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Dental implants have been extensively used in patients with defects or loss of dentition. However, the loss or failure of dental implants is still a critical problem in clinic. Therefore, many methods have been designed to enhance the osseointegration between the implants and native bone. Herein, the challenge and healing process of dental implant operation will be briefly introduced. Then, various surface modification methods and emerging biomaterials used to tune the properties of dental implants will be summarized comprehensively.

Keratoconus is a bilateral asymmetric corneal dilatation disease characterized by localized thinning and increased curvature of cornea. The alteration of the mechanical properties occurs earlier than morphological change owing to corneal structure destruction in the early stage of keratoconus. Therefore, the corneal biomechanics is especially important for early keratoconus screening. In this paper, we reviewed corneal biomechanical behaviors in vivo and corneal mechanical properties in vitro during the development of keratoconus and corneal cross-linking treatment. The role of finite element methods and animal models were also analyzed in the research of keratoconus disease. This review provides a reference for the diagnosis and treatment of keratoconus in clinic.

Multigranulation rough set theory is one of the most effective tools for data analysis and mining in multicriteria information systems. Six types of covering-based multigranulation fuzzy rough set (CMFRS) models have been constructed through fuzzy β-neighborhoods or multigranulation fuzzy measures. However, it is often time-consuming to compute these CMFRS models with a large fuzzy covering using set representation approaches. Hence, presenting novel methods to compute them quickly is our motivation for this paper. In this article, we study the matrix representations of CMFRS models to save time in data processing. Firstly, some new matrices and matrix operations are proposed. Then, matrix representations of optimistic CMFRSs are presented. Moreover, matrix approaches for computing pessimistic CMFRSs are also proposed. Finally, some experiments are proposed to illustrate the effectiveness of our approaches.

Mesoporous bioactive glass (MBG) is widely used in bone tissue repairing and drug loading. However, burst release of drug and poor compatibility with other materials limited its application. It is an effective way to modify MBG with a polymer brush to improve the properties. Herein, an alginate-modified MBG was prepared, and then, the effects of ALG on the properties of MBG were investigated. The results demonstrate that ALG could improve the drug loading efficiency, prolong drug release times, and make orderly deposition of apatite on the surface of MBG. Furthermore, MBG@ALG significantly promoted the osteogenic differentiation of MC3T3-E1 cells, demonstrating that surface modification of MBG by ALG can improve its properties, which will further broaden the application of MBG in tissue engineering.

Dental caries, a chronic and irreversible disease caused by caries-causing bacteria, has been listed as one of the three major human diseases to be prevented and treated. Therefore, it is critical to effectively stop the development of enamel caries. Remineralization treatment can control the progression of caries by inhibiting and reversing enamel demineralization at an early stage. In this process, functional materials guide the deposition of minerals on the damaged enamel, and the structure and hardness of the enamel are then restored. These remineralization materials have great potential for clinical application. In this review, advanced materials for enamel remineralization were briefly summarized, furthermore, an outlook on the perspective of remineralization materials were addressed.

Keratoconus is a bilateral progressive degenerative corneal disease characterized by localized corneal thinning and dilatation. The pathogenesis of keratoconus is not fully elucidated. To gain a better understanding of the pathophysiology of this disease and to explore potential treatments, animal models are essential for basic research. Several attempts have been made to establish animal models of corneal ectasia by using collagenase. However, continuous changes of the cornea have not been well-tracked for the model. In this study, corneal morphology and biomechanical behavior in vivo were determined before and after collagenase Ⅱ treatment at 2, 4, and 8 weeks. The elastic modulus and histology of cornea tissues ex vivo were measured at 8 weeks postoperatively. The results showed that the posterior corneal curvature (Km B) increased and central corneal thickness (CCT) decreased after collagenase treatment. The mechanical properties of ectatic corneas weakened significantly and the collagen fiber interval in the stromal layer was increased and disorganized. This study provides insights into the changes of corneal morphology and biomechanical properties in a rabbit model of corneal ectasia. Changes observed at 8 weeks indicated that the cornea was still undergoing remodeling.

