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1.
Molecules ; 29(13)2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38998927

RESUMO

2-methylfuran is a significant organic chemical raw material which can be produced by hydrolysis, dehydration, and selective hydrogenation of biomass hemicellulose. 2-methylfuran can be converted into value-added chemicals and liquid fuels. This article reviews the latest progress in the synthesis of liquid fuel precursors through hydroxyalkylation/alkylation reactions of 2-methylfuran and biomass-derived carbonyl compounds in recent years. 2-methylfuran reacts with olefins through Diels-Alder reactions to produce chemicals, and 2-methylfuran reacts with anhydrides (or carboxylic acids) to produce acylated products. In the future application of 2-methylfuran, developing high value-added chemicals and high-density liquid fuels are two good research directions.

2.
Molecules ; 28(13)2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-37446694

RESUMO

1,3-bis(cyclohexylmethyl)cyclopentane, a renewable high-density fuel, was first produced in a high overall carbon yield (79.5%) with vanillin and cyclopentanone, which can be derived from biomass. The synthetic route used in this work contains two steps. In the first step, 2,5-bis(4-hydroxy-3-methoxybenzylidene)cyclopentanone was synthesized by aldol condensation of vanillin and cyclopentanone under the catalysis of sulphuric acid. Over the optimized condensation, a high carbon yield (82.6%) of 2,5-bis(4-hydroxy-3-methoxybenzylidene) cyclopentanone was achieved at 80 ºC. In the second step, 2,5-bis(4-hydroxy-3-methoxybenzylidene) cyclopentanone was hydrodeoxygenated over the Pd/HY catalyst in cyclohexane as solvent. High carbon yields of 1,3-bis(cyclohexylmethyl)cyclopentane (96.2%) was obtained. The polycycloalkane mixture as obtained has a density of 0.943 g mL-1 and a freezing point of -35 °C. It can be blended into conventional high-density fuels (e.g., JP-10) for rockets and missile propulsion as a potential application.


Assuntos
Carbono , Ciclopentanos
3.
Lung ; 200(2): 261-268, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35290523

RESUMO

PURPOSE: To investigate the different imaging features of contrast-enhanced multidetector-row-computed tomography (MDCT) for distinguishing between silicosis and tuberculosis involving the mediastinal lymph nodes. METHODS: 86 silicosis patients and 61 tuberculosis patients with mediastinal lymphadenopathy based on contrast-enhanced MDCT were included. The enhanced patterns, anatomical distribution and calcification features of the enlarged lymph nodes were retrospectively compared between the groups using the Pearson chi-square test or Fisher's exact test. RESULTS: Homogeneous enhancement of the mediastinal lymph nodes was more commonly observed in silicosis (94.2%, 81/86) than in tuberculosis (19.7%, 12/61). Peripheral enhancement was more frequent in tuberculosis (n = 44, 72.1%) than in silicosis involving the mediastinal lymph nodes (n = 1, 1.2%), and multilocular appearance was more frequent in TB than in silicosis. Tuberculosis was more likely to affect regions 1R, 2R, 2L, 3A, 5 and 6 than silicosis (all p < 0.05), especially region 2R. Calcification of the lymph nodes was more common in the silicosis group than in tuberculosis group. The sensitivity, specificity, and accuracy of silicosis with lymphadenopathy with homogeneous enhanced pattern were 94.2%, 80.3% and 88.4%, respectively. The sensitivity, specificity, and accuracy of tuberculosis lymphadenopathy with peripheral enhanced pattern were 72.1%, 98.8%, and 87.7%, respectively. CONCLUSION: The predominant enhanced patterns, anatomical distribution, and calcification features of mediastinal lymph nodes were different between tuberculosis and silicosis. These radiographic features might help differentiate tuberculosis from silicosis, which provides imaging information for the differential diagnosis of the two diseases in a clinical setting.


Assuntos
Linfadenopatia , Silicose , Tuberculose dos Linfonodos , Humanos , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Linfadenopatia/diagnóstico por imagem , Linfadenopatia/etiologia , Linfadenopatia/patologia , Tomografia Computadorizada Multidetectores/métodos , Estudos Retrospectivos , Silicose/diagnóstico por imagem , Silicose/patologia , Tuberculose dos Linfonodos/diagnóstico por imagem , Tuberculose dos Linfonodos/patologia
4.
RSC Adv ; 13(14): 9466-9478, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36968059

RESUMO

Research progress of catalysts of the aldol condensation reaction of biomass based compounds is summarized for the synthesis of liquid fuel precursors and chemicals. In summary, an acidic catalyst, alkaline catalyst, acid-base amphoteric catalyst, ionic liquid and other catalysts can catalyze the aldol condensation reaction. The aldol condensation reaction catalyzed by an acid catalyst has the problems of low conversion and low yield. The basic catalyst catalyzes the aldol condensation reaction with high conversion and yield, but the existence of liquid alkali is difficult to separate from the product. The reaction temperature needed for oxide and hydrotalcite alkali is relatively high. The basic resin has good catalytic activity and at a low reaction temperature, and is easy to separate from the target product. Acid-base amphoteric catalysts have received extensive attention from researchers for their excellent activity and selectivity. Ionic liquid is a new type of material, which can also be used for the aldol condensation reaction. In the future application of aldol condensation, the development of strong alkaline resin is a good research direction.

