Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
J Chem Ecol ; 46(3): 308-316, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32016775

RESUMO

Polyphenol oxidases (PPOs) as inducible defense proteins, contribute to tea (Camellia sinensis) resistance against tea geometrid larvae (Ectropis grisescens), and this resistance has been associated with the jasmonic acid (JA) signaling by testing geometrid performance in our previous work. However, the regulation of PPO-based defense by JA and other hormone signaling underlying these defense responses is poorly understood. Here, we investigated the role of phytohormones in regulating the PPO response to tea geometrids. We profiled levels of defense hormones, PPO activity and CsPPO genes in leaves infested with tea geometrids. Then, hormone levels were manipulated by exogenous application of methyl jasmonate (MeJA), gibberellin acid (GA3), abscisic acid (ABA), JA biosynthesis inhibitors (sodium diethyldithiocarbamate trihydrate, DIECA and salicylhydroxamic acid, SHAM) and GA inhibitor (uniconazole, UNI). Upon geometrid attack, JA levels significantly increased, whereas GA levels notably decreased and ABA level was slightly decreased. And the PPO activity significantly increased in line with the transcript levels of CsPPO2 and CsPPO4 but not CsPPO1. There were an obvious antagonistic cross-talk between JA and GA signals and an association among JA signals, PPO response and herbivore resistance in tea plants. Pretreatment with MeJA increased PPO activity by activating the transcripts of CsPPO2 and CsPPO4, whereas application of JA inhibitor DIECA suppressed PPO activity. GA3 strongly enhanced PPO activity, but ABA did not alter PPO activity. These findings strongly suggest that JA is a central player in PPO-mediated tea resistance against tea geometrids in a manner that prioritizes defense over growth.


Assuntos
Antibiose , Camellia sinensis/metabolismo , Catecol Oxidase/metabolismo , Ciclopentanos/metabolismo , Mariposas/fisiologia , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/metabolismo , Ácido Abscísico/metabolismo , Acetatos/metabolismo , Animais , Antibiose/efeitos dos fármacos , Camellia sinensis/efeitos dos fármacos , Ciclopentanos/antagonistas & inibidores , Giberelinas/antagonistas & inibidores , Giberelinas/metabolismo , Herbivoria/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/fisiologia , Mariposas/efeitos dos fármacos , Oxilipinas/antagonistas & inibidores , Transdução de Sinais
3.
Ind Health ; 57(3): 342-350, 2019 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-30089766

RESUMO

This study assessed the relationship between occupation and Intracerebral Hemorrhage-related deaths and compared the differences in ICH-related deaths rates between the eastern and midwestern regions of Inner Mongolia. We used the case-control method. Cases included Intracerebral Hemorrhage-related deaths that occurred from 2009 to 2012 in Inner Mongolia while controls included non-circulatory system disease deaths that occurred during the same period. Odds ratios (ORs) for Intracerebral Hemorrhage-related deaths were calculated using logistic regression analysis, estimated according to occupation, and adjusted for marital status and age. The Intracerebral Hemorrhage mortality rate in the eastern regions (125.19/100000) was nearly 3 times higher than that in the midwestern regions (45.31/100000). ORs for agriculture-livestock workers, service professionals and general workers, professional workers and senior officials were in descending order. The age-adjusted OR for Intracerebral Hemorrhage-related deaths was lowest in unmarried men senior officials (OR 0.37, 95% CI 0.14-0.99). The Intracerebral Hemorrhage mortality rate in the eastern regions was much higher than that of the midwestern regions, since about 90% of Intracerebral Hemorrhage-related deaths in the eastern regions were those of agriculture-livestock workers who has the largest labor intensity of any other occupation assessed.


Assuntos
Hemorragia Cerebral/epidemiologia , Hemorragia Cerebral/mortalidade , Ocupações , Estudos de Casos e Controles , China/epidemiologia , Feminino , Humanos , Masculino , Estado Civil , Pessoa de Meia-Idade , Fatores de Risco
4.
Artigo em Chinês | MEDLINE | ID: mdl-26541033

