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1.
ACS Omega ; 9(15): 17491-17505, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38645376

RESUMEN

Geological bodies are important sources of greenhouse gas (GHG) emissions. Organic-rich oil shale in sedimentary basins is a good gas source rock, the GHG in which will be released into the atmosphere during crushing to affect climate change. Quantitative calculations of GHG emissions during oil shale crushing were carried out on oil shales from the Yaojie (YJ) and Fushun (FS) mining areas in China. Organic geochemistry, X-ray diffraction, and pore structure analysis experiments, as well as the relationship between storage time and GHG emissions, were analyzed to investigate the main controlling factors of GHG release in different types of oil shales. The results showed that the CH4 and CO2 released from the YJ oil shale were 0.002-0.145 mL/g and 0.011-0.054 mL/g, respectively; the CH4 and CO2 released from the FS oil shale were 0.0001-0.0008 mL/g and 0.002-0.045 mL/g, respectively. Residual CH4 release was closely related to total organic carbon (TOC) and maturity: the CH4 released from the organic-rich and mature YJ oil shale was much higher than that of the FS oil shale, which is relatively organic-lean and immature. The control factors of the released CO2 vary in different regions: CO2 released from the YJ oil shale was somewhat affected by the TOC, while that released from the FS oil shale was mainly controlled by carbonate minerals and their contributing pores. The results of pore structure and organic maceral analyses indicated that both organic and inorganic pores of the YJ oil shale are occupied by asphaltenes, forming a key gas preservation mechanism of residual CH4 and CO2 as solutes dissolved in asphaltenes. In addition, CO2 has a greater absorptive capacity than CH4 and is therefore more difficult to release during the same crushing time. As oil shale is stored for longer periods, residual CH4 will be preferentially released to the atmosphere, while residual CO2 will be released in large quantities during crushing.

2.
Med Sci Monit ; 27: e931969, 2021 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-34455415

RESUMEN

BACKGROUND Midfoot deformity and injury can affect the internal pressure distribution of the foot. This study aimed to use 3D finite element and biomechanical analyses of midfoot von Mises stress levels in flatfoot, clubfoot, and Lisfranc joint injury. MATERIAL AND METHODS Normal feet, flatfeet, clubfeet (30 individuals each), and Lisfranc injuries (50 individuals) were reconstructed by CT, and 3D finite element models were established by ABAQUS. Spring element was used to simulate the plantar fascia and ligaments and set hyperelastic coefficients in encapsulated bone and ligaments. The stance phase was simulated by applying 350 N on the top of the talus. The von Mises stress of the feet and ankle was visualized and analyzed. RESULTS The von Mises stress on healthy feet was higher in the lateral metatarsal and ankle bones than in the medial metatarsal bone. Among the flatfoot group, the stress on the metatarsals, talus, and navicular bones was significantly increased compared with that on healthy feet. Among patients with clubfeet, stress was mainly concentrated on the talus, and stress on the lateral metatarsal and navicular bones was significantly lower. The von Mises stress on the fractured bone was decreased, and the stress on the bone adjacent to the fractured bone was higher in Lisfranc injury. During bone dislocation alone or fracture accompanied by dislocation, the von Mises stress of the dislocated bone tended to be constant or increased. CONCLUSIONS Prediction of von Mises stress distribution may be used clinically to evaluate the effects of deformity and injury on changes in structure and internal pressure distribution on the midfoot.


