Leaf Volatiles from Host Tree Acer negundo : Diurnal Rhythm and Behavior Responses of Anoplophora glabripennis to Volatiles in Field

The volatile compounds from ash-leaf maple (Acer negundo L.) were examined by adsorption-thermodesorption and GC-MS. Thirty-two compounds, including alcohols, ketones, aldehydes, esters, terpenoids, carboxylic acids, etc. were identified. The analysis revealed that the diurnal rhythm of release of volatile compounds from maple differed in July and in August. In July, the releasing of most volatile compounds reached the peak at 14 o'clock, when in August, the emission of volatile compounds reached the peak at 10 o'clock. Besides diurnal rhythm, there also existed other differences in the releasing of volatiles and their relative contents in July and in August. A possible explanation for this phenomenon is the maturation of leaves, since the sampling conditions were the same both in July and August. At the same time, the response of Anoplophora glabrpennis Motschulsky to volatiles was examined with field bioassay with traps. cis-3-hexen-1-ol was found to be more effective to attract A. glabrpennis than other volatiles released by ash-leaf maple tree in field trapping test. A mixture of 1-butanol, 1-pentanol and 2-pentanol was tested to be the most attractive to A. glabripennis among all tested volatiles. More field trapping tests should be conducted.

Electrophysiological and Behavioral Responses of Adult Anoplophom glabripennis (Motschulsky) to Volatile Components of Host-Plant

Electrophysiological and behavioral responses of adult A. glabripennis (Motsch.) to volatiles from ashleaf maple (Acer negundo L.) were investigated to identify semiochemicals involved in host location. Measurable electroantennogram (BAG) responses were elicited to all compounds tested, the most effective antennal stimulants were trans-2-hexen-1-al,decyl aldehyde and trans-2-hexenl-ol.These profiles were similar between males and females. In Y-tube olfactometer bioassays, above three compounds with certain concentration, trans-2-hexen-l-al (1%), trans-2-hexen-l-ol (1%) and decyl aldehyde (10%), were significantly attractive to the adults in laboratory. The results show that either BAG or olfactory responding to a particular volatile compound are markedly influenced by the concentration.

Influence mechanism of tourists' environmentally responsible behavior in ethnic villages

With the economic development and multicultural exchange of ethnic villages,more and more ethnic villages have embarked on the road of tourism to become rich,but also brought the problem of ecological pollution.Few existing literatures discuss how to alleviate the ecological pollution in ethnic villages from the perspective of tourists’environmentally responsible behavior.In the context of ethnic villages,from the perspective of integration and the attitude-context-behavior theory,this paper constructs an EV-ABC-TERB model with four variables,namely environmental attitude,local atmosphere,emotional experience and tourists’environmentally responsible behavior,to explore the characteristics,influencing factors and influencing mechanism of tourists’environmental responsibility behavior in ethnic villages.Taking Xijiang Hmong Village as the research case,questionnaire survey method and structural equation model method were used.The results show that environmental attitude positively affects emotional experience and tourists’environmentally responsible behavior.Local atmosphere positively influences tourists’environmentally responsible behavior.Emotional experience negatively affects tourists’environmentally responsible behavior and plays an intermediary role in the way that environmental attitudes affect tourists’environmentally responsible behavior.The influence of environmental attitude on emotional experience is negatively regulated by local atmosphere.Finally,based on the analysis conclusion,it provides new ideas and inspiration for the sustainable development of the ethnic village tourism.

