The phase transformation from austenite to acicular ferrite in the simulated coarse grained heat affected zone of a high strength low alloy steel was investigated by means of analytical ...characterisation techniques such as in situ microscopy, transmission electron microscopy and electron backscattered diffraction analysis. The acicular ferrite grains nucleated on inclusions (Zr-Ti oxides) in coarse austenite grain grew in different directions and effectively partitioned coarse austenite grain into several finer and separate regions. The crystallographic grain size became small for coarse austenite grains due to the effective partitioning by acicular ferrite laths or plates.
Deep learning and neural network models have been new research directions and hot issues in the fields of machine learning and artificial intelligence in recent years. Deep learning has made a ...breakthrough in the applications of image and speech recognitions, and also has been extensively used in the fields of face recognition and information retrieval because of its special superiority. Bone X-ray images express different variations in black-white-gray gradations, which have image features of black and white contrasts and level differences. Based on these advantages of deep learning in image recognition, we combine it with the research of bone age assessment to provide basic datum for constructing a forensic automatic system of bone age assessment. This paper reviews the basic concept and network architectures of deep learning, and describes its recent research progress on image recognition in different research fields at home and abroad, and explores its advantages and application prospects in bone age asse
Zeroth-order complex dispersion equation of a cylindrical metallic nanowire has been solved analytically to get dispersion relations of surface plasmon-polaritons (SPPs) by approximate methods. The ...back bending of the dispersion relation can be well described by the analytical solutions, confirming that the back bending is originated from the metal Ohmic loss. Basing on the analytical solutions, the back bending point of the dispersion relation used for the measurement of the metallic Ohmic loss has also been suggested.
Several studies have recently demonstrated that G protein-coupled estrogen receptor (GPER) 30 directly binds to estrogen and mediates its action. The aim of the present study was to investigate the ...effects of GPER on cardiocyte apoptosis following ischemia/reperfusion injury (MIRI) in H9C2 myocardial cells. H9C2 cells were treated with a specific GPER agonist (G1), 17β-estradiol (E2) or the vehicle. The cells were subjected to 20 min of myocardial ischemia followed by 120 min of reperfusion. They were then randomly assigned to three experimental groups: Control, G1, E2. B-cell lymphoma 2 (Bcl-2) and Bcl-2 associated X (Bax) levels were measured, Hoechst 33258 staining was performed to assess apoptosis, and superoxide dismutase (SOD), tumor necrosis factor (TNF)-α and adenosine triphosphatase (ATPase) levels were determined. To test the specificity of G1, GPER-knockout cells were treated with G1 and analyzed as stated above. Compared with the vehicle-treated groups, G1 and E2-treated groups exhibited elevated Bcl-2 levels, decreased Bax levels and cell apoptosis, significantly increased SOD and ATP levels and decreased TNF-α levels following ischemia-reperfusion. However, G1 had no evident effects on the GPER-knockout cells. In conclusion, the present study suggested that GPER activation provided a cardioprotective effect following ischemia-reperfusion by inhibiting cardiocyte apoptosis.
Neo-intima development and atherosclerosis limit the long-term use of vein grafts for revascularization of ischemic tissues. Recently, studies have confirmed that proliferating cell nuclear antigen ...(PCNA) plays an important role in cell proliferation. Our research confirmed that 28 days after vein transplantation, PCNA expression increases significantly. Using rabbits, rather than rodents, for a more representative model of human vein grafts, we aimed to establish a time course of changes in cell proliferation and apoptosis using morphometric and immunohistochemical analyses, western blot, terminal deoxynucleotidyl transferase dUTP nick end labeling, and transmission electron microscopy (TEM). The external jugular veins of 42 healthy purebred male New Zealand white rabbits were grafted onto their common carotid arteries. The rabbits were divided into seven groups, with vein grafts being harvested before surgery, and at 1, 3, 7, 14, 28, and 90 days afterwards. The extent of stenosis and apoptosis, PCNA protein levels, and TEM morphology were subsequently examined. Intimal thickness was slightly decreased 1 day following surgery, but then increased continuously until the 90th day. Western blot and immunohistochemistry both indicated lowered PCNA expression on day 1, although levels subsequently increased, peaking at 7 days post-surgery. After surgery, apoptosis was lowest on day 7, and remained low thereafter. TEM revealed signs of apoptosis as vein graft restenosis progressed. Proliferation and apoptosis co-occurred following grafting, indicating that both processes were involved in vein graft remodeling. Apoptosis levels were highest between days 1 and 3 after surgery, whereas proliferation culminated on the 7th day.
To study the diversities of human B cell epitopes of five proteins (Mpt83, Mpt70, LpqH, PstS3, GroES) in Mycobacterium tuberculosis isolates from China.
