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1.
Int J Biol Macromol ; 276(Pt 1): 133739, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39002907

RESUMEN

Xylose plants (produce xylose from corncob through dilute acid treatment) generate a large amount of corncob residue (CCR), most of which are burned and lacked of valorization. Herein, to address this issue, CCR was directly used as starting material for high-solid loading enzymatic hydrolysis via a simple strategy by combining PFI homogenization (for sufficient mixing) with batch-feeding. A maximum glucose concentration of 187.1 g/L was achieved after the saccharification with a solid loading of 25 wt% and enzyme dosage of 10 FPU/g-CCR. Furthermore, the residue of enzymatic hydrolysis (REH) was directly used as a bio-adhesive for plywood production with both high dry (1.7 MPa) and wet (1.1 MPa) surface bonding strength (higher than the standard (0.7 MPa)), and the excellent adhesion was due to the interfacial crosslinking between the REH adhesive (containing lignin, free glucose, and nanosized fibers) and cell wall of woods. Compared with traditional reported adhesives, the REH bio-adhesive has advantages of formaldehyde-free, good moisture resistance, green process, relatively low cost and easy realization. This study presents a simple and effective strategy for better utilization of CCR, which also provides beneficial reference for the valorization of other kinds of lignocellulosic biomass.


Asunto(s)
Adhesivos , Fermentación , Lignina , Zea mays , Lignina/química , Hidrólisis , Zea mays/química , Adhesivos/química , Glucosa/metabolismo , Glucosa/química , Xilosa/química , Madera/química , Azúcares/química , Azúcares/metabolismo
2.
ISA Trans ; 152: 229-237, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38972822

RESUMEN

This article delves into the intricate challenge of implementing prescribed-time command filtered control in the context of uncertain nonlinear systems. Firstly, a prescribed-time function is defined to lay the groundwork for subsequent controller design. Subsequently, a novel prescribed-time command Filtered controller is proposed for high-order nonlinear systems featuring unknown parameters. This controller guarantees swift error convergence within a predefined time range, with the added capability of periodic error convergence to zero during subsequent controller operations. A pivotal innovation in this study lies in the controller's design, which remains unaffected by the system's initial conditions. This unique feature enables the prescribed time to be flexibly set within physical constraints, diverging markedly from conventional finite-time control theory. Theoretical analysis has conclusively shown that the controller achieves full-state tracking error convergence within the specified time frame. The efficacy of the research findings is substantiated through two simulation cases, underscoring a substantial contribution to the refinement and adaptability of nonlinear system control theory.