RESUMO

OBJECTIVE: To observe the microstructure and ultrastructure of Multiceps multiceps from the artificially infected dogs. METHEDS: Two male dogs were infected with the coenurus of M. multiceps from naturally-infected sheep (about 80-100 per dog). The adult worms of M. multiceps were recovered from the intestine, and fixed by the conventional method. The scolex, neck, immature proglottid, mature proglottid, and gravid proglottid were prepared for paraffin section and ultrathin sections with HE staining and uranyl acetate staining, and observed under light microscope and electron transmission microscope, respectively. RESULTS: Under light microscope, each proglottid consisted of cortical layer and parenchymal layer. The cortical layer was composed of microvilli, syncytium, and substrate layer. The parenchymal layer mainly consisted of muscle tissue, excretory system, and reproductive system. The microvilli layer of scolex was thinner than that of neck and mature proglottid, and the longest microvilli were mainly distributed in the binding site between the proglottids. The scolex was extremely muscular. The nervous system and excretory system were repeated in each proglottid. Mature proglottid had both male and female reproductive systems. Gravid proglottid had uterus and egg, and atrophic male reproductive organs. CONCLUSION: The special microstructure of Multiceps multiceps are that most microvilli in the cortex is cylindrical; the microvilli length in the binding sites between mature proglottids is longer than that of other parts.


Assuntos
Cestoides , Taenia , Animais , Cães , Feminino , Masculino , Microscopia , Ovinos , Coloração e Rotulagem
5.
J Chem Ecol ; 40(10): 1080-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25378120

RESUMO

Herbivore-induced plant volatiles have been reported to play a role in the host-searching behavior of herbivores. However, next to nothing is known about the effect of volatiles emitted from tea plants infested by Ectropis obliqua larvae on the behavior of conspecific adults. Here, we found that tea plants infested by E. obliqua caterpillars for 24 h were more attractive to both virgin male and female E. obliqua adults than were intact, uninfested tea plants; moreover, mated female E. obliqua moths were more attracted by infested tea plants and preferentially oviposited on these plants, whereas male moths were repelled by infested plants once they had mated. Volatile analysis revealed that the herbivore infestation dramatically increased the emission of volatiles. Among these volatiles, 17 compounds elicited antennal responses from both male and female virginal moths. Using a Y-tube olfactometer, we found that 3 of the 17 chemicals, benzyl alcohol, (Z)-3-hexenyl hexanoate, and (Z)-3-hexenal, were attractive, but two compounds, linalool and benzyl nitril, were repellent to virgin male and female moths. One chemical, (Z)-3-hexenyl acetate, was attractive only to virgin males. Mated females were attracted by three compounds, (Z)-3-hexenyl hexanoate, (Z)-3-hexenyl acetate, and (Z)-3-hexenal; whereas mated males were repelled by (Z)-3-hexenol. The findings provide new insights into the interaction between tea plants and the herbivores, and may help scientists develop new measures with which to control E. obliqua.


Assuntos
Comportamento Apetitivo , Herbivoria , Mariposas/fisiologia , Chá/fisiologia , Chá/parasitologia , Compostos Orgânicos Voláteis/metabolismo , Animais , Feminino , Interações Hospedeiro-Parasita , Larva/fisiologia , Masculino , Mariposas/anatomia & histologia , Oviposição
6.
Anal Chem ; 86(23): 11570-7, 2014 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-25343694

RESUMO

Hafnium content and its change are of significance in geochemistry and cosmochemistry; however, the determination of hafnium has always been problematic in analytical chemistry. In this paper, a new idea is proposed for the determination of hafnium in geochemical samples, including rocks, soils, and stream sediments. Through the comparison of two conventional open-type acid digestion methods (HF-HNO3-HClO4 and HF-HNO3-H2SO4), it was found that although neither of these methods could fully digest the zirconium and hafnium in a sample, the zirconium and hafnium digestion behaviors in one sample were consistent in the 60 experimental geochemical reference materials with different properties, so the experimentally determined Zr/Hf ratio in solution could be used to calculate the hafnium content in a sample. In addition, possible mass spectral interferences during the determination of zirconium and hafnium by high resolution inductively coupled plasma mass spectrometry (HR-ICPMS) were studied, and it was found that the mass spectral interferences of the selected isotopes (90)Zr and (178)Hf could be neglected. The mass spectral behaviors of (90)Zr and (178)Hf were also very consistent during the determination by HR-ICPMS. Since the hafnium content was calculated using the ratio value, all of the errors (including the errors in weighing process, the accidental errors during operation and the instrument fluctuation in the determination) of the Zr/Hf ratio could be effectively reduced or even eliminated. The relative standard deviation of the actual samples was lower than 3.2%, and the detection limit of the method (considering the dilution effect and matrix effect during measurement of the Zr/Hf ratio and zirconium content) was 0.04 µg/g. The proposed method could satisfy the requirement for the determination of hafnium in geochemical samples.

