Composite or Modified Hydroxyapatite Microspheres as Drug Delivery Carrier for Bone and Tooth Tissue Engineering.

Since hydroxyapatite (HAp) is an important constituent of bone and teeth, it has excellent biocompatibility and bioactivity, good osteoconductive effects and the ability to induce bone formation as a material for bone or tooth repair and replacement. At present, widely used HAp microspheres have some characteristics, such as large specific surface area, light mass, good injection properties, good fluidity, and low aggregation ability, but they are difficult to really meet the biological and clinical needs due to their own mechanical property defects, such as low strength, brittleness, and poor plasticity. Based on the current research status of HAp microspheres, we summarize the research progress of various types of composite microspheres, including inorganic materials, natural polymer materials and synthetic polymer materials, and further analyze the advantages of HAp composite microspheres loaded with drug molecules, proteins and bioactive factors, so as to explore the development prospect of HAp composite microspheres as scaffolds for constructing sustained release systems. It provides a theoretical basis and research direction to prepare HAp composite micro-spheres with superior comprehensive properties so that they can be better applied in bone tissue regeneration and tooth regeneration engineering.

Optimization of the morphological, structural, and physicochemical properties of maize starch using straw returning and nitrogen fertilization in Northeast China.

The combination of straw returning and nitrogen (N) fertilization is a popular tillage mode and essential strategy for achieving stable yield and high quality. However, the optimal combination strategy and the influence of tillage mode on the morphological, crystalline, and molecular structures of maize starch remain unclear. We conducted a long-term field experiment over 7 years in Northeast China using two tillage modes, rotary tillage with straw returning (RTS) and plow tillage with straw returning (PTS), and four N application rates. The relative crystallinity, 1045/1022 cm-1 value, and B2 and B3 chains of maize starch were higher under RTS than under PTS, resulting in increased stability of starch and improvements in gelatinization enthalpy and temperature. The surface of the starch granules induced by N fertilizer was smoother than that under the N0 (0 kg N ha-1) treatment. The proportion of amylose content, solubility, swelling power, and light transmittance increased under N2 (262 kg N ha-1) treatment, along with improvement in starch pasting properties. These results suggest that RTS combined with N2 treatment can regulate the morphological, structural, and physicochemical characteristics of maize starch, providing an essential reference for improving the quality of maize starch from an agronomic point of view.

Maternal exposure to E 551 during pregnancy leads to genome-wide DNA methylation changes and metabolic disorders in the livers of pregnant mice and their fetuses.

The widespread use of nanoparticles in the food industry has raised concerns regarding their potential adverse effects on human health, particularly in vulnerable populations, including pregnant mothers and fetuses. However, studies evaluating the reproductive and developmental toxicity of food-grade nanomaterials are limited. This study investigated the potential risks of prenatal dietary exposure to food-grade silica nanoparticles (E 551) on maternal health and fetal growth using conventional toxicological and epigenetic methods. The results showed that prenatal exposure to a high-dose of E 551 induces fetal resorption. Moreover, E 551 significantly accumulates in maternal and fetal livers, triggering a hepatic inflammatory response. At the epigenetic level, global DNA methylation is markedly altered in the maternal and fetal livers. Genome-wide DNA methylation sequencing revealed affected mCG, mCHG, and mCHH methylation landscapes. Subsequent bioinformatic analysis of the differentially methylated genes suggests that E 551 poses a risk of inducing metabolic disorders in maternal and fetal livers. This is further evidenced by impaired glucose tolerance in pregnant mice and altered expression of key metabolism-related genes and proteins in maternal and fetal livers. Collectively, the results of this study highlighted the importance of epigenetics in characterizing the potential toxicity of maternal exposure to food-grade nanomaterials during pregnancy.

Role of oxidative stress in the relationship between periodontitis and systemic diseases.

