Mechanical properties of sinter-forged Al2O3-ZrO2 ceramics

Two kinds of composites, Al₂O₃-25 wt% ZrO₂(2 mol% Y₂O₃) (Y-ZTA), Al₂O₃-25 wt% ZrO₂(8 mol% CeO₂) (Ce-ZTA) were produced by the sinter-forging process. The effect of presintering temperature on the mechanical properties of the composites was examined. The sinter-forging process increased the room-temperature bending strength in comparison with pressureless sintering, owing to the smaller grain size in sinter-forged bodies than in pressureless sintered ones. It was found necessary to keep the presintering temperature considerably lower than sinter-forging temperature in order to improve the room-temperature strength. The strength of sinter-forged Ce-ZTA was higher than that of sinter-forged Y-ZTA. The residual surface compressive stress induced by the phase transition during grinding in Ce-ZTA was found to be effective to further improve the strength and fracture toughness.     

Gross periostitis ossificans in mandibular osteomyelitis. Review of the English literature and radiographic variation

BACKGROUND: Although the airway epithelium participates in inflammation and repair, the circadian expression of epithelial cell markers involved in these processes has not been investigated. OBJECTIVE: We sought to determine whether expression of CD51 (vitronectin and fibronectin receptor), CD54 (intercellular adhesion molecule-1), HLA-DR (activation marker), CD29 (beta1 integrin), CD49b (collagen receptor), and CD11b (complement receptor) exhibit a circadian rhythm in asthma. METHODS: Eleven patients with nocturnal asthma (NA), 9 subjects with nonnocturnal asthma (NNA), and 10 control subjects underwent bronchoscopy at 4 PM and 4 AM in a random order 1 week apart, with brushing of the proximal and distal airways. The percentage of cells staining for a particular marker was determined. RESULTS: At 4 PM, HLA-DR in the proximal airways and CD54 in the distal airways was significantly greater in control subjects as compared with asthmatic subjects (HLA-DR, control subjects: 10.0% [range, 5.0% to 21.0%]; NNA: 8.0% [range, 4.0% to 14.5%] NA: 3.5% [range, 2.0% to 6.0%], P = .01; CD54, control subjects: 17.0% [range, 8.0% to 25.0%], NNA: 8.0% [range, 5.3% to 11.5%], NA: 7.0% [range, 4.0% to 15.0%], P = .O;). At 4 AM, CD51 in the distal airways was significantly greater in patients with NA as compared with patients with NNA and control subjects (control subjects, 23.0% [range, 13.8% to 30.5%]; NNA, 32.0% [range, 13.0% to 35.0%]; NA, 40.0% [range, 23.0% to 50.0%], P = .05). Expression of CD51 in the distal airways correlated with the degree of airway obstruction (r = -0.57, P = .001). Control subjects exhibited significant circadian variation in the expression of HLA-DR in the proximal airways and CD54 in the distal airways. CONCLUSION: The increased CD51 at night in patients with NA may be related to increased airway inflammation and repair processes in response to injury. The circadian changes in CD54 and HLA-DR in control subjects require further study to determine their significance. (J Allergy Clin     

Discrepancy between surgeon''s binocular parallax perception and manipulation in the neurosurgical operation

The present study was undertaken after the detection of one case of cutaneous leishmaniasis with presumed infection in one of the three remaining wooded areas in the urban area of the city of Maringá, Southern Brazil; also in view of the lack of knowledge about sand flies and their behavior. From June to September, 1995, sand flies were caught with Falc?o traps during the night in the remaining wooded areas (Parque do Ingá, Bosque Dois and Horto Florestal). A total of 2,907 sand flies were caught in Parque do Ingá; 1,723 of them were aught in forest traps and 1,184 in wild animal shelter traps at the zoo. The results show that Lutzomyia whitmani is better adapted to the three areas under study and that it frequently occurs in wild animal shelters within the urban perimeter of Maringá.     

Radical resection of primary malignant melanoma of the gallbladder with multiple metastases: report of a case

We present herein an usual case of primary malignant melanoma of the gallbladder in a 51-year-old man in whom an exploratory laparotomy for melena revealed six malignant melanoma lesions located in the gallbladder, main pancreatic duct, stomach, duodenum, jejunum, and a mesenteric lymph node. Total pancreatectomy was performed and histologically, junctional activity was seen only in the gallbladder, suggesting that this was the primary site. No melanotic lesions were found on the skin or eyes. The metastases to the main pancreatic duct and gastrointestinal tract appeared likely to have occurred as a consequence of the mucosal dissemination of the tumor cells shed into the bile. The post-operative course was uneventful and combined chemotherapy was administered for 16 months. No new metastatic lesions were found until 21 months postoperatively, when metastases were detected in the brain and thoracic spinal cord. These metastatic tumors were removed surgically, but the patient died from cerebral disturbance 26 months after the initial operation. Thus, we consider that aggressive surgical therapy was effective for extending the survival time and improving the quality of life of this patient.     

