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1.
Waste Manag ; 178: 311-320, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38428381

RESUMEN

Animal slurry storage is an important ammonia (NH3) emission source. Sulfuric acid (H2SO4)-modified vermiculite coverage is a new promising technology for controlling NH3 emission from slurry storage. However, the underlying mechanisms in controlling the mitigation effect remain unclear. Here, a series of experiments to determine the effect of H2SO4 on the modified vermiculite properties, floating persistence, and NH3 mitigation effect was conducted. Results showed that abundant H2SO4 and sulfate remained on the outer surface and in the extended inner pores of the vermiculite with acidifying H+ concentrations higher than 5 M. An initial strong instantaneous acidification of surface slurry released rich carbon dioxide bubbles, strengthening cover floating performance. An acidification in the vermiculite cover layer and a good coverage inhibition interacted, being the two leading mechanisms for mitigating NH3 during initial 40-50 days of storage. The bacterial-amoA gene dominated the conversion of NH3 to nitrous oxide after 50 days of storage. Vermiculite with 5 M H+ modification reduced the NH3 emissions by 90 % within the first month of slurry storage and achieved a 64 % mitigation efficiency throughout the 84 days period. With the development of the aerial spraying equipment such as agricultural drones, acidifying vermiculite coverage hold promise as an effective method for reducing NH3 emission while absorbing nutrients from liquid slurry storage tank or lagoon. This design should now be tested under field conditions.


Asunto(s)
Silicatos de Aluminio , Amoníaco , Ácidos Sulfúricos , Animales , Amoníaco/análisis , Agricultura , Estiércol , Óxido Nitroso/análisis
2.
ACS Appl Bio Mater ; 6(7): 2849-2859, 2023 07 17.
Artículo en Inglés | MEDLINE | ID: mdl-37340725

RESUMEN

Aggregation-induced emission (AIE) nanoparticles (NPs) have been applied in bioimaging for cancer diagnosis due to high fluorescence efficiency. However, the poor cell permeability as well as autofluorescence of biological cells/tissues caused by ultraviolet (UV) irradiation is still the key problem of AIE luminophores for biological imaging. Here, we report green-emitting organic AIE luminophores for fluorescence imaging of living cells/tissues, which possess high fluorescence quantum yields and strong AIE under two-photon excitation with near-infrared light beyond 800 nm. These AIE luminophores can bind with bovine serum albumin (BSA) to form biocompatible BSA/AIE-NPs due to their terminal aldehyde groups providing specific anchor sites with the receptor groups in BSA. Furthermore, one/two-photon fluorescence bioimaging for Hela cancer cells has been successfully carried out with BSA/AIE-NPs as the fluorescent probe, and BSA/AIE-NPs show excellent stain properties with a fast permeability of only 5 min, high cellular uptakes, and strong fluorescence. The results demonstrate the great advantages of BSA/AIE-NPs in fast fluorescence biological imaging as well as further cancer diagnosis and therapy.


Asunto(s)
Nanopartículas , Imagen Óptica , Humanos , Imagen Óptica/métodos , Fotones , Células HeLa , Rayos Infrarrojos
3.
Int J Mol Sci ; 23(16)2022 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-36012491

RESUMEN

To reduce the application of synthetic additives in the field of food preservation, this study utilized carvacrol as an antibacterial agent, and zein and sodium caseinate as carriers, to prepare composite nanoparticles loaded with carvacrol by the pH-driven method. The composite nanoparticles of zein/sodium caseinate had an excellent encapsulation efficiency (77.96~82.19%) for carvacrol, and it had remarkable redispersibility. The results of Fourier transform infrared spectroscopy showed that the formation of the composite nanoparticles mainly depended on the hydrogen bond and the hydrophobic zone force, and thermal gravimetric analysis showed that carvacrol was loaded successfully into nanoparticles, and loading efficiency reached 24.9%. Scanning electron microscopy showed that the composite nanoparticles were spherical, with a particle size range of 50~200 nm, and through the free radical scavenging method and the plate counting method to confirm the particle has stronger antioxidant and antibacterial properties, and with the composite nanoparticles with poly (vinyl alcohol) film applied to the preservation of banana together, it was found that PVA film containing 5 wt% CA-loaded composite NPs can significantly extend the storage period of banana. Therefore, when the composite nanoparticles were applied to food packaging, they could effectively inhibit food spoilage and lengthen the shelf life of food, which displays potential application prospects in the food industry.