7.
PLoS One ; 9(9): e106626, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25192424

RESUMO

Clickers might own a bright future in China if properly introduced although they have not been widely acknowledged as an effective tool to facilitate English learning and teaching in Chinese contexts. By randomly selecting participants from undergraduates in a university in China over four academic years, this study aims to identify the impact of clickers on college English listening and speaking skills, and differences in cognitive loads between clickers and traditional multimedia assisted instruction modes. It was concluded that in China's college English class, compared with multimedia assisted instruction, (1) clickers could improve college English listening skills; (2) clickers could improve college English speaking skills; and (3) clickers could reduce undergraduates' cognitive loads in College English Class. Reasons for the results and defects in this study were also explored and discussed, based on learning, teaching and cognitive load theories. Some Suggestions for future research were also raised.


Assuntos
Cognição , Instrução por Computador , Aprendizagem , Fala , Feminino , Humanos , Idioma , Masculino , Multimídia , Estudantes , Universidades
8.
Zhonghua Gan Zang Bing Za Zhi ; 21(10): 734-8, 2013 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-24331629

RESUMO

OBJECTIVE: To investigate the prevalence of nutritional risk and malnutrition among in-patients with liver diseases in Beijing, China, and to evaluate the relationship between nutritional risk and prognosis. METHODS: A total of 331 in-patients with liver diseases under care at the Artificial Liver Center of Beijing Youan Hospital were consecutively enrolled for study between April 2012 and December 2012. Nutritional status was determined by calculating each patient's ratio of real weight to clinically ideal weight, the triceps skin fold (TSF), and the mid-upper arm muscle circumference (MAMC). Nutritional risk was estimated using the Nutritional Risk Screening questionnaire 2002 (NRS-2002). In addition, each patient's Child-Pugh stage, body mass index (BMI), power of gripping, serum albumin and pre-albumin levels, lymphocyte count, hospital length of stay, complications, alcoholism history, and outcome after discharge were recorded for analysis. RESULTS: One-hundred-and-thirteen of the patients (34.1%) were defined as at nutritional risk upon hospital admission. The ratio of nutritional risk was lowest in patients with chronic hepatitis (17.0%) and highest in patients with acute on chronic liver failure (56.5%). The ratios of malnutrition evaluated by TSF and MAMC were 36.9% and 38.7%, respectively. Among the patients with liver cirrhosis or hepatocellular carcinoma, the ratio of Child-Pugh stage C was higher for individuals defined as at nutritional risk than for those without. When TSF-based ratio of malnutrition was higher for individuals with a history of alcoholism than for those without. BMI, power of gripping, serum albumin level, serum pre-albumin level, and lymphocyte count were all lower for individuals defined as at nutritional risk than for those without. Hospital stay, ratio of complication onset, and ratio of death were all higher for individuals defined as at nutritional risk than for those without. CONCLUSION: TSF and MAMC can be used to evaluate the nutritional status of in-patients with liver diseases. Patients with nutritional risk (as determined by the NRS-2002) have poorer prognosis and may benefit from nutritional intervention.


Assuntos
Pacientes Internados , Hepatopatias/epidemiologia , Desnutrição/epidemiologia , Estado Nutricional , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Prevalência , Adulto Jovem
9.
J Int Med Res ; 41(5): 1594-605, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24003055

RESUMO

OBJECTIVE: To determine the value of optic disc parameters and perimetric defects in the early diagnosis of patients with primary open-angle glaucoma (POAG). METHODS: Optic disc parameters and perimetry were compared among patients in the early stage of POAG, patients with suspected POAG and healthy control subjects, using Heidelberg retina tomography (HRT-II), optical coherence tomography (OCT) and a Humphrey 750i automatic field analyser, in order to determine whether these parameters could be used for early POAG diagnosis. RESULTS: A total of 55 participants were enrolled in the study. Significant differences in the optic disc parameter and perimetry values were observed between the three groups. HRT-II parameters showed good correlation with OCT parameters. The majority of the HRT-II and OCT parameters showed a good correlation with perimetry values. CONCLUSIONS: HRT-II and OCT optic disc parameters both reflect morphological changes of the optic disc. These current findings suggest that they can both detect glaucomatous optic neuropathy earlier than a white-on-white perimetry examination. In addition, OCT can detect optic disc parameter changes that cannot be detected by HRT-II.


