Objective: To design and develop a preadjusted appliance based on Chinese normal occlusion, and to apply it in treatment of malocclusion cases.Methods: According to the results of the research performed in Department of Orthodontics, School of Stomatology of Peking University about teeth position and morphology of 67 Chinese with normal occlusion, the preadjusted appliance with the optimal prescription for Chinese has been designed and developed (Z1 appliance). Z1 appliance has been used in treatment of malocclusion cases. The efficiency of Z1 appliance was evaluated. Results:The treatment of 30 non-extraction cases and 16 extraction cases has been completed with Z1 appliance. A quite good result of clinical application of Z1 appliance was represented. Conclusion: Z1 appliance could be used in treatment of Chinese malocclution. The bracket base for anterior teeth was too thick and need more improvement.

Objective:To investigate the relationship between surface hydrogen form and the bioactivity of titanium.Methods:Sandblast titanium was etched with the combination of sulfuric and hydrochloric acids(SLA group,n=3 ).Then etched titanium was heat at 450 ℃in air(SLA+HT group,n=3).Surface topography,roughness,hydrophility,surface chemical texture were observed. Finally,the titanium samples were soaked in body simulate fluid for 3 days,the mineral deposition properties were observed by X-ray diffraction.Results:Titanium hydride was formed on the titanium surface after etching.After heat treatment,surface texture and roughness were not changed,titanium hydride decomposed and hydrophility increased.More hydroxyapatite was found on the surface of the samples treated by SLA+HT and followed by SBF.Conclusion:Titanium hydride can not improve the bioactivity of titanium, heat treatment may increase the mineralization.

This study was aimed to establish a method for sensorial color digitalization of Chinese herbal medicines (CHMs) with the application of spectrocolorimeter. The discussion was focused on difficulties of distinguishing surface and section color of CHMs. Based on uniform color space system of CIE1976L*a*b*, two methods for determination of section and surface color were constructed with two different kinds of spectrocolorimeters taking Glycyrrhizae Radix et Rhizoma as the experimental objective. In this paper, different kinds of sample preparation methods were used. Based on results, the method of scraping and grinding was proposed to prepare samples for section color determination. The method of wet pressing and peeling was proposed to prepare samples for surface color determination. Besides, RSD and dE*ab were served as evaluation indexes. This paper provided a simple, rapid and reliable analysis method for the color determination of CHMs. It also gave insight to future research on digitalization and modernization of CHMs' organoleptic characteristics based on traditional macroscopic identification.

Glycyrrhizae Radix et Rhizoma is one of the traditional herbal medicine used in China, study on the correlation between the cross-section color and HPLC fingerprints of them have important significance for promoting the development of traditional disciplines. Quantitative analysis of the color of sample cross section was carried out by color digital method, fingerprint analysis was carried out by HPLC, and the canonical correlation analysis was carried out between them. The results showed that there was a significant correlation between the color of Glycyrrhizae Radix et Rhizoma cross section and the information of HPLC fingerprinting. Results indicated that, The digitized indexes of color of cross section could reflect the result of fingerprint analysis to some extent.

This study was aimed to establish an objective and convenient method to evaluate the quality of licorice through the study on correlation between the cross section color and contents of active ingredients of licorice.Therefore,colorimeter was introduced and applied to determinate cross section color of licorice.Meanwhile,contents of five active ingredients of licorice were also determined.HPLC was used to determine liquiritin and glycyrrhizic acid.Colorimetric method was used to determine total saponins.Ultraviolet spectrophotometry was used to determine total flavonoids.Sulphuric acid-phenol colorimetry was used to determine polysaccharides.Correlation between the cross section color and content determination result was analyzed.The results showed that the correlation coefficient of glycyrrhizic acid content and L* was-0.578,P ＜ 0.001,the correlation coefficient with b* was 0.596,P ＜ 0.001;the correlation coefficient of liquiritin content and L* was-0.503,P =0.002,the correlation coefficient with b* was 0.890,P ＜ 0.001;the correlation coefficient of total flavonoids content and L* was-0.729,P ＜ 0.001,the correlation coefficient with b* was 0.724,P ＜ 0.001;the correlation coefficient of polysaccharides content and L* was 0.230,P =0.190,the correlation coefficient with b* was-0.390,P =0.023;the correlation coefficient of total saponins content and L* was-0.411,P =0.016,the correlation coefficient with b* was 0.738,P ＜ 0.001.It was concluded that the cross section color index of licorice has significant correlation with contents of glycyrrhizic acid,liquiritin,total flavonoids and total saponins.There was no significant correlation with content of polysaccharides.It illustrated the close correlation between cross section color of licorice and its active ingredients.Through the digitalized determination on color,contents of chemical composition in licorice can be initially determined or predicted objectively.It provided a new idea and method for the quality evaluation of Chinese herbal medicine.