Asunto(s)
Nanopartículas , Zeína , Antibacterianos/química , Antibacterianos/farmacología , Caseínas/química , Cimenos , Concentración de Iones de Hidrógeno , Nanopartículas/química , Tamaño de la Partícula , Zeína/química
4.
Small ; 18(21): e2201046, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35451189

RESUMEN

Ti3 C2 Tx , as a newly investigated 2D material, has gained great attention owing to its metallic conductivity, tunable work function (WF ), and unique electrical property. However, its WF can be further adjusted to meet the needs of optoelectronic devices. Here, surface-engineered Ti3 C2 Tx is fabricated with tunable WF by treating with ethanolamine and rhodium chloride (RhCl3 ). Ethanolamine treated Ti3 C2 Tx can induce the chemical adsorption of NH2 on Ti3 C2 Tx with hydrogen-bonding, which causes the decreased WF , while chemical doping with RhCl3 leads to the improvement of WF , which is achieved by the downshift of Femi level of Ti3 C2 Tx . Moreover, the ethanolamine and RhCl3 can effectively passivate the vacancies of Ti. As such, the surface-engineered Ti3 C2 Tx is more suitable as buffer layer for polymer solar cells (PSCs) by enhancing the interfacing characteristics of the Ti3 C2 Tx /active layer. The PSCs with engineered Ti3 C2 Tx for electron or hole transport layers can exhibit a power conversion efficiency of 15.88% or 15.54%. These efficiencies can be compared with those of devices with a conventional transport layer. This work provides a facile strategy to realize the work function tunability of Ti3 C2 Tx , and also shows that the tuned Ti3 C2 Tx has a certain application prospect in photovoltaic devices.

5.
Macromol Biosci ; 22(2): e2100340, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34957668

RESUMEN

Bioadhesives have been widely used in healthcare and biomedical applications due to their ease-of-operation for wound closure and repair compared to conventional suturing and stapling. However, several challenges remain for developing ideal bioadhesives, such as unsatisfied mechanical properties, non-tunable biodegradability, and limited biological functions. Considering these concerns, naturally derived biopolymers have been considered good candidates for making bioadhesives owing to their ready availability, facile modification, tunable mechanical properties, and desired biocompatibility and biodegradability. Over the past several years, remarkable progress has been made on biopolymer-based adhesives, covering topics from novel materials designs and advanced processing to clinical translation. The developed bioadhesives have been applied for diverse applications, including tissue adhesion, hemostasis, antimicrobial, wound repair/tissue regeneration, and skin-interfaced bioelectronics. Here in this comprehensive review, recent progress on biopolymer-based bioadhesives is summarized with focuses on clinical translations and multifunctional bioadhesives. Furthermore, challenges and opportunities such as weak adhesion strength at the hydrated state, mechanical mismatch with tissues, and unfavorable immune responses are discussed with an aim to facilitate the future development of high-performance biopolymer-based bioadhesives.


