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1.
Bioprocess Biosyst Eng ; 46(4): 589-597, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36670301

RESUMO

Pre-hydrolysate liquor, as an inevitable by-product, contains a large amount of xylose, and is therefore an inexpensive feedstock that can be upgraded to value-added chemical xylonic acid. However, inhibitors, simultaneously formed in lignocellulose pretreatment process, are regarded as the major obstacle for effectively bio-converting xylose in pre-hydrolysate into xylonic acid. In this study, Gluconobacter oxydans, with highly selective and efficient, was employed for xylonic acid production; the impacts of five typical toxic inhibitory compounds on xylonic acid productivity and the activity of the membrane-bound dehydrogenase were evaluated. The results revealed that the inhibitors showed different degrees of influence toward xylonic acid production, and the order of inhibitory effect for acidic inhibitors was formic acid > acetic acid > levulinic acid; the inhibitory effect of aldehyde inhibitors was furfural > 5-hydroxymethyl-furfural. This study provides an important basis of metabolic modification and detoxification process for enhancing inhibitor tolerance and xylonic acid productivity.


Assuntos
Gluconobacter oxydans , Fermentação , Gluconobacter oxydans/metabolismo , Xilose/metabolismo , Furaldeído/metabolismo , Ácidos
2.
Bioresour Technol ; 348: 126811, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35131459

RESUMO

An acetic acid-mediated bio-oxidation strategy with Gluconobacter oxydans was developed to produce valuable 2-ketogluconic acid from lignocellulosic biomass. Metabolically, glucose is firstly oxidized to gluconic acid and further oxidized to 2-keto-gluconic acid by Gluconobacter oxydans. As a specific inhibitor for microbial fermentation generated from pretreatment, acetic acid was validated to have a down-regulated effect on bio-oxidizing glucose to gluconic acid. Nevertheless, it significantly facilitated 2-keto-gluconic acid accumulation and improved gluconate dehydrogenase activity. In the presence of 5.0 g/L acetic acid, the yield of 2-keto-gluconic acid increased from 38.0% to 80.5% using pure glucose as feedstock with 1.5 g/L cell loading. Meanwhile, 44.6 g/L 2-keto-gluconic acid with a yield of 83.5% was also achieved from the enzymatic hydrolysate. 2-keto-gluconic acid production, found in this study, laid a theoretical foundation for the industrial production of 2-keto-gluconic acid by Gluconobacter oxydans using lignocellulosic materials.


Assuntos
Gluconobacter oxydans , Ácido Acético , Fermentação , Gluconatos , Oxirredução
3.
Bioresour Technol ; 316: 123944, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32769000

RESUMO

Xylonic acid can be produced with high-yield from hemicelullosic xylose, which accounts for 25% of the total sugars in lignocellulosic material. The key barrier associated with efficient bio-oxidation of hemicellulosic xylose to xylonic acid is the serious foam formed in downstream air-aerated and agitated bioreaction process, which caused by the high viscosity of concentrated pre-hydrolysate. Powdered activated carbon treatment can selectively absorb the non-sugar compounds with relatively low losses of xylose, which is beneficial for the valuable xylose derivatives production. In this present study, powdered activated carbon was employed for treating the concentrated pre-hydrolysate from diluted acid pretreated corncob. The results indicated that the powdered activated carbon treatment significantly reduced the viscosity of concentrated pre-hydrolysate and the other non-sugar compounds, which enabled scale-up lignocellulosic xylonic acid production using the air-aerated and agitated bioreactor.


Assuntos
Gluconobacter oxydans , Carvão Vegetal , Fermentação , Polissacarídeos , Pós , Xilose
4.
Artigo em Inglês | MEDLINE | ID: mdl-28484503

RESUMO

Aims. To evaluate the efficacy of Lian-Se formula (LSF), one Chinese herb formulation for treating sialorrhea and frequent overnight urination in patients with Parkinson's disease (PD). Methods. 96 PD patients suffering from sialorrhea and/or frequent nighttime urination were divided into two groups: an LSF group (n = 48) treated with LSF for 6 weeks and a placebo group (n = 48) treated with a placebo formula whose appearance and taste were the same as LSF for 6 weeks. All patients were treated by standard antiparkinsonism medicine according to the PD guideline of China. The changes of the quantity of saliva (QS) (mL), frequency of nighttime urination (FNU) and early sleep activity (ESA), and nocturnal activity (NA) by analyzing actigraphic records as the primary results and the total score of unified Parkinson's disease rating scale (UPDRS) and the Epworth Sleepiness Scale (ESS) as the secondary results were used to evaluate the clinical efficacy in both groups. Results. There were no significant differences in the baseline values of QS, FNU, NA, ESA, UPDRS total score, and ESS between the two groups. At the end of week 6, the QS, FNU, NA, and ESA in the LSF group showed superior results to those of the placebo group with no differences in the total UPDRS score between the two groups during the investigation. The ESS was significantly improved at the end of week 6 compared with the baseline and the placebo group. Laboratory test results indicated there were no side effects in either group. Conclusion. The findings of LSF treatment have clear clinical effects in patients with sialorrhea and frequent overnight urination. LSF thus appears to be a potential choice as an additional drug that can improve the sialorrhea and frequent overnight urination symptoms of PD patients.

