Protective Effect of Iron Oxide Nanoparticles on Periodontal Injury in Rats by Inhibiting Collagenase-1 and Alkaline Phosphatase Expression.

This study intends to assess whether iron oxide nanoparticles affect periodontal injury and collagenase-1 (COL-1), and alkaline phosphatase (ALP) in rats. In this study, the ALP activity and Col-1 concentration in rats with periodontal injury were determined.We detected the periodontal histopathological changes and expression of periodontal pocket depth (PD) and attachment loss (AL) by Hematoxylin and eosin (HE) staining.We also detected Col-1 and ALP proteins in periodontal tissues by Western blot. Real-time reverse transcription-polymerase chain reaction (RT-PCR) detected Col-1 and ALP mRNA level in periodontal tissues of rats in each group, while ALP activity and Col-1 concentration in gingival crevicular fluid in model group increased compared to sham group (P < 0.05). After intervention by iron oxide nanoparticles, ALP activity and Col-1 concentration in the gingival crevicular fluid of model rats decreased greatly (P < 0.05). The gingival atrophy was more serious in model group, and many inflammatory cells infiltrated into the tissue and destroyed the alveolar tissue. Meanwhile, the periodontal tissue from rats in intervention group was greatly improved, and the degree of alveolar bone destruction was also significantly reduced, while the PD and AL periodontal indexes were significantly inhibited (P < 0.05). The protein and relative expression showed that the protein and mRNA expressions of ALP and Col-1 in periodontal tissue from model group were lower than those in sham group (P < 0.05). After intervention by iron oxide nanoparticles, the protein and mRNA expressions of ALP and Col-1 in the periodontal tissues in intervention group increased (P < 0.05). Iron oxide nanoparticles can thus inhibit the expression of ALP and COL-1 in periodontal injury rats, and improve the periodontal injury tissue.

The position of nitrogen in N-heteropentacenes matters.

An exploratory study on novel silylethynylated N-heteropentacenes, which have their N atoms on the terminal rings of the pentacene backbone, is reported. This study leads to both p- and n-channel organic thin-film transistors with high field-effect mobility and also reveals that the position of the N atoms plays an important role in tuning the structures and properties of organic semiconductors based on N-heteropentacenes.

N-heteroquinones: quadruple weak hydrogen bonds and n-channel transistors.

This study demonstrates that the easily synthesized N-heteroquinones, having unusual quadruple weak hydrogen bonds of a DDAA-AADD pattern, can function as n-type organic semiconductors in OTFTs with high electron mobility.

Unexpected photooxidation of H-bonded tetracene.

In our attempts of tuning the molecular packing of tetracene with H-bonding, we found that tetracenediamide was much more vulnerable to photooxidation than tetracene in crystals despite their similar sensitivity to photooxidation in solution. Unexpectedly photooxidation of tetracenediamide in solution and in crystals show different regioselectivities. To explain the regioselectivity, a mechanism involving H-bonding is proposed. This study indicates that molecular packing in solid state can play an important role in solid-gas reactions.

[Treatment of upper urinary calculi with the PCNL technique (Experience of 20 years)].

OBJECTIVE: To sum up experience of 20 years for treating upper urinary calculi with percutaneous nephrolithotomy (PCNL) at our institute and assess the safety, feasibility and superiority of the technique. METHODS: We retrospectively investigated 4,014 patients suffering from upper urinary calculi, who were treated with PCNL of 4,014 cases, traditional PCNL was performed in 358, two stage "mini perc" technique in 520 and minimally invasive PCNL in 3,136. RESULTS: The success rates were 90%, 95% and 98%, the stone free rates were 82%, 86% and 91%. Major complications rates were 5.3%, 1.2% and 0.5%, respectively,with single tract in 3,027 cases and multiple tracts in 987 cases. A total of 5,571 PCNLs were performed in 4,014 patients. CONCLUSION: By improvement and innovation of this technique, percutaneous nephrolithotomy can reach the high success rate and stone free rate, with less morbidity and wide clinical indications.