Periodontitis is a common inflammatory disease. It is characterized by destruction of the supporting structures of the teeth and could lead to tooth loss and systemic inflammation. Bacteria in inflamed gingival tissue and virulence factors are capable of entering the bloodstream to induce systemic inflammatory response, thus influencing the pathological process of many diseases, such as cardiovascular diseases, diabetes, chronic kidney disease, as well as liver injury. An increasing body of evidence show the complex interplay between oxidative stress and inflammation in disease pathogenesis. When periodontitis occurs, increased reactive oxygen species accumulation leads to oxidative stress. Oxidative stress contributes to major cellular components damage, including DNA, proteins, and lipids. In this article, the focus will be on oxidative stress in periodontal disease, the relationship between periodontitis and systemic inflammation, and the impact of periodontal therapy on oxidative stress parameters.

Traveling wave solutions of a coupled Schrödinger-Korteweg-de Vries equation by the generalized coupled trial equation method.

The coupled Schrödinger-Korteweg-de Vries equation is a critical system of in nonlinear evolution equations. It describes various processes in dusty plasma, such as Langmuir waves, dust-acoustic waves, and electromagnetic waves. This paper uses the generalized coupled trial equation method to solve the equation. By the complete discrimination system for polynomial, a series of exact traveling wave solutions are obtained, including discontinuous periodic solutions, solitary wave solutions, and Jacobian elliptical function solutions. In addition, to determine the existence of the solutions and understand their properties, we draw three-dimensional images of the modules of the solutions with Mathematica. We obtain more comprehensive and accurate solutions than previous studies, and the results give the system more profound physical significance.

Climate change drives NDVI variations at multiple spatiotemporal levels rather than human disturbance in Northwest China.

Changes in land management and climate alter vegetation dynamics; however, the factors driving vegetation changes remain elusive at multiple spatiotemporal levels. Here, we assess the drivers of changes in greenness from 2000 to 2015 in Northwest China (NW China). We used multiple stepwise linear regression (MSLR), redundancy analysis (RDA), and 12 other models to quantify the impacts of precipitation and temperature metrics, gross domestic product (GDP), population, and grazing intensity on the normalized difference vegetation index (NDVI) at three administrative levels (county, town, and village), four temporal levels (yearly, May, July, and September), two vegetation types (woodland and grassland), and at annual precipitation gradients of <200, 200-400, and >400 mm. The results suggest that NW China underwent vegetation greening from 2000 to 2015. Precipitation and temperature were the most influential factors contributing to the NDVI change. Population was the main determinant of NDVI under the precipitation gradient of <200 mm, and the effect of GDP on NDVI was moderate. On the temporal scale, annual precipitation, precipitation before the previous year, and precipitation in the current year determined the NDVI in May, July, and September, respectively, for both woodland and grassland. At multiple scales, climate change was the primary driver of vegetation change in NW China, rather than human disturbance. These findings expand our understanding on drivers of NDVI at multiple levels over a long period. Measures to manage decreasing vegetation coverage may be more effective and could be implemented sooner based on predicted climate change in drylands worldwide.

[Multiscale influences of urbanized landscape metrics on the diversity of indigenous plant species: A case study in Shunyi District of Beijing, China.] / åŸŽå¸‚åŒ–æ™¯è§‚æ ¼å±€å¯¹æœ¬åœŸæ¤ç‰©å¤šæ ·æ€§çš„å¤šå°ºåº¦å½±å“­­ä»¥åŒ—京市顺义区为例.

The effects of landscape pattern on plant diversity have been widely reported in literature, with that of urban landscape remaining largely unknown. To explore the impacts of urbanization landscape pattern on plant diversity and its scale effect, 105 plots were investigated in Shunyi District, Beijing. The α and ß diversity of each plot were calculated, and 43 urban landscape indices of 10 scales in the range of 100-1000 m were analyzed with 100 m as the step. The results showed that the urban landscape area metric, core metrics and edge metrics were negatively related with diversity of indigenous plant species at all the examined scales. Shape complexity metrics contributed to plant diversity at small scale, while the area-weighted complexity metrics contributed at large scale. Other metrics, such as connection, proximity, cohesion, fragmentation and interspersion juxtaposition of urban patches showed a slight and unsteady relationship with the diversity of indigenous plant species. The urbanization intensity was negatively related with scales and with plant diversity at all scales. Urban landscape could better conserve indigenous plant diversity by reasonably dividing an urbanized area into many small patches with simple edge. Our results presented suitable urban landscape indicators for preserving plant diversity and suggestions for the construction of ecological cities.