Regeneration of mature dermis by transplanted particulate acellular dermal matrix in a rat model of skin defect wound

Native mammalian extracellular matrix (ECM) has been made in various forms including particles, sheet and mesh which are appropriate for site-specific applications. The ECM particles are usually created by homogenization method and have a wider size distribution. This needs to be improved to produce more uniform ECM particles. In present study, we had successfully developed a method for preparing particulate acellular dermal matrix (PADM) in different gauges. The resultant PADM was approaching a rectangular parallelepiped or cubic shape, with a better or narrower size distribution than other ECM particles in previous reports. It also retained ultrastructure and functional molecules of native ECM. In vivo performances were evaluated after implantation of PADM in an acute full-thickness skin defect wound in rats. Histological analysis showed that allogeneic PADM used as dermal regeneration template could facilitate maturation and improving collagen bundle structure of regenerated dermis at the endpoint of 20 weeks post-surgery. The PADM could be used for further investigation in analyzing the impacts of cellularly and/or molecularly modified PADM on soft tissue regeneration

Arabidopsis Hormone Database: a comprehensive genetic and phenotypic information database for plant hormone research in Arabidopsis

Plant hormones are small organic molecules that influence almost every aspect of plant growth and development. Genetic and molecular studies have revealed a large number of genes that are involved in responses to numerous plant hormones, including auxin, gibberellin, cytokinin, abscisic acid, ethylene, jasmonic acid, salicylic acid, and brassinosteroid. Here, we develop an Arabidopsis hormone database, which aims to provide a systematic and comprehensive view of genes participating in plant hormonal regulation, as well as morphological phenotypes controlled by plant hormones. Based on data from mutant studies, transgenic analysis and gene ontology (GO) annotation, we have identified a total of 1026 genes in the Arabidopsis genome that participate in plant hormone functions. Meanwhile, a phenotype ontology is developed to precisely describe myriad hormone-regulated morphological processes with standardized vocabularies. A web interface (http://ahd.cbi.pku.edu.cn) would allow users to quickly get access to information about these hormone-related genes, including sequences, functional category, mutant information, phenotypic description, microarray data and linked publications. Several applications of this database in studying plant hormonal regulation and hormone cross-talk will be presented and discussed

Damage Mechanism of Copper Staves in a 3200 m³ Blast Furnace

Copper staves have been widely applied in large blast furnaces especially those whose inner volumes exceed 2000 m3 due to high cooling capacity. In the past decade, copper staves suffered severe damages in some blast furnaces, which not only shortened their campaign lives, but also caused huge economic losses. In order to make out this phenomenon, the damage mechanism of copper staves was investigated via analyzing the chemical composition, thermal conductivity, metallographic aspects and microstructure in this paper. As a result, the working state was more likely to damage copper staves instead of their materials. At the beginning, the poor quality of the coke and the large bosh angle promoted the development of edge airflow, which intensified the erosion of refractory materials, resulting in the fall-off of slag crusts and damage of cooling water pipes. After repair, the cooling capacity of copper staves still declined, causing the temperature to rise easily; consequently, hydrogen attack happened when the temperature reached 370 °C, which degraded the performance of copper staves. Therefore, copper staves were worn too quickly to form slag crusts, which finally failed under the hydrogen attack and the scouring of the edge airflow at high temperatures

Temperature Field Distribution of a Dissected Blast Furnace

The temperature field distribution of the upper part of a blast furnace (BF) is the result of the combination of charge distribution and gas flow. It is of great significance for both researchers and operators to study the thermal state and the phenomenon of the BF. The graphite box method is used in this study to obtain the temperature field distribution in the upper part of a 125 m(3) BE. Graphite boxes with a variety of different melting point metals were loaded into the BF with the charge. And the temperature field distribution was obtained after the boxes were taken out with position and temperature information during the dissection process. The results illustrate that the graphite boxes are unevenly distributed in the BF, which was related to the distribution of BF materials. Furthermore, the temperature field distribution is asymmetric, and the isotherms present an irregular "W" shape, which is caused mainly by the simultaneous development of the edge airflow and the central airflow. Moreover, the shape of the softening and melting zone observed in the dissection process has a good correspondence with the temperature field. We concluded that the deflection of the temperature field and the softening and melting zone is related to the strong gas flow in the direction of No. 3 tuyere, the existence of accretion in the hearth, and the filling of refractory materials in tuyeres before blowing out