Differences in the behavior characteristics between Daphnia magna and Japanese madaka in an on-line biomonitoring system

It is important to select suitable organisms to adapt the requirement of different environment monitoring purposes.Following our previous study,the behavioral responses of Daphnia magna and Japanese madaka （Oryzias latipes） were investigated and compared under flow-through conditions in an on-line biomonitoring system.The results showed that both D.magna and Japanese madaka had similar biological clock,but the circadian rhythms of Japanese madaka was more clearly recorded than that of D.magna.And the sensitivity of D.magna was about two orders of magnitudes higher than that of Japanese madaka in different types of toxic chemicals （dichlorovos,deltamethrin and cadmium chloride）.However,when both animals were used in an on-line biomonitoring system,the life span of D.magna was less than 7 days and Japanese madaka could last for more than one month without feeding.Therefore,D.magna was proposed to be a more sensitive bioindicator and was suitable for short term monitoring the pollution events at concentration level closing to the water quality standard,while Japanese madaka was more suitable for the long-term monitoring for accidental discharges.

Urban residents'behavioral response to climate change and its influencing factors:A case study of Tianjin,China

Climate change is a global issue that poses a significant risk to the global economy and therefore warrants coordinated collective action.Employing a questionnaire survey in China,this study presents urban residents'behavioral response to climate change and its influencing factors.The results indicated that urban residents in Tianjin often took low-cost,intuitive,and quickly implementable actions,namely behavioral coping responses.Proactive adaptive behavior was also evident,which involved greater financial investment.Furthermore,according to regression analysis results of urban residents'behavior and its influencing factors,knowledge of climate change manifested a positive correlation with urban residents'behavioral coping response.In contrast,cost manifested a negative correlation with urban residents'proactive adaptive behavior,which was a more complex,costly,and challenging anticipatory action.Knowledge of climate change manifested a positive correlation with both behavioral coping response and proactive adaptive behavior.Finally,recommendations for encouraging beneficial behaviors among urban residents are suggested.

Strengthening Mechanisms to Promote Tourists' Environmental Responsible Behaviors in the Context of All-for-One Tourism

The overall promotion of all-for-one tourism requires tourists' civilized behaviors. This paper focused on tourists' environmental responsible behaviors in the context of all-for-one tourism. On the basis of clarifying the connotation, dimension and driving factors of tourists' environmental responsible behaviors, this paper firstly analyzed the relationship between all-for-one tourism and tourists' environmental responsible behaviors, and proposed that the development of all-for-one tourism was an important path to optimize and upgrade China's tourism industry and a new concept of sustainable development of tourism industry. The emergence of all-for-one tourism has formed a new tourism trend, which will drive tourists to behave more civilly. Tourists' environmental responsible behaviors are a "subject and share" concept, and from tourists' point of view, all-for-one tourism development is the most basic requirement. Secondly, based on the theory of "value-belief-norm", this paper focused on the strengthening mechanism of "interaction effect" between all-for-one tourism and tourists' environmental responsible behaviors, and put forward the idea of "double internalization strengthening" to guide tourists' environmental responsible behaviors from being passive to active, from individuals to groups. Finally, this paper discussed the promotion of environmental responsible behaviors of tourist's specific strategies from two aspects, "external drive" and "internal drive" to enhance the level of all-for-one tourism construction and strengthen the environment responsibility of tourists. "External drives" were as follows:(1) to make a scientific development plan to implement the "host and guest sharing" mechanism;(2) to optimize the landscape, the environment, services, enhance the local attachment of visitors;(3) to improve the infrastructure system, pay attention to the details of visitors' experience;(4) to strengthen environment education and publicity, deepening the quality of tourists' civilization construction, and strengthen the environmental responsible behaviors of tourists. "Internal drives" were as follows:(1) to strengthen the sense of environmental responsibility of tourists;(2) to establish a model of environmental responsible behaviors;(3) to strengthen the supervision of environmental responsible behaviors.

