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1.
This study aimed to analyze the volatile chemical profile of Longjing tea, and further develop a prediction model for aroma quality of Longjing tea based on potent odorants. A total of 21 Longjing samples were analyzed by headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Pearson’s linear correlation analysis and partial least square (PLS) regression were applied to investigate the relationship between sensory aroma scores and the volatile compounds. Results showed that 60 volatile compounds could be commonly detected in this famous green tea. Terpenes and esters were two major groups characterized, representing 33.89% and 15.53% of the total peak area respectively. Ten compounds were determined to contribute significantly to the perceived aroma quality of Longjing tea, especially linalool (0.701), nonanal (0.738), (Z)-3-hexenyl hexanoate (−0.785), and β-ionone (−0.763). On the basis of these 10 compounds, a model (correlation coefficient of 89.4% and cross-validated correlation coefficient of 80.4%) was constructed to predict the aroma quality of Longjing tea. Summarily, this study has provided a novel option for quality prediction of green tea based on HS-SPME/GC-MS technique.  相似文献   

2.
Electroantennogram (EAG) evaluation of selected compounds from wilted leaves of black poplar, Populus nigra, showed that phenyl acetaldehyde, methyl salicylate, (E)-2-hexenal elicited strong responses from male antennae of Helicoverpa armigera. When mixed with sex pheromone (Ph), some volatiles, e.g. phenyl acetaldehyde, benzyl alcohol, phenylethanol, methylsalicylate, linalool, benzaldehyde, (Z)-3-hexenol, (Z)-3-hexenylacetate, (Z)-6-nonenol, cineole, (E)-2-hexenal, and geraniol elicited stronger responses from male antennae than Ph alone. Wind tunnel bioassay demonstrated that various volatiles could either enhance or inhibit the effect of synthetic sex pheromone. (E)-2-hexenal, (Z)-3-hexenol and linalool in combination with Ph could not induce any male to land on source at all, whereas phenyl acetaldehyde, benzaldehyde, (Z)-6-nonenol and salicylaldehyde combined with Ph enhanced male response rates by 58.63%, 50.33%, 51.85% and 127.78%, respectively, compared to Ph alone. These results suggested that some volatiles should modify sex pheromone caused behavior and that some of them couldpossibly be used as a tool for disrupting mating or for enhancing the effect of synthetic sex pheromone in the field. Project supported by Knowledge Innovation Program from Chinese Academy of Sciences (CAS) (No. KSCX2-02-5-2) and Shanghai Commission of Science and Technology (Nos. 023912004 and 01JC14051), China  相似文献   

3.
In Experiment 1, male rats were exposed to either aggressive (i.e., alpha) or nonaggressive conspecific colonies and tested 24 h later, with or without alpha odors, for freezing behavior and burying of a wall prod that had been the source of a brief electric shock. The results indicated that prior defeat experience and the presence of alpha odors alone during testing had no significant effects, but the combination of prior defeat and alpha-odor testing significantly decreased burying and increased freezing behavior. In Experiment 2, we examined the effects of noncontact exposure to a cat, as a predatory Stressor, during subsequent prod-shock tests involving the presence or absence of cat odors. Exposure to a cat failed to disrupt later prod burying and did not produce freezing. However, the presence of cat odors during testing significantly reduced the amount of defensive burying,without resulting in an increment in freezing. In Experiment 3, rats were given 1, 5, or 30 inescapable preshocks in the presence of either cat odors or a hedonically neutral citronella odor and were tested 24 h later for prod burying and freezing with or without these odors. Both the cat and the citronella odors resulted in a significant reduction in burying and an increase in freezing for rats given 5 and 30 preshocks and tested in the presence of these respective conditioned odors. For the groups that were given 5 preshocks, preshock and later testing in the presence of cat odors resulted in significantly less prod burying and more freezing than for rats that were preshocked and tested in the presence of citronella. The findings of these three ethoexperimental studies are discussed in terms of the learned-helplessness theory, the stress-coping-fear-defense (SCFD) theory, and the concept of selective CS-US associability.  相似文献   