Asunto(s)
Adhesivos Tisulares , Adhesivos , Materiales Biocompatibles/uso terapéutico , Biopolímeros/uso terapéutico , Adhesivos Tisulares/farmacología , Adhesivos Tisulares/uso terapéutico , Cicatrización de Heridas
7.
Huan Jing Ke Xue ; 42(1): 1-8, 2021 Jan 08.
Artículo en Chino | MEDLINE | ID: mdl-33372451

RESUMEN

Since 2013, the Chinese government implemented the Air Pollution Prevention and Control Action Plan. As a result, the atmospheric concentrations of sulfate reduced significantly, whereas the nitrate concentrations remain relatively high due to the excess of ammonia (NH3). To date, there is no official observation network monitoring NH3 concentrations in China. Previous studies have focused on NH3 or ammonium (NH4+) separately. These limitations hinder a complete understanding of their dynamic changes due to the rapid gas-to-particle conversion. In this study, the concentrations of NH3 and NH4+ were measured concurrently in urban Beijing during autumn 2019 utilizing an acid-coated denuder-filter combination with a time resolution from 2 h (PM2.5>35 µg·m-3) to 5 h (PM2.5<35 µg·m-3). The mean concentrations of NH3 and NH4+ during the study were (4.1±2.9)µg·m-3 and (1.7±1.4) µg·m-3, respectively. The temporal patterns of NH3 or NH4+ coincided with that of PM2.5, CO, and NO2 throughout the sampling period. The diurnal distributions of NH3 were bimodal, both on polluted (PM2.5>75 µg·m-3) and non-polluted (PM2.5<75 µg·m-3) days, peaking at 21:30-05:30 and 05:30-08:30, respectively. The NH3 concentrations on polluted days were relatively lower during 17:30-21:30, which may be related to higher wind speeds. In contrast to NH3, NH4+ had an obvious peak during 17:30-21:30 due to the formation of ammonium nitrate. The meteorological conditions favor the gas-to-particle conversion on polluted days, resulting in a lower NH3/NH4+ ratio of 0.8. However, this value may reach 2.8 on non-polluted days. The concentrations of NH3, CO, NO2, SO2, and PM2.5 in the emission control period showed a significant increase greater than or comparable to those in the non-control period by 54.2%, 40.4%, 33.3%, 0%, and 49.4%, respectively. This result shows that the stagnant conditions offset the benefit of emission control actions implemented during and before the National Celebration Day.

8.
Sci Total Environ ; 697: 134054, 2019 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-31476510

RESUMEN

Dissolved organic carbon (DOC) plays an important role in global and regional carbon cycles. However, the quantification of DOC in forest ecosystems remains uncertain. Here, the processed-based biogeochemical model TRIPLEX-DOC was modified by optimizing the function of soil organic carbon distribution with increasing depths, as well as DOC sorption-desorption efficiency. The model was validated by field measurements of DOC concentration and flux at five forest sites and Beijiang River basin in monsoon regions of China. Model validation indicated that seasonal patterns of DOC concentration across climatic zones were different, and these differences were captured by our model. Importantly, the modified model performed better than the original model. Indeed, model efficiency of the modified model increased from -0.78 to 0.19 for O horizon predictions, and from -0.46 to 0.42 for the mineral soils predictions. Likewise, DOC fluxes were better simulated by the modified model. At the site scale, the simulated DOC fluxes were strongly correlated with the observed values (R2 = 0.97, EF = 0.91). At the regional scale, the DOC flux predicted in the Beijiang River basin was 16.44 kg C/ha, which was close to the observed value of 17 kg C/ha. Using sensitivity analysis, we showed that temperature, precipitation and temperature sensitivity of DOC decomposition (Q10) were the most sensitive parameters when predicting DOC concentrations and fluxes in forest soils. We also found that both the percentage of DOC flux to forest net ecosystem productivity, and the retention of DOC by mineral soil were highly correlated with the amount of precipitation. Overall, our model validations indicated that the modified TRIPLEX-DOC model is a useful tool for simulating the dynamics of DOC concentrations and fluxes in forest ecosystems. We highlight that more accurate estimates of parameter Q10 in deep mineral soils can reduce model uncertainty, when simulating DOC concentrations and fluxes in forest soils.