Morphology and glucosinolate profiles of chimeric Brassica and the responses of Bemisia tabaci in host selection,oviposition and development

Plant structures and chemicals, which are developed from the shoot apical meristem（SAM）, form the main barriers to insect feeding. A plant chimera containing cells of different genetic origins in the SAM will be morphologically and chemically different compared with the parents and thus may result in differential resistance to herbivores. In this study, we explore if particular elements of plant resistance are localized in one of the layers of SAM; the replacement of one cell layer in a chimera may be linked to change of a single resistance trait to herbivores. The morphology and glucosinolate profiles of two periclinal chimeras（labeled as TTC and TCC, respectively） and grafted parents tuber mustard（labeled as TTT） and red cabbage（labeled as CCC） were compared and the performance of whitefly（Bemisia tabaci） in host selection, oviposition preference and development were assessed under controlled conditions. Both chimeras possessed leaf trichomes as parent tuber mustard TTT, however, TTC had significantly more trichomes than TCC and parent TTT. Leaf wax content of both chimeras was intermediate between the two parents. Five aliphatic and two indole glucosinolates were detected in both chimeras, whereas three aliphatic glucosinolates（3-methyl-sulfinylpropyl, 4-methyl-sulfinylbutyl and 2-hydroxy-3-butenyl） were not detected in tuber mustard, and one aliphatic glucosinolate（3-butenyl） was not detected in red cabbage. Unexpectedly for a chimera, the quantities of two aliphatic glucosinolates（3-methyl-sulfinylpropyl and 4-methyl-sulfinylbutyl） in both TTC and TCC were 3-to 5-fold higher than parents. In olfactory preference assays, B. tabaci showed preference to CCC, followed by TCC, TTC and TTT, and number of eggs laid showed the same pattern： CCC〉TCC〉TTC〉TTT. Interestingly, more whiteflies landed on TTT plants than the other three types in a free choice experiment and the developmental duration from egg to adult was the shortest on TTT and increased in the order TTT

The Influence of Tourists＇ Attitude and Self-efficacy Belief in Adopting Responsible Behavior in Bangladesh

This research examined tourists＇ intention to adopt responsible behavior （RB）. Toward this, two constructs of determinants （attitude and self-efficacy belief） of intention to adopt RB were identified through literature surveys. Also, three constructs of RB alternatives, namely, economically RB （ECNRB）, environmentally RB （ENVRB）, and socio-culturally RB （SCLRB）, were identified through a focus group discussion. A self-administrated questionnaire was surveyed among 351 professionals in Bangladesh. Confirmatory factor analysis of both the independent and dependent variables was done prior to employing them in the structured equation model to validate the model and test the hypotheses. The research found that in Bangladesh, the self-efficacy belief influences tourists＇ intention to choose RB more than the attitude does, but their influences on tourists＇ intention to adopt ECNRB, ENVRB, or SCLRB are varied. Moreover, tourists were found to have less intention to adopt ECNRB than ENVRB and SCLRB. For the policy makers or promoters of responsible tourism （RT）, those who want to promote any kind of RB in Bangladesh need to increase self-efficacy belief among tourists. The policy makers need to develop themes around tourists＇ positive experience, emotional and physiological states along with verbal persuasion in their communication messages （Bandura, 1997） and in any kind of interpretations at the destination whilst targeting a particular market segment.

Behavior configuration of tea farmers’ participation in ecotourism environmental responsibility from the perspective of system theory

The coordination and optimization of eco-tourism development and world heritage protection are related to the sustainable development of the two,and the behavior of tea farmers is affected by the multiple subjects of rural production and living system,which has nonlinear and complex characteristics.In view of this,based on the theory of human-land system,this study is using system theory and fuzzy set qualitative comparative analysis(fsQCA)to explore the internal mechanism of tea farmers‘environmental responsibility behavior.The results show that:(1)single factor,infrastructure environment perception constitutes a necessary condition for environmental responsibility behavior,and there is equivalence between infrastructure environment perception,Cultural environment perception,external intervention perception and environmental supervision perception.(2)Infrastructure environment perception and cultural environment perception are important internal driving forces for high environmental responsibility behavior,while external intervention perception and environmental supervision perception constitute external traction.(3)Infrastructure environment perception and cultural environment perception exist in all configurations in a single or common form.This provides enlightenment for changing the governance logic of ecotourism and improving the governance performance of ecotourism.

