A review: structure-activity relationship between saponins and cellular immunity.

Saponins, which exhibit many different biological and pharmacological activities, are present in a wide range of plant species and in some marine organisms. Notably, the researchers have found that saponins can activate the immune system in mammals. The strength of this function is closely related to the chemical structure of saponins. The present study of the structure-activity relationship suggests that aglycones, glycochains on aglycones and special functional groups of saponins affect the immune activity of saponins. This paper reviews the effects of different saponins on cellular immunity. As well as the structure-activity relationship of saponins. It is hoped that the information integrated in this paper will provide readers with information on the effects of saponins on cellular immunity and promote the further study of these compounds.

Application and mechanism of probiotics in skin care: A review.

BACKGROUND: Skin problems have been the focus of attention in recent years. Skin aging, wrinkles, pigmentation, dryness has been a problem that makes people feel troubled. Researchers have been devoted to find ways to solve these skin problems. Micro-ecological skin care is a popular concept these days, and improving skin health through the use of probiotics is a hot topic of discussion. OBJECTIVE: Many experimental studies have shown that probiotics have a good effect on improving skin problems. This paper aims to comprehensively review the application and mechanism of probiotics in skin care and provide theoretical basis for the application of probiotics in skin care. METHODS: Literatures in this review were searched in PubMed, China National Knowledge Infrastructure (CNKI), Web of Science, and Science Direct. RESULTS: Probiotics have potent effects on skin whitening, moisturizing, anti-aging, anti-wrinkle and removing body odor. CONCLUSIONS: The effects of probiotics on skin whitening, skin moisturizing, anti-aging, improving skin wrinkles and removing body odor were reviewed, which provided a new basis for the extensive application of probiotics in skin care.

Development of Environmentally Friendly Atom Transfer Radical Polymerization.

Atom transfer radical polymerization (ATRP) is one of the most successful techniques for the preparation of well-defined polymers with controllable molecular weights, narrow molecular weight distributions, specific macromolecular architectures, and precisely designed functionalities. ATRP usually involves transition-metal complex as catalyst. As the most commonly used copper complex catalyst is usually biologically toxic and environmentally unsafe, considerable interest has been focused on iron complex, enzyme, and metal-free catalysts owing to their low toxicity, inexpensive cost, commercial availability and environmental friendliness. This review aims to provide a comprehensive understanding of iron catalyst used in normal, reverse, AGET, ICAR, GAMA, and SARA ATRP, enzyme as well as metal-free catalyst mediated ATRP in the point of view of catalytic activity, initiation efficiency, and polymerization controllability. The principle of ATRP and the development of iron ligand are briefly discussed. The recent development of enzyme-mediated ATRP, the latest research progress on metal-free ATRP, and the application of metal-free ATRP in interdisciplinary areas are highlighted in sections. The prospects and challenges of these three ATRP techniques are also described in the review.

Facile Synthesis of Ultrahigh Molecular Weight Poly(Methyl Methacrylate) by Organic Halides in the Presence of Palladium Nanoparticles.

A facile and versatile approach for the synthesis of ultrahigh molecular weight poly(methyl methacrylate) (PMMA) at mild conditions was developed. Certain organic halides combined with a catalytical amount of palladium nanoparticles (Pd NPs) were found to be very effective in initiating polymerizations of methyl methacrylate (MMA), methyl acrylate, vinyl acetate and other vinyl monomers. An ultrahigh molecular weight PMMA with a number-average molecular weight of 4.65 × 106 Da and a weight-average molecular weight of 8.08 × 106 Da was synthesized at 70 °C using 2-bromoisobutyric acid ethyl ester (EBiB) as an initiator in the presence of catalytical amount (10.1 ppm) of Pd NPs. A kinetic investigation found that the orders of polymerization with respect to EBiB, Pd NP and MMA were 0.23, 0.50, and 0.58, respectively. Proton nuclear magnetic resonance (1H NMR) combined with matrix-assisted laser desorption ionization time of flight mass spectroscopy (MALDI-TOF) and gel permeation chromatography (GPC) were used to prove that the macromolecular chain had an end-group of EBiB residue. The electron spin resonance (ESR), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS) results reveal that the reaction of EBiB with Pd NPs caused a bromo atom (Br) transfer from EBiB to Pd NPs and resulted in the generation of EBiB residue radical to initiate the polymerization of MMA and the formation of PdIIBr2 on the surface of Pd nanoparticles.

[Comparative study of the condylar positions in different sagittal skeletal facial types with cone-beam computed tomography].

OBJECTIVE: To investigate the differences in the condylar position of subjects with skeletal class I and skeletal class II. To provide a basis of diagnosis and treatment. METHODS: Group A was composed of 50 subjects with skeletal class I (27 males and 26 females; age range = 18 years to 30 years; mean age=26 years). Group B comprised 50 subjects with skeletal class II (24 males and 26 females; age range = 18 years to 28 years; mean age=25 years). The condylar position and the shapes of the condyle and the glenoid fossa were linearly measured on the sagittal and coronal sections by cone-beam computed tomography (CBCT). Data were analyzed by SPSS 19.0. RESULTS: No statistically significant differences were found in the measurements of the condylar position between the sides of each group on the sagittal plane and the coronal plane (P > 0.05). There were significant differences on the anterior space and the posterior space between group A and B (P < 0.05). The A/P joint space ratio of group A was larger than that of group B (P < 0.05). CONCLUSION: The subjects of skeletal class I show an anterior condyle position. The subjects of skeletal class II show a posterior condyle position.