Pub Date : 2020-05-14DOI: 10.1186/s42649-020-00030-x
Yan Sun, Hyo-Jeong Kim, Myung-Jin Moon
The fine structural characteristics of cardiac muscle cells and its myofibril organization in the orb web spider N. clavata were examined by transmission electron microscopy. Although myofibril striations are not remarkable as those of skeletal muscles, muscle fibers contain multiple myofibrils, abundant mitochondria, extensive sarcoplasmic reticulum and transverse tubules (T-tubules). Myofibrils are divided into distinct sarcomeres defined by Z-lines with average length of 2.0?μm, but the distinction between the A-band and the I-bands is not clear due to uniform striations over the length of the sarcomeres. Dyadic junction which consisted of a single T-tubule paired with a terminal cisterna of the sarcoplasmic reticulum is found mainly at the A-I level of sarcomere. Each cell is arranged to form multiple connections with neighboring cells through the intercalated discs. These specialized junctions include three types of intercellular junctions: gap junctions, fascia adherens and desmosomes for heart function. Our transmission electron microscopy (TEM) observations clearly show that spider’s cardiac muscle contraction is controlled by neurogenic rather than myogenic mechanism since each cardiac muscle fiber is innervated by a branch of motor neuron through neuromuscular junctions.
{"title":"Fine structure of the cardiac muscle cells in the orb-web spider Nephila clavata","authors":"Yan Sun, Hyo-Jeong Kim, Myung-Jin Moon","doi":"10.1186/s42649-020-00030-x","DOIUrl":"https://doi.org/10.1186/s42649-020-00030-x","url":null,"abstract":"<p>The fine structural characteristics of cardiac muscle cells and its myofibril organization in the orb web spider <i>N. clavata</i> were examined by transmission electron microscopy. Although myofibril striations are not remarkable as those of skeletal muscles, muscle fibers contain multiple myofibrils, abundant mitochondria, extensive sarcoplasmic reticulum and transverse tubules (T-tubules). Myofibrils are divided into distinct sarcomeres defined by Z-lines with average length of 2.0?μm, but the distinction between the A-band and the I-bands is not clear due to uniform striations over the length of the sarcomeres. Dyadic junction which consisted of a single T-tubule paired with a terminal cisterna of the sarcoplasmic reticulum is found mainly at the A-I level of sarcomere. Each cell is arranged to form multiple connections with neighboring cells through the intercalated discs. These specialized junctions include three types of intercellular junctions: gap junctions, fascia adherens and desmosomes for heart function. Our transmission electron microscopy (TEM) observations clearly show that spider’s cardiac muscle contraction is controlled by neurogenic rather than myogenic mechanism since each cardiac muscle fiber is innervated by a branch of motor neuron through neuromuscular junctions.</p>","PeriodicalId":470,"journal":{"name":"Applied Microscopy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42649-020-00030-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4583745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-12DOI: 10.1186/s42649-020-00029-4
Yoon-Uk Heo
Two thickness measurement methods using an electron energy loss spectroscopy (EELS) and 10a convergent beam electron diffraction (CBED) were compared in an Fe-18Mn-0.7C alloy. The thin foil specimen was firstly tilted to satisfy 10a two-beam condition. Low loss spectra of EELS and CBED patterns were acquired in scanning transmission electron microscopy (STEM) and TEM-CBED modes under the two-beam condition. The log-ratio method was used for measuring the thin foil thickness. Kossel-M?llenstedt (K-M) fringe of the ( mathbf{13}overline{mathbf{1}} ) diffracted disk of austenite was analyzed to evaluate the thickness. The results prove the good coherency between both methods in the thickness range of 72?~?113?nm with a difference of less than 5%.
比较了电子能量损失谱(EELS)和10a会聚束电子衍射(CBED)两种测量Fe-18Mn-0.7C合金厚度的方法。首先对薄片试样进行倾斜,使其满足10a双梁条件。在扫描透射电子显微镜(STEM)和TEM-CBED模式下,获得了两束条件下EELS和CBED模式的低损耗谱。采用对数比法测量薄箔厚度。科塞尔- m ?分析了( mathbf{13}overline{mathbf{1}} )奥氏体衍射盘的llenstedt (K-M)条纹厚度。结果表明,两种方法在厚度为72?113?Nm,差值小于5%.
