Search

Periodontitis is a widespread disease worldwide, with the primary cause of tissue loss being an immune inflammatory response mediated by bacteria. Increasing evidence has revealed a significant correlation between mitochondrial dysfunction and the occurrence and progression of periodontitis. This paper provides a review of current research on the role of mitochondrial dysfunction in the occurrence and development of periodontitis and related therapies from the perspectives of oxidative stress, inflammatory responses, and the regulation of mitochondrial homeostasis. Mitochondria are the main source and target of cellular reactive oxygen species. Mitochondrial dysfunction can generate large amounts of reactive oxygen species, exacerbating local oxidative stress in periodontal tissues and causing cell toxicity and tissue damage. Mitochondria are also the center of cellular inflammatory responses, and the positive feedback loop of inflammation induced by mitochondrial dysfunction may explain the persistent and unresolved nature of periodontitis. Biomaterials loaded with pharmacological agents show potential in restoring mitochondrial function, controlling the development of periodontitis, and promoting periodontal tissue regeneration. However, the key sites of mitochondrial dysfunction in the occurrence and development of periodontitis are not yet fully understood, and the improvement of mitochondrial function in periodontal therapy is still in the experimental stage. Future research efforts should focus on the effect of mitochondrial dysfunction on periodontal cells and explore its specific mechanism in the occurrence and progression of periodontitis in order to provide new insights into the treatment of periodontitis.

Modified polyvinylidene fluoride (PVDF) membranes were prepared by the phase inversion method via blending in situ formed nanosilver (Ag) and nanozirconium dioxide (ZrO2). Scanning electron microscopy of the membranes revealed that the surface pore size of the membranes was increased and distributed widely with the addition of modified nanosilver (Ag) and nanozirconium dioxide (ZrO2). The pores of the membrane were reduced due to excessive modification of the material when the content of zirconium dioxide was increased to 0.4%. XRD characterization showed that in situ synthesis of nanosilver (Ag) and nanozirconium dioxide (ZrO2) had been successfully blended in the membranes. The contact angle of the modified membrane ranged from 82.72° to 67.37°, which showed that the hydrophilic properties of the membrane were improved. The pure water flux of the modified membrane increased from 28.43 to 143.2 L/m2 h, indicating that the hydrophilicity of the modified membrane was enhanced significantly. The flux recovery rate of the modified membrane was obviously increased in the fouling experiment with BSA as the source of organic pollutants. The antimicrobial contamination of the membrane was greatly enhanced with the E. coli microbial contamination experiment.

The imprinted polymers were prepared to absorb dichlorophen (DCP) by using mesoporous silica with ordered pores and high specific surface area. Both scanning electron microscopy and transmission electron microscopy results suggested that the mesoporous silica nanosphere pores had a periodic distribution. The imprinted layer of polymers was thin and uniform. The adsorption experiments showed that the adsorption of imprinted polymers was obviously improved due to the presence of mesoporous structure. The maximum adsorption capacity of MSNs@MIPs at 318 K was 91.1 mg/g, and the adsorption process rapidly reached the equilibrium within 40 min. The adsorption isotherm was well fitted by the Freundlich isotherm model, indicating that multimolecular layer adsorption mechanism governs the adsorption of DCP by the polymers. The adsorption of MSNs@MIPs complied with pseudo-second-order kinetic model. Both selective and regenerative experiments demonstrated that MSNs@MIPs can be successfully applied for selective adsorption of DCP.

In recent years, due to precise control of the amorphous mineral precursor in the demineralization of dentine collagen fibers in orderly deposition, forming apatite crystals similar to the natural mineralized dentin, the bottom-up remineralization approach which does not depend on the existence of seed crystallites, dentin biomimetic mineralization techniques gradually become a hotspot in the research field of restoration of demineralized dentin caused by dental caries. This paper reviews the changing concepts and practices of the remineralization of demineralized dentin, emphasizing biomimetic remineralization studies. The results of the literature review show that the traditional dentin remineralization method is usually a disordered mixture of demineralized dentin and minerals, so mineralized dentin is not comparable to natural mineralized dentin in terms of the morphological characteristics and mechanical properties. With its gradual increase in recent years, dentine biomimetic mineralization technology perfectly resembles the minerals in the dentin overlapping sequence arranged with the dentine collagen fiber structure characteristics, leading to greatly improved microstructural, physical and chemical properties. As a result, dentine biomimetic mineralization technology is expected to achieve new breakthroughs in the fields of resin-dentin bonding mixing layers and the decay of dentin. At present, the technical obstacles that need to be overcome in the clinical application of the biomimetic remineralization of dentin are how to continuously supplement all the active ingredients needed for mineralization in the process of remineralization and how to keep the mechanical properties of the parent material unchanged while slowly releasing all ingredients. Researchers have successively proposed three-step transportation of the biomimetic remineralization of raw materials, as well as the preparation of mineralization precursors stabilized by polymers in advance and the reuse of mesoporous silicon nanomaterials for the transportation of the mineralized ingredient system. The concept described above provides the preliminary in vitro experimental basis for the transformation of the biomimetic remineralization strategy of dentin in clinical applications.

With the coming of data era, even small business has ability to collect and store abundant data, which means doing customer segmentation based on data, instead of experience, is possible. This paper chooses a developing business in Chin—bath center, to make customer segmentation with data. In this research, neural net is used to deal with the distance to fit more with the true psychological distance and create the distance score to get more information from the variables about coming of the customers. Possible formula of distance score is also given as a reference. The distance score turns out to be a better measure of the psychological distance and the neural net has a better graph of the distance data than other methods. This paper gives a possible method for customer segmentation in a completely new business area.

With the improvement of coal mining mechanization level, dust has become a serious problem that restricts coal mine safety production and endangers occupational health. Wet dust collectors are widely used because of their low investment and simple structure. In order to further improve the performance of wet dust collector, the overall structure and principle are analyzed in detail, the components, working principle, influencing factors, advantages and disadvantages of the structure of power, dust removal and dehydration are analyzed systematically. On this basis, in view of the existing shortcomings of the existing wet dust collectors, it is proposed that the future should be considered from the perspective of integrity, locality, economy, environmental protection to develop a new type of wet dust collector with integrated structure, suitable for the narrow underground space, diversified functions, low maintenance cost, high dust removal efficiency, sewage and sludge recycling and intelligent management to provide technical support for the realization of safe production and the guarantee of occupational health of operators.