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1.
An apparatus designed to demineralize 54 specimens simultaneously is described. A drum with built-in specimen holders rotates continuously through a bath of acid, allowing a free exchange of demineralizing fluid over the specimens. Individual specimens can be easily introduced or withdrawn from the apparatus without disturbing others.  相似文献   

2.
A simple apparatus for emulsion coating is described. The apparatus is inexpensive and easily assembled in a standard glass shop. Emulsion coating for scanning electron microscope autoradiography with this apparatus consistently yields uniform layers. When used in conjunction with newly described fixation methods, this new approach produces reliable autoradiographs of undamaged specimens.  相似文献   

3.
In this paper an apparatus is described which facilitates the freeze-drying of specimens prior to their examination by scanning electron microscopy (SEM). The apparatus has been constructed following the principle of a Dewar flask. It enables the operator to keep his SEM specimens free from contamination until immediately prior to coating and examination in the microscope. Examples of a human dental plaque and of a pure colony of Bacterionema matruchotii as prepared by this method are illustrated.  相似文献   

4.
The biomechanics of whiplash is often studied using cadaveric cervical spine specimens. One of the most important points in this kind of study is to create realistic loading conditions. The aim of the present project therefore was to develop an acceleration apparatus, which allows the study of whiplash with human cadaveric cervical spine specimens under as realistic loading conditions as possible. The new acceleration apparatus mainly consisted of a sled, a pneumatic acceleration unit and a railtrack and offered several unique features to create more realistic loading conditions. Among these features, the possibility to simulate the passive movements of the trunk is of capital importance. In this new apparatus, first, the general feasibility of whiplash experiments was studied, second, the reproducibility of the impacts was quantified and third, the effect of simulated movements of the trunk on accelerations and loads was examined. In the new acceleration apparatus various types of collisions could reproducibly be simulated. Simulated passive movements of the trunk strongly influenced the loading pattern of the neck. Without pivoting a steep increase of all loading parameters could be observed. This increase was less pronounced if pivoting was allowed. In conclusion, biomechanical aspects of whiplash could reproducibly be examined in the new acceleration apparatus. Due to its significant effects on the loading of the neck, pivoting of the trunk should always be taken into account in future experiments on the biomechanics of whiplash in which isolated cervical spine specimens are used.  相似文献   

5.
A critical point drying method using dry ice (solid carbon dioxide) instead of liquid carbon dioxide is reported. After the specimens are placed in the chamber of the medical point drying apparatus, dry ice cut to the shape of the chamber is inserted. The chamber is closed and warmed to change the dry ice into liquid carbon dioxide. This method needs no gas cylinder and even minute or fragile specimens do not blow away because there is no flow of gas. This method can be used with any kind of critical point drying apparatus.  相似文献   

6.
Central to the discovery of neuroactive compounds produced by predatory marine snails of the superfamily Conoidea (cone snails, terebrids, and turrids) is identifying those species with a venom apparatus. Previous analyses of western Pacific terebrid specimens has shown that some Terebridae groups have secondarily lost their venom apparatus. In order to efficiently characterize terebrid toxins, it is essential to devise a key for identifying which species have a venom apparatus. The findings presented here integrate molecular phylogeny and the evolution of character traits to infer the presence or absence of the venom apparatus in the Terebridae. Using a combined dataset of 156 western and 33 eastern Pacific terebrid samples, a phylogenetic tree was constructed based on analyses of 16S, COI and 12S mitochondrial genes. The 33 eastern Pacific specimens analyzed represent four different species: Acus strigatus, Terebra argyosia, T. ornata, and T. cf. formosa. Anatomical analysis was congruent with molecular characters, confirming that species included in the clade Acus do not have a venom apparatus, while those in the clade Terebra do. Discovery of the association between terebrid molecular phylogeny and the occurrence of a venom apparatus provides a useful tool for effectively identifying the terebrid lineages that may be investigated for novel pharmacological active neurotoxins, enhancing conservation of this important resource, while providing supplementary information towards understanding terebrid evolutionary diversification.  相似文献   

7.
石福明  郑哲民 《昆虫学报》1999,42(4):401-405
报道了桑螽属三种雄性发声器结构并记述一新种长翅桑螽 Kuwayamaea longipennis sp. nov.,该新种与札幌桑螽 Kuwayamaea sapporensis Matsumura et Shiraki, 1908 和中华桑螽 Kuwayamaea chinensis (Brunner,1878) 相似,同前者的主要区别:雄性声锉和发声齿不同,下生殖板端部分枝,雌性后翅长于前翅;同后者的主要区别:雄性声锉和发声齿显著不同。模式标本保存于陕西师范大学动物研究所。  相似文献   