Gut Microbial Fatty Acid Metabolites Reduce Triacylglycerol Levels in Hepatocytes

Hydroxy and oxo fatty acids were recently found to be produced as intermediates during gut microbial fatty acid metabolism. Lactobacillus plantarum produces these fatty acids from unsaturated fatty acids such as linoleic acid. In this study, we investigated the effects of these gut microbial fatty acid metabolites on the lipogenesis in liver cells. We screened their effect on sterol regulatory element binding protein‐1c (SREBP‐1c) expression in HepG2 cells treated with a synthetic liver X receptor α (LXRα) agonist (T0901317). The results showed that 10‐hydroxy‐12(Z)‐octadecenoic acid (18:1) (HYA), 10‐hydroxy‐6(Z),12(Z)‐octadecadienoic acid (18:2) (γHYA), 10‐oxo‐12(Z)‐18:1 (KetoA), and 10‐oxo‐6(Z),12(Z)‐18:2 (γKetoA) significantly decreased SREBP‐1c mRNA expression induced by T0901317. These fatty acids also downregulated the mRNA expression of lipogenic genes by suppressing LXRα activity and inhibiting SREBP‐1 maturation. Oral administration of KetoA, which effectively reduced triacylglycerol accumulation and acetyl‐CoA carboxylase 2 (ACC2) expression in HepG2 cells, for 2 weeks significantly decreased Srebp‐1c, Scd‐1, and Acc2 expression in the liver of mice fed a high‐sucrose diet. Our findings suggest that the hypolipidemic effect of the fatty acid metabolites produced by L. plantarum can be exploited in the treatment of cardiovascular diseases or dyslipidemia.     

On tangible user interfaces,humans and spatiality

Like the prehistoric twig and stone, tangible user interfaces (TUIs) are objects manipulated by humans. Tangible user interface success will depend on how well they exploit spatiality, the intuitive spatial skills humans have with the objects they use. In this paper, we carefully examine the relationship between humans and physical objects, and related previous research. From this examination, we distill a set of observations and turn these into heuristics for incorporation of spatiality into TUI application design, a cornerstone for their success. Following this line of thought, we identify spatial TUIs, the subset of TUIs that mediate interaction with shape, space and structure. We then examine several existing spatial TUIs using our heuristics.     

Optimization of the Advanced Earth Observing Satellite II Global Imager channels by use of radiative transfer calculations

The channel specifications of the Global Imager onboard the Advanced Earth Observing Satellite II have been determined by extensive numerical experiments. The results show that there is an optimum feasible position for each ocean color channel. The bandwidth of the 0.763-microm channel should be less than 10 nm for good sensitivity to the cloud top height and geometric thickness of the cloud layer; a 40-nm bandwidth is suitable for the 1.38-microm channel to have the strongest contrast between cloudy and clear radiance with a sufficient radiant energy; and a 3.7-microm channel is better than a 3.95-microm channel for estimation of the sea surface temperature (SST) and determination of the cloud particle size when the bandwidth of the channel is 0.33 microm. A three-wavelength combination of 6.7, 7.3, and 7.5 microm is an optimized choice for water vapor profiling. The combination of 8.6, 10.8, and 12.0 microm is suitable for cloud microphysics and SST retrievals with the split-window technique.     

Increasing discrepancy between absolute and effective indexes of research output in a Brazilian academic department

We investigate possible effects from a strong encouragement for a large number of publications on the scientific production of a Brazilian cell biology department. An average increase in individual absolute production and a concomitant decrease in individual participation in each paper were detected by traditional bibliometric parameters, such as number of publications, citations, impact factors and h index, combined to their “effective” versions, in which co-authorship is taken into consideration. The observed situation, which might well represent a national trend, should be considered as a strong warning against current criteria of scientific evaluation heavily based on uncritical counting of publications.     

Characterization of deep levels in Si‐MOS structure using ICTS measurement

Interface traps and bulk traps induced by heavy metal impurities in Si‐MOS structure were characterized by isothermal capacitance transient spectroscopy (ICTS). In addition, the use of an MOS inversion time is proposed for the detection of a very low density of heavy metal impurities in the ICTS measurements. It is shown that heavy metal impurities enhanced interface trap densities as well as induced bulk traps. The degree of the enhancement varies with the species of heavy metal impurities. Interface traps may be enhanced by the substitutional heavy metal impurities. Moreover, it has been ascertained that a very low level of contamination by heavy metals can be detected by using the MOS inversion time. This has been experimentally shown by the use of a copper impurity. Furthermore, it has been clarified from the change of MOS inversion time that interface traps are also detrimental to the carrier generation lifetime. © 2000 Scripta Technica, Electr Eng Jpn, 130(4): 76–86, 2000     

Experimental Investigation of the Mixing Between Hot and Cold Gas in Two Cooling Processes

The mixing between a hot turbulent flow and a cold fluid, injected through a porous plate or using a discrete injection, is experimentally investigated. The blowing is shown to dramatically modify the dynamic and thermal fields, whereas the discrete injection has a weaker effect. The influence on the average quantities and fluctuating parts are found to be different. The effect of the main flow temperature is addressed and a discussion for the mixing in the blowing and discrete injection cases is proposed.