110 resultados para Porcelain, Chinese
Resumo:
One of the most widespread and abundant families of pharmacologically active peptides in amphibian defensive skin secretions is the bradykinins and related peptides. Despite retaining certain primary structural attributes that assign them to this peptide family, bradykinins and related peptides are unique among amphibian skin peptides in that they exhibit a wide range of primary structural variations, post-translational modifications and/or N-terminal or C-terminal extensions. Initially it was believed that their high degree of primary structural heterogeneity was reflective of random gene mutations within species, but latterly, there is an increasing body of evidence that the spectrum of structural modifications found within this peptide family is reflective of the vertebrate predator spectrum of individual species. Here we report the discovery of ornithokinin (avian bradykinin – Thr6, Leu8-bradykinin) in the skin secretion of the Chinese bamboo odorous frog, Odorrana versabilis. Molecular cloning of its biosynthetic precursor-encoding cDNA from a skin secretion-derived cDNA library revealed a deduced open-reading frame of 86 amino acid residues, encoding a single copy of ornithokinin towards its C-terminus. The domain architecture of this ornithokinin precursor protein was consistent with that of a typical amphibian skin peptide and quite different to that of the ornithokininogen from chicken plasma. Ornithokinin was reported to induce hypotension in the chicken and to contract the chicken oviduct but to have no obvious effect on the rat uterus. However, in this study, synthetic ornithokinin was found to contract the rat ileum (EC50 = 539 nM) and to increase contraction frequency in the rat uterus (EC50 = 1.87 μM).
Resumo:
As part of a UK-China science bridge project - a UK government funded initiative linking leading universities and businesses in selective partnering countries in 2009 a collaborative research programme was initiated between Queen's University and the Research Institute of High Performance Concrete (part of the Central Research Institute of Building and Construction) in Beijing.
For further details email b.magee@ulster.ac.uk
Resumo:
Using fMRI, we conducted two types of property generation task that involved language switching, with early bilingual speakers of Korean and Chinese. The first is a more conventional task in which a single language (L1 or L2) was used within each trial, but switched randomly from trial to trial. The other consists of a novel experimental design where language switching happens within each trial, alternating in the direction of the L1/L2 translation required. Our findings support a recently introduced cognitive model, the 'hodological' view of language switching proposed by Moritz-Gasser and Duffau. The nodes of a distributed neural network that this model proposes are consistent with the informative regions that we extracted in this study, using both GLM methods and Multivariate Pattern Analyses: the supplementary motor area, caudate, supramarginal gyrus and fusiform gyrus and other cortical areas.
Resumo:
An MS/MS based analytical strategy was followed to solve the complete sequence of two new peptides from frog (Odorrana schmackeri) skin secretion. This involved reduction and alkylation with two different alkylating agents followed by high resolution tandem mass spectrometry. De novo sequencing was achieved by complementary CID and ETD fragmentations of full-length peptides and of selected tryptic fragments. Heavy and light isotope dimethyl labeling assisted with annotation of sequence ion series. The identified primary structures are GCD[I/L]STCATHN[I/L]VNE[I/L]NKFDKSKPSSGGVGPESP-NH2 and SCNLSTCATHNLVNELNKFDKSKPSSGGVGPESF-NH2, i.e. two carboxyamidated 34 residue peptides with an aminoterminal intramolecular ring structure formed by a disulfide bridge between Cys2 and Cys7. Edman degradation analysis of the second peptide positively confirmed the exact sequence, resolving I/L discriminations. Both peptide sequences are novel and share homology with calcitonin, calcitonin gene related peptide (CGRP) and adrenomedullin from other vertebrates. Detailed sequence analysis as well as the 34 residue length of both O. schmackeri peptides, suggest they do not fully qualify as either calcitonins (32 residues) or CGRPs (37 amino acids) and may justify their classification in a novel peptide family within the calcitonin gene related peptide superfamily. Smooth muscle contractility assays with synthetic replicas of the S–S linked peptides on rat tail artery, uterus, bladder and ileum did not reveal myotropic activity.
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PURPOSE: This systematic review aimed to report and explore the survival of dental veneers constructed from non-feldspathic porcelain over 5 and 10 years.