9.
Exp Mol Pathol ; 111: 104300, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31442445

RESUMEN

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. Following the concerns raised about the background pattern of the Western Blots from Figures 1C and 3D, the corresponding author has contacted the journal to request the retraction of the article. Given the comments of Dr Elisabeth Bik regarding this article "This paper belongs to a set of over 400 papers (as per February 2020) that share very similar Western blots with tadpole-like shaped bands, the same background pattern, and striking similarities in title structures, paper layout, bar graph design, and - in a subset - flow cytometry panels", the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.


Asunto(s)
Ventrículos Cardíacos/patología , Inflamación/prevención & control , Lipopolisacáridos/toxicidad , MicroARNs/genética , Miocarditis/prevención & control , Miocitos Cardíacos/patología , ARN Circular/genética , Animales , Apoptosis , Supervivencia Celular , Citocinas , Regulación de la Expresión Génica , Ventrículos Cardíacos/efectos de los fármacos , Ventrículos Cardíacos/metabolismo , Inflamación/inducido químicamente , Inflamación/genética , Inflamación/patología , Miocarditis/inducido químicamente , Miocarditis/genética , Miocarditis/patología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , FN-kappa B/genética , FN-kappa B/metabolismo , Sustancias Protectoras/metabolismo , Ratas , Transducción de Señal , Regulación hacia Arriba , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
10.
Phys Chem Chem Phys ; 21(28): 15833-15844, 2019 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-31282504

RESUMEN

Ultrathin films of tetracyanoethylene (TCNE) on Co(100) were investigated by means of spin-integrated and spin-resolved photoemission spectroscopy ((sp-)UPS), X-ray photoemission spectroscopy (XPS), near edge X-ray absorption fine-structure spectroscopy (NEXAFS), and X-ray magnetic circular dichroism (XMCD). We found a coverage-dependent modulation of the interface dipole and a switching between a metallic and a resistive spin filtering at the interface triggered by two distinct adsorption geometries of TCNE. The strongest hybridization and spin structure modifications are found at low coverage with a face-on adsorption geometry indicating changes in the distance between the surface Co atoms beneath. TCNE has the potential to manipulate the magnetic moments in the Co surface itself, including the possibility of magnetic hardening effects. In summary, the system TCNE/Co offers an experimentally rather easy and controllable way to build up a stable molecular platform stabilizing the reactive ferromagnetic Co surface and customizing the electronic and magnetic properties of the resulting spinterface simultaneously. This makes this system very attractive for spintronic applications as an alternative, less reactive but highly spin polarized foundation beside graphene-based systems.

11.
RSC Adv ; 9(18): 9946-9950, 2019 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-35520928

RESUMEN

Tin oxide (SnO2) is widely used as electron transport layer (ETL) material in perovskite solar cells (PSCs). Numerous synthesis methods for SnO2 have been reported, but they all require a proper thermal treatment for the SnO2 ETLs. Herein we present a simple method to synthesize SnO2 nanoparticles (NPs) at room temperature. By using butyl acetate as a precipitator and a proper UV-Ozone treatment to remove Cl residuals, excellent SnO2 ETLs were obtained without any thermal annealing. The highest power conversion efficiency (PCE) of the prepared PSCs was 19.22% for reverse scan (RS) and 18.79% for forward scan (FS). Furthermore, flexible PSCs were fabricated with high PCEs of 15.27%/14.74% (RS/FS). The low energy consuming SnO2 ETLs therefore show great promise for the flexible PSCs' commercialization.

