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1.
J Colloid Interface Sci ; 650(Pt B): 1446-1456, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37481782

RESUMEN

The electrochemical CO2 reduction to specific multi-carbon product on copper-based catalysts is subjected to low activity and poor selectivity. Herein, catalyst structure, morphology, and chemical component are systematically studied for bolstering the activity and selectivity of as-prepared catalyzers in this study. Dendritic fibrous nano-silica spheres favor the loading of active species and the transport of reactant from the central radial channel. Cu/DFNS with high dispersion active sites are fabricated through urea-assisted precipitation way. The coexistence of Cu(I)/Cu(II) induces a close combination of Cu active sites and CO2 on the Cu/DFNS interface, promoting the CO2 activation and CC coupling. The Cu-O-Si interface (Cu phyllosilicate) can improve CO2 and CO attachment. Cu/DFNS show the utmost Faradaic efficiency of C2H4 with a value of 53.04% at -1.2 V vs. RHE. And more importantly, in-situ ATR-SEIRAS reveals that the CC coupling is boosted for effectively producing C2H4 as a consequence of the existence of *COL, *COOH, and *COH intermediates. The mechanism reaction path of Cu/DFNS is inferred to be *CO2 â†’ *COOH â†’ *CO â†’ *CO*COH â†’ C2H4. Our findings will be helpful to gain insight into the links between morphology, texture, chemical component of catalyzers, and electrochemical reduction of CO2, providing valuable guidance in the design of more efficient catalysts.

2.
Biomater Adv ; 149: 213390, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36963249

RESUMEN

The development of fascinating materials with functional properties has revolutionized the humankind with materials comfort, stopped the spreading of diseases, relieving the environmental pollution pressure, economized government research funds, and prolonged their serving life. The outbreak of Coronavirus Disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has triggered great global public health concern. Face masks are crucial tools to impede the spreading of SARS-CoV-2 from human to human. However, current face masks exhibit in a variety of colors (opaque), like blue, black, red, etc., leading to a communication barrier between the doctor and the deaf-mute patient when wearing a mask. High optical transparency filters can be utilized for both personal protection and lip-reading. Thus, shaping face air filter into a transparent appearance is an urgent need. Electrospinning technology, as a mature technology, is commonly used to form nanofiber materials utilizing high electrical voltage. With the alteration of the diameters of nanofibers, and proper material selection, it would be possible to make the transparent face mask. In this article, the research progress in the transparent face air filter is reviewed with emphasis on three parts: mechanism of the electrospinning process and light transmission, preparation of transparent face air filter, and their innovative potential. Through the assessment of classic cases, the benefits and drawbacks of various preparation strategies and products are evaluated, to provide general knowledge for the needs of different application scenarios. In the end, the development directions of transparent face masks in protective gear, particularly their novel functional applications and potential contributions in the prevention and control of the epidemic are also proposed.


Asunto(s)
Filtros de Aire , COVID-19 , Nanofibras , Humanos , COVID-19/prevención & control , SARS-CoV-2 , Filtración
3.
Front Surg ; 9: 829048, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35874127

RESUMEN

Background: Primary brainstem lymphoma (PBSL) is rare and malignant. An understanding of this disease is lacking. We aimed to characterize clinical features, estimate survival, and explore survival-related factors of PBSL. Methods: Patients with a histological diagnosis of primary lymphoma in the brainstem (C71.7) from 1975 to 2016 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) program. Log-rank tests and univariate and multivariate Cox proportional hazard analyses were used to identify survival-related factors. Results: PBSL constituted 2.7% of brainstem malignancies. The median age of the PBSL patients was 59.5 years. Diffuse large B cell lymphoma (n = 49, 84.5%) was the most prevalent histology among the 58 cases with reported specific lymphoma subtype. The majority of PBSLs were localized (n = 46, 52.3%), at low Ann Arbor Stage (I/II, n = 63, 70.5%), and presented as a single primary (n = 71, 80.7%). Chemotherapy was applied in 50 (56.8%) cases. Three-year overall survival (OS) and disease-specific survival (DSS) rates were 42.7% and 53.5%, respectively. Multivariate analyses showed that independent predictive/prognostic factors for OS were age (P = 0.004), tumor number (P = 0.029), and chemotherapy (P = 0.001); DSS-related factors only included age (P = 0.014) and chemotherapy (P = 0.008). Conclusions: We estimated survival rates for PBSL patients. Factors associated with OS and DSS were also identified. Our findings addressed the importance of chemotherapy in treating PBSL patients.

