127 research outputs found
Fractal model and Lattice Boltzmann Method for Characterization of Non-Darcy Flow in Rough Fractures.
The irregular morphology of single rock fracture significantly influences subsurface fluid flow and gives rise to a complex and unsteady flow state that typically cannot be appropriately described using simple laws. Yet the fluid flow in rough fractures of underground rock is poorly understood. Here we present a numerical method and experimental measurements to probe the effect of fracture roughness on the properties of fluid flow in fractured rock. We develop a series of fracture models with various degrees of roughness characterized by fractal dimensions that are based on the Weierstrass-Mandelbrot fractal function. The Lattice Boltzmann Method (LBM), a discrete numerical algorithm, is employed for characterizing the complex unsteady non-Darcy flow through the single rough fractures and validated by experimental observations under the same conditions. Comparison indicates that the LBM effectively characterizes the unsteady non-Darcy flow in single rough fractures. Our LBM model predicts experimental measurements of unsteady fluid flow through single rough fractures with great satisfactory, but significant deviation is obtained from the conventional cubic law, showing the superiority of LBM models of single rough fractures
Soft tissue recurrent ameloblastomas also show some malignant features: a clinicopathological study of a 15-year database
Background: To investigate the clinicopathological features of six cases of soft tissue recurrent ameloblastoma
and explore the role of increased aggressive biological behavior in the recurrences and treatment of this type of
ameloblastomas.
Material and Methods: In this study, we retrospectively reviewed recurrent ameloblastomas during a 15-year period; six cases were diagnosed as soft tissue recurrent ameloblastoma. The clinical, radiographic, cytological and
immunohistochemical records of these six cases were investigated and analyzed.
Results: All the six soft tissue recurrent ameloblastomas occurred after radical bone resection, and were located
in the adjacent soft tissues around the osteotomy regions. In Case 4, the patient developed pulmonary metastasis,
extensive skull-base infiltration and cytological malignancy after multiple recurrences and malignant transformation was diagnosed. In the other five cases, although there were no cytological signs are sufficient to justify
an ameloblastoma as malignant, some malignant features were observed. In Case 1, the tumor showed moderate
atypical hyperplasia and the Ki-67 staining percentage was 40% positive, which are strongly suggestive of potential malignance. In Case 5, the patient developed a second soft tissue recurrence in the parapharyngeal region
and later died of tumor-related complications. All the remaining three patients showed cytology atypia of varying
degrees and high expression of PCNA or Ki-67, which confirmed active cell proliferation.
Conclusions: Increased aggressiveness is an important factor of soft tissue recurrence. An intraoperative rapid
pathological examination and more radical treatment are suggested for these cases
Influence of synthetic superparamagnetic iron oxide on dendritic cells
Yongbin Mou1, Baoan Chen2, Yu Zhang3, Yayi Hou4, Hao Xie4, Guohua Xia2, Meng Tang5, Xiaofeng Huang1, Yanhong Ni1, Qingang Hu1,6 1Central Laboratory of Stomatology, Stomatological Hospital Affiliated Medical School, Nanjing University, 2Department of Hematology, Zhongda Hospital, Medical School, Southeast University, 3State Key Laboratory of Bioelectronics, Jiangsu Key Laboratory for Biomaterials and Devices, Southeast University, 4Immunology and Reproductive Biology Laboratory, Medical School, Nanjing University, 5Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, People's Republic of China; 6Leeds Dental Institute, Faculty of Medicine and Health, University of Leeds, Leeds, UK Background: This study investigated the influence of synthetic superparamagnetic iron oxide (SPIO) on dendritic cells and provides a possible method for labeling these cells. Methods: SPIO nanoparticles were prepared, and their morphology and magnetic properties were characterized. The particles were endocytosed by dendritic cells generated from mouse bone marrow. Labeling efficiency and cellular uptake were analyzed by Prussian blue staining and quantitative spectrophotometric assay. Meanwhile, the surface molecules, cellular apoptosis, and functional properties of the SPIO-labeled dendritic cells were explored by flow cytometry and the mixed lymphocyte reaction assay. Results: The synthetic nanoparticles possessed a spherical shape and good superparamagnetic behavior. The mean concentration of iron in immature and mature dendritic cells was 31.8 ± 0.7 µg and 35.6 ± 1.0 µg per 1 × 106 cells, respectively. After 12 hours of incubation with SPIO at a concentration of 25 µg/mL, nearly all cells were shown to contain iron. Interestingly, cellular apoptosis and surface expression of CD80, CD86, major histocompatibility II, and chemokine receptor 7 in mature dendritic cells were not affected to any significant extent by SPIO labeling. T cell activation was maintained at a low ratio of dendritic cells to T cells. Conclusion: SPIO nanoparticles have good superparamagnetic behavior, highly biocompatible characteristics, and are suitable for use in further study of the migratory behavior and biodistribution of dendritic cells in vivo. Keywords: superparamagnetic iron oxide, dendritic cell, cell labelin
The Effect of Superparamagnetic Iron Oxide Nanoparticle Surface Charge on Antigen Cross-Presentation.
