolated from costal cartilage of Sprague-Dawley rats and seeded on BMG/fibrin glue or chitosan/gelatin composite scaffolds. After different in vitro culture durations, the scaffolds were subjected to hematoxylin and eosin, Masson's trichrome, and toluidine blue staining, anti-collagen II and anti-aggrecan immunohistochemistry, and scanning electronic microscopy (SEM) analysis. After 2 weeks of culture, chondrocytes were distributed evenly on the surfaces of both scaffolds. Cell numbers and the presence of extracellular matrix components were markedly increased after 8 weeks of culture, and to a greater extent on the chitosan/gelatin scaffold. The BMG/fibrin glue scaffold showed signs of degradation after 8 weeks. Immunofluorescence analysis confirmed higher levels of collagen II and aggrecan using the chitosan/gelatin scaffold. SEM revealed that the majority of cells on the surface of the BMG/fibrin glue scaffold demonstrated a round morphology, while those in the chitosan/gelatin group had a spindle-like shape, with pseudopodia. Chitosan/gelatin scaffolds appear to be superior to BMG/ fibrin glue constructs in supporting chondrocyte attachment, proliferation, and biosynthesis of cartilaginous matrix components.

Delivery of the Sox9 gene promotes chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells in an in vitro model

SRY-related high-mobility-group box 9 (Sox9) gene is a cartilage-specific transcription factor that plays essential roles in chondrocyte differentiation and cartilage formation. The aim of this study was to investigate the feasibility of genetic delivery of Sox9 to enhance chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells (hUC-MSCs). After they were isolated from human umbilical cord blood within 24 h after delivery of neonates, hUC-MSCs were untreated or transfected with a human Sox9-expressing plasmid or an empty vector. The cells were assessed for morphology and chondrogenic differentiation. The isolated cells with a fibroblast-like morphology in monolayer culture were positive for the MSC markers CD44, CD105, CD73, and CD90, but negative for the differentiation markers CD34, CD45, CD19, CD14, or major histocompatibility complex class II. Sox9 overexpression induced accumulation of sulfated proteoglycans, without altering the cellular morphology. Immunocytochemistry demonstrated that genetic delivery of Sox9 markedly enhanced the expression of aggrecan and type II collagen in hUC-MSCs compared with empty vector-transfected counterparts. Reverse transcription-polymerase chain reaction analysis further confirmed the elevation of aggrecan and type II collagen at the mRNA level in Sox9-transfected cells. Taken together, short-term Sox9 overexpression facilitates chondrogenesis of hUC-MSCs and may thus have potential implications in cartilage tissue engineering.

[Reaction of serum growth hormone in patients with endemic cretinism to arginine and clonidine in continuous excitement tests]

Reaction of serum growth hormone in cretins whose pituitary and thyroid function have returned to normal in IDD-control by using iodized salt to arginine and clonidine in continuous excitement tests ws observed. The result is that during the phase of clonidine excitement, serum growth hormone in cretins was obviously lower than that in normal controls and the reaction peak value, maximum increase value and reaction time all markedly lower than those of the normal controls. 3 cases (18.8%) had no excitement reaction during the phase of arginine excitement, 8 cases (50.0%) no reaction during the phase of clonidine excitement and 2 cases (12.5%) no reaction in the entire process of continuous tests. The results indicate that patients with cretinism suffer from low reserve function of pituitary growth hormone and insufficiency of synthesis even after ther thyroid function has returned to normal.