8.
A self-contained, portable Gram staining apparatus (GSA) has been developed for use in the microgravity environment on board the Space Station Freedom. Accuracy and reproducibility of this apparatus compared with the conventional Gram staining method were evaluated by using gram-negative and gram-positive controls and different species of bacteria grown in pure cultures. A subsequent study was designed to assess the performance of the GSA with actual specimens. A set of 60 human and environmental specimens was evaluated with the GSA and the conventional Gram staining procedure. Data obtained from these studies indicated that the GSA will provide the Gram staining capability needed for the microgravity environment of space.  相似文献   

9.
A self-contained, portable Gram staining apparatus (GSA) has been developed for use in the microgravity environment on board the Space Station Freedom. Accuracy and reproducibility of this apparatus compared with the conventional Gram staining method were evaluated by using gram-negative and gram-positive controls and different species of bacteria grown in pure cultures. A subsequent study was designed to assess the performance of the GSA with actual specimens. A set of 60 human and environmental specimens was evaluated with the GSA and the conventional Gram staining procedure. Data obtained from these studies indicated that the GSA will provide the Gram staining capability needed for the microgravity environment of space.  相似文献   

10.
An apparatus has been designed to retain the spatial orientation of breast biopsies throughout surgery, transport and processing in the pathology laboratory. It does not interfere with regular surgical procedures and simplifies the surgeon's task of marking the orientation of a specimen. As the use of the apparatus does not involve either chemical or physical substances it is an appropriate handling procedure for those specimens requiring sensitive testing procedures such as cell culture.  相似文献   

11.
For studies on cathodoluminescence, we equipped a scanning electron microscope with a prism spectrometer and sensitive photomultiplier. The apparatus is described and our initial results are presented on the analyse of cathodoluminescence. The material observed promarily involved studies of immunofluorescent specimens. Humal lymphocytes were labelled with a fluorescent antibody and cryosections of rat kidney with Masugi nephritis were labelled with a fluorescent specific antibody. Our apparatus permitted monochromatic imaging of cathodoluminescence emissions and resulted in much improved micrographs. Some possible improvements of the technique are discussed.  相似文献   

12.
The extensor apparatus, an aponeurosis that covers the dorsal side of each finger, transmits force from a number of musculotendons to the phalanges. Multiple tendons integrate directly into the structure at different sites and the extensor apparatus attaches to the phalanges at multiple points. Thus, prediction of the force distribution within the extensor apparatus, or hood, and the transmission to the phalanges is challenging, especially as knowledge of the underlying mechanical properties of the tissue is limited. We undertook quantification of some of these properties through material testing of cadaver specimens. We punched samples at specified locations from 19 extensor hood specimens. Material testing was performed to failure for each sample with a custom material testing device. Testing revealed significant differences in ultimate load, ultimate strain, thickness, and tangent modulus along the length of the extensor hood. Specifically, thickness, ultimate load, and ultimate strain were greater in the more proximal sections of the extensor hood, while the tangent modulus was greater in the more distal sections. The variations in mechanical properties within the hood may impact prediction of force transmission and, thus, should be considered when modeling the action of the extensor apparatus. Across the extensor hood, tangent modulus values were substantially smaller than values reported for other soft tissues, such as the Achilles tendon and knee ligaments, while ultimate strains were much greater. Thus, the tissue in the extensor apparatus seems to have greater elasticity, which should be modeled accordingly.  相似文献   

13.
Summary For studies on cathodoluminescence, we equipped a scanning electron microscope with a prism spectrometer and sensitive photomultiplier. The apparatus is described and our initial results are presented on the analyse of cathodoluminescence.The material observed primarily involved studies of immunofluorescent specimens. Human lymphocytes were labelled with a fluorescent antibody and cryosections of rat kidney with Masugi nephritis were labelled with a fluorescent specific antibody. Our apparatus permitted monochromatic imaging of cathodoluminescence emissions and resulted in much improved micrographs. Some possible improvements of the technique are discussed.  相似文献   

14.
ABSTRACT. This paper describes a portable battery-powered freezing-point apparatus which uses readily available aerosol cans of refrigerant to cool the specimens. The instrument is directly calibrated and can be used to estimate osmolalities in nanolitre volumes over a wide concentration range.  相似文献   