MATERIALS AND METHODS: A total of 4,294 articles were identified through a systematic search involving all databases in the Cochrane Library, MEDLINE (OVID), EMBASE, Web of Knowledge, specific journals (hand-search), conference proceedings, clinical trials registers, and collegiate contacts. Articles, abstracts, and gray literature were sought by two independent researchers. There were no language limitations. One hundred sixteen studies were identified for full-text assessment, with 10 included in the analysis (5 qualitative, 5 quantitative). Study characteristics and survival (Kaplan-Meier estimated cumulative survival and 95% confidence interval [CI]) were extracted or recalculated. A failed veneer was one which required an intervention that disrupted the original marginal integrity, had been partially or completely lost, or had lost retention more than twice. A meta-analysis and sensitivity analysis of Empress veneers was completed, with an assessment of statistical heterogeneity and publication bias. Clinical heterogeneity was explored for results of all veneering materials from included studies.
RESULTS: Within the 10 studies, veneers were fabricated with IPS Empress, IPS Empress 2, Cerinate, and Cerec computer-aided design/computer-assisted manufacture (CAD/CAM) materials VITA Mark I, VITA Mark II, Ivoclar ProCad. The meta-analysis showed the pooled estimate for Empress veneers to be 92.4% (95% CI: 89.8% to 95.0%) for 5-year survival and 66% to 94% (95% CI: 55% to 99%) for 10 years. Data regarding other non-feldspathic porcelain materials were lacking, with only a single study each reporting outcomes for Empress 2, Cerinate, and various Cerec porcelains over 5 years. The sensitivity analysis showed data from one study had an influencing and stabilizing effect on the 5-year pooled estimate.
CONCLUSION: The long-term outcome (> 5 years) of non-feldspathic porcelain veneers is sparsely reported in the literature. This systematic review indicates that the 5-year cumulative estimated survival for etchable non-feldspathic porcelain veneers is over 90%. Outcomes may prove clinically acceptable with time, but evidence remains lacking and the use of these materials for veneers remains experimental.
Resumo:
PURPOSE: This systematic review reports on the survival of feldspathic porcelain veneers.
MATERIALS AND METHODS: The Cochrane Library, MEDLINE (OVID), Embase, Web of Knowledge, selected journals, clinical trials registers, and conference proceedings were searched independently by two reviewers. Academic colleagues were also contacted to identify relevant research. Inclusion criteria were human cohort studies (prospective and retrospective) and controlled trials assessing outcomes of feldspathic porcelain veneers in more than 15 patients and with at least some of the veneers in situ for 5 years. Of 4,294 articles identified, 116 studies underwent full-text screenings and 69 were further reviewed for eligibility. Of these, 11 were included in the qualitative analysis and 6 (5 cohorts) were included in meta-analyses. Estimated cumulative survival and standard error for each study were assessed and used for meta-, sensitivity, and post hoc analyses. The I2 statistic and the Cochran Q test and its associated P value were used to evaluate statistical heterogeneity, with a random-effects meta-analysis used when the P value for heterogeneity was less than .1. Galbraith, forest, and funnel plots explored heterogeneity, publication patterns, and small study biases.
RESULTS: The estimated cumulative survival for feldspathic porcelain veneers was 95.7% (95% confidence interval [CI]: 92.9% to 98.4%) at 5 years and ranged from 64% to 95% at 10 years across three studies. A post hoc meta-analysis indicated that the 10-year best estimate may approach 95.6% (95% CI: 93.8% to 97.5%). High levels of statistical heterogeneity were found.
CONCLUSIONS: When bonded to enamel substrate, feldspathic porcelain veneers have a very high 10-year survival rate that may approach 95%. Clinical heterogeneity is associated with differences in reported survival rates. Use of clinically relevant survival definitions and careful reporting of tooth characteristics, censorship, clustering, and precise results in future research would improve metaanalytic estimates and aid treatment decisions.