Asunto(s)
Pie Equinovaro/fisiopatología , Análisis de Elementos Finitos/estadística & datos numéricos , Pie Plano/fisiopatología , Traumatismos de los Pies/fisiopatología , Articulaciones del Pie/fisiopatología , Artropatías/fisiopatología , Estrés Mecánico , Adulto , Fenómenos Biomecánicos , Femenino , Estudios de Seguimiento , Articulaciones del Pie/lesiones , Humanos , Masculino , Pronóstico
3.
Sci Total Environ ; 574: 707-715, 2017 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-27664757

RESUMEN

Greenhouse gas (GHG) emissions from oil and gas exploration and development are major contributors to emission inventories in oil and natural gas (ONG) systems. For the developing countries, including China, studies of this aspect of the industry, being at an early stage, lack a unified method of calculation, and this leads to varied projections of national emissions. In this paper, progress is reported on direct measurement of CH4 and CO2 emissions along the oil and gas value chain, for four oil and gas fields. An improved calculation method (classification calculation method), which considers the production status of each type of oil and gas field in China, is proposed for the first time in this study. Based on in situ measurement, it is used to estimate the national CH4 and CO2 emissions from the process of petroleum exploration and development. The results showed that CH4 and CO2 emissions in 2013 were 73.29×104 and 20.32×104tonnes, respectively (in CO2 equivalent: 1559.36×104tonnes). Compared with the results (731.52×104tonnes of CH4, 1031.55×104tonnes of CO2, 16,393.48×104tonnes of CO2 equivalent) in 2013 determined by the Tier 1 method of the Intergovernmental Panel on Climate Change (IPCC), the carbon emissions from field measurement method were much lower than that of IPCC method, which indicated that carbon emissions of ONG systems in China were severely overrated by IPCC. Hence, the GHG emission results reported herein could fundamentally improve the knowledge and understanding of GHG emissions from ONG exploration and development in China.

4.
Front Plant Sci ; 8: 2107, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29321788

RESUMEN

This study was conducted to investigate the effects of soil water deficit on insecticidal protein expression in boll shells of cotton transgenic for a Bt gene. In 2014, Bt cotton cultivars Sikang 1 (a conventional cultivar) and Sikang 3 (a hybrid cultivar) were planted in pots and five soil water content treatments were imposed at peak boll stage: 15% (G1), 35% (G2), 40% (G3), 60% (G4), and 75% field capacity (CK), respectively. Four treatments (G2, G3, G4, and CK) were repeated in 2015 in the field. Results showed that the insecticidal protein content of boll shells decreased with increasing water deficit. Compared with CK, boll shell insecticidal protein content decreased significantly when soil water content was below 60% of maximum water holding capacity for Sikang 1 and Sikang 3. However, increased Bt gene expression was observed when boll shell insecticidal protein content was significantly reduced. Activity assays of key enzymes in nitrogen metabolism showed that boll shell protease and peptidase increased but nitrogen reductase and glutamic-pyruvic transaminase (GPT) decreased. Insecticidal protein content exhibited significant positive correlation with nitrogen reductase and GPT activities; and significant negative correlation with protease and peptidase activities. These findings suggest that the decrease of insecticidal protein content associated with increasing water deficit was a net result of decreased synthesis and increased decomposition.

5.
Insects ; 7(2)2016 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-27153095

RESUMEN

Hyphantria cunea (Drury) is an invasive pest of Morus alba L. in China. ß-ocimene and cis-2-penten-1-ol among eleven electro-physiologically active leaf volatiles from M. alba have been reported to influence captures of Hyphantria cunea moths when added into sex pheromone traps. This study further investigated influences of volatile types and their dosages on the electro-physiological responses in the antennae of male and female moths, as well as on mating and oviposition behaviors. Females were, regardless of dosages, more sensitive to ß-ocimene and cis-2-penten-1-ol in electro-physiological response tests than males. For males, a dose response was detected, i.e., a dosage of 10 µg and 100 µg of either chemical stimulated higher electric response in their antennae than 1 µg. Moth pairs either exposed respectively to a herbivore-induced M. alba volatile blend (HIPV), to a mechanically-damaged M. alba volatile blend (MDV), to ß-ocimene, to cis-2-penten-1-ol, or to pentane as a control showed that pairs exposed to ß-ocimene most likely mated, followed by HIPV blends and least by the other volatiles or the control. In contrast, ß-ocimene induced about 70% of the female oviposition behaviors and was nearly 4.5 times the oviposition rate than cis-2-penten-1-ol and 2 times than the control. However, none of the chemicals had any effect on the 48 h fecundity or on egg sizes. In conclusion, ß-ocimene from mulberry plants alone could promote mating and oviposition in H. cunea at a dosage of 1 mg. The results indicate that reproductive behaviors of H. cunea moths can be enhanced through HIPV blends and ß-ocimene induced by feeding of larvae. This contra phenomenon has revealed a different ecology in this moth during colonizing China as local pests would commonly be repelled by herbivore induced chemicals. These chemicals can be used for the development of biological control approaches such as being used together with sex pheromone traps.

