Theory and Application of Natural-Based Wavelet Method

Wavelet method is often used in analyzing trend and period of time sequence. When using wavelet method one serious problem is different chosen wavelet basis and scale would lead to different results. Sometimes, the results vary greatly. To overcome this problem and to improve the accuracy and efficiency, a new method denoted by Natural-based Wavelet Method is introduced and extended. It can be proved that the proposed method in fact is a special class of discrete wavelet. At first, two numerical examples are designed to show the capacity of the novel method. Second, this method is applied to a precipitation series. According to wavelet analysis and short-range precipitation prediction, this precipitation exists a faintly increasing trend. Through the analysis, the studied precipitation has two major periods: 11 and 41 years. The results validate that the Natural-based Wavelet Method used in application of multi-complicated observed data is suitable. It is easy to write the source code of the proposed method. When new information appears, new information can be easily added into the original sequence, this is another advantage of the proposed method.

Biomineralized polymer matrix composites for bone tissue repair:a review

Bone defects caused by trauma, infection or bone tumor resection, are highly prevalent. A small number(5%–10%) of these injuries fail to heal due to non-union and require surgical intervention. Currently, the principal treatment options for these defects are autografts, allografts, xenografts or synthetic grafts. The main problems associated with these therapies include pain,infection and donor site morbidity. Bone tissue engineering is a diverse field that focuses on the regeneration of bone by combining cells, scaffolds, growth factors and dynamic forces. There have been many recent studies utilizing biomineralized polymer matrix composites which mimic the natural structure of bone. The principal focus of this review is on recent advances in the synthesis of various types of biomineralized polymer matrix composite. Examples of the biomineralization of naturallyderived and synthetic polymers widely used for bone engineering are also summarized.

Tuning gelatin-based hydrogel towards bioadhesive ocular tissue engineering applications

Gelatin based adhesives have been used in the last decades in different biomedical applications due to the excellent biocompatibility,easy processability,transparency,non-toxicity,and reasonable mechanical properties to mimic the extracellular matrix(ECM).Gelatin adhesives can be easily tuned to gain different viscoelastic and mechanical properties that facilitate its ocular application.We herein grafted glycidyl methacrylate on the gelatin backbone with a simple chemical modification of the precursor,utilizing epoxide ring-opening reactions and visible light-crosslinking.This chemical modification allows the obtaining of an elastic protein-based hydrogel(GELGYM)with excellent biomimetic properties,approaching those of the native tissue.GELGYM can be modulated to be stretched up to 4 times its initial length and withstand high tensile stresses up to 1.95 MPa with compressive strains as high as 80%compared to Gelatin-methacryloyl(GeIMA),the most studied derivative of gelatin used as a bioadhesive.GELGYM is also highly biocompatible and supports cellular adhesion,proliferation,and migration in both 2 and 3-dimensional cell-cultures.These characteristics along with its super adhesion to biological tissues such as cornea,aorta,heart,muscle,kidney,liver,and spleen suggest widespread applications of this hydrogel in many biomedical areas such as transplantation,tissue adhesive,wound dressing,bioprinting,and drug and cell delivery.