New near-infrared emissions and energy transfer in Er3+ -doped MgAl layered double hydroxides.

A series of Er3+ -doped magnesium aluminium layered double hydroxides (Er3+ -doped, MgAl-LDHs) with different Mg2+ /(Al3+ +Er3+ ) molar ratios were synthesized using the hydrothermal method. Compositional and structural analyses suggest that the Er3+ -doped MgAl-LDHs kept a hexagonal structure while the Mg2+ /(Al3+ +Er3+ ) molar ratio was at 1.0-4.1. The downconverted emission spectra of the Er3+ -doped MgAl-LDHs showed a red emission at 650 nm and strong infrared emissions at 720, 780, and 850 nm. These infrared emissions were hardly observed in previous downconverted emission spectra of Er3+ -doped materials. In the analysis of the Er3+ energy levels and in relevant published literature, the energy transfer diagram for Er3+ -doped in MgAl-LDHs is described, and infrared emissions at 720, 780, and 850 nm may be attributed to 4 F7/2 →4 I13/2 , 2 H11/2 →4 I13/2 , and 4 S3/2 →4 I13/2 transitions of Er3+ , respectively. Er3+ -doped MgAl-LDHs could have potential application as marking and targeting agents in the processes for drug delivery in consideration of the strong near-infrared Er3+ emissions, as well as the special layered structure of MgAl-LDH.

[The changes and significance of red cell nature-immune-adhesion function in liver diseases at different stages].

OBJECTIVE: To study the changes of red cells nature immune adhesion function (RNIAF) in liver diseases at different stages, and the feasibility of RNIAF in evaluating the severity of liver diseases. METHODS: Venous blood was extracted from 682 patients with liver disease, including cirrhosis, chronic hepatitis, acute hepatitis, hepatitis gravis, and 50 healthy blood donors as controls. Suspension of red cells in self-plasma was mixed with solution of mouse ascites carcinoma cells. A tumor cell attached with 5 red cells or 2 lymphocytes/granulocytes was counted as one rosette. The adhesion rate was calculated. Serum soluble complement receptor 1 (sCR1) was measured with a newly established sandwich enzyme-linked immunosorbent assay (ELISA). The CR1 expressed on erythrocytes has assayed by cell-ELISA. RESULTS: The expression of CR1 on erythrocytes was lower among the patients with liver diseases. Compared with that in healthy controls, RNIAF decreased among the patients with various liver diseases (all P < 0.01) in the order of acute hepatitis, chronic hepatitis, cirrhosis Child's A, cirrhosis Child's B, cirrhosis Child's C, and hepatitis gravis. CHE and PTA decreased and PT increased among the patients with cirrhosis and hepatitis gravis (all P < 0.05 or P < 0.01). RNIAF was positively correlated with CHE, PT, and PTA in patents with cirrhosis. CHE, PT and PTA remained at low levels while RNIAF almost returned to its normal level in the convalescents of hepatitis gravis. CR1 expressed on erythrocytes and sCR1 in serum in various liver diseases were decreased at different degrees, however, they changed significantly later than RNIAF. Serum sCR1 significantly increased in the patients with cirrhosis, particularly in those in grades Child's A to C. CONCLUSION: Low-cost, easy to operate and with early change and stable results, RNIAF may be used as an important indicator to evaluate the severity of liver diseases. of CHE, PT/PTA. It is an important to evaluate the severity of liver function in clinic.