Electroantennogram and behavioral responses of Cotesia plutellae to plant volatiles

Plant volatiles have been demonstrated to play an important role in regulat- ing the behavior of Cotesia plutellae, a major larval parasitoid of the diamondback moth （DBM）, Plutella xylostella, but little is currently known about the function of each volatile and their mixtures. We selected 13 volatiles of the DBM host plant, a cruciferous veg- etable, to study the electroantennogram （EAG） and behavioral responses of C. plutellae. EAG responses to each of the compounds generally increased with concentration. Strong EAG responses were to 100 μL/mL of trans-2-hexenal, benzaldehyde, nonanal and cis-3- hexenol, and 10/zL/mL of trans-2-hexenal and benzaldehyde with the strongest response provoked by trans-2-hexenal at 100μL/mL. In the Y-tube olfactometer, C. plutellae, was significantly attracted by 1μL/mL of trans-2-hexenal and benzaldehyde.β-caryophyllene, cis-3-hexenol or trans-2-hexenal significantly attracted C. plutellae at 10μL/mL, while nonanal, benzyl alcohol, cis-3-hexenol or benzyl cyanide at 100μL/mL significantly at- tracted C. plutellae. Trans-2-hexenal significantly repelled C. plutellae at 100 μL/mL. EAG of C. plutellae showed strong responses to all mixtures made of five various com- pounds with mixtures 3 （trans-2-hexenal, benzaldehyde, nonanal, cis-3-hexenol, benzyl cyanide, farnesene, eucalyptol） and 4 （trans-2-hexenal, benzaldehyde, benzyl alcohol, （R）- （＋）-limonene,β-ionone, farnesene, eucalyptol） significantly attracting C. plutellae. These findings demonstrate that the behavior of C. plutellae can be affected either by individual compounds or mixtures of plant volatiles, suggesting a potential of using plant volatiles to improve the efficiency of this parasitoid for biocontrol ofP. xylostella.

A larval specific OBP able to bind the major female sex pheromone component in Spodoptera exigua(Hübner)

Odorant binding proteins （OBPs） in insects are postulated to solubilize and transport the hydrophobic odorants across the hydrophilic antennal lymph to the olfactory receptors （ORs） located on the dendrite membrane of the sensory neurons. OBPs in adult insects have been intensively reported, but those in larvae are rarely addressed. In our study, a full-length OBP cDNA, namely SexiOBP13, was cloned by RT-PCR and RACE strategy from the heads of Spodoptera exigua larvae. The quantitative real-time PCR （qPCR） measurement indicated that SexiOBP13 was highly expressed in larval head, but very low in other parts of larva and was not detected in any tissues of adult. The binding affinities of SexiOBP13 to plant volatiles and female sex pheromone components were measured by competitive binding assays. Interestingly, SexiOBP13 displayed a high binding affinity （Ki=3.82 IJmol L-1） to Z9,E12-14：Ac, the major sex pheromone component of S. exigua, while low affinities to the tested host plant volatiles （Ki〉27 μmol L-l）. The behavioral tests further confirmed that Z9,E12-14：Ac was indeed active to elicit the behavioral activity of the third instar larvae of S. exigua. Taken together, our results suggest that SexiOBP13 may play a role in reception of female sex pheromone in S. exigua larvae. The ecological significance of the larvae preference to the adult female sex pheromone was discussed.

Bacterial volatiles elicit differential olfactory responses in insect species from the same and different trophic levels