3.
Front Pharmacol ; 14: 1279519, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38074138

RESUMEN

Objective: Evaluate the impact of adjusting the overall dose, Gypsum Fibrosum [Mineral; Gypsum] (ShiGao, SG) dose, and Prunus armeniaca L. [Rosaceae; Semen Armeniacae Amarum] (KuXingRen, KXR) dose on the efficacy of MaXingShiGan Decoction (MXSG) in treating children with bronchial pneumonia (Wind-heat Blocking the Lung), in order to provide strategy supported by high-quality evidence for the selection of rational clinical doses of MXSG. Methods: Based on the basic dose of MXSG, we conducted three randomized, double-blind, dose parallel controlled, multicenter clinical trials, involving adjustments to the overall dose, SG dose, and KXR dose, and included 120 children with bronchial pneumonia (Wind-heat Blocking the Lung) respectively. And the patients were divided into low, medium, and high dose groups in a 1:1:1 ratio, with 40 cases in each group. The intervention period lasted for 10 days. The primary outcome was the clinical cured rate, while the secondary outcomes included the effectiveness in alleviating major symptoms of bronchial pneumonia (including fever, cough, dyspnea, and phlegm congestion). And the occurrence of adverse events was recorded. Results: We first recorded and analyzed the baseline characteristics of the three studies, including age, gender, height, and so on. The results indicated that there were no significant differences among the dose groups within each study. For the study adjusting the overall dose of MXSG, the results showed that both the medium-dose group and high-dose group had significantly higher clinical cured rates compared to the low-dose group (Chi-square value 9.01, p = 0.0111). However, there was no significant benefit between the high-dose group and the medium-dose group (81.58% vs. 81.08%). Regarding phlegm congestion, excluding fever, cough, and dyspnea, both the medium-dose group and high-dose group had significantly higher clinical cured rates than the low-dose group (Chi-square value 6.31, p = 0.0426), and there was no significant benefit between the high-dose group and the medium-dose group (69.23% vs. 75.00%). A total of 5 adverse events were observed, of which only 1 case in the medium-dose group was possibly related to the experimental medication. For the study adjusted the SG dose in MXSG, the results showed that the high-dose group had the highest clinical cured rate, but the inter-group difference was not statistically significant (Chi-square value 3.36, p = 0.1864). The area under the curve (AUC) for cough in the medium-dose group was significantly lower than in the low-dose group and high-dose group (F-test value 3.14, p = 0.0471). Although no significant differences were observed in fever and dyspnea among the groups, the AUC in the high-dose group was lower than in the medium-dose and low-dose groups. In comparing the complete defervescence time, both the high-dose group (p < 0.0001) and the medium-dose group (p = 0.0015) achieved faster than the low-dose group. The high-dose group slightly outperformed the medium-dose group (0.50 (0.50, 0.80) vs. 0.80 (0.40, 1.40)), although the difference was not significant. In the medium-dose group, 1 adverse event was observed, but it was not related to the experimental medication. For the study adjusted the KXR dose in MXSG, the results showed that both the medium-dose group and high-dose group had significantly higher cured rates compared to the low-dose group (Chi-square value 47.05, p < 0.0001). However, there was no significant benefit comparing the high-dose group to the medium-dose group (90.00% vs. 92.50%). Regarding clinical symptoms, the results indicated that for cough (F-test value 3.16, p = 0.0460) and phlegm congestion (F-test value 3.84, p = 0.0243), the AUC for both the medium-dose group and high-dose group were significantly lower than in the low-dose group. Although there was benefit in the high-dose group compared to the medium-dose group, it was not statistically significant. No adverse events were observed during the study period. Conclusion: The synthesis of the three conducted clinical studies collectively indicates that for children with bronchial pneumonia (Wind-heat Blocking the Lung), the basic clinical dose of MXSG may represents an optimal intervention dose based on the accumulated clinical experience of doctors. If the dose is insufficient, the clinical effects might be compromised, but using a higher dose does not significantly enhance benefits. Concerning different symptoms, increasing the overall formula's dose has a favorable impact on improving phlegm congestion, increasing the SG is effective in improving symptoms such as fever, cough, and dyspnea, while higher dose of KXR is effective in alleviating cough and phlegm congestion. These findings suggest that for MXSG, achieving the optimal intervention dose is crucial to achieve better clinical efficacy. For the SG and KXR, if certain symptoms are more severe, increasing the dose can be considered within safe limits, can lead to significant clinical benefits in symptom improvement. This also explains why the dose of MXSG might vary among clinical doctors, while maintaining a balance between safety and effectiveness. Of course, our study is still exploratory clinical trials, and further studies are needed to confirm our findings. Clinical Trial Registration: https://www.chictr.org.cn/index.html; Identifier: ChiCTR-TRC-13003093, ChiCTR-TRC-13003099.

4.
Artículo en Inglés | MEDLINE | ID: mdl-36497660

RESUMEN

Based on the data from 35 major cities in China in 2020, this paper applies the Simpson's diversity index, the entropy value method, and the coupling coordination degree model to comprehensively measure the coupling coordination level of mixed land use and urban vitality in major cities in China and further analyze their spatial distribution characteristics. In addition, this paper analyzes the factors affecting the spatial variation of the coupling coordination level with the help of the geographic probe model. The study finds that: (1) The overall level of coupling coordination between mixed land use and urban vitality is high in 35 major cities in China. There is no disorder between mixed land use and urban vitality. (2) In terms of the spatial distribution of the coupling coordination between mixed land use and urban vitality in 35 cities in China, five cities, namely Beijing, Shenzhen, Shanghai, Guangzhou, and Chengdu, have the highest level of coupling coordination between mixed land use and urban vitality, reaching "good coordination" with a discrete spatial distribution. Central cities such as Hangzhou and Nanjing have the second highest level of coupling coordination and are at the "intermediate coordinate" with a "strip-like distribution" in space. Twenty cities in the north and south have the lowest coupling coordination levels and are in the "primary coordination." Among these twenty cities, seven cities in the south have a higher level of coupling coordination than thirteen cities in the north, with a spatial distribution of a "C" shape. The northern cities have the lowest level of coupling coordination, with a "W"-shaped distribution in space. (3) Population size plays an essential role in guiding the level of coupling coordination between mixed land use and urban vitality in major cities in China, followed by government regulation and economic level. At the same time, transportation conditions and industrial structure have the weakest influence on the level of coupling coordination between mixed land use and urban vitality in major cities in China.