Resumo:
PURPOSE: Disordered sleep and myopia are increasingly prevalent among Chinese children. Similar pathways may be involved in regulation of both sleep cycles and eye growth. We therefore sought to examine the association between disordered sleep and myopia in this group. METHODS: Urban primary school children participating in a clinical trial on myopia and outdoor activity underwent automated cycloplegic refraction with subjective refinement. Parents answered questions about children's sleep duration, sleep disorders (Children's Sleep Habits Questionnaire [CSHQ]), near work and time spent outdoors. RESULTS: Among 1970 children, 1902 (96.5%, mean [standard deviation SD] age 9.80 [0.44] years, 53.1% boys) completed refraction and questionnaires. Myopia < = -0.50 Diopters was present in both eyes of 588 (30.9%) children (1329/3804 = 34.9% of eyes) and 1129 children (59.4%) had abnormal CSHQ scores (> 41). In logistic regression models by eye, odds of myopia < = -0.50D increased with worse CSHQ score (Odds Ratio [OR] 1.01 per point, 95% Confidence Interval [CI] [1.001, 1.02], P = 0.014) and more night-time sleep (OR 1.02, 95% CI [1.01, 1.04, P = 0.002], while male sex (OR 0.82, 95% CI [0.70, 0.95], P = 0.008) and time outdoors (OR = 0.97, 95% CI [0.95, 0.99], P = 0.011) were associated with less myopia. The association between sleep duration and myopia was not significant (p = 0.199) for total (night + midday) sleep. CONCLUSIONS: Myopia and disordered sleep were both common in this cohort, but we did not find consistent evidence for an association between the two. TRIAL REGISTRATION: clinicaltrials.gov NCT00848900.
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Purpose: To identify the specific characteristics making glasses designs, particularly those compatible with adjustable glasses, more or less appealing to Chinese children and their parents. Patients and Methods: Primary and secondary school children from urban and rural China with < = -1.00 diopters of bilateral myopia and their parents ranked four conventional-style frames identified by local optical shops as popular versus four child-specific frames compatible with adjustable spectacles. Scores based on the proportion of maximum possible ranking were computed for each style. Selected children and their parents also participated in Focus Groups (FGs) discussing spectacle design preference. Recordings were transcribed and coded by two independents reviewers using NVivo software. Results: Among 136 urban primary school children (age range 9-11 years), 290 rural secondary school children (11-17 years) and 16 parents, all adjustable-style frames (scores on 0-100 scale 25.7-62.4) were ranked behind all conventional frames (63.0-87.5). For eight FGs including 12 primary children, 26 secondary children and 16 parents, average kappa values for NVivo coding were 0.81 (students) and 0.70 (parents). All groups agreed that the key changes to make adjustable designs more attractive were altering the round lenses to rectangular or oval shapes and adding curved earpieces for more stable wear. The thick frames of the adjustable designs were considered stylish, and children indicated they would wear them if the lens shape were modified. Conclusions: Current adjustable lens designs are unattractive to Chinese children and their parents, though this study identified specific modifications which would make them more appealing.
Resumo:
Importance: This article provides, to our knowledge, the first longitudinal population-based data on refractive error (RE) in Chinese persons.
Objective: To study cohort effects and changes associated with aging in REs among Chinese adults.
Design, Setting, and Participants: A 2-year, longitudinal population-based cohort study was conducted in southern China. Participants, identified using cluster random sampling, included residents of Yuexiu District, Guangzhou, China, aged 35 years or older who had undergone no previous eye surgery.
Methods: Participants underwent noncycloplegic automated refraction and keratometry in December 2008 and December 2010; in a random 50% sample of the participants, anterior segment ocular coherence tomography measurement of lens thickness, as well as measurement of axial length and anterior chamber depth by partial coherence laser interferometry, were performed.
Main Outcomes and Measures: Two-year change in spherical equivalent refraction (RE), lens thickness, axial length, and anterior chamber depth in the right eye.
Results: A total of 745 individuals underwent biometric testing in both 2008 and 2010 (2008 mean [SD] age, 52.2 [11.5] years; 53.7% women). Mean RE showed a 2-year hyperopic shift from −0.44 (2.21) to −0.31 (2.26) diopters (D) (difference, +0.13; 95% CI, 0.11 to 0.16). A consistent 2-year hyperopic shift of 0.09 to 0.22 D was observed among participants aged 35 to 64 years when stratifying by decade, suggesting that a substantial change in RE with aging may occur during this 30-year period. Cross-sectionally, RE increased only in the cohort younger than 50 years (0.11 D/y; 95% CI, 0.06 to 0.16). In the cross-sectional data, axial length decreased at −0.06 mm/y (95% CI, −0.09 to −0.04), although the 2-year change in axial length was positive and thus could not explain the cross-sectional difference. These latter results suggest a cohort effect, with greater myopia developing among younger persons.
Conclusions and Relevance: This first Chinese population-based longitudinal study of RE provides evidence for both important longitudinal aging changes and cohort effects, most notably greater myopia prevalence among younger persons.