4.
J Colloid Interface Sci ; 619: 407-418, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35405573

RESUMEN

Heterojunction engineering is a very prospective approach to modulate the photocatalytic behaviors of semiconductors. Herein, Venus flytrap-like NiCo hydroxide nanoflowers (HNF) with surface modification by different contents of CoSn(OH)6 were fabricated in situ for the first time. Interestingly, CoSn(OH)6 nanocubes (NC) are monodispersed on the nanosheet surface of NiCo HNF. Experimental characterizations and theoretical calculations comprehensively demonstrate the surface Sn atoms of CoSn(OH)6 are effectively embedded into the NiCo HNF interlayers, and co-sharing of the hydroxyl enables intimate contact in the heterointerface of NiCo HNF/CoSn(OH)6 hybrids and thereby largely shortens the charge migrating distance, contributing to an efficient interfacial charge migration and promoting charge separation. The optimized NiCo HNF/CoSn(OH)6 exhibits the remarkably enhanced photocatalytic efficiency for CO2 reduction with a TON of 601.2 and the CO and CH4 yield is about 3 folds that over CoSn(OH)6 NC. DRIFTS reveals the reaction intermediates in the CO2 photocatalytic process and proposes a possible mechanism for photocatalytic CO2 reaction. These findings may pave the way for rational engineering design of non-precious highly-dispersed broadband visible-light-driven CO2 reduction heterostructure catalysts.

5.
Dalton Trans ; 51(8): 3331-3340, 2022 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-35137742

RESUMEN

Poly(ionic liquid)s (PILs) have gained widespread attention in recent years due to their excellent properties similar to both ionic liquids and polymers. However, their further applications are limited because abundant and flexible ions easily block nanopores in the PIL catalysts, thus blocking the active sites and ultimately leading to decreased catalytic activity. This work reports the synthesis of a PIL/graphene composite catalyst (iPOP-ZnTPy@GNFs) based on an in situ surface preparation strategy, which effectively controlled the particle size and dispersion state of ionic liquids. The iPOP-ZnTPy@GNFs exhibited a larger surface area and more exposed active sites, which intensified the catalytic activity in the CO2 cycloaddition reaction with propylene oxide with almost double the reaction rate as compared to that of iPOP-ZnTPy-2 at 100 °C and S/C = 1000. As expected, the iPOP-ZnTPy@GNF catalyst efficiently converted epoxides to cyclic carbonates at room temperature or atmospheric pressure, which can significantly reduce the process cost. In addition, iPOP-ZnTPy@GNFs exhibited excellent broad substrate scope, catalytic diversity, and remarkable reusability. The reaction mechanism of CO2 cycloaddition was studied via density functional theory calculations and was validated by experimental findings. This work provides a feasible method for improving the utilization of active sites in PILs as a highly robust catalyst for CO2 cycloaddition and can be further extended to other types of catalytic reactions in practical applications.

6.
World J Clin Cases ; 10(1): 296-303, 2022 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-35071531

RESUMEN

BACKGROUND: Primary intracranial alveolar soft-part sarcoma (PIASPS) is a rare malignancy. We aimed to investigate the clinical profiles and outcomes for PIASPS. CASE SUMMARY: We firstly reported five consecutive cases from our institute. Then, the cases from previous studies were pooled and analyzed to delineate the characteristics of this disease. Our cohort included two males and three females. The median age was 21-years-old (range: 8-54-years-old). All the patients received surgical treatment. Gross total resection (GTR), radiotherapy, and chemotherapy were administered in 3 patients, 4 patients, and 1 patient, respectively. After a median follow-up of 36 mo, tumor progression was noticed in 4 patients; and 3 patients died of the disease. Pooled data (n = 14) contained 5 males and 9 females with a median age of 19 years. The log-rank tests showed that GTR (P = 0.011) could prolong progression-free survival, and radiotherapy (P < 0.001) resulted in longer overall survival. CONCLUSION: Patients with PIASPS suffer from poor outcomes. Surgical treatment is the first choice, and GTR should be achieved when the tumor is feasible. Patients with PIASPS benefit from radiotherapy, which should be considered as a part of treatment therapies.