Asunto(s)
Transportes , Urbanización , China , Ciudades , Beijing , Desarrollo Económico
5.
Front Pharmacol ; 13: 948831, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36120338

RESUMEN

Background: As one of the most commonly used Chinese medicine formula in the manage of respiratory diseases, Maxing Ganshi Decoction (MGD) has been demonstrated to improve the clinical symptoms of pneumonia. To evaluate the efficacy and safety of MGD in treating children with community-acquired pneumonia (CAP), we conducted the clinical trial. Methods: A randomized, double-blind, placebo-controlled, multicenter trial was conducted in 3 study sites in Tianjin, China. MDG or placebo were randomly given to patients aged 3-6 years with onset of CAP within 48 h. Changes in disease efficacy during the study period (which was measured as recovery, significant effect, improvement and no effect) was evaluated as the primary outcome. Time from enrollment to fever resolution was assessed as the secondary outcome. The adverse event was analyzed as safety evaluation. Results: A total of 71 patients (36 in MGD and 35 in placebo) were randomized and completed the whole study. The patient demographics and other characteristics at baseline were similar between the 2 groups (p > 0.05). After 10 days of intervention, the proportion of recovered and significant effective patients was increased significantly in the MGD group (34.85% [95% CI, 12.44%-57.26%]; p < 0.05) compared with the control group. Besides, the symptom score of the MGD group was lowered significantly (p < 0.001). The estimated time to fever resolution in the MGD group was also reduced compared with the control group (p < 0.05). During the whole study, no side effects were observed in both MGD and control groups. Conclusion: MGD was effective in improving disease efficacy, clinical symptoms and reducing time to fever resolution in patients with childhood CAP, which suggested that MGD may be used as an alternative therapy in the treatment of childhood CAP. Clinical Trial Registration: http://www.chictr.org.cn/showproj.aspx?proj=5612, identifier 13003955.

6.
ISA Trans ; 90: 138-146, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30711340

RESUMEN

This paper investigates a complicated class of cooperative tracking problems with time-varying number of tracking agents and communication time delays. During the entire tracking process, tracking agents are dynamically changing and the number is not fixed. This results in jumping of tracking errors and dynamic dimensions of the corresponding Laplacian matrices. Consequently, the stability analysis turns to be difficult especially when the effect of communication time delays is taken into consideration. In order to solve this issue, a new type of average Lyapunov function is constructed to compensate the unmatched dimensions of communication topologies over different time intervals. Generalized reciprocally convex Lemma and a more relaxed switched technique are employed to achieve a less conservative switched stability condition for the multi-agent system with variable tracking number and time delays. Finally, through a series of numerical simulations, the effectiveness and feasibility of derived results are verified. The relationship between maximum allowable communication time delays and various control parameters is obtained in a quantitative way.

7.
R Soc Open Sci ; 5(1): 171488, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29410851

RESUMEN

Biomarkers are important biochemical indicators, which could be used for identification, early diagnosis and monitoring of diseases during the course of treatment. However, biomarker diagnosis has some shortcomings such as requiring a large amount of samples, long test time and high cost, which seriously influences the correctness and timely treatment to patients. Here, a relatively fast and efficient plasmonic hot spot-localized surface imprinting of Ag spheres using biomarker template immobilization and hydrogel copolymerization is described. The technique takes a fine control of the imprinting process at the nanometre scale and provides a biosensor with high sensitivity. Proof of the opinion is established by detection of biomarker using surface-enhanced Raman scattering (SERS) spectroscopy. This work represents a valuable step towards SERS with biomarkers for cost-saving and time-saving diagnostic assay. It is expected that the new surface imprinted hydrogel plasmonic material can drive possibilities in advancing application of biomarkers in plasmonic biosensors.

8.
ISA Trans ; 71(Pt 1): 25-31, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28693833

RESUMEN

This paper investigates a situation where smart agents capable of sensory and mobility are deployed to monitor a designated area. A preset number of agents start tracking when a target intrudes this area. Some of the tracking agents are possible to be out of order over the tracking course. Thus, we propose a cooperative relay tracking strategy to ensure the successful tracking with existence of damaged agents. Relay means that, when a tracking agent quits tracking due to malfunction, one of the near deployed agents replaces it to continue the tracking task. This results in jump of tracking errors and dynamic switching of topology of the multi-agent system. Switched system technique is employed to solve this specific problem. Finally, the effectiveness of proposed tracking strategy and validity of the theoretical results are verified by conducting a numerical simulation.