BACKGROUND: The silk fibroin/type II collagen composite scaffold has been prepared by low-temperature bio-3D printing technology in the previous study and the scaffold has good mechanical properties. Studies have shown that mechanical stimulation is beneficial to bone remodeling, and gradient loading strain is beneficial to the activation of osteoblasts and osteoclasts. OBJECTIVE: To co-culture silk fibroin/type II collagen composite scaffolds with chondrocytes under compression loading, to observe the proliferation of cells, and to observe the preliminary repair effect of silk fibroin/type II collagen composite scaffold on cartilage defects. METHODS: The silk fibroin/type II collagen composite scaffold was prepared by low-temperature 3D printing to detect the porosity of the scaffold. The passage 3 mouse chondrocytes ADTC-5 were inoculated on the silk fibroin/type II collagen composite scaffold and cultured under static culture and mechanical load respectively. (1) Static culture: blank scaffold was set as control, and cell proliferation was detected by MTT assay at 1, 3, 5, 7, 10, 14 days of inoculation. (2) Culture under mechanical load: blank scaffold was set as control. At 1 day after inoculation, 0％, 1％, 5％, 10％, 15％, 20％ compressive strains were applied to the cell-scaffold complex, and continued to load for 3 days. Cell proliferation was detected by MTT assay, and the distribution, adhesion and morphology of the cells on the scaffold were observed by scanning electron microscopy and hematoxylin-eosin staining. A cartilage defect of 3.5 mm in diameter was made in the bilateral knee joint of New Zealand rabbits. The silk fibroin/type II collagen composite scaffold was implanted onto the left side, and no material was implanted onto the right side. The repair site was observed at 8 weeks after surgery. RESULTS AND CONCLUSION: (1) The porosity of the scaffold was (89.3±3.26)％, which was conducive to cell attachment. (2) After 5 days of static culture, the chondrocytes proliferated well on the surface of the composite scaffold. Under 0％, 1％, 5％, 10％, 15％, 20％ compressive strains, the cell proliferation on the scaffold first increased and then decreased, wherein the cell proliferation was highest under 10％ compressive strain, and lowest under 20％ compressive strain. (4) Under the scanning electron microscopy, the chondrocytes in the 0％ load group were distributed in the surface of the scaffold with irregularities, the cell morphology was obvious, and the cell protrusions were fully extended. There were few or no chondrocytes on the contact surface of the 10％ load group, and more cells distributed on the lateral and internal surfaces of the first layer, but the cell morphology was flat with obvious protrusions. (5) Hematoxylin-eosin staining showed that the chondrocytes in the 0％ load group were concentrated on the surface of the scaffold, and there were almost no cells in the pores, while the chondrocytes in the 10％ load group were distributed in the scaffold pores. (6) There was still a circular defect model with no scaffold implantation, and no obvious repair appeared; similar hyaline cartilage appeared in the defect after scaffold implantation, but there was no adhesion to the surrounding defected cartilage, and the new hyaline cartilage was independent. Overall, the adsorption, proliferation and growth of chondrocytes on the silk fibroin-type II collagen scaffolds is better when the compressive strain is 10％, and the composite scaffold can be used as a repair material for cartilage defects.

OBJECTIVETo investigate the effects of β-elemene in suppressing the proliferation and apoptosis of SGC7901 gastric cancer cells in vitro and explore the underlying mechanisms.

METHODSUsing MTT assay, flow cytometry, and clonogenic survival assay, we assessed the effects of β-elemene on the viability, apoptosis, cell cycle distribution, and clonogenic survival of gastric cancer SGC7901 cells and gastric mucosal epithelial GES-1 cells. Western blotting was employed to determine the changes in the protein expression profiles in SGC7901 cells in response to β-elemene treatment.

RESULTSβ-elemene significantly suppressed the cell viability and increased the apoptosis of SGC7901 cells, and these effects were less obvious in GES-1 cells. β-elemene decreased clonogenic survival of SGC7901 cells, increased the proportion of G2/M phase cells, decreased the expression of Bcl-2, and increased the expression of Bax and cleaved caspase-3. β-elemene did not obviously affect the expression of total p21-activated protein kinase 1 (Pak1) but decreased the level of phospho-Pak1 (Thr423) and phospho-ERK1/2 (Thr202/Tyr204) in SGC7901 cells.

CONCLUSIONβ-elemene inhibits the proliferation and induces apoptosis of gastric cancer cells possibly by inhibiting Pak1/ERK signaling and regulating apoptosis-associated proteins such as Bcl-2 and Bax.