13.
ACS Appl Mater Interfaces ; 10(17): 14922-14929, 2018 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-29633612

RESUMEN

Organic-inorganic metal halide perovskite solar cells (PSCs) have been emerging as one of the most promising next generation photovoltaic technologies with a breakthrough power conversion efficiency (PCE) over 22%. However, aiming for commercialization, it still encounters challenges for the large-scale module fabrication, especially for flexible devices which have attracted intensive attention recently. Low-temperature processed high-performance electron-transporting layers (ETLs) are still difficult. Herein, we present a facile low-temperature synthesis of crystalline SnO2 nanocrystals (NCs) as efficient ETLs for flexible PSCs including modules. Through thermal and UV-ozone treatments of the SnO2 ETLs, the electron transporting resistance of the ETLs and the charge recombination at the interface of ETL/perovskite were decreased. Thus, the hysteresis-free highly efficient rigid and flexible PSCs were obtained with PCEs of 19.20 and 16.47%, respectively. Finally, a 5 × 5 cm2 flexible PSC module with a PCE of 12.31% (12.22% for forward scan and 12.40% for reverse scan) was fabricated with the optimized perovskite/ETL interface. Thus, employing presynthesized SnO2 NCs to fabricate ETLs has showed promising for future manufacturing.

14.
PLoS One ; 11(10): e0165039, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27755581

RESUMEN

The lateral transport of dissolved organic carbon (DOC) plays an important role in linking the carbon cycles of terrestrial and aquatic ecosystems. Neglecting the lateral flow of dissolved organic carbon can lead to an underestimation of the organic carbon budget of terrestrial ecosystems. It is thus necessary to integrate DOC concentrations and flux into carbon cycle models, particularly with regard to the development of models that are intended to directly link terrestrial and ocean carbon cycles. However, to achieve this goal, more accurate information is needed to better understand and predict DOC dynamics. In this study, we compiled an inclusive database of available data collected from the Yangtze River, Yellow River and Pearl River in China. The database is collected based on online literature survey and analysed by statistic method. Overall, our results revealed a positive correlation between DOC flux and discharge in all three rivers, whereas the DOC concentration was more strongly correlated with the regional net primary productivity (NPP). We estimated the total DOC flux exported by the three rivers into the China Sea to be approximately 2.73 Tg yr-1. Specifically, the annual flux of DOC from the Yangtze River, Yellow River and Pearl River was estimated to be 1.85 Tg yr-1, 0.06 Tg yr-1 and 0.82 Tg yr-1, respectively, and the average annual DOC concentrations were estimated to be 2.24 ± 0.53 mg L-1, 2.70 ± 0.38 mg L-1 and 1.51 ± 0.09 mg L-1, respectively. Seasonal variations in DOC concentrations are greatly influenced by the interaction between temperature and precipitation. NPP is significantly and positively related to the DOC concentration in the Yangtze River and the Pearl River. In addition, differences in climate and the productivity of the vegetation may influence both the flux and concentrations of DOC transported by the rivers and thus potentially affect estuarine geochemistry.


Asunto(s)
Carbono/análisis , Ríos/química , China , Bases de Datos Factuales , Ecosistema , Monitoreo del Ambiente , Océanos y Mares , Lluvia , Estaciones del Año , Temperatura
15.
PLoS One ; 10(2): e0116591, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25706724

RESUMEN

Afforestation, the conversion of non-forested land into forest, is widespread in China. However, the dynamics of soil organic carbon (SOC) after afforestation are not well understood, especially in plateau climate zones. For a total of 48 shrub- and/or tree-dominated afforestation sites on the Qinghai Plateau, Northwestern China, post-afforestation changes in SOC, total nitrogen (TN), the carbon-to-nitrogen ratio (C/N) and soil bulk density (BD) were investigated to a soil depth of 60 cm using the paired-plots method. SOC and TN accumulated at rates of 138.2 g C m(-2) yr(-1) and 4.6 g N m(-2) yr(-1), respectively, in shrub-dominated afforestation sites and at rates of 113.3 g C m(-2) yr(-1) and 6.7 g N m(-2) yr(-1), respectively, in tree-dominated afforestation sites. Soil BD was slightly reduced in all layers in the shrub-dominated afforestation plots, and significantly reduced in soil layers from 0-40cm in the tree-dominated afforestation plots. The C/N ratio was higher in afforested sites relative to the reference sites. SOC accumulation was closely related to TN accumulation following afforestation, and the inclusion of N-fixing species in tree-dominated afforestation sites additionally increased the soil accumulation capacity for SOC (p < 0.05). Multiple regression models including the age of an afforestation plot and total number of plant species explained 75% of the variation in relative SOC content change at depth of 0-20 cm, in tree-dominated afforestation sites. We conclude that afforestation on the Qinghai Plateau is associated with great capability of SOC and TN sequestration. This study improves our understanding of the mechanisms underlying SOC and TN accumulation in a plateau climate, and provides evidence on the C sequestration potentials associated with forestry projects in China.