Insect communities consist of species from several trophic levels that have to forage for suitable resources among and within larger patches of nonresources.To locate their resources,insects use diverse stimuli,including olfactory,visual,acoustic,tactile and gustatory cues.While most research has focused on cues derived from plants and other insects,there is mounting evidence that insects also respond to volatile organic compounds(VOCs)emitted by microorganisms.However,to date little is known about how the olfactory response of insects within and across different trophic levels is affected by bacterial VOCs.In this study,we used Y-tube bioassays and chemical analysis of VOCs to assess how VOCs emitted by bacteria affect the olfactory response of insects of the same and different trophic levels.Experiments were performed using two aphid species(Amphorophora idaei Börner and Myzus persicae var.nicotianae Blackman),three primary parasitoid species(Aphidius colemani Viereck,A.ervi Haliday,and A.matricariae Viereck),and two hyperparasitoid species(Asaphes suspensus Nees and Dendrocerus aphidum Rondani).Olfactory responses were evaluated for three bacterial strains(Bacillus pumilus ST18.16/133,Curtobacterium sp.ST18.16/085,and Staphylococcus saprophyticus ST18.16/160)that were isolated from the habitat of the insects.Results revealed that insects from all trophic levels responded to bacterial volatiles,but olfactory responses varied between and within trophic levels.All bacteria produced the same set of volatile compounds,but often in different relative concentrations.For 11 of these volatiles we found contrasting correlations between their concentration and the behavior of the primary parasitoids and hyperparasitoids.Furthermore,olfactometer experiments on three of these compounds confirmed the contrasting olfactory responses of primary parasitoids and hyperparasitoids.The potential of these findings for the development of novel semiochemical-based strategies to improve biological aphid control has been discussed.

Involvement of group Ⅲ metabotropic glutamate receptors in the modulation of spinal nociceptive signals

BACKGROUND： Previous morphological studies have demonstrated that group Ⅲ metabotropic glutamate receptors （mGluRs） are commonly found in nociceptive pathways, particularly in the terminals of primary afferent fibers in the spinal dorsal horn. OBJECTIVE： To investigate the role of group Ⅲ mGluRs in a rat model of spinal nociception by intrathecal administration of a selective agonist, L-Serine-O-phosphate （L-SOP）. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment. The study was performed at the Department of Physiology and Neurobiology, Shanxi Medical University, between March 2007 and May 2008. MATERIALS： L-SOP of group Ⅲ mGluRs （Tocris Cookson Ltd, UK）, formalin （Sigma, USA）, rabbit anti-c-Fos polyclonal antibody and biotin-labeled goat anti-rabbit IgG （Cell Signaling Technology, USA） were used in this study. METHODS： A total of 26 healthy Wistar rats, aged 1 month and weighing 100-120 g, were subjected to intrathecal catheter implantation. After 5-8 days, 10 rats were selected according to experimental requirements. L-SOP 250 nmol in 10 μL, or the equivalent volume of normal saline, was administered by intrathecal injection into the L3-5 region of the spinal cord in the experimental and control groups, respectively. After 15 minutes, formalin （5%, 50 μL） was subcutaneously injected into the plantar of the left hindpaw of each rat to establish formalin-induced pain models. MAIN OUTCOME MEASURES： Nociceptive behavioral responses and immunohistochemical examination of Fos expression. RESULTS： Intrathecal injection of L-SOP significantly attenuated the second phase nociceptive response compared with the control group （P 〈 0.05）, and Fos expression in the spinal dorsal horn was significantly decreased along with the number of Fos-like immunoreactive neurons （P 〈 0.05）. CONCLUSION： Group Ⅲ mGluRs are involved in the modulation of nociceptive signals, and their activation suppresses the transmission of nociceptive signals.

Response to Pain by Different Gestational Age Neonates

One hundred infants were divided into the following 3 gestational age (GA) groups: (Ⅰ) premature infants ( n =30) with the gestational age between 29 and 32 weeks; (Ⅱ) premature infants ( n =30) with the gestational age between 33 and 36 weeks; (Ⅲ) full term infants ( n =40). The recorded responses of all infants to pain included the behavioral responses to painful stimuli (cry, facial activity and limbs movement) and the variety of heart rate. The results indicated that the infants of 3 groups had different degree response to various painful stimuli. Pain expression in full term infants was more significant than premature infants to same stimuli. 33 weeks GA infants were differential from 29 weeks GA infants. Full term infants showed more vertical mouth stretch and more taut tongue and more hand to mouth than premature infants, but more horizontal mouth stretch in premature infants.

