فهرست مطالب q. chen

To explore the diagnosis and evaluation efficacy of liver iron concentration (LIC) based on magnetic resonance quantitative technique in liver iron overload in patients with long-term transfusion.

From November 2021 to January 2023, 30 chronic aplastic anemia (CAA) patients with long-term blood transfusion admitted to our hospital were included as the study group. Simultaneously, 20 healthy volunteers with matched gender and age were included in the control group. The serum ferritin (SF), serum iron, total iron binding capacity and transferrin saturation (TSAT) between the two groups was calculated and compared. LIC was evaluated using Liver Magnetic resonance imaging (MRI)-T2* map imaging. The correlation between LIC and SF and TSAT was analyzed, and the diagnosis value of LIC in hepatic iron overload was calculated. Low-risk patients (n=22) diagnosed with iron overload received continuous regular iron removal treatment and the SF, TSAT and LIC were measured after 6 months.

SF, TSAT and LIC were higher in CAA patients relative to the healthy controls (P<0.05). LIC was positively correlated with SF (r=0.74, P<0.001) and TSAT (r=0.67, P<0.001). The sensitivity and specificity of LIC in the diagnosis of hepatic iron overload were 80.00% and 100% based on SF, and 76.0% and 100% based on TSAT, respectively. Additionally, SF, TSAT and LIC were all declined after 6 months of treatment (P<0.05).

The detection of LIC based on MRI-T2* is an effective and non-invasive means for the assessment of liver iron load in patients with long-term transfusion.

In this paper, a new installation of flat plate deflector which attached on the bottom of the bogie frame is proposed and its anti-snow accumulation performance with different attack angles is numerically studied. The wind-snow two-phase flow in the bogie region is simulated based on the Reynolds Averaged Navier-Stokes (RANS) equations combined with the Realizable k-ε turbulence model and the Lagrangian particle phase method. The adopted numerical simulation methodology is verified and validated by comparing with previous wind tunnel tests. In this paper, three typical attack angles (30°, 60°, 90°) for deflector are studied. The results show that: the 30° case has a medium influence on the flow field and reduces snow accumulation by 35.14%; the 60° case guides the high-speed airflow downward and has the best effect with 62.46% reduction in snow accumulation; the 90° case has the smallest reduction with 20.30% in the mass. Overall, all deflectors with three different installation angles can reduce the mass of snow accumulated on the bogie surface.

Salmonella can cause serious human gastroenteritis and is frequently isolated from various food samples. The cell culturing, immunoassay, and polymerase chain reactions (PCR) are the current methods to detect such pathogenic agents. However, these methods are time-consuming and labor-intensive, and thus unavailable for rapid-monitoring of Salmonella.

This study aimed to develop an immunocapture-loop-mediated isothermal amplification (IC-LAMP) for rapid and sensitive detection of Salmonella.

Salmonella was used as antigen to produce monoclonal antibody (mAb) and mAbs were prepared via subcloning three times. The mAb 1B12 with high affinity was coated on the surface of the immuno-magnetic beads (IMBs) to capture Salmonella. The enriched products (IMBs-Salmonella) were used for LAMP using the special primers targeted the conserved invA gene of Salmonella.

The IC-LAMP was developed based on mAb 1B12 and LAMP. Targeting the conserved invA gene of Salmonella, the detection time was shortened to 50 min from three days. If the reaction contains Salmonella, the green fluorescence and the trapezoidal strip can be clearly observed. Importantly, the method combines the specificity of antibody and LAMP with a detection limit of 5 CFU/ml in artificially contaminated water and milk. The specificity of this method was demonstrated by testing other similar bacteria. The results indicate that the IC-LAMP reacts only with Salmonella and does not cross-react with other similar bacteria.

The IC-LAMP assay developed here is a rapid, sensitive, one-step-visual method to screen for the presence of Salmonella in food samples. This method is faster than traditional PCR, LAMP, and other methods, and can be used as a primary screening method for the detection.