7.
Membranes (Basel) ; 11(6)2021 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-34203059

RESUMEN

N,N-dimethylformamide (DMF) is a commonly-used solvent in industry and pharmaceutics for extracting acetylene and fabricating polyacrylonitrile fibers. It is also a starting material for a variety of intermediates such as esters, pyrimidines or chlordimeforms. However, after being used, DMF can be form 5-25% spent liquors (mass fraction) that are difficult to recycle with distillation. From the point of view of energy-efficiency and environment-friendliness, an emergent separation technology, pervaporation, is broadly applied in separation of azeotropic mixtures and organic-organic mixtures, dehydration of aqueous-organic mixtures and removal of trace volatile organic compounds from aqueous solutions. Since the advances in membrane technologies to separate N,N-dimethylformamide solutions have been rarely reviewed before, hence this review mainly discusses the research progress about various membranes in separating N,N-dimethylformamide aqueous solutions. The current state of available membranes in industry and academia, and their potential advantages, limitations and applications are also reviewed.

8.
Blood Press Monit ; 25(5): 295-298, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32842022

RESUMEN

OBJECTIVE: A new smartphone app called Anura can measure blood pressure (BP) any time and any place without cuffs or special equipment from video of the face. This study assessed its accuracy in close conformity with the American National Standards Institute/Association for the Advancement of Medical Instrumentation/International Organization for Standardization (ANSI/AAMI/ISO) 81060-2:2013 standard for BP measurement devices. METHODS: We validated Anura in reference to auscultation using a mercury sphygmomanometer and then assessed accuracy against the two accuracy criteria described in the guideline (n = 85 subjects; three measurement pairs per subject). RESULTS: The mean difference between the Anura measurement and its paired auscultatory reference measurement across all 255 measurement pairs was -0.4 ± 6.7 mmHg for systolic blood pressure (SBP) and 1.2 ± 7.0 mmHg for diastolic blood pressure (DBP). Both are within the acceptable limit of 5 ± 8 mmHg and thus satisfy accuracy criterion 1. When mean differences are averaged for each subject, the mean across all 85 subjects is -0.4 ± 5.8 mmHg for SBP and 1.2 ± 6.7 mmHg for DBP. Both are within acceptable limits (based on the mean difference) and thus satisfy accuracy criterion 2. CONCLUSIONS: Anura meets ANSI/AAMI/ISO 81060-2:2013 standard with respect to BP measurement accuracy. As the ANSI/AAMI/ISO 81060-2:2013 standard has not been developed for cuffless devices, further research assessing additional accuracy issues specific to such devices is needed.


Asunto(s)
Teléfono Inteligente , Presión Sanguínea , Determinación de la Presión Sanguínea , Monitores de Presión Sanguínea , Humanos , Tecnología
9.
Macromol Rapid Commun ; 41(12): e2000144, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32400906

