Leukemic predisposition of mice transplanted with gene-modified hematopoietic precursors expressing flt3 ligand

flt3/flk-2 ligand (FL) is a cytokine that exhibits synergistic activities in combination with other early acting factors on subpopulations of hematopoietic stem/progenitor cells. In addition to normal hematopoietic precursors, expression of the FL receptor, flt3R, has been frequently demonstrated on the blast cells from patients with acute B-lineage lymphoblastic, myeloid, and biphenotypic (also known as hybrid or mixed) leukemias. Because many of these leukemic cell types express FL, the possibility has been raised that altered regulation of FL-mediated signaling might contribute to malignant transformation or expansion of the leukemic clone. In humans, FL is predominantly synthesized as a transmembrane protein that must undergo proteolytic cleavage to generate a soluble form. To investigate the consequences of constitutively expressing the analogous murine FL isoform in murine hematopoietic stem/progenitor cells, lethally irradiated syngeneic mice (18 total) were engrafted with post-5-fluorouracil-treated bone marrow cells transduced ex vivo with a recombinant retroviral vector (MSCV-FL) encoding murine transmembrane FL. Compared with control mice (8 total), MSCV-FL mice presented with a mild macrocytic anemia but were otherwise healthy for more than 5 months posttransplant (until 22 weeks). Subsequently, all primary MSCV-FL recipients observed for up to 1 year plus 83% (20 of 24) of secondary MSCV-FL animals that had received bone marrow from asymptomatic primary hosts reconstituted for 4 to 5 months developed transplantable hematologic malignancies (with mean latency periods of 30 and 23 weeks, respectively). Phenotypic and molecular analyses indicated that the tumor cells expressed flt3R and displayed B-cell and/or myeloid markers. These data, establishing that dysregulated expression of FL in primitive hematopoietic cells predisposes flt3R+ precursors to leukemic transformation, underscore a potential role of this cytokine/receptor combination in certain human leukemias.     

Fabrication, Microstructural Characterization, and Mechanical Properties of Polycrystalline t'-Zirconia

Large-grained (100- to 200-μm), yttria-doped, polycrystalline t '-zirconia ceramics were fabricated by heat-treating presintered samples at temperatures 2100°C. Polarized light microscopy revealed the ferroelastic domain structure in the t ' samples. XRD showed that no monoclinic phase was detected on as-polished, ground and fracture surfaces, or on surfaces while under a tensile stress as high as 400 MPa. By contrast, relative changes occurred in the tetragonal peak intensities, which were attributed to ferroelasatic domain switching. The higher toughness of 3-mol%-Y₂O₃-doped t ' samples (7.7 MPa · m^1/2) compared to that of 8 mol% Y₂O₃ cubic samples (2.4 MPa · m^1/2) was explained in part by ferroelastic domain switching.     

Evaluating non-speech sound visualizations for the deaf

Sounds such as co-workers chatting nearby or a dripping faucet help us maintain awareness of and respond to our surroundings. Without a tool that communicates ambient sounds in a non-auditory manner, maintaining this awareness is difficult for people who are deaf. We present an iterative investigation of peripheral, visual displays of ambient sounds. Our major contributions are: (1) a rich understanding of what ambient sounds are useful to people who are deaf, (2) a set of visual and functional requirements for a peripheral sound display, based on feedback from people who are deaf, (3) lab-based evaluations investigating the characteristics of four prototypes, and (4) a set of design guidelines for successful ambient audio displays, based on a comparison of four implemented prototypes and user feedback. Our work provides valuable information about the sound awareness needs of the deaf and can help to inform further design of such applications.     

金属与陶瓷界面波阻性能与材料状态关系研究

利用一维Hopkinson压杆实验装置做应力波发生源在陶瓷装甲钢复合结构中产生应力波 ,用应变片测量陶瓷与不同回火状态装甲钢间界面反射和透射应力波的能力。结果发现 ,不同状态的装甲钢具有不同的反射和透射应力波的能力     

Automatic fuzzy ontology generation for semantic help-desk support

Customer service support is an important operation for most multinational manufacturing companies. With the advancement of internet technologies, customer services nowadays are supported through web-based systems. More recently, rapid development of the semantic web and semantic web services has prompted us to develop a semantic help-desk for supporting customer services over the semantic web environment, which is presented in this paper. In particular, a fuzzy formal concept analysis (FCA)-based approach is developed for automatic generation of fuzzy machine service ontology that can deal with uncertain information. The proposed automatic fuzzy ontology generation technique consists of the following steps: fuzzy formal concept analysis, fuzzy conceptual clustering, and ontology generation. As such, the supporting machine services provided by the proposed system will potentially improve customer satisfaction in terms of reducing machine down time and increasing productivity. In this paper, an experiment has also been conducted for performance evaluation. The experimental result shows that the proposed approach has attained good performance in terms of both accuracy and efficiency when the queries are associated with appropriate membership values, and a suitable confident threshold is set.     

Intraorbital air simulating an intraocular foreign body

PURPOSE: To present an ultrasonographic finding that simulated an intraocular foreign body after repair of a ruptured globe. METHOD: Case report. An ultrasonogram of a post-trauma eye was correlated with a computed tomographic scan. RESULTS: B-scan ultrasonography was performed on an eye after repair of a corneoscleral laceration. The ultrasonogram showed a highly reflective echo source suggestive of a foreign body; however, an orbital computed tomographic scan demonstrated that the lesion was intraorbital air. CONCLUSION: Although a highly reflective echo source in the presence of a ruptured globe may suggest a foreign body, the presence of orbital air should also be considered when interpreting ultrasonograms used in the preoperative and postoperative management of globe trauma.     

X-linked female band heterotopia-male lissencephaly syndrome

OBJECTIVE: The purpose of this study was to determine if a small pneumothorax would influence the pleurodesis resulting from talc instillation. METHODS: Sixty rabbits received an intrapleural injection of 400 mg/kg talc slurry. One half also received 10 mL of air intrapleurally after the talc. Ten rabbits in each group were killed 2, 14, and 28 days after instillation. RESULTS: Two days after the injection, the mean volume of air in the animals that had received the air was 7.5+/-0.4 mL. There was no air present in any other rabbits. The volume of pleural fluid and the pleural fluid glucose, protein, cell count, and differential were similar in both groups on day 2, while the LDH level was significantly higher in the air group (p<0.05). The degree of gross adhesions and microscopic fibrosis was similar in both groups and increased with time. CONCLUSIONS: A small pneumothorax does not decrease the efficacy of talc pleurodesis in our experimental model. These results suggest that the presence of a small amount of intrapleural air is not a contraindication to talc pleurodesis in humans.