{"title":"Comparative study on the specimen thickness measurement using EELS and CBED methods","authors":"Yoon-Uk Heo","doi":"10.1186/s42649-020-00029-4","DOIUrl":"https://doi.org/10.1186/s42649-020-00029-4","url":null,"abstract":"<p>Two thickness measurement methods using an electron energy loss spectroscopy (EELS) and 10a convergent beam electron diffraction (CBED) were compared in an Fe-18Mn-0.7C alloy. The thin foil specimen was firstly tilted to satisfy 10a two-beam condition. Low loss spectra of EELS and CBED patterns were acquired in scanning transmission electron microscopy (STEM) and TEM-CBED modes under the two-beam condition. The log-ratio method was used for measuring the thin foil thickness. Kossel-M?llenstedt (K-M) fringe of the <span>( mathbf{13}overline{mathbf{1}} )</span> diffracted disk of austenite was analyzed to evaluate the thickness. The results prove the good coherency between both methods in the thickness range of 72?~?113?nm with a difference of less than 5%.</p>","PeriodicalId":470,"journal":{"name":"Applied Microscopy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42649-020-00029-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4507294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-27DOI: 10.1186/s42649-020-00027-6
Hyun-Wook Kim, Seung Hak Oh, Se Jeong Lee, Ji eun Na, Im Joo Rhyu
The cerebellum is a region of the brain that plays an important role in motor control. It is classified phylogenetically into archicerebellum, paleocerebellum and neocerebellum. The Purkinje cells are lined in a row called Purkinje cell layer and it has a unique dendritic branches with many spines.
The previous study reported that there is a difference of synapse density according to the lobules based on large two-dimensional data. However, recent study with high voltage electron microscopy showed there was no differences in dendritic spine density of the Purkinje cell according to its phylogenetic lobule. We analyzed Purkinje cell density in the II, VI and X lobules by stereological modules and synaptic density was estimated by double disector based on Purkinje cell density in the molecular layer of each lobule.
The results showed that there was significant difference in the Purkinje cell density and synapse number according to their phylogenetic lobules. The number of Purkinje cell in a given volume was larger in the archicerebellum, but synapse density was higher in the neocerebellum.
These data suggest that cellular and synaptic organization of the Purkinje cell is different according to their phylogenetic background.
{"title":"Differential synapse density between Purkinje cell dendritic spine and parallel fiber varicosity in the rat cerebellum among the phylogenic lobules","authors":"Hyun-Wook Kim, Seung Hak Oh, Se Jeong Lee, Ji eun Na, Im Joo Rhyu","doi":"10.1186/s42649-020-00027-6","DOIUrl":"https://doi.org/10.1186/s42649-020-00027-6","url":null,"abstract":"<p>The cerebellum is a region of the brain that plays an important role in motor control. It is classified phylogenetically into archicerebellum, paleocerebellum and neocerebellum. The Purkinje cells are lined in a row called Purkinje cell layer and it has a unique dendritic branches with many spines.</p><p>The previous study reported that there is a difference of synapse density according to the lobules based on large two-dimensional data. However, recent study with high voltage electron microscopy showed there was no differences in dendritic spine density of the Purkinje cell according to its phylogenetic lobule. We analyzed Purkinje cell density in the II, VI and X lobules by stereological modules and synaptic density was estimated by double disector based on Purkinje cell density in the molecular layer of each lobule.</p><p>The results showed that there was significant difference in the Purkinje cell density and synapse number according to their phylogenetic lobules. The number of Purkinje cell in a given volume was larger in the archicerebellum, but synapse density was higher in the neocerebellum.</p><p>These data suggest that cellular and synaptic organization of the Purkinje cell is different according to their phylogenetic background.</p>","PeriodicalId":470,"journal":{"name":"Applied Microscopy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42649-020-00027-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5034762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-27DOI: 10.1186/s42649-020-00026-7
Sung-Il Baik, Young-Woon Kim
Tantalum nitride (TaNx) thin films were grown utilizing an inductively coupled plasma (ICP) assisted direct current (DC) sputtering, and 20–100% improved microhardness values were obtained. The detailed microstructural changes of the TaNx films were characterized utilizing transmission electron microscopy (TEM), as a function of nitrogen gas fraction and ICP power. As nitrogen gas fraction increases?from 0.05 to 0.15, the TaNx phase evolves from body-centered-cubic (b.c.c.) TaN0.1, to face-centered-cubic (f.c.c.) δ-TaN, to hexagonal-close-packing (h.c.p.) ε-TaN phase. By increasing ICP power from 100?W to 400?W, the f.c.c. δ- TaN phase becomes the main phase in all nitrogen fractions investigated. The higher ICP power enhances the mobility of Ta and N ions, which stabilizes the δ-TaN phase like a high-temperature regime and removes the micro-voids between the columnar grains in the TaNx film. The dense δ-TaN structure with reduced columnar grains and micro-voids increases the strength of the TaNx film.