RESUMEN

A new polymer acceptor poly{(N,N'-bis(2-ethylhexyl)-1,4,5,8-naphthalenedicarboximide-2,6-diyl)-alt-5,5-(3,3'-didodecyl-2,2'-bifuran)} (NDI-BFR) made from naphthalenediimide (NDI) and furan-derived head-to-head-linked 3,3'-dialkyl-2,2'-bifuran (BFR) units is reported in this study. Compared to the benchmark polymer poly(naphthalenediimide-alt-bithiophene) (N2200), NDI-BFR exhibits a larger bathochromic shift of absorption maxima (842 nm) with a much higher absorption coefficient (7.2 × 104 m-1 cm-1 ), leading to an ultranarrow optical bandgap of 1.26 eV. Such properties ensure good harvesting of solar light from visible to the near-infrared region in solar cells. Density functional theory calculation reveals that the polymer acceptor NDI-BFR possesses a higher degree of backbone planarity versus the polymer N2200. The polymer NDI-BFR exhibits a decent electron mobility of 0.45 cm2 V-1 s-1 in organic thin-film transistors (OTFTs), and NDI-BFR-based all-polymer solar cells (all-PSCs) achieve a power conversion efficiency (PCE) of 4.39% with a very small energy loss of 0.45 eV by using the environmentally friendly solvent 1,2,4-trimethylbenzene. These results demonstrate that incorporating head-to-head-linked BFR units in the polymer backbone can lead to increased planarity of the polymer backbone, reduced optical bandgap, and improved light absorbing. The study offers useful guidelines for constructing n-type polymers with narrow optical bandgaps.


Asunto(s)
Suministros de Energía Eléctrica , Furanos/química , Imidas/química , Naftalenos/química , Polímeros/química , Energía Solar , Teoría Funcional de la Densidad , Transistores Electrónicos
10.
Dalton Trans ; 49(2): 312-321, 2020 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-31782449

RESUMEN

Bimetal mixed MOFs of [CoZn][(BDC)(DABCO)0.5] (CZ-BDO), [CoNi][(BDC)(DABCO)0.5] (CN-BDO), and [NiZn][(BDC)(DABCO)0.5] (NZ-BDO) were prepared under solvothermal conditions and further employed as highly active accelerants for converting carbon dioxide into cyclic carbonates. The characteristics of the bimetal compounds were revealed via various techniques, including ICP-OES, XRD, FT-IR, Raman, XPS, SEM, EDS maps, N2 adsorption, TG-DTG, and CO2/NH3-TPD. The catalytic results revealed that CZ-BDO is superior to the other samples for obtaining a satisfactory chloropropene carbonate (CPC) yield. The excellent catalytic activity may be owing to the presence of a solid solution within the Co and Zn bimetal sample, which provides synergistic catalysis in the carbon dioxide cycloaddition. In addition, the synergistic catalysis was further confirmed by the NH3-TPD profiles, whereby the amount of CZ-BDO basic sites was obviously enhanced compared to the other samples. Furthermore, DFT calculations were also performed to reveal the synergistic catalysis between Co and Zn for the coupling reaction. Additionally, when the coupling reaction was carried out at 100 °C for 5 h in the presence of 0.5 wt% epichlorohydrin (ECH) as a catalyst at 3.0 MPa, 99.31% conversion of ECH and 97.05% yield of CPC were obtained over the optimal CZ-BDO sample. Moreover, the bimetal sample can also efficiently convert other epoxides into the corresponding cyclic carbonates.

11.
Med Sci Monit ; 24: 1097-1103, 2018 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-29467361

RESUMEN

BACKGROUND Traumatic brain injury (TBI) is characterized by cognitive deficits, which was associated with brain oxidative stress and apoptosis. Resveratrol (RSV) is an anti-apoptotic and anti-oxidative. This study aimed to investigate neuroprotective effects and involved molecular mechanisms in TBI. MATERIAL AND METHODS RSV and p38 inhibitor were administrated to TBI rats. Cognitive deficits were evaluated by Morris water maze assay. Reactive oxygen species (ROS) and apoptosis were detected in rat brains by fluorescent staining. Western blotting was used to assess the phosphorylation of p38 and the expression levels of Nrf2, HO1, and activated caspase-3. RESULTS RSV administration attenuated cognitive deficits of TBI rats. The ROS generation and apoptosis in the brain of TBI rats were suppressed by RSV treatment. Moreover, RSV treatment recovered activation of p38/Nrf2/HO1 signaling pathway. The co-administration of p38 inhibitor impaired RSV's attenuating effects on cognitive deficits, brain apoptosis, and ROS generation. CONCLUSIONS RSV attenuated cognitive deficits of TBI by inhibiting oxidative stress-mediated apoptosis via targeting p38/Nrf2 signaling.