Apoptosis ; Apoptosis Regulatory Proteins ; metabolism ; Cell Cycle ; Cell Division ; Cell Line, Tumor ; drug effects ; Cell Proliferation ; Cell Survival ; Humans ; Sesquiterpenes ; pharmacology ; Signal Transduction ; Stomach Neoplasms ; pathology

The rapid absorption of labial alveolar bone after tooth extraction not only reduces the aesthetic effect of implant repair but also affects the long-term success rate of implants. The socket shield technique is reported as the latest alveolar preservation technique in the aesthetic zone from both domestic and international case reports and shows a high success rate of short-term osseointegration and excellent aesthetic effects. However, some investigations have shown short- and long-term complications with the socket shield technique, such as failure of osseointegration, loss of crestal bone and buccal bone, inflammation, etc. In this review, the socket shield technique will be reported in detail with its pros and cons. Although the socket shield technique has achieved good clinical effects and short-term success rates in many cases, there are still no conclusions regarding the surgical procedure, such as the thickness, the position of the shield, whether to put the graft material between the shield and implant, etc. Due to the lack of long-term research or a large amount of clinical literature support and technical sensitivity, the socket shield technique should be carefully used in clinical application to reduce unexpected risks.

Objective: To investigate the effect of pure titanium surface of large diameter TiO2 nanotubes modified by RGD peptide on the adhesion and proliferation of MG63 osteoblasts. to provide theoretical proof for developing titanium implants. Methods: Commercially pure titanium discs were divided into four groups and treated with SLA to obtain a microrough surface (SLA group). Then, nanotubes were imposed on this microrough surface by anodization (SLA+80 group). The surface was then modified by dopamine (DOPA) (DOPA Group), after which bioactive RGD peptide layers were generated on the TiO2 nanotube surfaces via electrochemical and molecular self-assembly techniques (RGD group). The titanium surface morphology and elemental composition of each group were characterized by field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS). MG63 cells were cultured in vitro to evaluate biological activities of titanium before and after treatment, including the evaluation of early-stage cell adhesion capacity by fluorescence microscopy, proliferation capacity by MTS assay, and mRNA expression of the cell osteoblast-related genes alkaline phosphatase (ALP) and osteocalcin (OCN) by qRT-PCR. Results: FE-SEM and XPS showed that hierarchical micro/nanosurfaces decorated with TiO2 nanotubes were produced on titanium using sandblasting and large grit etching combined with anodization, dopamine was then self-polymerized to form a polydopamine film on the TiO2 nanotube surfaces, and RGD peptides were then conjugated to the polydopamine film, finally forming RGD peptide-modified bioactive layers. In vitro experiments showed that compared with the other three materials, the RGD-modified material was more conducive to cell adhesion and proliferation (P < 0.05). The expression levels of ALP and OCN mRNA in the RGD group were significantly higher than those in the SLA group and DOPA group (P < 0.05). Conclusion Hierarchical micro/nanosurfaces decorated with TiO2 nanotubes functionally modified with RGD peptides have good biocompatibility and could be used for developing titanium implants and further improving early osseointegration.

Objective To construct a two-dimensional (2D) composite membrane and a three-dimensional (3D) biomimetic scaffold by silk fibroin (SF), type I collagen (Col-I) and hydroxyapatite (HA) blends in vitro, so as to study its physicochemical properties, as well as biocompatibility and explore the feasibility of its application in tissue engineering scaffold materials. Methods 2D composite membranes and 3D scaffolds were prepared by blending SF/Col-I/HA at the bottom of cell culture chamber and low temperature 3D printing combined with vacuum freeze drying. The biocompatibility was evaluated by mechanical property testing, scanning electron microscope and Micro-CT to examine the physicochemical properties of the material, and cell proliferation was detected to evaluate its biocompatibility. Results Stable 2D composite membrane and 3D porous structural scaffolds were obtained by blending and low temperature 3D printing. The mechanical properties were consistent. The pore size, water absorption, porosity and elastic modulus were all in accordance with the requirements of constructing tissue engineering bone. The scaffold was a grid-like white cube with good internal pore connectivity; HA was evenly distributed in the composite membrane, and the cells were attached to the composite membrane in a flat shape; the cells were distributed around pore walls of the scaffold. The shape of the shuttle was fusiform, and the growth and proliferation were good. Conclusions The composite membrane and 3D scaffold prepared by SF/Col-I/HA blending system had better pore connectivity and pore structure, which was beneficial to cell and tissue growth and nutrient transport. Its physicochemical properties and biocompatibility could meet the requirements of bone tissue engineering biomaterials.