{"title":"Microstructural evolution of tantalum nitride thin films synthesized by inductively coupled plasma sputtering","authors":"Sung-Il Baik, Young-Woon Kim","doi":"10.1186/s42649-020-00026-7","DOIUrl":"https://doi.org/10.1186/s42649-020-00026-7","url":null,"abstract":"<p>Tantalum nitride (TaN<sub>x</sub>) thin films were grown utilizing an inductively coupled plasma (ICP) assisted direct current (DC) sputtering, and 20–100% improved microhardness values were obtained. The detailed microstructural changes of the TaN<sub>x</sub> films were characterized utilizing transmission electron microscopy (TEM), as a function of nitrogen gas fraction and ICP power. As nitrogen gas fraction increases?from 0.05 to 0.15, the TaN<sub>x</sub> phase evolves from body-centered-cubic (b.c.c.) TaN<sub>0.1</sub>, to face-centered-cubic (f.c.c.) δ-TaN, to hexagonal-close-packing (h.c.p.) ε-TaN phase. By increasing ICP power from 100?W to 400?W, the f.c.c. δ- TaN phase becomes the main phase in all nitrogen fractions investigated. The higher ICP power enhances the mobility of Ta and N ions, which stabilizes the δ-TaN phase like a high-temperature regime and removes the micro-voids between the columnar grains in the TaN<sub>x</sub> film. The dense δ-TaN structure with reduced columnar grains and micro-voids increases the strength of the TaN<sub>x</sub> film.</p>","PeriodicalId":470,"journal":{"name":"Applied Microscopy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42649-020-00026-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5035768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-10DOI: 10.1186/s42649-019-0024-2
Daeyoung Kim, Hye Jung Chang, Hyunjoo Choi
Metallic matrix composites reinforced with carbon nanomaterials continue to attract interest because of their excellent mechanical, thermal, and electrical properties. However, two critical issues have limited their commercialization. Uniform distribution of carbon nanomaterials in metallic matrices is difficult, and the interfaces between the nanomaterials and matrices are weak. Microscope-based analysis was recently used to quantitatively examine these microstructural features and investigate their contributions to the composites’ mechanical, thermal, and electrical properties. The impacts of the microstructure on these properties are discussed in the first section of this review. In the second section, the various microscopic techniques used to study the distribution of carbon nanomaterials in metallic matrices and their interfaces are described.
{"title":"Microscopic analysis of metal matrix composites containing carbon Nanomaterials","authors":"Daeyoung Kim, Hye Jung Chang, Hyunjoo Choi","doi":"10.1186/s42649-019-0024-2","DOIUrl":"https://doi.org/10.1186/s42649-019-0024-2","url":null,"abstract":"<p>Metallic matrix composites reinforced with carbon nanomaterials continue to attract interest because of their excellent mechanical, thermal, and electrical properties. However, two critical issues have limited their commercialization. Uniform distribution of carbon nanomaterials in metallic matrices is difficult, and the interfaces between the nanomaterials and matrices are weak. Microscope-based analysis was recently used to quantitatively examine these microstructural features and investigate their contributions to the composites’ mechanical, thermal, and electrical properties. The impacts of the microstructure on these properties are discussed in the first section of this review. In the second section, the various microscopic techniques used to study the distribution of carbon nanomaterials in metallic matrices and their interfaces are described.</p>","PeriodicalId":470,"journal":{"name":"Applied Microscopy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42649-019-0024-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4417905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-31DOI: 10.1186/s42649-019-0015-3
Jeong Eun Chae, Ji-Soo Kim, Sang-Yeol Nam, Min Su Kim, Jucheol Park
Electron energy loss spectroscopy (EELS) is an analytical technique that can provide the structural, physical and chemical information of materials. The EELS spectra can be obtained by combining with TEM at sub-nanometer spatial resolution. However, EELS spectral information can’t be obtained easily because in order to interpret EELS spectra, we need to refer to and/or compare many reference data with each other. And in addition to that, we should consider the different experimental variables used to produce each data. Therefore, reliable and easily interpretable EELS standard reference data are needed.
