Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
1.
Chin J Traumatol ; 2024 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-39107172

RESUMEN

PURPOSE: To judge the injury mode and injury severity of the real human body through the measured values of anthropomorphic test devices (ATD) injury indices, the mapping relationship of lumbar injury between ATD and human body model (HBM) was explored. METHODS: Through the ATD model and HBM simulation, the mapping relationship of lumbar injury between the 2 subjects was explored. The sled environment consisted of a semi-rigid seat with an adjustable seatback angle and a 3-point seat belt system with a seatback-mounted D-ring. Three seatback recline states of 25°, 45°, and 65° were designed, and the seat pan angle was maintained at 15°. A 23 g, 47 km/h pulse was used. The validity of the finite element model of the sled was verified by the comparison of ATD simulation and test results. ATD model was the test device for human occupant restraint for autonomous vehicles (THOR-AV) dummy model and HBM was the total human model for safety (THUMS) v6.1. The posture of the 2 models was adjusted to adapt to the 3 seat states. The lumbar response of THOR-AV and the mechanical and biomechanical data on L1-L5 vertebrae of THUMS were output, and the response relationship between THOR-AV and THUMS was descriptive statistically analyzed. RESULTS: Both THOR-AV and THUMS were submarined in the 65° seatback angle case. With the change of seatback angle, the lumbar spine axial compression force (Fz) of THOR-AV and THUMS changed in the similar trend. The maximum Fz ratio of THOR-AV to THUMS at 25° and 45° seatback angle cases were 1.6 and 1.7. The flexion moment (My) and the time when the maximum My occurred in the 2 subjects were very different. In particular, the form of moment experienced by the L1 - L5 vertebrae of THUMS also changed. The changing trend of My measured by THOR-AV over time can reflect the changing trend of maximum stress of L1 and L2 of THUMS. CONCLUSION: The Fz of ATD and HBM presents a certain proportional relationship, and there is a mapping relationship between the 2 subjects on Fz. The mapping function can be further clarified by applying more pulses and adopting more seatback angles. It is difficult to map My directly because they are very different in ATD and HBM. The My of ATD and stress of HBM lumbar showed a similar change trend over time, and there may be a hidden mapping relationship.

2.
Small ; 17(52): e2104195, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34729918

RESUMEN

The authors proposed a novel template-free strategy, urease-mediated interfacial growth of NH4 Ga(OH)2 CO3 nanotubes at 20-50 °C, to fabricate the porous Ga2 O3 nanotubes. The subtlety of the proposed strategy is all the products from urea enzymolysis are utilized in formation of NH4 Ga(OH)2 CO3 precipitates, and the key for interfacial growth of NH4 Ga(OH)2 CO3 nanotubes is the dynamic match between the rate of CO2 bubble fusion and NH4 Ga(OH)2 CO3 precipitation. The proposed strategy works well for the doped porous Ga2 O3 nanotubes. As a proof-of-concept, the porous ß-Ga2 O3 and ß-Ga2 O3 :Cr0.001 nanotubes are used as photocatalysts or co-catalysts with Pt, for H2 evolution from water splitting. The H2 evolution rate of porous ß-Ga2 O3 nanotubes reach 39.3 mmol g-1 h-1 with solar-to-hydrogen (STH) conversion efficiency of 2.11% (Hg lamp) or 498 µmol g-1 h-1 with STH of 0.03% (Xe lamp) respectively, both about 3 times of ß-Ga2 O3 nanoparticles synthesized at pH 9.0 without urease. The Cr-doping enhances the in-the-dark H2 evolution rate pre-lighted by Hg lamp, and Pt co-catalysis further elevates the H2 evolution rate, for instance, the H2 evolution rate of Pt-loaded ß-Ga2 O3 :Cr0.001 nanotubes reaches 54.7 mmol g-1 h-1 with STH of 2.94% under continuous lighting of Hg lamp and 1062 µmol g-1 h-1 in-the-dark.