6.
Tumour Biol ; 35(12): 12535-43, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25217321

RESUMEN

Here, we explored the expression of S100A4 in esophageal squamous cell cancer (ESCC) tissues and investigated its role in hypoxia-induced invasion and metastasis in ESCC cell lines EC-1 and EC-9706. Immunohistochemistry analysis demonstrated that S100A4 was overexpressed in human ESCC tissues especially in ESCC tissues with deep invasion and lymph node metastasis. Hypoxia-induced S100A4 overexpression was observed in EC-1 and EC-9706 cells, in which it was associated with invasion and metastasis. Furthermore, we used EC-1 and EC-9706 cells again to upregulate or knockdown the expression S100A4 to investigate the mechanism role of S100A4 in hypoxia-induced invasion and metastasis in ESCC cells. And the results showed that S100A4 played an important role in promoting the invasion and metastasis of EC-1 and EC-9706 cells under hypoxia. Therefore, S100A4 overexpression might be an important mechanism by which hypoxia induced invasion and metastasis, and S100A4 could also be a potential target for the treatment of ESCC.


Asunto(s)
Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patología , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patología , Hipoxia/metabolismo , Proteínas S100/metabolismo , Adulto , Anciano , Línea Celular Tumoral , Movimiento Celular/genética , Carcinoma de Células Escamosas de Esófago , Esófago/metabolismo , Femenino , Expresión Génica , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Membrana Mucosa/metabolismo , Invasividad Neoplásica , Metástasis de la Neoplasia , Estadificación de Neoplasias , Interferencia de ARN , ARN Interferente Pequeño/genética , Proteína de Unión al Calcio S100A4 , Proteínas S100/genética
7.
Lab Chip ; 14(6): 1117-22, 2014 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-24452784

RESUMEN

We report finger-actuated digital microfluidics (F-DMF) based on the manipulation of discrete droplets via the electrowetting on dielectric (EWOD) phenomenon. Instead of requiring an external power supply, our F-DMF uses piezoelectric elements to convert mechanical energy produced by human fingers to electric voltage pulses for droplet actuation. Voltage outputs of over 40 V are provided by single piezoelectric elements, which is necessary for oil-free EWOD devices with thin (typically <1 µm) dielectric layers. Higher actuation voltages can be provided using multiple piezoelectric elements connected in series when needed. Using this energy conversion scheme, we confirmed basic modes of EWOD droplet operation, such as droplet transport, splitting and merging. Using two piezoelectric elements in series, we also successfully demonstrated applications of F-DMF for glucose detection and immunoassay. Not requiring power sources, F-DMF offers intriguing paths for various portable and other microfluidic applications.


Asunto(s)
Técnicas Electroquímicas , Dedos , Técnicas Analíticas Microfluídicas , Humectabilidad , Técnicas Electroquímicas/instrumentación , Técnicas Electroquímicas/métodos , Glucosa/análisis , Humanos , Inmunoensayo/instrumentación , Inmunoensayo/métodos , Técnicas Analíticas Microfluídicas/instrumentación , Técnicas Analíticas Microfluídicas/métodos
8.
Artículo en Inglés | MEDLINE | ID: mdl-25004484