4.
Electroantennogram (EAG) evaluation of selected compounds from wilted leaves ofblack poplar,Populus nigra,showed that phenyl acetaldehyde, methyl salicylate, (E)-2-hexenal elicited strong responses from male antennae of Helicoverpa armigera. When mixed with sex pheromone (Ph), some volatiles, e.g. phenyl acetaldehyde, benzyl alcohol,phenylethanol, methylsalicylate, linalool, benzaldehyde, (Z)-3-hexenol, (Z)-3-hexenylacetate, (Z)-6-nonenol, cineole, (E)-2-hexenal, and geraniol elicited stronger responses from male antennae than Ph alone. Wind tunnel bioassay demonstrated that various volatiles could either enhance or inhibit the effect of synthetic sex pheromone. (E)-2-hexenal, (Z)-3-hexenol and linalool in combination with Ph could not induce any male to land on source at all, whereas phenyl acetaldehyde, benzaldehyde, (Z)-6-nonenol and salicylaldehyde combined with Ph enhanced male response rates by 58.63%,50.33%, 51.85% and 127.78%, respectively, compared to Ph alone. These results suggested that some volatiles should modify sex pheromone caused behavior and that some of them could possibly be used as a tool for disrupting mating or for enhancing the effect of synthetic sex pheromone in the field.  相似文献   

5.
BackgroundUnderstanding different longitudinal patterns of traumatic stress reactions in children exposed to intimate partner violence (IPV) can promote early identification of at-risk children.ObjectiveOur study aims to explore trajectories of traumatic stress reactions following childhood IPV exposure, and their relation with parental traumatic stress and child emotional security in the interparental subsystem.Participants and SettingThe sample comprised 303 children (age 3–10, M = 6.20) from families referred to institutions for IPV. Data were collected at home.MethodsThree waves of parent-reported questionnaire data were analyzed using latent class growth analysis and linear regression.ResultsFive trajectories were identified: ‘resilient’, ‘moderate stable’, ‘struggling’, ‘improving’, and ‘elevated adjusting’. Only the ‘struggling’ trajectory had dysfunctional symptom levels at the final wave. Higher parental traumatic stress predicted ‘improving’ trajectory membership (β = 0.17, p = .033), whereas lower parental traumatic stress (β = −0.20, p = .003) and child emotional insecurity (β = −0.45, p = < .001) predicted ‘resilient’ trajectory membership. Higher child emotional insecurity predicted membership in trajectories with higher initial traumatic stress (improving: β = 0.26, p < .001; struggling: β = 0.31, p < .001; elevated adjusting: β = 0.27, p < .001). Child emotional security did not buffer the effect of parental traumatic stress on likelihood of dysfunctional trajectory membership (β = 0.04, p =.380).ConclusionsChildren exposed to IPV show different trajectories of traumatic stress reactions, partly corresponding to trajectories identified in other populations. Child emotional security and parental traumatic stress predict trajectory membership.  相似文献   

6.
SPME／GC—MS法分析柠檬草挥发气体成分   总被引：1，自引：0，他引：1  
利用固相微萃取SPME／GC—MS技术分析了柠檬草的挥发气体成分。结果表明：柠檬草中共鉴定出25种主要挥发性化合物,以碳氢化合物和醛类物为主,包括β-月桂稀（34．34％）、石竹烯（0．493％）、莰烯（0．646％）、D-柠檬烯（0．126％）、1R-α-蒎烯（0．73％）、柠檬醛（26．5％）、3,7二甲基-2,6-辛二稀醛（26．63％）等。经过精制的柠檬草精油含有酮和烃类化合物,主要有：2-十一酮（0．606％）、2-甲基-5-（1-甲基乙基）环己酮（1．83％）、（1S）-6,6-二甲基-二乙基二环-[3,1,1]-庚烷,（0．34％）、1,4-双亚甲基-环已烷,（0．176％）,3-丙基-环已基（0．1667％）。  相似文献   