Assuntos
Glaucoma de Ângulo Aberto , Disco Óptico/patologia , Adolescente , Adulto , Estudos de Casos e Controles , Diagnóstico Precoce , Feminino , Glaucoma de Ângulo Aberto/diagnóstico , Glaucoma de Ângulo Aberto/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia , Tomografia de Coerência Óptica , Testes de Campo Visual
10.
J Chem Ecol ; 39(10): 1284-96, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24043430

RESUMO

Volatile organic compounds derived from non-host plants, Ocimum basilicum, Rosmarinus officinalis, Corymbia citriodora, and Ruta graveolens, can be used to mask host plant odors, and are repellent to the tea geometrid, Ectropis obliqua. Volatile compounds were collected by headspace absorption, and the components were identified and quantified by using gas chromatography/mass spectrometry. The responses of antennae of female E. obliqua to the compounds were evaluated with gas chromatography/electroantennography detection. Qualitative and quantitative differences were found among the four odor profiles. Consistent electroantennographic activity was obtained for eight of the volatiles from the four plants: ß-myrcene, α-terpinene, γ-terpinene, linalool, cis-verbenol, camphor, α-terpineol, and verbenone. In a Y-tube bioassay, six chemicals, ß-myrcene, γ-terpinene, (R)-(-)-linalool, (S)-(-)-cis-verbenol, (R)-(+)-camphor, and (S)-(-)-verbenone, were the main compounds responsible for repelling E. obliqua. An eight-component mixture including all of the bioactive compounds (in a ratio of 13:2:13:8:1:24:6:17) from R. officinalis was significantly more effective at repelling the moths than any single compound or a mixture of equal amounts of the eight compounds. Field results demonstrated that intercropping tea plants with R. officinalis effectively suppressed E. obliqua infestations in a tea plantation. Our findings suggests that odor blends of R. officinalis play a role in disturbing host orientation behavior, and in repelling E. obliqua adults, and that R. officinalis should be considered when developing "push-pull" strategies aimed at optimizing the control of E. obliqua with semiochemicals.


Assuntos
Comportamento Animal/efeitos dos fármacos , Camellia sinensis , Repelentes de Insetos/análise , Repelentes de Insetos/farmacologia , Lepidópteros/efeitos dos fármacos , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/farmacologia , Animais , Feminino , Masculino , Odorantes/análise
11.
J Chem Ecol ; 39(6): 744-51, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23702702

RESUMO

Polyphenol oxidases (PPOs) have been reported to play an important role in protecting plants from attack by herbivores. However, little is known about their role in tea. Here, we investigated the effect of PPOs on interactions between tea plants and the tea geometrid Ectropis obliqua, one of the most important insect pests of tea. Jasmonic acid (JA) treatment resulted in increases in PPO activity, and the effect of JA was dose dependent. Ectropis obliqua caterpillars grew and developed more slowly on JA-treated tea plants than on control plants, and larval weight gains depended on the JA dosage. Artificial diet complemented with PPOs reduced the growth and survival rate of E. obliqua caterpillars, and there was a negative relationship between PPO level and larval growth and survival. Unlike mechanical wounding, which is an effective inducer of tea plant PPO activity, wounding plus the herbivore regurgitant or herbivore infestation suppressed the wound-induced PPO activities, especially at 4 days after treatment. These results suggest that PPOs are an important anti-herbivore factor in tea plants, defending them against E. obliqua larvae, and that E. obliqua larvae have evolved to elude the tea plant's defense by inhibiting the production of PPOs.