Our Electron Energy Loss Data Center (EELDC) has been designated as National Standard Electron Energy Loss Data Center No. 34 to develop EELS standard reference (SR) data and to play a role in dissemination and diffusion of the SR data to users. EELDC has developed and collected EEL SR data for the materials required by major industries and has a total of 82 EEL SR data. Also, we have created an online platform that provides a one-stop-place to help users interpret quickly EELS spectra and get various spectral information. In this paper, we introduce EEL SR data, the homepage of EELDC and how to use them.
{"title":"Introduction to the standard reference data of electron energy loss spectra and their database: eel.geri.re.kr","authors":"Jeong Eun Chae, Ji-Soo Kim, Sang-Yeol Nam, Min Su Kim, Jucheol Park","doi":"10.1186/s42649-019-0015-3","DOIUrl":"https://doi.org/10.1186/s42649-019-0015-3","url":null,"abstract":"<p>Electron energy loss spectroscopy (EELS) is an analytical technique that can provide the structural, physical and chemical information of materials. The EELS spectra can be obtained by combining with TEM at sub-nanometer spatial resolution. However, EELS spectral information can’t be obtained easily because in order to interpret EELS spectra, we need to refer to and/or compare many reference data with each other. And in addition to that, we should consider the different experimental variables used to produce each data. Therefore, reliable and easily interpretable EELS standard reference data are needed.</p><p>Our Electron Energy Loss Data Center (EELDC) has been designated as National Standard Electron Energy Loss Data Center No. 34 to develop EELS standard reference (SR) data and to play a role in dissemination and diffusion of the SR data to users. EELDC has developed and collected EEL SR data for the materials required by major industries and has a total of 82 EEL SR data. Also, we have created an online platform that provides a one-stop-place to help users interpret quickly EELS spectra and get various spectral information. In this paper, we introduce EEL SR data, the homepage of EELDC and how to use them.</p>","PeriodicalId":470,"journal":{"name":"Applied Microscopy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42649-019-0015-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5172509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-31DOI: 10.1186/s42649-019-0018-0
Giriraj Tailor, Jyoti Chaudhay, Deepshikha Verma, Bhupendra Kr. Sarma
The present study reports the novel synthesis of Zinc nanoparticles (Zn NPs) by thermal decomposition method and its characterisation by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and X-ray Diffraction Measurements (XRD). Synthesis of Zn NPs was achieved by using thermosetting polymer and zinc salts as precursor. Zn NPs were obtained on calcination at 850?°C for 30?min. SEM study reveals that synthesized nanoparticles are spherical in shape. XRD analysis shows that the Zn NPs formed are low crystalline in nature.
{"title":"Microscopic study of zinc nanoparticles synthesised using thermosetting polymer","authors":"Giriraj Tailor, Jyoti Chaudhay, Deepshikha Verma, Bhupendra Kr. Sarma","doi":"10.1186/s42649-019-0018-0","DOIUrl":"https://doi.org/10.1186/s42649-019-0018-0","url":null,"abstract":"<p>The present study reports the novel synthesis of Zinc nanoparticles (Zn NPs) by thermal decomposition method and its characterisation by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and X-ray Diffraction Measurements (XRD). Synthesis of Zn NPs was achieved by using thermosetting polymer and zinc salts as precursor. Zn NPs were obtained on calcination at 850?°C for 30?min. SEM study reveals that synthesized nanoparticles are spherical in shape. XRD analysis shows that the Zn NPs formed are low crystalline in nature.</p>","PeriodicalId":470,"journal":{"name":"Applied Microscopy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42649-019-0018-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5173576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-24DOI: 10.1186/s42649-019-0022-4
Ki Woo Kim
Two distinct layers in terms of texture and electron density were observed in the leaf cuticle of Ficus elastica using transmission electron microscopy. As depicted in a model, an inner polysaccharide-rich layer and an outer cutin (or cutan)-rich layer may support the composite, heterogeneous concept of the leaf cuticle.