7.
BackgroundInstitutional rearing is associated with increased risk for reactive attachment disorder (RAD) and disinhibited social engagement disorder (DSED). Disorders of attachment involve disturbances in children’s primary caregiving relationships, and are likely to disturb multiple domains of social functioning.ObjectiveTo examine associations between signs of RAD and DSED and social functioning in early adolescence.Participants and settingOur participants were 110 children with a history of institutional rearing and 50 community comparison adolescents from the Bucharest Early Intervention Project, based in Bucharest, Romania. Participants were assessed at age 12 years (M age in years = 12.80, SD = 0.71).MethodSigns of RAD and DSED were obtained through caregiver report. Reports of social functioning were provided by caregivers and teachers. General and specific domains of social functioning were identified using bi-factor modeling. A general social functioning factor and four specific factors were revealed: peer conflict, caregiver views as victim, teacher views as victim, and social competence.ResultsSigns of RAD predicted poorer general social functioning (β=-0.36, p < .01, 95% confidence interval [CI] [-.33, -.09]) and poorer social competence (β=-0.38, p < .01, 95% CI[-0.05, -.01]) above and beyond time spent in institutional care and placement disruptions. Signs of DSED (β=-0.38, p < .001, 95% CI[-0.49, -.16]) along with placement disruptions (β=-0.22, p < .05, 95% CI[-.29, -.01]) predicted poorer general social functioning above and beyond time spent in institutional care. Signs of DSED predicted higher scores on caregiver views as victim (β = 0.29, p < .05, 95% CI[0.02, 0.14]) and lower scores on social competence (β=-0.29, p < .01, 95% CI[-.06, -.01]) above and beyond time spent in institutional care and placement disruptions.ConclusionsAttachment disorder signs in early adolescence are problematic for social functioning, although the manifestation of these social difficulties differs based on whether RAD or DSED signs are present.  相似文献   

8.
Naturally fermented pickles harbour many lactic acid bacteria (LAB). Forty-three LAB strains with conjugated linoleic acid (CLA)-producing ability were isolated from three naturally fermented pickle brines. Of these isolates, lp15 identified as Lactobacillus plantarum by API 50 CHL system and full-length 16S rDNA sequence analysis exhibited the highest CLA-producing ability (26.1% conversion) at 48 h in de Man Rogosa Sharpe (MRS) broth in the presence of 100 μg/ml of linoleic acid (LA). Compared to other strains, L. plantarum strain lp15 showed the highest tolerance upon increased levels of LA in the medium, i.e., up to 600 μg/ml. This strain converted about 25% of LA into CLA isomers [predominantly cis-9, trans-11 CLA (9-CLA) and trans-10, cis-12 CLA (10-CLA)], of which 75% was 9-CLA. Interestingly, though the conversion rate of LA into CLA by lp15 remained stable between 100 to 600 μg/ml LA levels in the medium, it dropped sharply at 1000 μg/ml. Taken together, the lp15 strain displayed relatively high LA tolerance with higher conversion rate, which implies that this strain is a valuable candidate for enhancing the CLA content in food-sources like pickles.  相似文献   

9.
Extensive chemocommunication occurs between individuals of different species. We examined the interaction between Mongolian gerbils (Meriones unguiculatus) and between domestic cats (Felis domestica). Experiments indicated that stressed gerbils produce blood odors that stimulate physiological arousal and cause conspecifics to avoid areas contaminated with these odors. Domestic cats preferred these same odors and differentially consumed food contaminated with these odors. Both reactions are ecologically important in the interaction between prey and predator.  相似文献   