The shape of nanoparticles can determine their physical properties and then greatly impact the physiological reactions on cells or tissues during treatment. Traditionally spherical nanoparticles are more widely applied in biomedicine but are not necessarily the best. The superiority of anisotropic nanoparticles has been realized in recent years. The synthesis of the distinct-shaped metal/metal oxide nanoparticles is easily controlled. However, their biotoxicity is still up for debate. Hence, we designed CaCO3 nanorods for drug delivery prepared at mild condition by polysaccharide-regulated biomineralization in the presence of fucoidan with sulfate groups. The CaCO3 nanorods with a pH sensitivity–loaded antitumor drug mitoxantrone hydrochloride (MTO) showed excellent antitumor efficacy for the HeLa cells and MCF-7 cells in vitro. We believe that anisotropic nanoparticles will bring forth an emblematic shift in nanotechnology for application in biomedicine.

In this paper, we introduce the fractional p-adic Hardy operators and its conjugate operators and obtain its optimal weak type estimates on the p-adic Lebesgue product spaces.

Conventional photothermal therapy (PTT) irradiates the tumor tissues by elevating the temperature above 48 °C to exert thermal ablation, killing tumor cells. However, thermal ablation during PTT harmfully damages the surrounding normal tissues, post-treatment inflammatory responses, rapid metastasis due to the short-term mass release of tumor-cellular contents, or other side effects. To circumvent this limitation, mild-temperature photothermal therapy (MTPTT) was introduced to replace PTT as it exerts its activity at a therapeutic temperature of 42–45 °C. However, the significantly low therapeutic effect comes due to the thermoresistance of cancer cells as MTPTT figures out some of the side-effects issues. Herein, our current review suggested the mechanism and various strategies for improving the efficacy of MTPTT. Especially, heat shock proteins (HSPs) are molecular chaperones overexpressed in tumor cells and implicated in several cellular heat shock responses. Therefore, we introduced some methods to inhibit activity, reduce expression levels, and hinder the function of HSPs during MTPTT treatment. Moreover, other strategies also were emphasized, including nucleus damage, energy inhibition, and autophagy mediation. In addition, some therapies, like radiotherapy, chemotherapy, photodynamic therapy, and immunotherapy, exhibited a significant synergistic effect to assist MTPTT. Our current review provides a basis for further studies and a new approach for the clinical application of MTPTT.

With the increase in engine power density, the temperature and stress carried by the cylinder head during operation also increase. The thermal engine fatigue life prediction of the cylinder head needs to consider accurate and reasonable creep-constitutive models and parameters. In view of the wide range of temperature and stress working conditions of the compacted graphite cast iron (CGI) cylinder head, the creep test of CGI under the conditions of temperature 450~550 °C and stress 100~300 MPa was carried out, and CGI under the conditions of wide temperature and stress was proposed to characterize a creep-constitutive model for minimum creep rate. Research indicated that under wide temperature and stress conditions, CGI was more prone to creep damage than under low load, and creep deformation was dominated by grain boundary sliding (GBS), intragranular dislocation glide (IDG), and dislocation climb (IDC). With the deformation mechanism-based true stress (DMTS) creep model, combined with the multiobjective optimization method, a creep-constitutive model of CGI was constructed, and 73% of the predicted values of the model were within twice the error range. Compared with the linear regression method, the multiobjective optimization method could still fit the accurate model parameters in the case of small samples.

Bacterial infection has been a critic problem for implant infections. Poly(L-lactide) (PLLA) membrane has great potential for Guided bone regeneration (GBR), however, PLLA lack antibacterial property and thus may face bacterial infections. In this work, a mussel inspired method was used to treat PLLA membrane with dopamine and formed polydopamine (PDA) coated PLLA (PLLA@PDA), and then silver Nanoparticles (AgNPs) was immobilized on the surface of PLLA via the reduction effect of PDA. The XPS results showed that the silver element contents may be tuned from 1.6% to 15.4%. The AgNPs coated PLLA (PLLA@Ag) showed good antibacterial property (98.3% bactericidal efficiency may be obtained) and good biocompatibility, implying that the PLLA@Ag membrane have potential application as antibacterial GBR membrane, which may enhance the application of PLLA.

