BACKGROUND:The degradable poly-L-lactic acid (PLLA) biliary-enteric composite stent has been developed. OBJECTIVE:To analyze the solubility and biocompatibility of the degradable PLLA biliary-enteric composite stent. METHODS:Solubility:the PLLA composite stent was implanted into artificial gastric acid to detect the dissolution rate within 12 weeks. Pyrogen test:the PLLA composite stent extracts were injected into the rabbits via ear vein to detect the changes of body temperature. Hemolysis test:the PLLA composite stent extracts, normal saline and distil ed water were added into the rabbit anticoagulant, respectively, to detect the hemolysis ratio. Cytocompatibility test:Caco-2 cel s were respectively cultured in the DMEM medium containing 10%fetal bovine serum, rubber material extracts and the PLLA composite stent extracts, and the cel proliferation was detected at 12, 24, 36 and 48 hours;the lactic dehydrogenase release was detected at 2 days. RESULTS AND CONCLUSION:The PLLA composite stent showed a long stability in vivo, and approximately 80%was dissolved at about 20 weeks. No reactions of pyrogen and henolysis were observed in the pyrogen and hemolysis tests. The PLLA composite stent made no effects on the Caco-2 cel proliferation and lactic dehydrogenase release. In conclusion, the PLLA composite material holds a good solubility and cytocompatibility.

OBJECTIVETo evaluate the effect of pretreatment with ethanol on dentin to compensate premature volatilization of self-etch adhesive system.

METHODSThirty-two intact human molars were randomly divided into two groups using a table of random numbers (n = 16): A, an acetone-base adhesive (G-bond) and B, an ethanol-based adhesive (Clearfile S(3) bond). Then each group was randomly assigned into foursub groups (n = 4) : group 1, no premature volatilization; group 2, premature volatilization; group 3, premature volatilization + stepwise ethanol pretreatments; and group 4, premature volatilization + absolute ethanol treatment. After composite resin building, microtensile bond strengths (MTBS) of each subgroup were then tested. Fracture modes were classified by stereomicroscopy and representative interface was observed by field-emission scanning electron microscopy (FE-SEM).

RESULTSFor adhesive A, there was significant difference on MTBS among different subgroups (P < 0.05); the MTBS of group A2 [(26 ± 12) MPa] and A4 [(27 ± 7) MPa] was lower than that of group A1 [(41 ± 11) MPa] and A3 [(40 ± 11) MPa] (P < 0.05). No significant different was found between group A2 and A4 (P > 0.05); neither between group A1 and A3 (P > 0.05). For adhesive B, there was no difference on MTBS among different subgroups (P > 0.05).FE-SEM showed that the main fracture mode was located at the bottom of the hybrid layer for adhesive A groups, the collagen fibrils were capsulated by resin monomers more densely in group A1 and group A3 in comparison with other two subgroups.For adhesive B groups, the main failure modes were at the top of the hybrid layer.

CONCLUSIONSPremature volatilization can obviously decrease the bonding strength of acetone-base self-etch adhesives, but has no significant effect on ethanol-based self-etch adhesives. Dentin pretreatment with a series of increasing ethanol concentrations can effectively compensate the adverse effect of premature volatilization of acetone-base self-etch adhesives on bonding strength.

Adhesives ; Composite Resins ; Dental Bonding ; Dental Materials ; Dental Stress Analysis ; Dentin ; Dentin-Bonding Agents ; Ethanol ; chemistry ; Humans ; Methacrylates ; Microscopy, Electron, Scanning ; Molar ; Resin Cements ; Tensile Strength ; Volatilization

Objective: To improve the clinician′s recognition of Gerstmann-Sträussler-Scheinker syndrome (GSS). Methods: The detailed clinical information, neuropsychological examination, cerebrospinal fluid examination, imaging characteristics, electroencephalogram examination and gene detection were analyzed in a case of GSS similar to Creutzfeldt-Jakob disease (CJD) in symptomatology. The differences between the two different prion diseases were compared in combination with the literature review. Results: The patient is a 62-year-old woman, with cerebellar ataxia as the first symptom, followed by rapid dementia, accompanied by pyramidal and extrapyramidal signs. Magnetic resonance imaging showed hyper-intense signal in diffusion weighted imaging in caudatum and cortical ribboning, and protein 14-3-3 was negative. PRNP gene analysis showed P102L gene mutation. Conclusions The typical clinical manifestation of GSS is hereditary ataxia followed by cognitive decline of varying severity. Detection of PRNP plays an important role in the diagnosis of GSS.

In the past ten years, the research and application of microbiome has continued to increase. The microbiome has gradually become the research focus in the fields of life science, environmental science, and medicine. Meanwhile, many countries and organizations around the world are launching their own microbiome projects and conducting a multi-faceted layout, striving to gain a strategic position in this promising field. In addition, whether it is scientific research or industrial applications, there has been a climax of research and a wave of investment and financing, accordingly, products and services related to the microbiome are constantly emerging. However, due to the rapid development of microbiome sequencing and analysis related technologies and methods, the research and application from various countries have not yet unified on the standards of technology, programs, and data. Domestic industry participants also have insufficient understanding of the microbiome. New methods, technologies, and theories have not yet been fully accepted and used. In addition, some of the existing standards and guidelines are too general with poor practicality. This not only causes obstacles in the integration of scientific research data and waste of resources, but also gives related companies unfair competition opportunity. More importantly, China still lacks national standards related to the microbiome, and the national microbiome project is still in the process of preparation. In this context, the experts and practitioners of the microbiome worked together and developed the consensus of experts. It can not only guide domestic scientific research and industrial institutions to regulate the production, learning and research of the microbiome, the application can also provide reference technical basis for the relevant national functional departments, protect the scale and standardized corporate company's interests, strengthen industry self-discipline, avoid unregulated enterprises from disrupting the market, and ultimately promote the benign development of microbiome-related industries.
China ; Consensus ; Humans ; Industry ; Microbiota