5.
J Hazard Mater ; 386: 121659, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31776080

RESUMO

Although in-vivo exposure of PM2.5 has been suggested to initiate a disorder on vascular permeability, the effects and related mechanism has not been well defined. In this work, an obvious increase on vascular permeability has been confirmed in vivo by vein injection of PM2.5 into Balb/c mouse. Human umbilical vein vascular endothelial cells and the consisted ex-vivo vascular endothelium were used as model to investigate the effects of PM2.5 on the vascular permeability and the underlying molecular mechanism. Upon PM2.5 exposure, the vascular endothelial growth factor receptor 2 on cell membrane phosphorylates and activates the downstream mitogen-activated protein kinase (MAPK)/ERK signaling. The adherens junction protein VE-cadherin sheds and the intercellular junction opens, damaging the integrity of vascular endothelium via paracellular pathway. Besides, PM2.5 induces the intracellular reactive oxygen species (ROS) production and triggers the oxidative stress including activity decrease of superoxide dismutase, lactate dehydrogenase release and permeability increase of cell membrane. Taken together, the paracellular and transcellular permeability enhancement jointly contributes to the significant increase of endothelium permeability and thus vascular permeability upon PM2.5 exposure. This work provides an insight into molecular mechanism of PM2.5 associated cardiovascular disease and offered a real-time screening method for the health risk of PM2.5.


Assuntos
Permeabilidade Capilar/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Material Particulado/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Acetilcisteína/farmacologia , Junções Aderentes/efeitos dos fármacos , Animais , Antígenos CD/metabolismo , Butadienos/farmacologia , Caderinas/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Junções Intercelulares/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Nitrilas/farmacologia , Estresse Oxidativo/efeitos dos fármacos
6.
Artigo em Chinês | WPRIM | ID: wpr-905441

RESUMO

Objectives:To investigate the factors related to the long-term outcome for patients after severe traumatic brain injury. Methods:From January, 2015 to December, 2018, 135 patients with severe traumatic brain injury were selected. Their gender, age (of onset), education level, injury sites, and lesion side were recorded, and they were assessed with Disability Rating Scale (DRS), Mini-Mental State Examination (MMSE), Fugl-Meyer Assessment (FMA) for motor and balance and modified Barthel Index (MBI). They were assessed with DRS again one year after discharge. Results:The age (r = 0.188), early DRS score (r = 0.530), MMSE score (r = -0.376), FMA for motor (r = -0.284) and balance (r = -0.425) score, MBI score (r = -0.480), brain stem injury (r = 0.194) and diffuse brain injury (r = 0.202) were related to DRS scores as follow-up (P < 0.05); while, the gender (r = -0.175), early DRS score (r = 0.586), MMSE score (r = -0.242), FMA for motor (r = -0.301) and balance (r = -0.228) score, MBI score (r = -0.367) and occipital lobe injury (r = 0.209) were related to difference of DRS (P < 0.05). Conclusion:The age, early cognitive and motor dysfunction are related with the outcome of one year of patients after severe traumatic brain injury. More researches are needed to explore the impact of injury sites on the outcome.

7.
Chinese Journal of Traumatology ; (6): 271-274, 2016.
Artigo em Inglês | WPRIM | ID: wpr-235730

RESUMO

<p><b>PURPOSE</b>To investigate the profiles of cognitive impairment through Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) in patients with chronic traumatic brain injury (TBI) or stroke and to evaluate the sensitivity of the two scales in patients with TBI.</p><p><b>METHODS</b>In this cohort study, a total of 230 patients were evaluated, including TBI group (n = 103) and stroke group (n = 127). The cognitive functions of two groups were evaluated by designated specialists using MoCA (Beijing version) and MMSE (Chinese version).</p><p><b>RESULTS</b>Comparedwith the patientswith stroke, the patientswith TBI received significantly lower score in orientation subtest and recall subtest in both tests.MoCA abnormal rates in the TBI group and stroke group were 94.17% and 86.61% respectively,whileMMSE abnormal rateswere 69.90% and 57.48%, respectively. In the TBI group, 87.10% patientswith normalMMSE score had abnormalMoCA score and in the stroke group, about 70.37% patients with normal MMSE score had abnormal MoCA score. The diagnostic consistency of two scales in the TBI group and the stroke group were 72% and 69%, respectively.</p><p><b>CONCLUSION</b>In our rehabilitation center, patients with TBI may have more extensive and severe cognitive impairments than patients with stroke, prominently in orientation and recall domain. In screening post- TBI cognitive impairment, MoCA tends to be more sensitive than MMSE.</p>