Asunto(s)
Carbonatos , Galio , Hidrógeno , Nanotubos , Ureasa , Catálisis , Porosidad
3.
ACS Appl Mater Interfaces ; 15(4): 5273-5282, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36648244

RESUMEN

Photocatalysts for regeneration of reduced nicotinamide adenine dinucleotide (NADH) usually work with continuous lighting and electron mediators, which causes impracticability under dark conditions, risk of NADH reoxidation, and complex separation. To solve these problems, we present a new catalyst of tiny Pt nanoparticles photodeposited on chromium-doped zinc gallate (CZGO@Pt). Upon being light-triggered, the photogenerated electrons are stored in the traps of CZGO and then gradually released and transferred by Pt to directly reduce NAD+ after stoppage of illumination. Three lighting modes are compared to demonstrate the feasibility and advantage of this light-triggered dark catalysis. Within 4 h of reaction, the in-the-dark NADH yield reaches 75.0% under prelighting CZGO@5%Pt and it reaches 80.0% under prelighting CZGO@5%Pt and triethanolamine (TEOA). However, the NADH yield is only 53.5% under continuous lighting of CZGO@5%Pt, TEOA, and NAD+. Consequently, the light-triggered dark catalytic regeneration of NADH not only saves energy and operates easily but also significantly elevates the NADH yield. It thus would secure wide interests and applications in places where no light or only intermittent light is available.

4.
Carbohydr Res ; 501: 108276, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33662813

RESUMEN

With the development of dye and printing, production wastewater has become one of the most primary pollution sources of water and soil pollution. Most of the dyes are toxic substances, which have the "three-way" effect of carcinogenic, teratogenic and mutagenic. Therefore, it is a very difficult but significant issue to deal with the dye in the wastewater. Here, we report a study on low-cost, high-capacity hydrogels that remove water-soluble dyes. The hydrogel is prepared by crosslinking the ß-cyclodextrin and functional monomer: acrylamido and 2-acrylamide-2-methylpropane sulfonic acid by aqueous solution polymerization, meanwhile, alkaline hydrolysis is also an important step for adsorption performance. After alkaline hydrolysis, the amide and sulfonic groups in the hydrogel were converted into carboxylate and sulfonate, which was beneficial to the adsorption of cationic dyes. This polymer could remove 96.58% methylene blue (400 mg/L) and only requires 0.02 wt%. Its maximum adsorption capacity for methylene blue could reach 2638.22 mg/g under equilibrium condition. It is the most powerful adsorbent used to treat dye wastewater, according to the report. It also provides some references for hydrogel treatment of dye wastewater.


Asunto(s)
Hidrogeles/química , Azul de Metileno/aislamiento & purificación , Contaminantes Químicos del Agua/aislamiento & purificación , beta-Ciclodextrinas/química , Adsorción , Azul de Metileno/química , Estructura Molecular , Tamaño de la Partícula , Propiedades de Superficie , Contaminantes Químicos del Agua/química
5.
Zool Res ; 41(4): 437-443, 2020 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-32400976

RESUMEN

Sleep is indispensable for human health, with sleep disorders initiating a cascade of negative consequences. As our closest phylogenetic relatives, non-human primates (NHPs) are invaluable for comparative sleep studies and exhibit tremendous potential for improving our understanding of human sleep and related disorders. Previous work on measuring sleep in NHPs has mostly used electroencephalography or videography. In this study, simultaneous videography and actigraphy were applied to observe sleep patterns in 10 cynomolgus monkeys ( Macaca fascicularis) over seven nights (12 h per night). The durations of wake, transitional sleep, and relaxed sleep were scored by analysis of animal behaviors from videography and actigraphy data, using the same behavioral criteria for each state, with findings then compared. Here, results indicated that actigraphy constituted a reliable approach for scoring the state of sleep in monkeys and showed a significant correlation with that scored by videography. Epoch-by-epoch analysis further indicated that actigraphy was more suitable for scoring the state of relaxed sleep, correctly identifying 97.57% of relaxed sleep in comparison with video analysis. Only 34 epochs (0.13%) and 611 epochs (2.30%) were differently interpreted as wake and transitional sleep compared with videography analysis. The present study validated the behavioral criteria and actigraphy methodology for scoring sleep, which can be considered as a useful and a complementary technique to electroencephalography and/or videography analysis for sleep studies in NHPs.


