[Clinical application of laser in crown lengthening].

Crown lengthening is one of the most common surgeries in clinical practice. Under the premise of ensuring the biologic width, the adequate crown is exposed by resecting the periodontal soft tissue and (or) hard tissue to meet the prosthodontic and (or) aesthetic requirements. Considering the various advantages of oral laser, such as safe, precise, minimally invasive and comfort, laser has become a promising technology which can be used to improve the traditional crown lengthening. In this review, the principles and characteristics of laser application in crown lengthening, especially in the minimally invasive or flapless crown lengthening will be reviewed. Its pros and cons will also be discussed.

[Effect and mechanism of astragaloside â £ on Toll-like receptor pathway in fibrotic mice after renal ischemia-reperfusion].

The aim of this paper is to study the effect of astragaloside Ⅳ on renal fibrosis mice with ischemia-reperfusion injury (IRI) and discuss the mechanism. Male C57BL/6 50 mice were randomly divided into four groups, namely Sham-operated group, model group, AS-Ⅳ prevention group and AS-Ⅳ treatment group. Since the day of surgery, the mice in astragaloside Ⅳ prevention group were treated with astragaloside Ⅳ by gavage for 30 days at the dose of 30 mg·kg⁻¹·d⁻¹. At the 60th day after surgery, the mice in astragaloside Ⅳ treatment group were treated with astragaloside Ⅳ 100 by gavage for 30 days at the dose of 30 mg·kg⁻¹·d⁻¹. The mice in Sham-operated group and model group were treated with double distilled water containing 0.1% ethanol instead of astragaloside Ⅳ. Serum creatinine and blood urea nitrogen were detected by chemical methods. Histopathological changes and collagen deposition of affected kidneys were observed under optical microscope by HE and Masson staining. The expression levels of Toll like receptor pathway related molecules (TLR4,MyD88,TRAF6,TRAM,TRIF,NF-κB,TNF-α,IL-6, IFN-γ) in affected kidneys were observed by immunohistochemistry, Western blot methods and reverse transcription-PCR atprotein and mRNA levels in each group. The results showed that the degrees of fibrosis and histopathological damage of affected kidneys of mice in model group were the most obvious. And the expression levels of TLR4/MyD88 dependent signaling pathway-related molecules (TLR4 and MyD88, TRAF6 and NF-κB) in affected kidneys of mice in model group were the highest. At the same time, there was no difference in the expression levels of TLR4/MyD88 independent signaling pathway-related molecules（TRAM, TRIF）among sham-operated group, model group, astragaloside IV prevention group and astragaloside Ⅳ treatment group. In astragaloside Ⅳ prevention group and astragaloside Ⅳ treatment group, the injury of affected kidney was obviously reduced, and the protein expression levels of TLR4/MyD88 dependent signaling pathway-related molecules were also correspondingly reduced; at the same time, the expressions of terminal inflammatory cytokines (TNF-α,IL-6, IFN-γ) were suppressed. Therefore, astragaloside Ⅳ may improve renal interstitial fibrosis in mice after IRI by inhibiting the expression of TLR4/MyD88 dependent signaling pathway and the release of inflammatory cytokines (TNF-α,IL-6, IFN-γ), while the TLR4/MyD88 independent signaling pathway may not be involved in the process of renal fibrosis after ischemia-reperfusion injury.

SMART Design of a Bulk-Capped Supramolecular Segment for the Assembly into Organic Interdigital Lipid Bilayer-Like (ILB) Nanosheets.

Rational molecular design for the organic nanocrystal morphology still remains a challenge due to the structural diversity and complicated weak intermolecular interactions. In this work, a typical attractor-repulsor molecule N,N-diphenyl-4-(9-phenyl-fluoren-9-yl) phenylamine (TPA-PF) is designed to explore a general assembly strategy for 2D nanocrystals. Via an interdigital lipid bilayer-like (ILB) molecular packing mode, large-sized lamellar 2D nanosheets are obtained with a length:width:thickness ratio as ≈2500:1000:1. The d-spacing of the largest (001) plane is 1.32 nm, which equals to the thickness of a single interdigital stacking layer. The synergetic effect of the attractive supramolecular segment (TPA) and the repulsive bulky group (PF) is supposed to be the critical factor for the ILB packing that leads to the 2D structures. The attractor-repulsor molecule design is expected to be an effective strategy for the growth of 2D nanocrystals based on small organic molecules.