15.
Six illustrative cases are reported to demonstrate the versatility of the Terry biopsy needle as a useful instrument for obtaining satisfactory biopsy specimens from the liver and from other tissues as well. The apparatus and method of use are described and illustrated.  相似文献   

16.
Body dimensions of organisms can have a profound impact on their functional and structural properties. We examined the morphological proportions of the feeding apparatus of 105 chameleon specimens representing 23 species in seven genera, spanning a 1,000‐fold range in body mass to test whether the feeding apparatus conforms to the null hypotheses of geometric similarity that is based on the prevalence of geometric similarity in other ectothermic vertebrates. We used a phylogenetically corrected regression analysis based on a composite phylogenetic hypothesis to determine the interspecific scaling patterns of the feeding apparatus. We also determined the intraspecific (ontogenetic) scaling patterns for the feeding apparatus in three species. We found that both intraspecifically and interspecifically, the musculoskeletal components of the feeding apparatus scale isometrically among themselves, independent of body length. The feeding apparatus is thus of conserved proportions regardless of overall body length. In contrast, we found that the tongue apparatus as a whole and its musculoskeletal components scale with negative allometry with respect to snout‐vent length—smaller individuals have a proportionately larger feeding apparatus than larger individuals, both within and among species. Finally, the tongue apparatus as a whole scales with negative allometry with respect to body mass through ontogeny, but with isometry interspecifically. We suggest that the observed allometry may be maintained by natural selection because an enlarged feeding apparatus at small body size may maximize projection distance and the size of prey that smaller animals with higher mass‐specific metabolic rates can capture. J. Morphol. 2012. © 2012 Wiley Periodicals, Inc.  相似文献   

17.
An apparatus for measuring and recording the resistance to penetration of endocranial tissue has been planned and built. The probe carrier, driven by a constant-speed electric motor, is fitted onto a stereotactic head frame which is used to guide the tool to the intended target. The displacement and resistance encountered when the tool penetrates intracranial structures are measured and recorded on an x-y recorder. Preliminary tests performed on calf brain specimens have documented that the apparatus can measure the different consistencies of normal cerebral tissue and suggest a new technique for morphological investigations based on the mechanical consistency of normal and pathological organic tissue. Moreover, the hypothesis of a plastic deformation in cerebral tissue has been confirmed, in that the same apparatus permits one to measure the displacement of tissues caused by the advancement of the surgical tool.  相似文献   

18.
Histochemical studies of developing human fetal small intestine   总被引:2,自引:0,他引:2  
Summary The histochemical characteristics of absorptive and mucus-producing cells have been described in 16 specimens of small intestine from human fetuses between 7 and 22 weeks of age. In the youngest specimens a slight to moderate reaction was found for all enzymes examined which included those known from biochemical or ultrastructural studies to be located predominantly in Golgi apparatus (thiamine pyrophosphatase), surface membrane (alkaline phosphatase, adenosine triphosphatase, leucine aminopeptidase), lysosomes (acid phosphatase), and mitochondria (succinic dehydrogenase). Mucus granules of somehat unusual location and staining properties were also found at this time. A progressive intensification of a majority of these histochemical reactions was observed between 3 and 6 fetal months.These findings indicate that the histochemical apparatus for degradation and absorption of nutrients and for elaboration of protein and mucus is already well established in the human fetus by the end of this 6 month period. It is not known, however, whether these activities occur in utero or whether they contribute significantly to fetal nutrition.  相似文献   

19.
Specifically stained pancreatic granules have been assessed quantitatively by measuring light transmission through areas of p-cytoplasm. Measurements were made with a comparison photometer from images produced on a ground glass screen by an optical microscope. Standard conditions were observed in the preparation of specimens and in the use of the apparatus.  相似文献   

20.
核果茶属的气孔器类型及其系统学意义   总被引:3,自引:0,他引:3  
杨世雄  刘爱忠  彭华  吴征镒 《广西植物》2003,23(3):250-252,I001
为了检验有关核果茶属气孔器类型不同的研究结果 ,使用从模式标本上获取的实验材料重新观察了耿煊 (H .Keng)在 1 962年报道过的具有毛茛型气孔器的核果茶属 3个种的叶片下表皮 ,得到了与耿煊不同的研究结果 ,即核果茶属的气孔器属大头茶型 ,与邻近的石笔木属、拟核果茶属乃至山茶亚科的气孔器类型一致。结果提示 ,气孔器类型可以作为划分山茶亚科和厚皮香亚科的依据  相似文献   

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