Asunto(s)
Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Lesiones Traumáticas del Encéfalo/metabolismo , Cognición/efectos de los fármacos , Disfunción Cognitiva/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Estilbenos/farmacología , Animales , Antioxidantes , Apoptosis/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Lesiones Traumáticas del Encéfalo/enzimología , Lesiones Traumáticas del Encéfalo/psicología , Disfunción Cognitiva/tratamiento farmacológico , Disfunción Cognitiva/enzimología , Disfunción Cognitiva/patología , Femenino , Masculino , Fármacos Neuroprotectores/farmacología , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Resveratrol
12.
Neurocrit Care ; 26(2): 292-300, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-27995513

RESUMEN

OBJECTIVE: This study was to investigate the role of Nrf2/ARE signaling pathway in the pleiotropic neuroprotective effect of progesterone (PROG) on traumatic brain injury (TBI). METHODS: The Nrf2-knockout (Nrf2-/-) and C57 mice were respectively subjected to a lateral cortical impact injury caused by a free-falling object and randomly divided into three groups: sham-operated, trauma, and trauma + PROG treatment group. The PROG treatment group was given PROG (32 mg/kg of body weight, intraperitoneal injection) immediately after injury. For all groups, a series of brain samples were obtained after trauma at 24 and 72 h, respectively. The cerebral edema was evaluated; the expression of IL-1ß, IL-6, and TNF-α was measured using ELISA array, and the apoptosis index was detected by TUNEL. Flow cytometry was used to detect the intracellular calcium concentration. RESULTS: The water content, the apoptosis index, the levels of inflammatory cytokine, and the intracellular calcium ion were significantly decreased with the PROG treatment in C57 mice with TBI model. However, the effect of PROG on TBI was not found in the Nrf2-/- mouse model of TBI. CONCLUSIONS: PROG reduced cerebral edema, apoptosis, inflammatory reaction, and intracellular calcium ion overload effects after TBI. These beneficial effects were not seen in the Nrf2-/- mouse model of TBI. The results from this study suggested that the Nrf2/ARE signal pathway may be involved in the pleiotropic neuroprotective effect of PROG on TBI.


Asunto(s)
Elementos de Respuesta Antioxidante/fisiología , Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Factor 2 Relacionado con NF-E2/metabolismo , Fármacos Neuroprotectores/farmacología , Progesterona/farmacología , Transducción de Señal/fisiología , Animales , Modelos Animales de Enfermedad , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos ICR , Ratones Noqueados , Fármacos Neuroprotectores/administración & dosificación , Progesterona/administración & dosificación
13.
Bioresour Technol ; 225: 293-298, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27898320

RESUMEN

Cyanobacteria were catalytically pyrolyzed over Mg-Al layered double oxide/ZSM-5 composites (MgAl-LDO/ZSM-5) to produce bio-oil. MgAl-LDO/ZSM-5 with a Mg/Al molar ratio of four was proved to be the best catalyst. Under the optima condition that the final temperature was 823K, heating rate was 10K/min and catalyst/algae mass ratio was 0.75, a maximum yield of liquid (41.1%) was achieved at 823K with a heating rate of 10K/min and a catalyst/algae mass ratio of 0.75, which was much higher than the one obtained without catalyst. The element analysis results proved that this bio-oil had much lower O/C molar ratio and higher HHV. The GC-MS results showed that the bio-oil had less nitrogenous compounds. MgAl4-LDO/ZSM-5 was proved to be an applicable and effective catalyst to obtain bio-oil from catalytic pyrolysis of water-blooming algae.


Asunto(s)
Óxido de Aluminio/química , Biocombustibles , Cianobacterias , Óxido de Magnesio/química , Nitrógeno , Catálisis , Cianobacterias/química , Cianobacterias/metabolismo , Nitrógeno/análisis , Nitrógeno/metabolismo , Temperatura
14.
Beilstein J Org Chem ; 12: 2443-2449, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28144311

RESUMEN

We report a green and convenient protocol to prepare 4,7,12,15-tetrachloro[2.2]paracyclophane, the precursor of parylene D, from 2,5-dichloro-p-xylene. In the first bromination step, with H2O2-HBr as a bromide source, this procedure becomes organic-waste-free and organic-solvent-free and can appropriately replace the existing bromination methods. The Winberg elimination-dimerization step, using aqueous sodium hydroxide solution instead of silver oxide for anion exchange, results in a significant improvement in product yield. Furthermore, four substituted [2.2]paracyclophanes were also prepared in this convenient way.