We selected 179 strains isolated from patients ...with tuberculosis in different regions of China, and cultured these strains by L-J medium. The gene sequences of these 5 proteins were amplified and sequenced by PCR. The variations (single nucleotide polymorphisms, SNP) of the DNA sequences were compared and analyzed according to the immune epitope database (IEDB). The synonymous mutation rate (dS), non-synonymous mutation rate (dN) and dN/dS values were calculated with MEGA6 software.
Among the 179 clinical MTBC isolates, 7 SNP mutations were found in the mpt83gene. The dN/dS value of the whole mpt83 gene was 0.88. One SNP mutation was found in the mpt70 gene. The dN/dS values of the whole pstS3 gene and non-B epitopes areas were 1.74 and 1.40 respectively. But no mutation was found in the groES gene.
The mpt83, lpqH and pstS3 genes of 179 MTBC strains contain
The first principle modelling and experimental approach were used to investigate the role of oxide on ferrite formation. Ti
2
O
3
was found to be effective in inducing ferrite formation owing to its ...lower cation vacancy energy. Al
2
O
3
was inert in promoting the formation of ferrite because it has high cation and anion vacancy energies due to its strongest s-p bonding. There was no alteration of the lattice when ZrO
2
doped with Mn because the radius of Mn
2+
is almost the same as that of Zr
4+
. Therefore, a manganese depleted zone can be formed in the vicinity of ZrO
2
. The vacancy energy and electron densities of states were calculated by first principles, and the results were in good agreement with the experiments.
To investigate the relationship between D-cycloserine resistance and the gene mutations of
,
and
of
(
)
, as well as the association between D-cycloserine resistance and spoligotyping genotyping.
A ...total of 145
strains were selected from the strain bank. D-cycloserine resistant phenotypes of the strains were determined by the proportion method and the minimal inhibitory concentration was determined by resazurin microtiter assay. PCR amplification and DNA direct sequencing methods were used for the analysis of gene mutations. Relationship between the resistance phenotype and genotype was analyzed by
-square test.
Of the 145 clinically collected strains, 24 (16.6%) of them were D-cycloserine resistant and 121 (83.4%) were sensitive. There were only synonymous mutations noticed on
,
and
in sensitive strains. Of the 24 D-cycloserine resistant strains, 3 (12.5%) isolates'
and 1 (4.2%) isolates'
happened to be non-synonymous mutations, in which the codes were 188, 318 and 508 of
, and 261 of
, respectively. Results
In this study, plasma nanocoatings with thickness of less than 50
nm were deposited onto two types of intravascular stents made of nitinol (NiTi alloy) and stainless steel from gas mixtures of ...trimethylsilane (TMS) and oxygen (O
2) in a direct current (DC) plasma reactor system. The surface properties, surface morphology, and surface chemistry of the plasma coated stents were characterized using surface contact angle measurements, scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS). In order to investigate their surface endothelialization effects, plasma coated stents were seeded with human umbilical vein endothelial cells (HUVECs) for cell culture study. The cell culture data showed that plasma nanocoatings deposited from a gas mixture of TMS:O
2
=
1:3 gave rise to a statistically significant increase in adhered cell numbers, which were 79.75
±
6.18 on nitinol stents vs. 41.25
±
9.38 cells on uncoated bare controls and 119.50
±
12.40 on stainless stents vs. 56.85
±
12.53 cells on uncoated bare controls. These results evidently demonstrated that plasma nanocoatings prepared from appropriate plasma chemistry or gas composition could significantly enhance the surface endothelialization on both nitinol stents and stainless steel intravascular stents.
Oli goglycerol fatty acid esters (OGEs) are an important kind of polyglycerol fatty acid esters (PGEs) which have been widely used as emulsifiers in food, medicine and cosmetic industries. The aim of ...this study was to investigate the preparation of OGEs by the esterification of olig oglycerol with linoleic acid in a solvent- free system using Lipozyme 435 as the catalyst. The effects of substrate molar ratio, reaction time, reaction temperature, enzyme dosage, and water addition on the efficiency of esterification (EE) were studied. Single factor experiments and response surface methodology (RSM) were employed to optimize the reaction parameters. The optimum conditions were obtained as follows: reaction time 4.52 h, reaction temperature 90 °C, enzyme dosage 2 wt% (based on the total substrate mass), the molar ratio of oligoglycerol to linoleic acid 1.59:1 and no water addition. Under these conditions, the experimental EE (95.82±0.22%) fitted well with that predicted by RSM (96.15%). Similar results were obtained when the process was scaled up to a production of 500 g in a pilot bubble column reactor (BCR). The enzyme maintained 98.2% of the relative activity after 10 batches of reaction in the BCR. Electro spray ionization mass spectrum was employed to rapidly analyze the esterification products, and most species of OGEs have been identified.
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