Asunto(s)
Secuestro de Carbono , Carbono/análisis , Bosques , Suelo/química , China , Nitrógeno/análisis , Árboles
16.
Huan Jing Ke Xue ; 32(7): 1899-907, 2011 Jul.
Artículo en Chino | MEDLINE | ID: mdl-21922807

RESUMEN

Two non-CO2 greenhouse gas emissions (methane and nitrous oxide) and related environmental factors were measured within rice growing season under five treatments including non-fertilization (CK), balanced fertilization (BF), decreased nitrogen and phosphate 1 (DNP1), decreased nitrogen and phosphate 2 (DNP2) and increased nitrogen and phosphate 1 (INP) in double rice fields of red clay soil in 2009, using the method of static chamber-gas chromatograph techniques. The results showed that the average CH4 emission fluxes for treatments of BF, DNP1, DNP2 and INP were 4.57, 5.42, 4.70 and 4.65 mg x (m2 x h)(-1) during early rice growing period, which increased by 39%, 49%, 41% and 40% compared with non-fertilizer treatment, respectively. The average CH4 emission fluxes in late rice growing season was higher than preseason's. Compared to CK, CH4 emission increased by 11%, 1%, 26% and - 4% in treatments of BF, DNP1, DNP2 and INP within late rice growing season. Applying nitrogen and phosphate enhanced CH4 emission in turning green period for early and late rice. No significant difference was observed between the CH4 emissions of five treatments during early and late rice growing season (p > 0.05). N2O emission was very little during mid-seasonal drainage period. In contrast, N2O emission peaks were observed in period of alternation of wetting and drying after mid-seasonal drainage in this experiment. N2O emission was, on average, equivalent to 0.18% of the nitrogen applied in double rice growing season. Statistically, air temperature, soil Eh and soil moisture (water-filled pore space, WFPS) at 0-10cm depth significantly affected the fluctuations of the seasonal CH4 flux, but no significant correlationship has been found between N2O flux and related environmental factors. CH4 was the dominated greenhouse gas in double rice fields which contributed approximately 90% for the integrated global warming potential of CH4 and N2O released during the rice growing season. Therefore, the mitigation options should focus on how to reduce CH4 emission in local area. The result indicates that BF is a recommended fertilization method for early rice production, and a optimum fertilization for late season can increase rates of nitrogen and phosphate fertilizers on the basis of BF treatment slightly by considering total global warming potential and grain yield. The rates of BF treatment were 150-90-90 kg x hm(-2) N-P2O5-K2O for early rice, and 180-90-135 kg x hm(-2) N-P2O5-K2O for late rice, respectively.