An OSM Data-Driven Method for Road-Positive Sample Creation

Determining samples is considered to be a precondition in deep network training and learning, but at present, samples are usually created manually, which limits the application of deep networks. Therefore, this article proposes an OpenStreetMap (OSM) data-driven method for creating road-positive samples. First, based on the OSM data, a line segment orientation histogram (LSOH) model is constructed to determine the local road direction. Secondly, a road homogeneity constraint rule and road texture feature statistical model are constructed to extract the local road line, and on the basis of the local road lines with the same direction, a polar constraint rule is proposed to determine the local road line set. Then, an iterative interpolation algorithm is used to connect the local road lines on both sides of the gaps between the road lines. Finally, a local texture self-similarity (LTSS) model is implemented to determine the road width, and the centerpoint autocorrection model and random sample consensus (RANSAC) algorithm are used to extract the road centerline; the road width and road centerline are used to complete the creation of the road-positive samples. Experiments are conducted on different scenes and different types of images to demonstrate the proposed method and compare it with other approaches. The results demonstrate that the proposed method for creating road-positive samples has great advantages in terms of accuracy and integrity

Investigation of non-isothermal and isothermal gasification process of coal char using different kinetic model

Isothermal and non-isothermal gasification kinetics of coal char were investigated by using thermogravimetric analysis (TGA) in CO2 atmosphere, and the experimental data were interpreted with the aids of random pore model (RPM), unreacted shrinking core model (URCM) and volume model (VM). With the increase of heating rate, gasification curve moves into high temperature zone and peak rate of gasification increases; with the increase of gasification temperature, gasification rate increases and the total time of gasification is shortened. The increase of both heating rate and gasification temperature could improve gasification process of coal char. Kinetics analysis indicates that experimental data agree better with the RPM than with the other two models. The apparent activation energy of non-isothermal and isothermal gasification of coal char using RPM is 193.9 kJ/mol and 212.6 kJ/mol respectively, which are in accordance with reported data. Gasification process of coal char under different heating rates and different temperatures are predicted by the RPM derived in this study, and it is found that the RPM predicts the reaction process satisfactorily. Keywords: Coal char, Gasification, Thermogravimetric analysis, Kinetics mode

Research on Reaction Mechanism of Vacuum Carbon Thermal Reduction and Dephosphorization in High Phosphate Iron Ore

According to the mineral composition characteristics of high-phosphorus iron ore, the reaction mechanism of fluorapatite was investigated using pure substance and gangue under vacuum carbon thermal reduction (VCTR) conditions. The effects of reduction temperature, basicity, and C/O ratio on the metallization ratio, dephosphorization ratio, and phosphorus content of pellets were studied. The reaction process of fluorapatite in high-phosphorus iron ore was investigated. The results showed that when the metallization ratio of pellets reached maximum (95%), the dephosphorization ratio was only 5.6%, thus indicating adverse result. The reduction processes of high-phosphorus iron ore under vacuum and nitrogen environment were, respectively, compared under the optimal condition. It was found that the metallization ratio of pellets in the vacuum condition was higher than that under the nitrogen condition, while the dephosphorization ratio showed an opposite result. This indicated that in the process of vacuum reduction, fluorapatite not only reacted with carbon to form gaseous phosphide, but also with iron to form compounds containing the Fe⁻P bond. Therefore, a new mechanism of reduction of fluorapatite was proposed as follows: 2Ca5(PO4)3F + 12Fe + 9SiO2 + 15C = 9CaSiO3 + 6Fe2P + 15CO + CaF2