Asunto(s)
Haplorrinos/fisiología , Sueño , Grabación en Video/métodos , Actigrafía/métodos , Actigrafía/veterinaria , Animales
6.
Zhonghua Yi Xue Za Zhi ; 89(16): 1088-92, 2009 Apr 28.
Artículo en Zh | MEDLINE | ID: mdl-19595135

RESUMEN

OBJECTIVE: To investigate the effects of Notch signaling on scars in a rabbit ear model of hypertrophic scarring. METHODS: The hypertrophic scar of rabbits' ears was reproduced. The left rabbit's ear wounds as the N-[N-(3,5-difluorophenacetyl-L-alanyl)]-(S)-phenylglycine t-butyl ester (DAPT) treated group were treated intradermally with the gamma-secretase inhibitor DAPT to inhibit the activation of Notch at 1, 3, 7 and 14 day time points. The right ears as the control group were treated with normal saline at the same time points. Experimental and control wounds were harvested on days 14, 21, 28 and 35 post wounding, and then examined histologically to quantify hypertrophic index and fibroblasts. The expression of epidermal differentiation markers-keratin 14 (K14), keratin 19 (K19), Involucrin and Notch downstream molecules-P21, P63 were examined and analyzed with immunohistochemistry staining. RESULTS: Both hypertrophic index (1.93 +/- 0.32, 1.82 +/- 0.36, 1.79 +/- 0.25) and number of fibroblasts [(4.08 +/- 0.88), (3.30 +/- 0.53), (3.19 +/- 0.73) x 10(3)/mm(2)] in the DAPT treated group were significantly reduced on days 21, 28 and 35, compared with the control group [2.56 +/- 0.29, 2.61 +/- 0.30, 2.58 +/- 0.39, and (5.45 +/- 0.99), (4.80 +/- 1.13), (4.43 +/- 1.17) x 10(3)/mm(2), all P < 0.01)]. The K19, K14 and P63 increased their expression in the DAPT treated group (28.6% +/- 5.7%, 53.1% +/- 4.5%, 57.0% +/- 5.8%) relative to the control group (10.1% +/- 2.8%, 30.8% +/- 4.9%, 16.5% +/- 2.2%, all P < 0.01) on day 14 post wounding, while the Involucrin and P21 decreased their expression in the DAPT treated group (12.3% +/- 1.9%, 11.0% +/- 1.7%) relative to the control group (29.3% +/- 4.6%, 44.3% +/- 3.5%, both P < 0.01). CONCLUSION: Inactivation of Notch signaling will inhibit scar epidermis to over-differentiation, and thereby inhibit proliferation of hypertrophic scars in the rabbit ears.


Asunto(s)
Cicatriz Hipertrófica/metabolismo , Cicatriz Hipertrófica/patología , Receptores Notch/metabolismo , Animales , Diferenciación Celular , Modelos Animales de Enfermedad , Femenino , Masculino , Conejos
7.
Nat Nanotechnol ; 11(7): 613-20, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26974957

RESUMEN

Methamphetamine (METH) abuse is a serious social and health problem worldwide. At present, there are no effective medications to treat METH addiction. Here, we report that aggregated single-walled carbon nanotubes (aSWNTs) significantly inhibited METH self-administration, METH-induced conditioned place preference and METH- or cue-induced relapse to drug-seeking behaviour in mice. The use of aSWNTs alone did not significantly alter the mesolimbic dopamine system, whereas pretreatment with aSWNTs attenuated METH-induced increases in extracellular dopamine in the ventral striatum. Electrochemical assays suggest that aSWNTs facilitated dopamine oxidation. In addition, aSWNTs attenuated METH-induced increases in tyrosine hydroxylase or synaptic protein expression. These findings suggest that aSWNTs may have therapeutic effects for treatment of METH addiction by oxidation of METH-enhanced extracellular dopamine in the striatum.