5.
Artigo em Inglês | MEDLINE | ID: mdl-27110267

RESUMO

Aim. To determine one traditional Chinese medicine (TCM) Nao-Xue-Shu oral liquid which protects and improves secondary brain insults (SBI) in hypertensive cerebral hemorrhage (HCH). Methods. 158 patients with HCH were divided into routine clinical medicine plus Nao-Xue-Shu oral liquid (n = 78) as treatment group, and routine clinical medicine (n = 80) only served as the control group. The incidence of SBI and the classification of a favorable prognosis and a bad prognosis using the Glasgow outcome scale (GOS) were assessed to evaluate the clinical effects. The changes of IL-6 and TNF-α levels were determined to study the mechanism of the effects for the TCM. Results. The incidence of SBI at the end of week 2 was 8.97% in the treatment group and 23.75% in the control group, and the difference was significant (P < 0.001). The incidence of a favorable prognosis was 48.72% in the treatment group and 32.72% in the control group, and the difference was significant (P < 0.01) at the end of week 2. These findings indicate clear differences for IL-6 and TNF-α at the end of week 1 and week 2 compared with before treatment for the treatment group and a marked difference at the end of week 2 between the two groups. It also shows a significant difference between the end of week 2 and before treatment for IL-6 and TNF-α for the control group, although the difference was much smaller than the treatment group. Conclusion. Nao-Xue-Shu oral liquid could protect against the occurrence of SBI and improve HCH and SBI patients. It may also decrease the damage and the mass effects of the hematoma by reducing IL-6 and TNF-α to obtain the effects, and thus it is a potentially suitable drug for HCH and SBI.

6.
Artigo em Inglês | MEDLINE | ID: mdl-26557863

RESUMO

Objective. The objective is to observe whether the traditional Chinese medicine (TCM) Nao-Xue-Shu oral liquid improves aphasia of mixed stroke. Methods. A total of 102 patients with aphasia of mixed stroke were divided into two groups by a single blind random method. The patients treated by standard Western medicine plus Nao-Xue-Shu oral liquid (n = 58) were assigned to the treatment group while the remaining patients treated only by standard Western medicine (n = 58) constituted the control group. Changes in the Western Aphasia Battery (WAB), Modified Rankin Scale (mRS), National Institutes of Health Stroke Scale (NIHSS), and hemorheology parameters were assessed to evaluate the effects of the treatments. Results. Excluding the patients who dropped out, 54 patients in the treatment group and 51 patients in the control group were used to evaluate the effects. Significant and persistent improvements in the WAB score, specifically comprehension, repetition, naming, and calculating, were found in the treatment group when the effects were evaluated at the end of week 2 and week 4, respectively, compared with baseline. The naming and writing scores were also improved at the end of week 4 in this group. The comprehension and reading scores were improved at the end of week 4 in the control group compared with the baseline, but the improvements were smaller than those in the treatment group. The percentages of patients at the 0-1 range of mRS were increased at the end of week 2 and week 4 in both groups, but the improvements in the treatment group were much larger than those in the control group. Greater improvements in the NIHSS scores and the hemorheology parameters in the treatment group were also observed compared with the control group at the end of week 2 and week 4. Conclusion. Nao-Xue-Shu oral liquid formulation improved aphasia in mixed stroke patients and thus might be a potentially effective drug for treating stroke aphasia.

7.
Artigo em Inglês | MEDLINE | ID: mdl-25763089

RESUMO

We evaluated the effects of acupuncture in patients with restless legs syndrome (RLS) by actigraph recordings. Among the 38 patients with RLS enrolled, 31 (M = 12, F = 19; mean age, 47.2 ± 9.7 years old) completed the study. Patients were treated with either standard acupuncture (n = 15) or randomized acupuncture (n = 16) in a single-blind manner for 6 weeks. Changes in nocturnal activity (NA) and early sleep activity (ESA) between week 0 (baseline), week 2, week 4, and week 6 were assessed using leg actigraph recordings, the International Restless Legs Syndrome Rating Scale (IRLSRS), and Epworth Sleepiness Scale (ESS). Standard but not randomized acupuncture reduced the abnormal leg activity of NA and ESA significantly in week 2, week 4, and week 6 based on the changes in the clinical scores for IRLSRS and ESS in week 4 and week 6 compared with the baseline. No side effects were observed. The results indicate that standard acupuncture might improve the abnormal leg activity in RLS patients and thus is a potentially suitable integrative treatment for long-term use.

8.
J Vis ; 14(1)2014 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-24464165

RESUMO

We propose an image quality model based on phase and amplitude differences between a reference and a distorted image. The proposed model is motivated by the fact that polar representations can separate visual information in a more independent and efficient manner than Cartesian representations in the primary visual cortex (V1). We subsequently estimate the model parameters from a large subjective data set using maximum likelihood methods. By comparing the various model hypotheses on the functional form about the phase and amplitude, we find that: (a) discrimination of visual orientation is important for quality assessment and yet a coarse level of such discrimination seems sufficient; and (b) a product-based amplitude-phase combination before pooling is effective, suggesting an interesting viewpoint about the functional structure of the simple cells and complex cells in V1.


Assuntos
Córtex Visual/fisiologia , Percepção Visual/fisiologia , Discriminação Psicológica , Humanos , Modelos Logísticos , Orientação/fisiologia
9.
IEEE Trans Image Process ; 18(5): 1025-36, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19342337

RESUMO

We propose a video coding scheme that departs from traditional Motion Estimation/DCT frameworks and instead uses Karhunen-Loeve Transform (KLT)/Joint Spatiotemporal Prediction framework. In particular, a novel approach that performs joint spatial and temporal prediction simultaneously is introduced. It bypasses the complex H.26x interframe techniques and it is less computationally intensive. Because of the advantage of the effective joint prediction and the image-dependent color space transformation (KLT), the proposed approach is demonstrated experimentally to consistently lead to improved video quality, and in many cases to better compression rates and improved computational speed.

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