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51.
R Viana P Lunkenheimer J Hemberger R B?hmer A Loidl 《Canadian Metallurgical Quarterly》1994,50(1):601-604
The purpose of this report is to present two cases of natal and neonatal teeth including discussion on the various features concerning these conditions as well as the possible management strategies. The first case is a natal tooth in a newborn Saudi girl while the second case is two neonatal teeth in a Saudi boy. 相似文献
52.
E Viana CH da Silva M Tabak H Imasato R Garratt 《Canadian Metallurgical Quarterly》1998,1383(1):130-142
We have previously reported that rhodacyanine dyes, such as 1 and 2, exhibited a potent inhibitory effect on the growth of several tumor cells and that 4-oxothiazolidine (rhodanine) was an essential moiety for antitumor activity. On the basis of our foregoing work, two types of rhodacyanine dyes, which categorized into class I and II depending on the methine length, were synthesized and evaluated as a novel antitumor agent. Attention was particularly focused on the structure-activity study of two heteroaromatic rings. In class I, where the A rings were conjugated to rhodanine via two methine groups, compounds 1, 20, 23, and 24 were found to be efficacious in tumor-bearing nude mice model study, but they did not have the chemical properties (stability, solubility) suitable for clinical use. In contrast, in class II, where the A rings were directly conjugated to rhodanine, compounds 13 and 25, which possessed a benzothiazole moiety for the A ring, exhibited the favorable biological and chemical properties. Therefore, we decided to have a benzothiazole moiety as the A ring and introduce various heterocyclic groups for the B ring. As a result, the pyridinium ring was selected as the optimal moiety for the B ring (compound 13). Further, the variation of counteranion had a profound effect on solubility in water without influence on antitumor activity. Chloride anion was selected as the favorable anion with respect to synthetic method as well as solubility in water. Our study finally led us to the identification of compound 3 (MKT 077, 1-ethyl-2-[[3-ethyl-5-(methylbenzothiazolin-2-ylidene)-4-oxothi azolidin-2 -ylidene]methyl]pyridinium chloride) as the candidate for clinical trials and is currently subjected to further investigation as a potent antitumor agent in phase I clinical trial for the treatment of solid tumors. 相似文献
53.
J.C. Viana 《Polymer Engineering and Science》2006,46(2):181-187
This work explores the fracture behavior of an injection‐molded engineering thermoplastic, poly(oxymethylene), POM. Lateral gated discs of 120 mm diameter and 1.5 mm thick were molded with variations of the melt temperature and injection flow rate. The local thermomechanical environment was characterized by computer simulations of mould filling phase. This also allows the computation of two thermomechanical indices related to the morphological state of the moldings. From the molded discs, double edge notched tensile (DENT) specimens were meticulously cut at different angles with respect to the flow direction and with distinct ligament lengths. The fracture tensile tests were performed at 2 mm/min at controlled room temperature. As the test configuration (specimen geometry) imposes a plane stress state, the stress intensity factor, KI, was calculated as function of the processing conditions and orientation angle with respect to the flow direction. The KI values and their degree of anisotropy are dependent upon processing conditions. Finally, the dependences of KI values upon the thermomechanical indices (and therefore on the expected morphological state of the moldings) are established. POLYM. ENG. SCI. 46:181–187, 2006. © 2005 Society of Plastics Engineers 相似文献
54.
M. Céu Viana Luís C. Oliveira Ana I. Mata 《International Journal of Speech Technology》2003,6(1):83-94
This paper describes a set of experiments aiming at the construction and evaluation of a new phrasing module for European Portuguese text-to-speech synthesis, using classification and regression trees learned from hand-labelled texts. Using the assessment criteria of matching boundary predictions against the corresponding labelled ones, the best solution achieves an overall performance of 91.9%, with 86.3% of correctly assigned breaks and 4.3% of false insertions. Although in absolute terms such scores may be considered surprisingly good given the size of the training set, the total number of exact matches at the sentence level is much lower (22%). This suggested a more formal experiment to test the acceptability of the predicted phrasing in the judgement of human evaluators. As the model was not trained on a labelled speech corpus but on hand-labelled texts, the reference phrasing needed also to be assessed. The evaluation experiment involved 90 participants who were asked to grade both the automatic and the reference phrasings, and also to express their opinion on where the breaks should be placed. As expected, the results showed a large variability among the subjects in their acceptance of a specific sentence partition, and criteria had to be defined to summarise the data from the different evaluators. With the adopted criteria, the performance of the automatic assignment procedure at the sentence level is better rated by human evaluators than by simple matching with the reference corpus (78% vs. 22%, respectively). 相似文献
55.
56.