Asunto(s)
Conducta Animal/efectos de los fármacos , Cuerpo Estriado/efectos de los fármacos , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/efectos de los fármacos , Dopamina/metabolismo , Metanfetamina/farmacología , Nanotubos de Carbono , Animales , Peso Corporal/efectos de los fármacos , Cuerpo Estriado/química , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/metabolismo , Ingestión de Alimentos/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Unión Proteica , Tirosina 3-Monooxigenasa/efectos de los fármacos , Tirosina 3-Monooxigenasa/metabolismo
8.
Zhonghua Liu Xing Bing Xue Za Zhi ; 33(11): 1155-8, 2012 Nov.
Artículo en Zh | MEDLINE | ID: mdl-23290903

RESUMEN

OBJECTIVE: To understand the epidemiological trend on the number of influenza-like cases and to explore the feasibility of early warning systems of influenza in Gansu province. METHODS: Based on data from the influenza sentinel surveillance program, a sequence chart was used to analyze the epidemiological trend on the number of influenza-like illness (ILI) cases. Both control chart and mobile percentile method were used to select the threshold of premium alert for the ILI of sentinel surveillance program. Warning effects were assessed by statistical model. RESULTS: The prevalence of influenza were both low in 2007 and 2008. Alert thresholds for ILI of Sentinel surveillance was built. The thresholds were higher alert in winter, but lower in summer. Both Seasonal Exponential Smoothing Model and Multiplicative Seasonal ARMA Model (1, 1, 1) (0, 1, 0) were used to dynamically predict the weekly percentage of outpatient visits for influenza-like illness (ILI%) of 2011. The concordance rates (predicted = actual) were 100% for both of them. According to the RMSE values, the dynamically predicted effect of the seasonal exponential smoothing model was superior to ARIMA. CONCLUSION: Dynamic prediction on the number of influenza-like cases could reflect the epidemiological trend of influenza in Gansu province, but with some limitations.


Asunto(s)
Gripe Humana/prevención & control , Vigilancia de Guardia , China/epidemiología , Predicción , Humanos , Gripe Humana/epidemiología , Modelos Estadísticos
9.
Zhonghua Zheng Xing Wai Ke Za Zhi ; 25(1): 41-5, 2009 Jan.
Artículo en Zh | MEDLINE | ID: mdl-19408725

RESUMEN

OBJECTIVE: To study the expression of Notch receptors, ligands and downstream target genes in hypertrophic scar and normal skin, and to investigate its role in the development of hypertrophic scar. METHODS: By immunohistochemistry, the expression of epidermal differentiation markers- beta1 integrin, keratin 14 (K14) and keratin 19 (K19), as well as Notch 1-4 and Jagged1 were examined in hypertrophic scars and normal skins. The expression of Notch downstream genes- P21 and P63 was analyzed with real-time quantitative PCR and immunohistochemistry staining. RESULTS: Histological analysis revealed a significant epidermal thickening in the hypertrophic scars, with excessive cell layers above the basal layer. Compared to the normal epidermis, the expression of beta1 integrin, K19 and K14 decreased in hypertrophic scars (P <0.05). Positive expression rate of Notch1 and Jagged1 in keratinocytes was significantly higher in hypertrophic scar than in normal skin (P < 0.05), while there was no difference in Notch2 and 3 positive expression rate. Furthermore, the expression of P21 was significantly up-regulated, while the expression of P63 was down-regulated in keratinocytes of hypertrophic scar (P < 0.05). CONCLUSIONS: Notch signal may play an important role in hypertrophic scar pathogenesis. Over-differentiation of Keratinocytes in hypertrophic scar may be related to the overexpression of Notch1 and Jagged1, up-regulation of P21 gene and down-regulation of P63 gene.


Asunto(s)
Cicatriz Hipertrófica/metabolismo , Epidermis/metabolismo , Receptor Notch1/metabolismo , Adulto , Proteínas de Unión al Calcio/metabolismo , Estudios de Casos y Controles , Cicatriz Hipertrófica/patología , Regulación hacia Abajo , Epidermis/patología , Femenino , Humanos , Integrina beta1/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Proteína Jagged-1 , Queratina-14/metabolismo , Queratina-19/metabolismo , Masculino , Proteínas de la Membrana/metabolismo , Proteínas Serrate-Jagged , Transducción de Señal , Regulación hacia Arriba , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA