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1.
双叉犀金龟Allomyrina dichotoma是一种重要的森林资源昆虫,本文研究了环境温度(20℃、23℃、26℃、29℃、32℃)及菌糠含水量(35%、45%、55%、65%)对双叉犀金龟成虫寿命及子代数量的影响。结果表明,双叉犀金龟雌雄虫寿命均随温度的升高呈显著缩短,20℃~26℃下雌虫寿命在55~62 d之间,显著长于29℃~32℃处理;20℃~23℃下的雄虫寿命在33~48 d之间,显著长于26℃~32℃处理;环境温度及菌糠含水量均对双叉犀金龟成虫子代数量有显著影响,26℃时,4个菌糠含水量处理的平均子代数量为31.42 头/雌,显著高于其它温度处理,菌糠含水量55%~65%时,5个温度处理的平均子代数量为18.83~19.12 头/雌,显著高于其它菌糠含水量处理,其中以温度26℃、菌糠含水量55%处理的双叉犀金龟子代数量最高,达45.42 头/雌。各温度下双叉犀金龟繁殖子代数量均随时间的延长呈先上升后下降的趋势,各温度下产卵繁殖的高峰时间存在明显差异。在26℃时,双叉犀金龟各时间段子代数量均高于其它温度,在35~45 d时,达到产卵高峰期(12.33 头/雌),综合各指标,建议利用菌糠饲养双叉犀金龟时,其成虫最佳环境条件为26℃,菌糠含水量55%。  相似文献   

2.
This report reveals the structure of a virus extracted from the Korean horn beetle Allomyrina dichotoma. The purified virus particle was 100% identical to Allomyrina virus lef‐8 sequence registered as KM_233709.1. The structure of this virus was confirmed to be closely related to that of the Nudiviridae family, and it was rod shaped and enveloped, and observed to be of approximately the mean length of a single viral nucleocapsid of 200–210 nm and mean diameter of 100–110 nm. These results provide an insight into the structural characteristics of the Nudiviridae family that can be used for nudiviral identification.  相似文献   

3.
采用显微动态图像分析技术无扰、实时、在位地研究了低于0.005%浓度的戊二醛对年轻、老龄红细胞膜变形能力的作用.实验结果表明随着戊二醛浓度的增加,年轻、老龄红细胞膜的弯曲弹性模量明显变大,而老龄红细胞增加幅度更大;且随着戊二醛固定时间的延长,年轻、老龄红细胞膜变形能力的差距越来越大.说明作为免疫分析中常用固定剂的戊二醛对年轻、老龄红细胞细胞骨架的影响差异较大。研究结果可为适当选取在免疫分析测定中,以及以年轻红细胞作为药物载体时需采用的戊二醛浓度提供依据。  相似文献   

4.
Bone allografting is the most common form of allotransplantation in modern medicine. Bone banking is usually the major part of most tissue banks throughout the world. Several years ago, many standards of bone banking were set empirically, and have never been evaluated. One particular parameter or standard was outdating graft materials after 5 years of storage. This study was conducted to evaluate the effect of prolonged cryopreservation on the biomechanical properties of bone allografts and establish whether graft materials become contaminated during long-term storage.Proximal humeral bone allografts were obtained from the bone bank after 1, 3 and 5 years of –80°C cryopreservation. Samples of each humeral head, i.e., cartilage, subchondral bone and spongy bone were histologically examined for inter- and intra-cellular changes. A three-point mechanical bending test was used on identical pieces of cortical bone to compare fresh and cryopreserved materials. Fresh-retrieved cortical bone using identically-sized segments, served as a control. Cultures were taken from each respective sample to determine contamination or sterility.Results of both the histological and mechanical testing showed that there were no significant, qualitative histological, or quantitative mechanical differences among the samples. All the cultures were negative. Therefore, based on this study's parameters, bone allografts can safely be used after a cryopreservation period of over 5 years and should not be discarded.  相似文献   