Correlation among thresholds of evoked otoacoustic emissions,behavioral responses and auditory brainstem responses

In 35 adult human subjects (58 ears) thresholds of rarefaction click evoked otoacoustic emission (EOAE), behavioral response (BR) and auditory brainstem response (ABR) were measured and compared, and correlation coefficients (r) among them calculated. The results revealed that 86 % of the measured thresholds were in the range from 10 to 45 dB (nHL) for EOAE, 88 % from 10 to 25 dB for BR and 88 % from 10 to 35 for ABR. The correlation coefficients for the whole threshold sample were 0.415 (p< 0.002) for EOAE vs. BR, 0.501 (p< 0.001) for EOAE vs. ABR and 0.702 (p< 0.001) for ABR vs. BR, all indicating highly significant correlation. However, for those ears whose BR, ABR or EOAE thresholds were elevated, equaling to or exceeding 25 dB, there is no significant correlation between thresholds of EOAE and BR and of EOAE and ABR (r range: 0.176-0.310, p>0.05). In contrast, significant correlation between BR and ABR thresholds in the same conditions still remained (r: 0.533-0.720, p<0.05). The experimental results indicate that the correlation between EOAE and hearing thresholds is significant only for subjects with normal or slightly lost hearing. EOAE is valuable in audiometry only as an accessory tool.

The temporal-spatial expression and functional analysis of three gustatory receptor genes in Solenopsis invicta using sweet and bitter compounds

The insect gustatory system participates in identifying potential food sources and avoiding toxic compounds.During this process,gustatory receptors(GRs)recognize feeding stimulant and deterrent compounds.However,the GRs involved in recognizing stimulant and deterrent compounds in the red imported fire ant,Solenopsis invicta,remain unknown.Therefore,we conducted a study on the genes SinvGR1,SinvGR32b,and SinvGR28a to investigate the roles of GRs in detecting feeding stimulant and deterrent compounds.In this current study,we found that sucrose and fructose are feeding stimulants and the bitter compound quinine is a feeding deterrent.The fire ant workers showed significant behavior changes to avoid the bitter taste in feeding stimulant compounds.Reverse transcription quantitative real-time polymerase chain reaction results from developmental stages showed that the SinvGR1,SinvGR32b,and SinvGR28a genes were highly expressed in fire ant workers.Tissue-specific expression profiles indicated that SinvGR1,SinvGR32b,and SinvGR28a were specifically expressed in the antennae and foreleg tarsi of workers,whereas SinvGR32b gene transcripts were also highly accumulated in the male antennae.Furthermore,the silencing of SinvGRI or SinvGR32b alone and the co-silencing of both genes disrupted worker stimulation and feeding on sucrose and fructose.The results also showed that SinvGR28a is required for avoiding quinine,as workers with knockdown of the SinvGR28a gene failed to avoid and fed on quinine.This study first identified stimulant and deterrent compounds of fire ant workers and then the GRs involved in the taste recognition of these compounds.This study could provide potential target gustatory genes for the control of the fire ant.

On Pragmatic "Borrowing Transfer":Evidence from Chinese EFL Learner's Compliment Response Behavior

本研究通过考察中国英语学习者的恭维应答语,试图为语用"外借迁移"提供更多的实证数据。92份问卷调查(DCT)被分发给两组不同的受试(英语专业和非英语专业)。通过对比两组受试的恭维应答语,研究发现,英专组比非英专组更倾向于选择"接受"策略,而非英专组比英专组更倾向于选择"不接受"策略。L2的规范对中国英语学习者恭维应答语的影响似乎与L2学习时间长短和L2水平有关。本研究的结果为语用"外借迁移"提供了初步实证数据。

The role of chemosensory protein 10 in the detection of behaviorally active compounds in brown planthopper, Nilaparvata lugens