Asunto(s)
Contaminantes Atmosféricos/análisis , Fertilizantes , Metano/análisis , Óxido Nitroso/análisis , Oryza/crecimiento & desarrollo , Nitrógeno , Fosfatos
17.
Nat Genet ; 43(4): 345-9, 2011 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-21378986

RESUMEN

Coronary artery disease (CAD) causes more than 700,000 deaths each year in China. Previous genome-wide association studies (GWAS) in populations of European ancestry identified several genetic loci for CAD, but no such study has yet been reported in the Chinese population. Here we report a three-stage GWAS in the Chinese Han population. We identified a new association between rs6903956 in a putative gene denoted as C6orf105 on chromosome 6p24.1 and CAD (P = 5.00 × 10⁻³, stage 2 validation; P = 3.00 × 10⁻³, P = 1.19 × 10⁻8 and P = 4.00 × 10⁻³ in three independent stage 3 replication populations; P = 4.87 × 10⁻¹², odds ratio = 1.51 in the combined population). The minor risk allele A of rs6903956 is associated with decreased C6orf105 mRNA expression. We report the first GWAS for CAD in the Chinese Han population and identify a SNP, rs6903956, in C6orf105 associated with susceptibility to CAD in this population.


Asunto(s)
Pueblo Asiatico/genética , Enfermedad de la Arteria Coronaria/genética , Alelos , Estudios de Casos y Controles , China , Cromosomas Humanos Par 6/genética , Femenino , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Humanos , Desequilibrio de Ligamiento , Masculino , Polimorfismo de Nucleótido Simple , ARN Mensajero/genética , Factores de Riesgo
18.
J Zhejiang Univ Sci B ; 9(7): 572-7, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18600788

RESUMEN

The rice water weevil (RWW) Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae) is an invasive insect pest of rice Oryza sativa L. in China. Little is known about the interactions of this weevil with indigenous herbivores. In the present study, adult feeding and population density of the weevil, injury level of striped stem borer Chilo suppressalis (Walker) (Lepidoptera: Pyralidae) and pink stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) to rice, as well as growth status of their host plants were surveyed in a rice field located in Southeastern Zhejiang, China, in 2004 with the objective to discover interspecific interactions on the rice. At tillering stage, both adult feeding of the weevil and injury of the stem borers tended to occur on larger tillers (bearing 5 leaves) compared with small tillers (bearing 2~4 leaves), but the insects showed no evident competition with each other. At booting stage, the stem borers caused more withering/dead hearts and the weevil reached a higher density on the plants which had more productive tillers and larger root system; the number of weevils per tiller correlated negatively with the percentage of withering/dead hearts of plants in a hill. These observations indicate that interspecific interactions exist between the rice water weevil and the rice stem borers with negative relations occurring at booting or earlier developmental stages of rice.


Asunto(s)
Escarabajos/crecimiento & desarrollo , Oryza/parasitología , Gorgojos/crecimiento & desarrollo , Animales , Oryza/crecimiento & desarrollo , Densidad de Población
19.
J Zhejiang Univ Sci B ; 8(1): 33-8, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17173360

RESUMEN

The rice water weevil, Lissorhoptrus oryzophilus Kuschel, has two generations in southern Zhejiang, China. To determine oogenesis in first-generation females (summer females) and its relations to temperature, females were collected from a rice field in early and mid-July and reared on young rice plants at 28, 31 and 34 degrees C in the laboratory. Percentage of females having oocytes, number of oocytes of different stages (stage-I, from early previtellogenesis to middle vitellogenesis; stage-II, late vitellogenesis; and mature-oocyte stage), and length of ovarioles were determined every 10 d of feeding. At each temperature, oogenesis took place in over 40% of females after 20~40 d of feeding, but only 0.0~3.3 stage-I, 0.0~0.8 stage-II and 0.0~1.1 mature oocytes were observed at each observation date. Temperature had significant effect on number of stage-I oocytes but not on number of stage-II and mature oocytes in early July females; temperature had no significant effect on number of oocytes of either stage in mid-July females. Conclusively, in southern Zhejiang, summer L. oryzophilus females have great potential to become reproductive on rice, but their oogenesis activity is very low, with the overall procedures little affected by temperature.


Asunto(s)
Gorgojos/genética , Animales , China , Femenino , Oogénesis , Oryza/parasitología , Estaciones del Año , Temperatura , Gorgojos/patogenicidad
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