5.
Abstract.  1. In horned beetles selection favours males that adjust their investment in horn development in relation to cues that predict adult body size. Here it is shown that in the Japanese horned beetle, Allomyrina dichotoma . There is a significant discontinuity in the horn length body size allometry. This can be described as a linear relationship that is shifted towards an increased horn length to body length ratio in males with horns longer than 16 mm.
2. Larval nutrition explains morph determination in A. dichotoma . However, unlike other species, variation in larval nutrition was the result of a seasonal time constraint that limits the time available for feeding prior to the onset of winter diapause.
3. Even when eggs were reared with an ad libitum food supply, minor morphs were still observed. Individuals that were oviposited later in the season had less time to feed, shorter development times, eclosed as smaller individuals and, in the case of males, were more likely to be hornless. Major morphs, minor morphs, and females all reduced their body size in response to seasonal time constraints in the same way. However, males that were laid later in the season had faster development times than females laid at the same time, but showed no reduction in their size relative to females, suggesting seasonal time constraints increase growth rates in males but not in females.
4. No evidence was found that seasonal time constraints resulted in a reduction of size-corrected fat reserves at eclosion, or that minor morphs gained any developmental advantage by reducing investment in horn length.  相似文献   

6.
Hemocytes of the last larva of the Japanese rhinoceros beetle A. dichotoma (Linnaeus) (Coleoptera: Scarabaeidae) were classified as granulocytes, plasmatocytes, oenocytoids, spherulocytes, prohemocytes, and adipohemocytes. Among these cell types, only the granulocytes became immunologically activated with obvious morphological changes, displaying large amoeba-like, lobopodia-like, and fan-like structures. In addition, their cytoplasmic granules became larger and greatly increased in number. To explore whether these granules could be immunologically generated as phagosomes, total hemocytes were stained with LysoTracker. Greater than 90% of the granulocytes retained the LysoTracker dye at 4 h post-bacterial infection. In flow cytometry analysis, the red fluorescent signal was highly increased at 4 h post-bacterial infection (60.36%) compared to controls (5.08%), as was confirmed by fluorescent microscopy. After 12 h post-infection, these signals returned to basal levels. The uptake of pathogens by granulocytes rapidly triggered the translocation of the microtubule-associated protein 1 light chain 3 alpha (LC3) to the phagosome, which may result in enhanced pathogen killing.  相似文献   

7.
This study reports the effects of dietary iron (Fe) deficiency and recovery on bone mineral composition and strength in anemic rats submitted to a hemoglobin (Hb) repletion assay. Weanling male Wistar rats were fed a low-Fe diet (12 mg/kg) for 15 days followed by 2 weeks of Fe repletion with diets providing 35 mg Fe/kg as either ferrous sulfate (n = 8) or ferric pyrophosphate (FP; n = 12). At final day of each period (depletion and repletion), Fe-adequate animals were also euthanized. Iron status (blood Hb, Hb Fe pool, Hb regeneration efficiency), tibia mineral concentrations (Ca, Mg, Fe, Cu, and Zn) and biomechanical properties were evaluated. Iron-deficient rats had lower tibia Fe and Mg levels and bone strength when compared to controls. Yield load and resilience were positively related to tibia Mg levels (r = 0.47, P = 0.02 and r = 0.56, P = 0.004, respectively). Iron repletion did not recover tibia Mg concentrations impaired by Fe deficiency. Moreover, bone elastic properties were negatively affected by FP consumption. In conclusion, bone mineral composition and strength were affected by Fe deficiency, whereas dietary Fe source influenced tibia Mg and resistance in the period during which rats were recovering from anemia.  相似文献   

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11.
Effects of Dragonfly Wing Structure on the Dynamic Performances   总被引:2,自引:0,他引:2  
The configurations of dragonfly wings, including the corrugations of the chordwise cross-section, the microstructure of the longitudinal veins and membrane, were comprehensively investigated using the Environmental Scanning Electron Microscopy (ESEM). Based on the experimental results reported previously, the multi-scale and multi-dimensional models with different structural features of dragonfly wing were created, and the biological dynamic behaviors of wing models were discussed through the Finite Element Method (FEM). The results demonstrate that the effects of different structural features on dynamic behaviors of dragonfly wing such as natural frequency/modal, bending/torsional deformation, reaction force/torque are very significant. The corrugations of dragonfly wing along the chordwise can observably improve the flapping frequency because of the greater structural stiffness of wings. In updated model, the novel sandwich microstructure of the longitudinal veins remarkably improves the torsional deformation of dragonfly wing while it has a little effect on the flapping frequency and bending deformation. These integrated structural features can adjust the deformation of wing oneself, therefore the flow field around the wings can be controlled adaptively. The fact is that the flights of dragonfly wing with sandwich microstructure of longitudinal veins are more efficient and intelligent.  相似文献   