Numerous transmitter receptors are linked via GTP-binding proteins (G proteins) to membrane phosphoinositide metabolism by phospholipase C (PLC) and generation of second messengers such as activated protein kinase C (PKC), inositol trisphosphate (IP3) and/or elevations in intracellular calcium. In many cases, these same receptors also inhibit a resting ('leak') potassium current (IK(L)), thereby depolarizing neurons. It is unclear if activation of this PLC pathway mediates inhibition of IK(L) by neurotransmitter receptors. Therefore, we tested the contribution of this pathway to the TRH-induced inhibition of IK(L) in rat hypoglossal motoneurons (HMs) using conventional intracellular recording in brainstem slices. When HMs were recorded with electrodes containing 3 M KCl or 30 mM GTP (in KCl), TRH induced a depolarization that recovered quickly (within 8-10 min) and could be repeated with only modest tachyphylaxis (< 20%). However, with electrodes containing the non-hydrolyzable G protein activator, GTP gamma S (10 mM), the TRH-induced depolarization was long lasting (up to 1 h); with electrodes containing the G protein inhibitor, GDP beta S (20 mM) the tachyphylaxis with repeated TRH application was exaggerated (approximately 60%). Activation of PKC by phorbol dibutyrate (10 microM in perfusate) neither mimicked nor occluded the effects of TRH. There were no effects on membrane potential, input resistance (RN) or the response to TRH in HMs during long recordings with electrodes containing high concentrations of IP3 (60 mM).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
57.
PURPOSE: The authors sought to provide relevant data regarding the demographic and clinical aspects of spontaneous and traumatic vitreous hemorrhages to guide clinicians in better delineating the expected etiologic patterns of these hemorrhages in an urban environment. METHODS: The records of 253 consecutive patients with newly diagnosed vitreous hemorrhage seen in a general eye clinic were selected for retrospective analysis. To minimize selection bias of a tertiary care center, patients who were referred to the clinic by outside ophthalmologists for vitreoretinal consultation or those with a history of recent intraocular surgery, postoperative complications, or loss to follow-up were excluded from study. Demographic, ocular, and general medical variables were tabulated for the 200 patients (230 eyes) who met our inclusion criteria. RESULTS: Fifty percent of the patients were black, 26% were white, 23% were Hispanic, and 1% was Oriental. The causes of vitreous hemorrhage were proliferative diabetic retinopathy (PDR) (35.2%), trauma (18.3%), retinal vein occlusion (7.4%), retinal tear without a detachment (7.0%), posterior vitreous detachment (6.5%), proliferative sickle retinopathy (5.7%), retinal tear with a detachment (4.8%), subretinal neovascularization from macular degeneration (2.2%), hypertensive retinopathy (1.7%), unknown (2.5%), and other causes (8.7%). Among black patients with spontaneous vitreous hemorrhage, sickle cell retinopathy and retinal vein occlusion were major causes, each accounting for more than 15% of the cases. Systemic hypertension was associated with vitreous hemorrhage from retinal vein occlusion. CONCLUSION: The authors propose that despite the wide array of causative factors of vitreous hemorrhage, the evaluation of demographic, ocular, and medical variables can significantly aid clinicians in identifying its etiologic patterns. 相似文献
58.
59.
Jovani L. Favero Paulo Laranjeira da Cunha Lage Flávio da Silva Francisco Tatiane F. Machado Luiz Fernando L. R. Silva Fábio P. Santos 《加拿大化工杂志》2024,102(2):941-964
An analysis was conducted on the displacement of a heavy fluid by a miscible light fluid in the flow assurance operation of injecting diesel oil to displace heavy oil in an insulated offshore production line. A three-dimensional computational fluid dynamics model was developed and implemented in OpenFOAM®. It stimulates the production stages, no-touch time, and oil displacement, considering heat transfer through natural convection and conjugated heat transfer through the solid layers of the pipeline. The specific test case focused on the first 180 m of an existing offshore production line. The simulations revealed two primary mechanisms of mixing: turbulence and secondary flows generated by the pipeline curves. Remarkably, the results demonstrate that by injecting a volume of lighter oil 1.3 times the pipeline volume, approximately 90%–95% of the heavy oil can be effectively removed. 相似文献
60.
Ingrid Lessa Leal Yasmin Carolino da Silva Rosa Josenai da Silva Penha Paulo Romano Cruz Correia Pollyana da Silva Melo Danilo Hansen Guimarães Josiane Dantas Viana Barbosa Janice Izabel Druzian Bruna Aparecida Souza Machado 《应用聚合物科学杂志》2019,136(43):48150
In this study, formulations of cassava starch and poly(butylene adipate-co-terephthalate) flexible films were developed, with glycerol, coconut nanocellulose, annatto, and citric acid in different concentrations, as well as the effectiveness of the selected materials in fresh-cut mangoes storage was evaluated. The tensile strength of the different formulations varied from 1.90 (E4) to 6.65 MPa (E3c), and the strain varied from 206.31 (E1c) to 278.41% (E8); this variation was dependent on the percentage of the polymer matrix incorporated. The aw values of the formulations ranged from 0.396 (E2) to 0.569 (E3c). The Formulations E4 and E7 (with additives) presented good properties and were selected to condition mangoes. The micrographs of these films showed regions of micropores that can facilitate the diffusion of water from the packaged product to the surface, allowing decreases in moisture and aw, which is associated with higher color maintenance during fruit storage. E7 presented better barrier properties than E4 (lower values of WVP and water solubility) which may have influenced in a positive way to maintain the stability of the package in the studied period. E7 can be considered as a viable alternative for minimally processed mango storage. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48150. 相似文献