RESUMEN

(1120)-textured ZnO films are deposited on Rsapphire substrate by RF magnetron sputtering and the effects of deposition conditions on ZnO films are investigated. The chemical compositions of the ZnO films are characterized by X-ray photoelectron spectroscopy and the results indicate that the ratio of latticed oxygen to zinc increases with increasing of oxygen concentration in the sputtering gas, which demonstrates the improvement of crystal structures in ZnO films. To investigate the characteristics of surface acoustic waves excited by the (1120)-textured ZnO films, SAW delay lines based on layered structures of (1120) ZnO film/R-sapphire substrate are fabricated, in which Rayleigh and Love modes are excited along the (0001)- and (1100)-directions of the ZnO films, respectively. The phase velocities and electromechanical coupling factors of both wave modes are characterized as functions of the film-thickness-to-wavelength ratio. The acoustic properties of the layered structures are calculated using the transfer matrix method. The experimental and theoretical results are in good agreement with each other.

9.
J Insect Physiol ; 58(9): 1209-16, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22732233

RESUMEN

The sex pheromone blend of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a multi-component system, as is that of many other moths, and (Z)-11-hexadecenal 90-99%+(Z)-9-hexadecenal 10-1% was recommended as a standard blend for attracting the species. However, this fails to account for the significance of other compounds that exist in the sex gland. The aim of the present study was to investigate the function of other compounds present in the female sex gland of H. armigera. Extract of female sex glands were analysed by GC-MS combined with GC-EAD. Total 10 compounds were identified, which two novel were reported in female sex gland: heptanal and nonanal, and some previously identified compounds were confirmed. We developed bioassays to evaluate the potential roles of these 10 compounds. In Y-tube bioassays, the gland constituents hexadecanal, (Z)-7-hexadecenal and (Z)-9-tetradecenal increased male attractiveness when added as a three-compound admixture to the standard blend. Field trapping tests showed that (Z)-9-tetradecenal doubled trap catch in comparison with the standard blend, but that the addition of (Z)-7-hexadecenal and hexadecanal did not significantly increase trap catch. These results indicated that while (Z)-7-hexadecenal and hexadecanal function well only at short range, (Z)-9-tetradecenal plays a very important role at both short and long ranges. We suggest that that (Z)-9-tetradecenal as a previously overlooked sex pheromone component of H. armigera, it should be added to sex pheromone lure formulations to improve pheromone trap sensitivity and the efficacy of commercial mating disruption.


Asunto(s)
Aldehídos/aislamiento & purificación , Mariposas Nocturnas/química , Atractivos Sexuales/química , Animales , Antenas de Artrópodos/fisiología , Femenino , Masculino , Mariposas Nocturnas/fisiología , Atractivos Sexuales/fisiología
10.
Ying Yong Sheng Tai Xue Bao ; 18(1): 224-8, 2007 Jan.
Artículo en Chino | MEDLINE | ID: mdl-17396528

RESUMEN

The study on the community structure of arthropod in the alpine cabbage fields of Hubei Province showed that the dominant pests were Brevicoryne brassicae, Mamestra brassicae and Plutella xylostella, while the dominant natural enemies were Diaeretiella rapae, Cotesia plutella, Erigonidum gramiaicolum and Syrphus corollae. The richness, diversity index, evenness index and dominance index of pest and natural enemy sub-communities all changed with time. The dominance index of pest sub-community was higher, while its diversity and evenness indices were lower than those of natural enemy sub-community. Based on fuzzy clustering analysis, the pest and natural enemy subcommunities of 14 time sequences were grouped into 4 and 3 sorts, respectively.


Asunto(s)
Artrópodos/crecimiento & desarrollo , Brassica/parasitología , Control Biológico de Vectores , Conducta Predatoria/fisiología , Altitud , Animales , Brassica/crecimiento & desarrollo , Análisis por Conglomerados , Dinámica Poblacional
11.
J Econ Entomol ; 99(5): 1636-40, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17066793