12.
Patellar tendon allografts, retrieved from cadaveric human donors, are widely used for replacement of damaged cruciate ligaments. In common with other tissue allografts originating from cadaveric donors, there are concerns regarding the potential for disease transmission from the donor to the recipient. Additionally, retrieval and subsequent processing protocols expose the graft to the risk of environmental contamination. For these reasons, disinfection or sterilisation protocols are necessary for these grafts before they are used clinically. A high-level disinfection protocol, utilising peracetic acid (PAA), has been developed and investigated for its effects on the biocompatibility and biomechanics of the patellar tendon allografts. PAA disinfection did not render the grafts either cytotoxic or liable to provoke an inflammatory response as assessed in vitro . However, the protocol was shown to increase the size of gaps between the tendon fibres in the matrix and render the grafts more susceptible to digestion with collagenase. Biomechanical studies of the tendons showed that PAA treatment had no effect on the ultimate tensile stress or Young's modulus of the tendons, and that ultimate strain was significantly higher in PAA treated tendons.  相似文献   

13.
Abstract

The aim of this study was to evaluate the stress distributions and deformations of the temporomandibular joint (TMJ) during different periods before and after sagittal split ramus osteotomy (SSRO). A three-dimensional finite element model of the mandible and TMJ was established, based on the preoperative CT of a patient with mandibular prognathism. Numerical SSRO was performed and the models of three postoperative periods were established. Contact elements were used to simulate the interaction between the articular discs and the articular cartilages. Nonlinear cable elements were used to simulate the disc attachments and the ligaments. Muscle forces and boundary conditions corresponding to the central occlusion were applied on all the models. The results showed that the stress distributions of the patient’s TMJs were not the same as those of asymptomatic subjects. The stress distributions and deformations of the disc, condylar and temporal cartilage were changed at different periods after SSRO. The biomechanical parameters of TMJ were improved after SSRO. And the postoperative results showed that appropriate functional training could help to avoid TMJ diseases. Therefore SSRO could improve the stress distributions of the TMJ and relieve the symptoms of temporomandibular disorder (TMD).  相似文献   

14.

Objectives

To explore the anatomy of the plantar aponeurosis (PA) and its biomechanical effects on the first metatarsophalangeal (MTP) joint and foot arch.

Methods

Anatomic parameters (length, width and thickness of each central PA bundle and the main body of the central part) were measured in 8 cadaveric specimens. The ratios of the length and width of each bundle to the length and width of the central part were used to describe these bundles. Six cadaveric specimens were used to measure the range of motion of the first MTP joint before and after releasing the first bundle of the PA. Another 6 specimens were used to evaluate simulated static weight-bearing. Changes in foot arch height and plantar pressure were measured before and after dividing the first bundle.

Results

The average width and thickness of the origin of the central part at the calcaneal tubercle were 15.45 mm and 2.79 mm respectively. The ratio of the length of each bundle to the length of the central part was (from medial to lateral) 0.29, 0.30, 0.28, 0.25, and 0.27, respectively. Similarly, the ratio of the widths was 0.26, 0.25, 0.23, 0.19 and 0.17. The thickness of each bundle at the bifurcation of the PA into bundles was (from medial to lateral) 1.26 mm, 1.04 mm, 0.91 mm, 0.84 mm and 0.72 mm. The average dorsiflexion of the first MTP joint increased 10.16° after the first bundle was divided. Marked acute changes in the foot arch height and the plantar pressure were not observed after division.

Conclusions

The first PA bundle was not the longest, widest, or the thickest bundle. Releasing the first bundle increased the range of motion of the first MTP joint, but did not acutely change foot arch height or plantar pressure during static load testing.  相似文献   

15.
Phenology, the timing of developmental events such as oviposition or pupation, is highly dependent on temperature; since insects are ectotherms, the time it takes them to complete a life stage (development time) depends on the temperatures they experience. This dependence varies within and between populations due to variation among individuals that is fixed within a life stage (giving rise to what we call persistent variation) and variation from random effects within a life stage (giving rise to what we call random variation). It is important to understand how both types of variation affect phenology if we are to predict the effects of climate change on insect populations.  相似文献   