9.
J Antibiot (Tokyo) ; 64(4): 333-7, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21364596

RESUMEN

An allyl group was attached to 3-keto function of ketolides in the presence of allyl bromide and KOtBu. Consequently, the Heck reaction of the resulting 2, 3-dehydro-3-O-allyl-10, 11-anhydroclarithromycin derivatives, in the presence of palladium (II) acetate and tri(o-tolyl)phosphine, afforded a 3-O-(3-aryl-E-prop-2-enyl) sidechain, not the previously reported 3-O-(3-aryl-Z-prop-1-enyl) sidechain. The results suggested that some steric factors in ß-hydrogen elimination might regulate the isomerization. The activity of 2, 3-dehydro-3-O-(3-aryl-E-prop-2-enyl)-10, 11-anhydroclarithromycin derivatives was low.


Asunto(s)
Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Claritromicina/farmacología , Antibacterianos/síntesis química , Claritromicina/análogos & derivados , Farmacorresistencia Bacteriana , Pruebas de Sensibilidad Microbiana , Relación Estructura-Actividad
10.
Eur J Med Chem ; 45(9): 3627-35, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20627377

RESUMEN

A facile and efficient route was presented to achieve 3-keto-clarithromycin 9-O-(3-aryl-E-2-propenyl) oxime derivatives 8, 2,3-dehydro-3-O-allyl-clarithromycin 9-O-(3-aryl-E-2-propenyl) oxime derivatives 11, and 3-O-allyl-clarithromycin 9-O-(3-aryl-E-2-propenyl) oxime derivatives 12. Among them, compound 8, particularly 8d (Ar = 6-quinolyl), exhibited improved antibacterial activities against erythromycin-susceptible Staphylococcus aureus and Streptococcus pneumoniae, and greatly enhanced activities against the resistant strains encoded by erm and mef genes, as compared to clarithromycin and azithromycin.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Éteres/química , Cetólidos/química , Cetólidos/farmacología , Antibacterianos/síntesis química , Farmacorresistencia Bacteriana/efectos de los fármacos , Farmacorresistencia Bacteriana/genética , Cetólidos/síntesis química , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/genética , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pneumoniae/genética
11.
J Environ Sci (China) ; 22(2): 225-9, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20397410

RESUMEN

MnO2-loaded D301 weak basic anion exchange resin has been used as adsorbent to simultaneously remove lead and cadmium ions from aqueous solution. The effects of adsorbent dosage, solution pH and the coexistent ions on the adsorption were investigated. Experimental results showed that with the adsorbent dosage more than 0.6 g/L, both Pb2+ and Cd2+ were simultaneously removed at pH range 5-6. Except for HPO4(2-), the high concentration coexistent ions such as Na+, K+, Cl-, NO3-, SO4(2-) and HCO3-, showed no significant effect on the removal efficiency of both Pb2+ and Cd2+ under the experimental conditions. The coexistence of Mg2+, Ca2+ caused the reduction of Cd2+ removal, but not for Pb2+. The adsorption equilibrium for Pb2+ and Cd2+ could be excellently described by the Langmuir isotherm model with R2 > 0.99. The maximum adsorption capacity was calculated as 80.64 mg/g for Pb2+ and 21.45 mg/g for Cd2+. The adsorption processes followed the pseudo first-order kinetics model. MnO2-loaded D301 resin has been shown to have a potential to be used as an effective adsorbent for simultaneous removal of lead and cadmium ions from aqueous solution.


Asunto(s)
Resinas de Intercambio Aniónico/química , Cadmio/química , Plomo/química , Compuestos de Manganeso/química , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Contaminantes Químicos del Agua , Purificación del Agua
12.
J Antibiot (Tokyo) ; 62(11): 605-11, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19713989

RESUMEN

A series of novel 3-O-(3-aryl-propenyl)clarithromycin derivatives were designed, synthesized and evaluated for their in vitro antibacterial activities. Regioselective allylation at 3-OH was efficiently achieved in the presence of 9-oxime ether, compared with 9-keto. Most of the side chains were identified as the 3-O-(3-aryl-Z-prop-1-enyl) group, not the expected 3-O-(3-aryl-E-prop-2-enyl) group. Some derivatives of this series showed improved activities against erythromycin-resistant Staphylococcus aureus and Staphylococcus pneumoniae compared with the reference compound, clarithromycin, but weaker activities against susceptible strains.


Asunto(s)
Antibacterianos/síntesis química , Claritromicina/análogos & derivados , Diseño de Fármacos , Antibacterianos/farmacología , Claritromicina/farmacología , Espectroscopía de Resonancia Magnética , Relación Estructura-Actividad
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