RESUMO
Quickly quantifying the PM2.5 or O3 response to their precursor emission changes is a key point for developing effective control policies. The polynomial function-based response surface model (pf-RSM) can rapidly predict the nonlinear response of PM2.5 and O3 to precursors, but has drawbacks of overload computation and marginal effects (relatively larger prediction errors under strict control scenarios). To improve the performance of pf-RSM, a novel self-adaptive RSM (SA-RSM) was proposed by integrating the machine learning-based stepwise regression for establishing robust models to increase the computational efficiency and the collinearity diagnosis for reducing marginal effects caused by overfitting. The pilot study case demonstrated that compared with pf-RSM, SA-RSM can effectively reduce the training number by 70% and 40% and the fitting time by 40% and 52%, and decrease the prediction error by 49% and 74% for PM2.5 and O3 predictions respectively; moreover, the isopleths of PM2.5 or O3 as a function of their precursors generated by SA-RSM were more similar to those derived by chemical transport model (CTM), after successfully addressing the marginal effect issue. With the improved computation efficiency and prediction performance, SA-RSM is expected as a better scientific tool for decision-makers to make sound PM2.5 and O3 control policies.
Assuntos
Poluentes Atmosféricos , Poluição do Ar , Ozônio , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Monitoramento Ambiental , Aprendizado de Máquina , Ozônio/análise , Material Particulado/análise , Projetos PilotoRESUMO
Purpose: To explore the therapeutic effect of a dietary supplement on dry eye with meibomian gland dysfunction (MGD). Methods: Sixty patients with MGD-related dry eye were included in this prospective and randomized, placebo-controlled study. All the subjects were treated with eye hot compress, artificial tears, and antibiotic ointment. After that, the patients received dietary supplementary or placebo daily for 12 weeks. The dry eye signs, function of MG, and visual quality of the patients were assessed at 4, 8, and 12 weeks after the treatment. Results: Twelve weeks after the treatment, patients who received dietary supplement had a significantly better improvement of dry eye symptoms, in terms of ocular surface diseases index and tear breaking-up time (TBUT), than those who received placebo (P < 0.05). The functions of MG, in terms of meibum quality and MG exclusion and MG obstruction scores, were significantly improved in both dietary supplement and placebo groups (P < 0.05). Patients who received dietary supplement had a significantly better improvement in the MG structure, in terms of acinar diameter and acinar density, than those who received placebo (P < 0.05). The number of inflammatory cells near MG was significantly lower in the dietary supplement group when compared with the placebo group (P < 0.05). The objective visual quality was significantly improved in the dietary supplement group, but not in the placebo group (P < 0.05). Conclusion: The dietary supplement can effectively improve the symptoms and signs of MGD-related dry eye, reduce the inflammatory reaction of MG, restore the gland structure, and indirectly improve the visual quality.
RESUMO
This study was aimed at observing the morphological changes of the cornea with ocular in vivo confocal microscopy (IVCM) in patients with Terrien's marginal degeneration (TMD). Ten patients (20 eyes) with TMD treated in the Department of Ophthalmology, Xiangya Hospital, and 10 healthy controls (20 eyes) were included in the current study. A detailed slit lamp microscopy, anterior segment photography, and corneal IVCM examination were performed for each eye. The density of central and marginal corneal epithelial cells, stromal cells, and subepithelial nerve fibers was compared between the two groups using the Wilcoxon rank sum test. Compared with the control group, the corneal epithelial and endothelial cells in the TMD group showed granular highly reflective substances and thinner subepithelial nerve fibers. The uneven dot-like highly reflective substances without cell structures appeared in the stromal layer of the cornea. The density of central and marginal corneal epithelial cells, stromal cells, and subepithelial nerve fibers was lower in the TMD group (p < 0.05), and they were negatively correlated with severity of the disease (p < 0.05). Our study demonstrated that the density of corneal epithelial cells, stromal cells, and sensory plexus nerve fibers was significantly reduced in the TMD group. The pathological changes were more obvious in the marginal cornea, and it is correlated with severity of the disease.
RESUMO
AIM: To investigate clinical features of optic nerve sheath meningioma (ONSM) that was misdiagnosed, and to find methods to reduce the misdiagnoses. METHODS: Retrospective series study. Twenty-five misdisgnosed patients with unilateral ONSM were collected from Jan. 2008 to Jan. 2015 and the clinical records reviewed. RESULTS: Patients were misdiagnosed with acute papillitis most frequently (n=17), immediately followed by optic atrophy (n=8), ischemic optic neuropathy (n=5), acute retrobulbar optic neuritis (n=5), optic disc vasculitis (n=3). For each patient, the minimum frequency of misdiagnoses was once and the maximum was 4 times. As for the lasting time of being misdiagnosed, the shortest was 1.5mo and the longest was 45mo. Twenty-one cases (84%) were once treated with glucocorticoids, and its side effects was found in seventeen patients. Twenty patients (80%) complained with varying degree of vision loss. When a definite diagnosis was made, sixteen cases (64%) showed slight exophthalmos and eighteen cases (72%) had the tubular ONSM. CONCLUSION: ONSM without loss obvious exophthalmos is easily misdiagnosed in clinic, and for most of these ONSMs are tubular.