16.
The contact angles of distilled water and methanol solution on the wings of butterflies were determined by a visual contact angle measuring system. The scale structures of the wings were observed using scanning electron microscopy, The influence of the scale micro- and ultra-structure on the wettability was investigated. Results show that the contact angle of distilled water on the wing surfaces varies from 134.0° to 159.2°. High hydrophobicity is found in six species with contact angles greater than 150°. The wing surfaces of some species are not only hydrophobic but also resist the wetting by methanol solution with 55% concentration. Only two species in Parnassius can not resist the wetting because the micro-structure (spindle-like shape) and ultra-structure (pinnule-like shape) of the wing scales are remarkably different from that of other species. The concentration of methanol solution for the occurrence of spreading/wetting on the wing surfaces of different species varies from 70% to 95%. After wetting by methanol solution for 10 min, the distilled water contact angle on the wing surface increases by 0.8°-2.1°, showing the promotion of capacity against wetting by distilled water.  相似文献   

17.
In this study, the center-of-mass diffusion and shape fluctuations of large unilamellar 1-palmitoyl-2-oleyl-sn-glycero-phosphatidylcholine vesicles prepared by extrusion are studied by means of neutron spin echo in combination with dynamic light scattering. The intermediate scattering functions were measured for several different values of the momentum transfer, q, and for different cholesterol contents in the membrane. The combined analysis of neutron spin echo and dynamic light scattering data allows calculation of the bending elastic constant, κ, of the vesicle bilayer. A stiffening effect monitored as an increase of κ with increasing cholesterol molar ratio is demonstrated by these measurements.  相似文献   

18.
Effects of DNA Base Analogues on the Scales of the Wing of Ephestia   总被引:1,自引:1,他引:0  
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19.
The response of the central nervous system to stress is often critical to the adaptation of an organism to its environment. However, in humans the response to stress also can be maladaptive, resulting in the expression or exacerbation of many neurological and psychiatric disorders. In this review, we examine the impact of stress on the synthesis and release of dopamine within mesocortical, mesoaccumbens, and nigrostriatal dopamine projections. We note that whereas stress increases the neurochemical activity of each of these populations of dopamine neurons, heterogeneities do exist. Specifically, acute stress evokes a greater increase in dopamine metabolism and release within the prefrontal cortex than the subcortical sites. Furthermore, whereas prior exposure to chronic stress enhances the response of mesocortical dopamine neurons to an acute novel stressor, this does not occur in the subcortical sites. In addition to these regional heterogeneities, we also note that even within a single dopamine projection there can be heterogeneous regulation of dopamine synthesis and release. Specifically, whereas stress-induced dopamine release in the neostriatum is mediated by an action of glutamate on the dopamine cell body, stress-induced dopamine synthesis in the neostriatum is mediated by an action of glutamate on the dopamine nerve terminal. Finally, we propose that regional heterogeneities in the responsiveness of central dopamine neurons to stress may ultimately play a role in the expression and exacerbation of symptoms associated with schizophrenia.  相似文献   

20.
Photoinhibition of photosynthesis in the brown alga, Dictyota dichotoma, was studied with a PAM fluorometer (Walz, Effeltrich, Germany) and a homemade oxygen measuring device. As a measure of fluorescence, Fv/Fm, and for the photosynthetic yield, ΔF/Fm', were used. Oxygen measurements show clearly that the observed degree, as well as the time course, of photoinhibition depends on the fluence rate of the light used to measure changes of the production rate. After photoinhibition of photosynthesis the depression of oxygen production caused by non-saturating fluence rates was generally much more pronounced than that caused by saturating or nearly saturating fluence rates. At minimal photoinhibition the initial slope and the convexity of the fluence rate-response curve of oxygen evolution decrease, whereas the level of light saturation decreases only after strong photoinhibition. Nevertheless, at different degrees of photoinhibition, changes in the degree of the upper bending of the fluence rate-response curve of oxygen production are also linearly correlated to changes in the fluorescence ratios (Fv/Fm and ΔF/Fm'). The action spectrum of photoinhibition, calculated on the basis of changes of Fv/Fm, indicates that the reaction center of PS I is not involved in photoinhibition. The lower effectiveness of blue light in comparison to effects of green and red light may be due to chloroplast displacement, as in the so-called strong light position, the light absorbed by the thalli in vivo is decreased.  相似文献   

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