RESUMEN

The synthetic aphid alarm pheromone (E)-beta-farnesene (EBF) is released by aphids in response to predation or other disturbances that occur in the colony. This is presumed to benefit the population by allowing increased survival of related individuals taking successful evasive action after perception of the pheromone. The effect of pheromone perception by aphids in the absence of real threats was investigated to determine the baseline effect of this communication on aphid survival, development, and fecundity in the laboratory. All four nymphal stages of cotton aphid, Aphis gossypii Glover (Homoptera: Aphididae), were stimulated with EBF. No significant difference in survival rates was observed in the aphids stimulated with EBF compared with the untreated control. Developmental times of the aphids were significantly prolonged in first and third instars when they were stimulated with EBF. Significantly lower fecundity and lighter weight of adult aphids were observed in aphids stimulated with EBF at as first instars compared with untreated controls and other instars. Results indicate that exposure of the first instar of A. gossipii to the synthetic alarm pheromone adversely affects subsequent development and fecundity of the population. This reduces aphid fitness that must be compensated by increased survival from predation for the pheromone to confer a selective advantage to the species.


Asunto(s)
Áfidos/efectos de los fármacos , Estadios del Ciclo de Vida/efectos de los fármacos , Sesquiterpenos/farmacología , Animales , Peso Corporal , Fertilidad , Crecimiento Demográfico , Reproducción/efectos de los fármacos , Factores de Tiempo
12.
Ultrasonics ; 44 Suppl 1: e603-6, 2006 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-16793103

RESUMEN

At the present moment, the smallest piezoelectric ultrasonic micro-motors utilizing miniature PZT piezoelectric ceramic tubes were developed. The motor consists of a PZT-metal composite tube stator, two steel rotors and a thin shaft that keeps the two rotors pressing on both ends of the stator elastically. The dimensions of the PZT tube are 1.0 mm in outer diameter, 0.6 mm in inner diameter and 5.0 mm in length. The diameter and total length of the assembled micro-motor is 1.0 mm and 8 mm (including an adjusting spring), respectively. The tube-type micro-motor is driven by two pairs of alternative voltages with phase shift 90 degrees between the adjacent electrodes and operated in the first circular-bending vibration mode of the stator with the resonance frequency about 58 kHz. The experimental results show that the tube-type micro-motors have perfect performances: (i) high rotation frequency over 3000 rpm and (ii) large starting torque over 7.8 microN m under the conditions of the input voltage of 110 V(p-p) and the resonance frequency. The micro-motor is well suitable for operating in micro-spaces, such as in intravascular, micro-robots and micro-craft applications.

13.
J Chem Ecol ; 31(1): 39-48, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15839478

RESUMEN

Extracts of female sex pheromone gland of the carpenterworm moth, Holcocerus hippophaecolus Hua, a pest of sandthorn, Hippophae rhamnoides L. were found to contain (E)-3-tetradecenyl acetate (E3-14:Ac), (Z)-3-tetradecenyl acetate (Z3-14:Ac), (Z)-7-tetradecenyl acetate (Z7-14:Ac), the corresponding alcohols, E3-14:OH, Z3-14:OH, Z7-14:OH, and (E)-9-tetradecenyl acetate (E9-14:Ac). Electroantennographic (EAG) analysis of these chemicals and their analogs demonstrated that Z7-14:Ac elicited the largest male EAG response, followed by E3-14:Ac. In field trials, traps baited with either Z7-14:Ac or E3-14:Ac alone caught no male moths, whereas a combination of these two components in a 1:1 ratio caught more males than control traps. Addition of Z7-14:OH and Z3-14:OH or the alcohols plus E9-14:Ac did not enhance trap catches. We conclude that the sex pheromone of H. hippophaecolus is composed of Z7-14:Ac and E3-14:Ac. Optimal ratios and doses of these two components, and the possible role of other minor components, remain to be determined.


Asunto(s)
Mariposas Nocturnas/fisiología , Órganos de los Sentidos/fisiología , Atractivos Sexuales/química , Acetatos/química , Animales , China , Glándulas Exocrinas/química , Glándulas Exocrinas/fisiología , Femenino , Cromatografía de Gases y Espectrometría de Masas , Masculino , Mariposas Nocturnas/química , Atractivos Sexuales/análisis , Extractos de Tejidos/química
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