Magnetic nanoparticles (NPs) of superparamagnetic iron oxide (SPIO) have been explored for different kinds of applications in biomedicine, mechanics, and information. Here, we explored the synthetic SPIO NPs as an adjuvant on antigen cross-presentation ability by enhancing the intracellular delivery of antigens into antigen presenting cells (APCs). Particles with different chemical modifications and surface charges were used to study the mechanism of action of antigen delivery. Specifically, two types of magnetic NPs, γF
A simplified mathematical study of thermochemical preparation of particle oxide under counterflow configuration for use in biomedical applications
This study mathematically presents a counterflow non-premixed thermochemical technique for preparing a particle oxide used for cancer diagnosis and treatment. For this purpose, preheating, reaction, melting, and oxidation processes were simulated considering an asymptotic concept. Mass and energy conservation equations in dimensional and non-dimensional forms were solved using MATLAB®. To preserve the continuity in the system and calculate the locations of melting and flame fronts, promising jump conditions were derived. In this research, variations in flame temperature, flame front location and mass fractions of the particle, particle oxide and oxidizer, with position, Lewis number and initial temperature of the particles were investigated. The simulation results were compared with those obtained from an earlier experimental study under the same conditions. Regarding the comparison, an appropriate compatibility was observed between the results. Based on the simulation results, flame temperature was found to be about 1310 K. Positions of flame and melting fronts were found to be − 1.8 mm and − 1.78 mm, respectively
Therapeutic antitumor efficacy of tumor-derived autophagosome (DRibble) vaccine on head and neck cancer
ATR/Chk1/Smurf1 pathway determines cell fate after DNA damage by controlling RhoB abundance
该研究论文首次发现Smurf1可以作为RhoB的E3泛素连接酶,并位于ATR/Chk1信号通路下游参与介导单链DNA损伤引起的细胞凋亡,也为进一步的抗肿瘤药物的研发提供了可靠的细胞生物学和分子生物学依据。
该论文的共同第一作者为生命科学学院2009级博士生郭磊、2011级博士生王梅林和2013级博士生吴勤刚。ATM- and RAD3-related (ATR)/Chk1 and ataxia–telangiectasia mutated (ATM)/Chk2 signalling pathways play critical roles in the DNA damage response. Here we report that the E3 ubiquitin ligase Smurf1 determines cell apoptosis rates downstream of DNA damage-induced ATR/Chk1 signalling by promoting degradation of RhoB, a small GTPase recognized as tumour suppressor by promoting death of transformed cells. We show that Smurf1 targets RhoB for degradation to control its abundance in the basal state. DNA damage caused by ultraviolet light or the alkylating agent methyl methanesulphonate strongly activates Chk1, leading to phosphorylation of Smurf1 that enhances its self-degradation, hence resulting in a RhoB accumulation to promote apoptosis. Suppressing RhoB levels by overexpressing Smurf1 or blocking Chk1-dependent Smurf1 self-degradation significantly inhibits apoptosis. Hence, our study unravels a novel ATR/Chk1/Smurf1/RhoB pathway that determines cell fate after DNA damage, and raises the possibility that aberrant upregulation of Smurf1 promotes tumorigenesis by excessively targeting RhoB for degradation
FIGURE 10 in First records of the family Xylococcidae (Hemiptera: Coccomorpha) in China, with description of a new species
FIGURE 10. Morphology of pre-adult female of Xylococcus castanopsis sp. nov. (A) antenna; (B) large simple pore; (C) thoracic spiracle; (D) small simple pore; (E) invaginated bilocular pores; (F) Pergande's "brownish organ"; (G) multilocular pore with bilocular center; (H) seta on abdomen; (I) anal tube and adjacent region; (J) abdominal spiracle; (K) seta on head.Published as part of Dong, Qingang, 2017, First records of the family Xylococcidae (Hemiptera: Coccomorpha) in China, with description of a new species, pp. 547-556 in Zootaxa 4312 (3) on page 551, DOI: 10.11646/zootaxa.4312.3.8, http://zenodo.org/record/85836
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