10.
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11.
BackgroundForensic interviewers are at a heightened risk for secondary traumatic stress (STS) due to their frequent interactions with victims of child maltreatment (Bonach & Heckert, 2012). To date, however, few studies have examined the negative effects of this work on interviewers’ social and emotional well-being.ObjectiveThe present study seeks to explore the effect of STS on the relationships of forensic interviewers, including those with friends, family, and their respective children.Participants and settingData are derived from a sample of 367 forensic interviewers (FIs) recruited from across the United States.MethodsThe current study used a cross-sectional research design to obtain qualitative and quantitative data from an online survey of certified forensic interviewers.ResultsPersonal-level predictors of STS included interviewers’ sex (β = 0.11, p = 0.02), trauma history (β = 0.13, p = 0.004), and frequency of socializing with family members outside of work (β = -0.12, p = 0.01). Work-related predictors included the frequency of direct (β = 0.10, p = 0.04) and indirect exposures to graphic details of child maltreatment (β = 0.09, p = 0.05), burnout (β = 0.58, p = 0.000), and years of experience investigating crimes against children (β = 0.10, p = 0.03). Factors such as parental status and external social support were not significantly associated with STS in the qualitative analysis.ConclusionsForensic interviewers experience both positive and negative effects of exposure to crimes against children, with work-related factors being particularly impactful on the potential for STS.  相似文献   

12.
Gene and drug therapies are being developed to alleviate vision loss in patients with Stargardt’s disease and age-related macular degeneration (AMD). To evaluate the therapeutic effects of these treatments, organic solvents are routinely used to extract and quantify bisretinoid lipofuscin constituents, such as N-retinylidene-N-retinyl-ethanolamine (A2E) and all-trans-retinal dimer (ATR-dimer). By high-performance liquid chromatography (HPLC), we found that A2E and ATR-dimer were both altered by tetrahydrofuran (THF) and chloroform, but were stable in dimethyl sulfoxide (DMSO) or methanol (MeOH). In addition, cyclohexane and ethanol (EtOH) did not alter ATR-dimer, whereas an alteration of A2E occurred in EtOH. On the basis of these findings, we designed processes II–IV, generated by modifications of process I, a routine method to measure bisretinoid compounds in vivo. Extra amounts of either ATR-dimer or A2E in mouse eyecups were released by processes II–IV versus process I. Efforts to clarify the effects of organic solvents on lipofuscin pigments are important because such studies can guide the handling of these fluorophores in related experiments.  相似文献   

13.
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14.
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15.
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16.
BackgroundChild maltreatment has been associated with the development of various mental health problems, including the development of personality disorders.ObjectiveThis study investigated the association between child maltreatment and personality disorder symptoms in 125 women who transitioned out of residential care.MethodThe Child Trauma Questionnaire was used for the measurement of child maltreatment, and Personality disorder symptoms were measured using the Personality Diagnostic Questionnaire 4 + . The Psychological Distress Index was used to control for symptoms of distress.ResultsA Stepwise regression analysis showed that the majority of the associations were found between self-reported emotional abuse, neglect and personality disorder symptoms. Emotional abuse was significantly related to the Paranoid (β = .42, p<0.001), Schizoid (β = .18, p <0.05), Schizotypal (β = .18, p<0.05), Histrionic (β = .22, p<0.05), Avoidant (β = .31, p < .001), Dependent (β = 0.31, p < .001), Obsessive Compulsive (β = 0.29, p = .001), Passive Aggressive (β = 0.23, p<0.01) and the Depressive personality disorder (β = .38, p < .001). Emotional neglect was significantly associated to the Borderline Personality Disorder (β = .32, p<0.001) and the Paranoid Personality Disorder (β =-0.22, p<0.05).ConclusionsThe current study underlines the detrimental effects of childhood maltreatment, and in particular the effects of emotional abuse and neglect.  相似文献   

