Large and fast single-crystal resistive humidity sensitivity of metal pnictide halides containing van der Waals host-guest interactions.

Two new metal pnictide halides, (Hg(9.75)As(5.5))(GaCl4)3 and (Hg13Sb8)(ZnBr4)4, have been prepared by solid-state reactions. Their structures feature 3D cationic host frameworks built of mercury pnictide polyhedra and form 1D tunnels filled with discrete guest halide polyanions; the guests and hosts are assembled by van der Waals interactions. Both complexes exhibit good single-crystal humidity sensitivity, with a humidity sensitivity factor as big as three orders of magnitude, a quick resistance response, fast recovery, and good reproducibility. This study provide a new way to design promising resistive humidity detectors by introducing van der Waals host-guest interactions into their structures.

[Changes of lens capsule after phacoemulsification].

OBJECTIVE: To observe the changes in the lens capsule after phacoemulsification and its effects on the position of intraocular lens (IOL) and to demonstrate the best position of IOL in relation to the anterior capsule. METHODS: The present series comprised 141 eyes in 127 patients underwent phacoemulsification and foldable lens implantation with 5 mm continuous curvilinear capsulorhexis. The changes in the lens capsule and the position of IOL with dilated pupil were observed using slit lamp microscope 3 months after the operation. RESULTS: Capsular bag shrinkage and white Soemmering ring along the margin of capsulorhexis were observed in all cases. Three different kinds of relationship between anterior capsule opening and the IOL optic surface were found, including the non-capture (68 eyes), partial-capture (52 eyes) and total-capture (21 eyes) relationships. The incidence of central posterior capsule opacification (PCO) was significantly higher in the total-capture group (47.6%) than that in the non-capture (11.7%) and partial-capture (21.2%) groups (P < 0.01). IOL in well centered position was significantly higher in the non-capture (91.2%) and total-capture (81.0%) groups than that in the partial-capture group (42.3%) (P < 0.01). CONCLUSION: In the present study, various changes in the lens capsule were observed after phacoemulsification and foldable lens implantation. It is suggested that keeping the IOL in a non-capture position is a key point to avoid the occurrence of PCO and IOL decentration.

[Effects of exogenous p21 gene on cells cycle of human lens epithelial cells].

OBJECTIVE: To investigate the effects of transfected exogenous p21 gene on the cells cycle of HLE-B3 cells line. The feasibility of prevention of secondary cataract by gene therapy was evaluated. METHODS: Total length of human p21 gene cDNA was cloned on the parent's plasmid pcDNA3 to construct the recombinant plasmids of pcDNA3/p21, a large amount of pcDNA3/p21 plasmid DNA was prepared by QIAGEN endofree maxi kit. After harvest of the plasmid DNA, the HLE-B3 cells line was transfected. The cell growth was observed and the cells cycle was analyzed by flow cytometry. The expression of p21 mRNA was detected by RT-PCR and the expression of p21 protein was detected by immunohistochemistry and western blot analysis. RESULTS: Forty eight hours after transfection, the growth of transfected cells became slower, some cells floated and died; the control cells and blank plasmid (blank pcDNA3) transfected cells grew normally. Flow cytometry analysis revealed that the number of cells in G(1) phase increased markedly in transfected cells. The RT-PCR showed that the product of p21 in the transfected cells (dead or alive cells) was obviously higher than that of the controls. Immunohistochemical studies showed few positive cells in the controls, and very high positive signal was detected after transfection. Western blot showed a positive band at the level of 21 000 in transfected cells, no positive band could be found in the controls. CONCLUSION: Exogenous p21 gene can transfect the HLE-B3 cells and can be expressed. The transfection can affect the cells cycle by G(1) arrest and induces cells death through the apoptosis process. This result suggests that it is possible to prevent the occurrence of secondary cataract by gene therapy.