Carbon nanotubes (CNTs) have attracted great interest in biomedical fields. However, the potential toxicity and poor dispersion of CNTs have greatly limited its application. In this work, a mussel-inspired method combined with the “thiol-Michael” click reaction was used to modify the surface of CNT and improve its properties. Firstly, a CNT was treated with dopamine, and then alginate grafted with L-cysteine was anchored onto the surface of CNT via click reaction, which realized the long-time dispersion of CNT in water. Furthermore, the in vitro test also demonstrated that the alginate may improve the biocompatibility of CNT, and thus may broaden the application of CNT in the biomedical field.

Hydroxyapatite (HA) is widely used in bone tissue engineering for its bioactivity and biocompatibility, and a growing number of researchers are exploring ways to improve the physical properties and biological functions of hydroxyapatite. Up to now, HA has been used as inorganic building blocks for tissue engineering or as nanofillers to blend with polymers, furthermore, various methods such as ion doping or surface modification have been also reported to prepare functionalized HA. In this review, we try to give a brief and comprehensive introduction about HA-based materials, including ion-doped HA, HA/polymer composites and surface modified HA and their applications in bone tissue engineering. In addition, the prospective of HA is also discussed. This review may be helpful for researchers to get a general understanding about the development of hydroxyapatite based materials.

New development of biomaterial scaffolds remains a prominent issue for the regeneration of lost or fractured bone. Of these scaffolds, a number of bioactive polymers have been synthesized and fabricated for diverse biological roles. Although recent evidence has demonstrated that composite scaffolds such as HA/PLLA have improved properties when compared to either HA or PLLA alone, recent investigations have demonstrated that the phase compatibility between HA and PLLA layers is weak preventing optimal enhancement of the mechanical properties and making the composites prone to breakdown. In the present study, poly (γ-benzyl-L-glutamate) modified hydroxyapatite/(poly (L-lactic acid)) (PBLG-g-HA/PLLA) composite scaffolds were fabricated with improved phase compatibility and tested for their osteogenic properties in 18 Wistar female rats by analyzing new bone formation in 3 mm bilateral femur defects in vivo. At time points, 2, 4 and 8 weeks post surgery, bone formation was evaluated by µ-CT and histological analysis by comparing 4 treatment groups; 1) blank defect, 2) PLLA, 3) HA/PLLA and 4) PBLG-g-HA/PLLA scaffolds. The in vivo analysis demonstrated that new bone formation was much more prominent in HA/PLLA and PBLG-g-HA/PLLA groups as depicted by µ-CT, H&E staining and immunohistochemistry for collagen I. TRAP staining was also utilized to determine the influence of osteoclast cell number and staining intensity to the various scaffolds. No significant differences in either staining intensity or osteoclast numbers between all treatment modalities was observed, however blank defects did contain a higher number of osteoclast-like cells. The results from the present study illustrate the potential of PBLG-g-HA/PLLA scaffolds for bone tissue engineering applications by demonstrating favorable osteogenic properties.

It is proved that if a ring R is semiabelian, then so is the skew polynomial ring R[x;σ], where σ is an endomorphism of R satisfying σ(e)=e for all e∈E(R). Some characterizations and properties of semiabelian rings are studied.

We introduce in this paper the concept of left 𝑊𝑀𝐶2 rings and concern ourselves with rings containing an injective maximal left ideal. Some known results for left idempotent reflexive rings and left 𝐻𝐼 rings can be extended to left 𝑊𝑀𝐶2 rings. As applications, we are able to give some new characterizations of regular left self-injective rings with nonzero socle and extend some known results on strongly regular rings.

In this paper, we focus on partial isometry elements and strongly EP elements on a ring. We construct characterizing equations such that an element which is both group invertible and MP-invertible, is a partial isometry element, or is strongly EP, exactly when these equations have a solution in a given set. In particular, an element a ∈ R# ∩ R† is a partial isometry element if and only if the equation x = x(a†)*a† has at least one solution in {a, a#, a†, a*, (a#)*, (a†)*}. An element a ∈ R#∩R† is a strongly EP element if and only if the equation (a†)*xa† = xa†a has at least one solution in {a, a#, a†, a*, (a#)*, (a†)*}. These characterizations extend many well-known results. [ABSTRACT FROM AUTHOR]