17.
研究目的：为茉莉酸甲酯诱导来提高茶叶香气品质提供理论依据,为新型花香红茶的研制提供技术支持。创新要点：首次将茉莉酸甲酯应用于诱导茶叶香气品质提高,初步验证了茶叶香气品质提高的本质原因：相关酶活性提高,基因表达上调。研究方法：采用顶空固相微萃取法（HS-SPME）对红茶香气进行富集,气相色谱-质谱联用仪（GC-MS）进行解吸附分析,实时定量多聚酶链式反应（qRT-PCR）分析茶鲜叶中香气相关酶基因表达。重要结论：茉莉酸甲酯诱导后的茶鲜叶中多酚氧化酶（PPO）活性上升,β-葡萄糖苷酶活性下降;PPO和β-樱草糖苷酶基因表达上调,β-葡萄糖苷酶基因表达下调。茉莉酸甲酯诱导后的茶鲜叶能明显提高由其制成的红茶香气品质,且萜烯醇类和萜烯类含量明显提高。  相似文献   

18.
Background: Experiences of childhood adversity are consistently associated with compromised behavioral health later in life. Less clear is the intergenerational influence of maternal childhood adversity on developmental outcome in children. Completely unknown are the mechanisms linking teen mother’s childhood adversity to child developmental outcomes.Objective: The present study tested whether aspects of parenting (parenting stress, physical discipline, and disagreement with grandparents) served as the pathways between teen mother’s childhood adversity and the externalizing behaviors of their offspring at age 11, by gender.Participants and setting: Data were from a longitudinal panel study of teen mothers and their children, the Young Women and Child Development Study (N = 495; 57% male).Methods: The pathways from teen mother’s childhood adversity to their offspring’s externalizing behavior were tested by two subscales: rule-breaking behavior and aggressive behavior. In addition, multiple-group analysis was examined for potential gender differences.Results: Teen mother’s childhood adversity was positively associated with greater use of parenting stress (β = 0.16, p < .01) and physical discipline (β=0.11, p < .05). In addition, parenting stress, physical discipline, and disagreement with grandparent were all associated with increased rule-breaking and aggressive behaviors in children. Multiple group analysis revealed that the path between physical discipline and externalizing behavior differed by gender, with the path only significant for girls.Conclusions: These findings have implications for early intervention efforts that emphasize the need to intervene with children and parents, particularly helping teen mothers gain knowledge and skills to offset the impact of their experiences of childhood adversity on their parenting behaviors.  相似文献   

19.
In order to investigate the effects of methyl ester moiety on polycyclic aromatic hydrocarbons (PAHs) and NO x formation in biodiesel combustion, the combined models were developed based on detailed methyl butanoate (MB) oxidation model and n-butane model. Also, PAHs detailed reaction mechanism and NO x formation mechanism were added to the detailed models to form the combined models. The combined models were used to compare the combustion of n-butane and MB in a shock tube simulation to understand the effects of methyl ester moiety. The results indicated that compared with n-butane, the methyl ester moiety in MB leads to different reaction pathways, more CO and CO 2 formation and less formation of PAHs precursors such as ethylene and acetylene. In addition, a better chemical insight into the effects of methyl ester moiety on NO x formation was given, which will help to understand the combustion process of biodiesel.  相似文献   

20.
Garter snakes (Thamnophis radix), hognose snakes (Heterodon platyrhinos), and rattlesnakes (Crotalus species) flick their tongues and crawl about in an open field containing no food or sexual (i.e., reproductive) odors. As Experiment I shows, the taxa differ reliably in both rate of tongue flicking and rate of locomotion. In Experiment II, garter snakes (Thamnophis radix) placed into an open field for 5 min showed more tongue flicking than snakes that were handled and placed directly back into their home cages, indicating that the first group was exploring the apparatus rather than responding only to handling. During Minutes 3 through 5 (Experiment III) in the open field, garter snakes emitted fewer tongue flicks than they did during the first minute, and after 20 min, the rate of tongue flicking was virtually zero. However, snakes were capable of responding to presentation of new objects and/or odors, indicating that the previous response decrement was not derived from effector fatigue but rather from some habituatory process. Experiment IV revealed that satiated snakes habituated more rapidly than hungry snakes during exploration of the open field. Hence, exploratory behavior in these snakes is at least partially under the control of the same factors which mediate food-related appetitive activities.  相似文献   

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