Chemosensory proteins(CSPs)play important roles in insects’chemoreception,although their specific functional roles have not been fully elucidated.In this study,we conducted the developmental expression patterns and competitive binding assay as well as knock‐down assay by RNA interference both in vitro and in vivo to reveal the function of NlugCSP10 from the brown planthopper(BPH),Nilaparvata lugens(Stål),a major pest in rice plants.The results showed that NlugCSP10 messenger RNA was significantly higher in males than in females and correlated to gender,development and wing forms.The fluorescence binding assays revealed that NlugCSP10 exhibited the highest binding affinity with cis‐3‐hexenyl acetate,eicosane,and(+)‐β‐pinene.Behavioral assay revealed that eicosane displayed attractant activity,while cis‐3‐hexenyl acetate,similar to(+)‐β‐pinene significantly repelled N.lugens adults.Silencing of NlugCSP10,which is responsible for cis‐3‐hexenyl acetate binding,significantly disrupted cis‐3‐hexenyl acetate communication.Overall,findings of the present study showed that NlugCSP10 could selectively interrelate with numerous volatiles emitted from host plants and these ligands could be designated to develop slow‐release mediators that attract/repel N.lugens and subsequently improve the exploration of plans to control this insect pest.

Low-Cycle Fatigue and Creep-Fatigue Behaviors of a Second-Generation Nickel-Based Single-Crystal Superalloy at 760℃

Low-cycle fatigue(LCF)behaviors of a second-generation nickel-based single-crystal superalloys with[001]orientation at 760℃ have been investigated.Different strain amplitudes were introduced to investigate the creep-fatigue effects.The LCF life of none tensile holding(NTH)was higher than that of the 60-s tensile hold(TH)at any strain amplitude.As the strain amplitude was 0.7%,the stacking and cross-slip dislocations appeared together at the γ/γ’coherent microstructure in both TH and NTH specimens.At the strain amplitude of 0.9%,plenty of the cross-slip dislocations appeared inγchannel and other dislocations were stacking at γ/γ’interfaces.However,the SFs still appeared in γ’phase with 60-s TH which caused cyclic softening.As the strain amplitude increased up to 1.2%,the dislocations are piling up at the γ/γ’interfaces and cutting through the γ’phase in both TH and NTH tests,which caused cyclic hardening.The influences of strain amplitude and holding time were complicated.Different stress response behaviors occurred in different loading conditions.The surface characteristic and fracture mechanism were observed by scanning electron microscopy.This result is helpful for building the relationship of various blade fatigue failure modes,cyclic stress response and microstructure deformation under different strain amplitudes.

In Vivo Study on Degradation Behavior and Histologic Response of Pure Magnesium in Muscles

When an orthopedics device is implanted into bone injury site, it will contact the soft tissue （skeletal muscle, fascia, ligament etc.） except for bone. Magnesium based biodegradable metals are becoming an important research object in orthopedics due to their bioactivity to promote bone healing. In this study, pure Mg rods with and without chemical conversion coating were implanted into the muscle tissue of rabbits. Implants and their surrounding tissues were taken out for weight loss measurement, cross- sectional scanning electron microscopy observation, elemental distribution analysis and histological examination. The results showed that the chemical conversion coating would increase the in vivo cor- rosion resistance of pure Mg and decrease the accumulation of calcium （Ca） and phosphorus （P） elements around the implants. For the bare magnesium implant, both Ca and P contents in the surrounding tissues increased at the initial stage of implantation and then decreased at 12 weeks implantation, while for the magnesium with chemical conversion coating, Ca and P contents in the surrounding tissues de- creased with the implantation time, but were not significant. The histological results demonstrated that there was no calcification in the muscle tissue with implantation of magnesium for up to 12 weeks. The chemical conversion coating not only increased the in vivo corrosion resistance of pure Mg, but also avoided the depositions of Ca and P in the surrounding tissues, meaning that pure magnesium should be biosafe when contacting with muscle tissues,