15.
Bioresour Technol ; 192: 68-74, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26011693

RESUMEN

Catalytic co-pyrolysis of black-liquor lignin and waste plastics (polyethylene, PE; polypropylene PP; polystyrene, PS) was conducted in a fluidized bed. The effects of temperature, plastic to lignin ratio, catalyst and plastic types on product distributions were studied. Both aromatic and olefin yields increased with increasing PE proportion. Petrochemical yield of co-pyrolysis of PE and lignin was LOSA-1 > spent FCC > Gamma-Al2O3 > sand. The petrochemical yield with LOSA-1 is 43.9% which is more than two times of that without catalyst. The feedstock for co-pyrolysis with lignin is polystyrene > polyethylene > polypropylene. Catalytic co-pyrolysis of black-liquor lignin with PS produced the maximum aromatic yield (55.3%), while co-pyrolysis with PE produced the maximum olefin yield (13%).


Asunto(s)
Lignina/química , Plásticos/química , Reactores Biológicos , Catálisis , Polietileno/química , Polipropilenos/química , Poliestirenos/química , Temperatura
16.
Exp Ther Med ; 8(3): 893-898, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25120620

RESUMEN

The present study aimed to investigate the effect of NVP-BEP800, a novel heat shock protein (Hsp) 90 inhibitor of the 2-aminothieno[2,3-d]pyrimidine class, in combination with radiation on glioblastoma cells. T98G human glioblastoma cells were treated with dimethyl sulfoxide (DMSO), NVP-BEP800, NVP-BEP800 in combination with X-ray irradiation (10 Gy, 20 min), or X-ray irradiation only, and cultured for 40 h. Cell viability was measured upon completion of the treatments. In addition, apoptosis was measured and immunoblot analysis was performed to analyze the expression levels of cellular protein inhibitory κB kinase ß (IKKß). The combined treatment with NVP-BEP800 and X-ray irradiation resulted in the synergistic destruction of malignant cells. Furthermore, NVP-BEP800 significantly induced apoptosis in the human glioblastoma cells. The immunoblot analysis data indicated that NVP-BEP800 markedly reduced the expression level of IKKß. The results also revealed that X-ray irradiation significantly attenuated the increase in the level of Hsp70 in cells treated with NVP-BEP800. Since elevated levels of Hsp70 are associated with drug resistance induced by Hsp90 inhibitors, the effects of X-ray irradiation on Hsp70 levels may be associated with the enhanced effect on cells of the presence of irradiation. The results of the current study suggest that irradiation enhances the inhibitory effect of NVP-BEP800 on the proliferation of malignant glioblastoma cells by downregulating the expression level of cellular signaling protein IKKß and attenuating the upregulation of Hsp70 that is induced by NVP-BEP800.

17.
Bioresour Technol ; 159: 286-91, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24657760

RESUMEN

Production of biodiesel from the transesterification between soybean oil and methanol was conducted in this study by a membrane reactor, in which ceramic membrane was packed with MCM-41 supported p-toluenesulfonic acid (PTSA). Box-Behnken design and response surface methodology (RSM) were used to investigate the effects of reaction temperature, catalyst amount and circulation velocity on the yield of biodiesel. A reduced cubic model was developed to navigate the design space. Reaction temperature was found to have most significant effect on the biodiesel yield while the interaction of catalyst amount and circulation velocity have minor effect on it. 80°C of reaction temperature, 0.27 g/cm(3) of catalyst amount and 4.15 mL/min of circulation velocity were proved to be the optimum conditions to achieve the highest biodiesel yield.