Assuntos
Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Lesões Encefálicas Traumáticas , Psicologia , Disfunção Cognitiva , Estudos de Coortes , Escalas de Graduação Psiquiátrica , Acidente Vascular Cerebral , Psicologia
8.
Artigo em Chinês | WPRIM | ID: wpr-310956

RESUMO

Sixteen compounds including daphnoretin (1), isofraxidin (2), scopoletin (3), kaempferol (4), quercetin (5), guaijaverin (6), astragalin (7), quercetin-3-O-β-D-glucopyranoside (8), naringenin-7-O-β-D-glucopyranoside (9), 5-O-methylapi- genin-7-O-β-D-glucopyranoside (10), methyl gallate (11), prionitiside A (12), (2S)-2,3-dihydroxypropyl-1,6,8-trihydroxy-3- methyl-9,10- dioxoanthracene-2-carboxylate (13), 3,3'-di-O-methyl ellagic acid (14), 3'-O-methyl-3,4-O,O-metheneellagic acid-4'-O-β-D- glucopyranoside (15) and 3,4-methylenedioxy-3'-O-methylellagic acid (16), were isolated from the 70% acetone extract of Euphorbia dracunculoides Lam. Among them, compounds 1-3, 6-9, 11, and 14 were isolated from E. dracunculoides for the first time, and compounds 10, 12, 13, 15, and 16 were firstly obtained from the genus Euphorbia. Their structures were elucidated by spectroscopic analysis, including 1H-NMR, 13C-NMR, and ESI-MS.


Assuntos
Medicamentos de Ervas Chinesas , Química , Euphorbia , Química , Estrutura Molecular , Folhas de Planta , Química , Caules de Planta , Química , Espectrometria de Massas por Ionização por Electrospray
9.
Chinese Journal of Stomatology ; (12): 684-688, 2012.
Artigo em Chinês | WPRIM | ID: wpr-260209

RESUMO

<p><b>OBJECTIVE</b>To compare the penetration abilities of resin infiltration into proximal lesions in primary molars with those of adhesive in vitro.</p><p><b>METHODS</b>Thirty-two extracted or exfoliated primary molars showing proximal white spot lesions were selected. Roots of the teeth were removed, and the crowns were cut across the white spot lesions perpendicular to the surface. Cut surfaces were examined (by stereo microscopy) and classified with respect to histological lesion extension (C1-C4): lesions confined to the outer half on enamel (C1), lesions confined to the inner half on enamel (C2), lesions confined to the outer half on dentin (C3), lesions extending into the inner half of dentin (C4). Corresponding lesion halves were etched for 120 s with 15% hydrochloric acid gel and were subsequently treated with either adhesive or resin infiltration. Specimens were observed with laser scanning confocal microscope (LSCM) in dual fluorescence mode. In confocal microscopic images, lesion depth and penetration depth of the resin infiltration or the adhesive in corresponding halves were measured, and penetration percentages were calculated respectively. Differences of the data between two groups were analyzed by Wilcoxon signed rank test. Variations of histological caries extensions were detected with Kruskal-Wallis H test.</p><p><b>RESULTS</b>At the same grading level (C1-C3) in histological caries extension, penetration depths of the resin infiltration group and the adhesive group were 240 (230, 260) µm vs 190 (150, 210) µm, 405 (300, 523) µm vs 180 (160, 200) µm, and 590 (430, 640) µm vs 180 (160, 200) µm respectively. There was significant statistical difference in the data between two groups (P < 0.05). Statistically significant difference in penetration depths of the resin infiltration group (at C1-C3) were found (P < 0.01). At the same grading level (C1-C3) in histological caries extension, percentage penetrations of the resin infiltration group and the adhesive group were [100.0% (96.2%, 100.0%)], [99.1% (95.7%, 100.0%)], [82.0% (81.1%, 92.2%)] and [79.2% (68.4%, 87.5%)], [41.8% (29.1%, 74.5%)], [30.2% (29.2%, 39.6%)], respectively. The difference between the above data was also significant (P < 0.05). Percentage penetrations of the resin infiltration group at C1 and C2 level was higher than those at C3 level (P < 0.05).</p><p><b>CONCLUSIONS</b>The resin infiltration is capable of penetrating almost completely into proximal lesions in primary molars.</p>


Assuntos
Humanos , Condicionamento Ácido do Dente , Métodos , Resinas Compostas , Química , Cárie Dentária , Patologia , Terapêutica , Cimentos Dentários , Química , Esmalte Dentário , Patologia , Permeabilidade do Esmalte Dentário , Ácido Clorídrico , Farmacologia , Dente Molar , Patologia , Propriedades de Superfície , Dente Decíduo , Patologia
10.
Artigo em Chinês | WPRIM | ID: wpr-348033

RESUMO

3 root canals were found when a left lower first premolar, which preoperative radiograph showing root canal variety, was treated and were verified by postoperative radiograph. The root canal variety of lower premolars should be paid more attention to prevent root canal from losing.


Assuntos
Humanos , Dente Pré-Molar , Cavidade Pulpar , Mandíbula , Período Pós-Operatório , Tratamento do Canal Radicular
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