{"title":"Composite cuticle with heterogeneous layers in the leaf epidermis of Ficus elastica","authors":"Ki Woo Kim","doi":"10.1186/s42649-019-0022-4","DOIUrl":"https://doi.org/10.1186/s42649-019-0022-4","url":null,"abstract":"<p>Two distinct layers in terms of texture and electron density were observed in the leaf cuticle of <i>Ficus elastica</i> using transmission electron microscopy. As depicted in a model, an inner polysaccharide-rich layer and an outer cutin (or cutan)-rich layer may support the composite, heterogeneous concept of the leaf cuticle.</p>","PeriodicalId":470,"journal":{"name":"Applied Microscopy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42649-019-0022-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4925385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-23DOI: 10.1186/s42649-019-0023-3
Hyun Tae Kim, Seung Woon Yun, Jong Young Park
The detailed anatomy, ultrastructure and histology of the olfactory organ of Micropterus salmoides were investigated by a stereo microscope, a light microscope, and a scanning electron microscope. Its external structure shows a tube-like anterior nostril to stick out and a posterior nostril flat to the skin surface. Meanwhile, its internal structure, the olfactory chamber, contains a fan-shaped rosette structure with 9 to 11 lamellae in adult fish over 35?cm in standard length (SL) and two accessory nasal sacs (ethmoidal and lacrimal sacs) were found. Interestingly, the rosette in young fish under 15?cm in SL was a longitudinal structure in parallel with each of 4–5 lamellae. Histologically, the sensory epithelium (SE) on the olfactory chamber consists of 5 types of cells: olfactory receptor neurons, supporting cells, basal cells, lymphatic cells and mucous cells. In contrast, the non-sensory epithelium (NSE) has stratified epithelial cells, lymphatic cells and mucous cells. The mucous cells of the SE are abundant and distributed densely in one row on the outermost superficial surface, but the one of the NSE are less than the SE. From these results, the olfactory characters of M. salmoides may be related with its ecological habit spending in the middle layer of stagnant water contaminated, more or less.
{"title":"Anatomy, ultrastructure and histology of the olfactory organ of the largemouth bass Micropterus salmoides, Centrarchidae","authors":"Hyun Tae Kim, Seung Woon Yun, Jong Young Park","doi":"10.1186/s42649-019-0023-3","DOIUrl":"https://doi.org/10.1186/s42649-019-0023-3","url":null,"abstract":"<p>The detailed anatomy, ultrastructure and histology of the olfactory organ of <i>Micropterus salmoides</i> were investigated by a stereo microscope, a light microscope, and a scanning electron microscope. Its external structure shows a tube-like anterior nostril to stick out and a posterior nostril flat to the skin surface. Meanwhile, its internal structure, the olfactory chamber, contains a fan-shaped rosette structure with 9 to 11 lamellae in adult fish over 35?cm in standard length (SL) and two accessory nasal sacs (ethmoidal and lacrimal sacs) were found. Interestingly, the rosette in young fish under 15?cm in SL was a longitudinal structure in parallel with each of 4–5 lamellae. Histologically, the sensory epithelium (SE) on the olfactory chamber consists of 5 types of cells: olfactory receptor neurons, supporting cells, basal cells, lymphatic cells and mucous cells. In contrast, the non-sensory epithelium (NSE) has stratified epithelial cells, lymphatic cells and mucous cells. The mucous cells of the SE are abundant and distributed densely in one row on the outermost superficial surface, but the one of the NSE are less than the SE. From these results, the olfactory characters of <i>M. salmoides</i> may be related with its ecological habit spending in the middle layer of stagnant water contaminated, more or less.</p>","PeriodicalId":470,"journal":{"name":"Applied Microscopy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42649-019-0023-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5189630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}