Assuntos
Camellia sinensis/metabolismo , Catecol Oxidase/metabolismo , Ciclopentanos/metabolismo , Herbivoria , Mariposas/fisiologia , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Animais , Camellia sinensis/enzimologia , Larva/crescimento & desenvolvimento , Larva/fisiologia , Mariposas/crescimento & desenvolvimento , Espectrofotometria
12.
J Chem Ecol ; 37(4): 412-9, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21416158

RESUMO

The pine caterpillar moth, Dendrolimus kikuchii Matsumura (Lepidoptera: Lasiocampidae), is a pest of economic importance on pine in southwest China. Three active compounds were detected during analyses of solvent extracts and effluvia sampled by solid phase microextraction (SPME) from virgin female D. kikuchii using gas chromatography (GC) coupled with electroantennographic (EAG) recording with antennae from a male moth. The compounds were identified as (5Z,7E)-5,7-dodecadien-1-yl acetate (Z5,E7-12:OAc), (5Z,7E)-5,7-dodecadien-1-ol (Z5,E7-12:OH), and (5Z)-5-dodecenyl acetate (Z5-12:OAc) by comparison of their GC retention indices, mass spectra, and EAG activities with those of synthetic standards. Microchemical reactions of gland extracts provided further information confirming the identifications of the three components. Solvent extractions and SPME samples of pheromone effluvia from virgin calling females provided 100:18:0.6 and 100:7:1 ratios of Z5,E7-12:OAc:Z5,E7-12:OH:Z5-12:OAc, respectively. Field behavioral assays showed that Z5,E7-12:OAc and Z5,E7-12:OH were essential for attraction of male D. kikuchii moths. However, the most attractive blend contained these three components in a 100:20:25 ratio in a gray rubber septa. Our results demonstrated that the blend of Z5,E7-12:OAc, Z5,E7-12:OH, and Z5-12:OAc comprise the sex pheromone of D. kikuchii. The optimized three-component lure blend is recommended for monitoring D. kikuchii infestations.


Assuntos
Acetatos/química , Acetatos/isolamento & purificação , Álcoois Graxos/química , Álcoois Graxos/isolamento & purificação , Mariposas , Atrativos Sexuais , Compostos Orgânicos Voláteis/análise , Animais , Cromatografia Gasosa , Feminino , Masculino , Espectrometria de Massas , Mariposas/anatomia & histologia , Mariposas/química , Atrativos Sexuais/análise , Atrativos Sexuais/química , Microextração em Fase Sólida
13.
J Chem Ecol ; 36(4): 388-95, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20349338

RESUMO

The tea weevil, Myllocerinus aurolineatus (Voss) (Coleoptera: Curculionidae), is a leaf-feeding pest of Camellia sinensis (O.Ktze.) with aggregative behaviors that can seriously reduce tea yield and quality. Although herbivore-induced host plant volatiles have been shown to attract conspecific individuals of some beetle pests, especially members of the Chrysomelidae family, little is known about the volatiles emitted from tea plants infested by M. aurolineatus adults and their roles in mediating interactions between conspecifics. The results of behavioral bioassays revealed that volatile compounds emitted from tea plants infested by M. aurolineatus were attractive to conspecific weevils. Volatile analyses showed that infestations dramatically increased the emission of volatiles, (Z)-3-hexenal, (Z)-3-hexenol, (E)-beta-ocimene, linalool, phenylethyl alcohol, benzyl nitrile, indole, (E, E)-alpha-farnesene, (E)-nerolidol, and 31 other compounds. Among the induced volatiles, 12 chemicals, including gamma-terpinene, benzyl alcohol, (Z)-3-hexenyl acetate, myrcene, benzaldehyde, (Z)-3-hexenal, and (E, E)-alpha-farnesene, elicited antennal responses from both sexes of the herbivore, whereas (E)-beta-ocimene elicited antennal responses only from males. Using a Y-tube olfactometer, we found that six of the 13 chemicals, gamma-terpinene, benzyl alcohol, (Z)-3-hexenyl acetate, myrcene, benzaldehyde, and (Z)-3-hexenal, were attractive to both males and females; two chemicals, (E/Z)-beta-ocimene and (E, E)-alpha-farnesene, were attractive only to males; and four chemicals, (E)-4,8-dimethyl-1,3,7-nonatriene, phenylethyl alcohol, linalool, and (Z)-3-hexenol, were attractive only to females. The findings provide new insights into the interactions between tea plants and their herbivores, and may help scientists develop new strategies for controlling the herbivore.


Assuntos
Comportamento Apetitivo/efeitos dos fármacos , Camellia sinensis/química , Comportamento Alimentar , Compostos Orgânicos Voláteis/farmacologia , Gorgulhos/efeitos dos fármacos , Animais , Camellia sinensis/parasitologia , Cromatografia Gasosa , Fenômenos Eletrofisiológicos/efeitos dos fármacos , Fezes , Feminino , Masculino , Odorantes , Compostos Orgânicos Voláteis/isolamento & purificação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...