Asunto(s)
Bencenosulfonatos/química , Biocombustibles , Reactores Biológicos , Biotecnología/instrumentación , Biotecnología/métodos , Membranas Artificiales , Dióxido de Silicio/química , Análisis de Varianza , Catálisis , Ésteres/química , Modelos Teóricos , Porosidad , Reciclaje , Aceite de Soja , Temperatura , Factores de Tiempo
18.
Bioresour Technol ; 155: 57-62, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24413482

RESUMEN

Chemical liquid deposition (CLD) with KH550, TEOS and methyl silicone oil as the modifiers was used to modify ZSM-5 and deposit its external acid sites. The characteristics of modified catalysts were tested by catalytic conversion of biomass pyrolysis-derived compounds. The effects of different modifying conditions (deposited amount, temperature, and time) on the product yields and selectivities were investigated. The results show KH550 modified ZSM-5 (deposited amount of 4%, temperature of 20°C and time of 6h) produced the maximum yields of aromatics (24.5%) and olefins (16.5%), which are much higher than that obtained with original ZSM-5 catalyst (18.8% aromatics and 9.8% olefins). The coke yield decreased from 44.1% with original ZSM-5 to 26.7% with KH550 modified ZSM-5. The selectivities of low-molecule-weight hydrocarbons (ethylene and benzene) decreased, while that of higher molecule-weight hydrocarbons (propylene, butylene, toluene, and naphthalene) increased comparing with original ZSM-5.


Asunto(s)
Biocombustibles , Biomasa , Hidrocarburos/aislamiento & purificación , Lignina/química , Zeolitas/química , Catálisis , Calor , Propiedades de Superficie , Factores de Tiempo
19.
Acta Pharmacol Sin ; 34(12): 1485-90, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24241345

RESUMEN

Traumatic brain injury is the leading cause of morbidity and mortality in young adults. The secondary injury in traumatic brain injury consists of a complex cascade of processes that simultaneously react to the primary injury to the brain. This cascade has been the target of numerous therapeutic agents investigated over the last 30 years, but no neuroprotective treatment option is currently available that improve neurological outcome after traumatic brain injury. Progesterone has long been considered merely a female reproductive hormone. Numerous studies, however, show that progesterone has substantial pleiotropic properties as a neuroprotective agent in both animal models and humans. Here, we review the increasing evidence that progesterone can act as a neuroprotective agent to treat traumatic brain injury and the mechanisms underlying these effects. Additionally, we discuss the current progress of clinical studies on the application of progesterone in the treatment of traumatic brain injuries.


Asunto(s)
Lesiones Encefálicas/prevención & control , Fármacos Neuroprotectores/uso terapéutico , Progesterona/uso terapéutico , Ensayos Clínicos como Asunto , Evaluación Preclínica de Medicamentos , Humanos
20.
Bioresour Technol ; 140: 256-62, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23707913

RESUMEN

Zeolite catalysts with micropores present good catalytic characteristics in biomass catalytic pyrolysis process. However, large-molecule oxygenates produced from pyrolysis cannot enter their pores and would form coke on their surfaces, which decreases hydrocarbon yield and deactivates catalyst rapidly. This paper proposed adding some mesoporous and macroporous catalysts (Gamma-Al2O3, CaO and MCM-41) in the microporous catalyst (LOSA-1) for biomass catalytic pyrolysis. The added catalysts were used to crack the large-molecule oxygenates into small-molecule oxygenates, while LOSA-1 was used to convert these small-molecule oxygenates into olefins and aromatics. The results show that all the additives in LOSA-1 enhanced hydrocarbon yield obviously. The maximum aromatic+olefin yield of 25.3% obtained with 10% Gamma-Al2O3/90% LOSA-1, which was boosted by 39.8% compared to that obtained with pure LOSA-1. Besides, all the additives in LOSA-1 improved the selectivities of low-carbon components in olefins and aromatics significantly.


Asunto(s)
Alquenos/síntesis química , Biomasa , Biotecnología/métodos , Calor , Hidrocarburos Aromáticos/síntesis química , Oryza/química , Óxido de Aluminio/química , Compuestos de Calcio/química , Carbono/análisis , Catálisis , Óxidos/química , Porosidad , Dióxido de Silicio/química , Residuos
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