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1.
Sci Rep ; 13(1): 14335, 2023 08 31.
Article En | MEDLINE | ID: mdl-37653069

Numerous studies have focussed on the mechanisms of entry of pesticides into insect body parts such as oral intake, penetration through the integument of the body wall, and inhalation through spiracles. However, little is known about how insecticides spread to the points of entry or the paths on the body surface that are used to reach the target sites. In this study, elemental signals of pesticide-mimicking test solutions were tracked and their routes of spreading in experimental insects (Blattella germanica L.) were investigated using NanoSuit (a method of surface modification) and energy dispersive X-ray spectroscopy, combined with high-resolution scanning electron microscopy. When the test solution initially adhered to the dorsal and/or ventral body surface, it tended to spread horizontally to reach lateral plates. Whereas, when the solution directly adhered to the anterior side of the lateral plates, it spread to posterior segments. In this case, however, spreading in the opposite direction (i.e., the solution directly adhered to the posterior side of the lateral plates) was interrupted at a boundary erected by different groups of fine structures; each protrusion was large, and the arrangement was rather dense in the posterior segments. Morphological features of these fine structures and chemical characteristics of the hydrophobic surface substances potentially regulate the strength of the capillary force, which determines pesticide spreading.


Blattellidae , Insecticides , Pesticides , Animals , Integumentary System , Microscopy, Electron, Scanning
3.
Sci Rep ; 10(1): 14574, 2020 09 03.
Article En | MEDLINE | ID: mdl-32884008

Energy dispersive X-ray spectroscopy (EDS) carried out alongside scanning electron microscopy (SEM) is a common technique for elemental analysis. To investigate "wet" biological specimens, complex pre-treatments are required to stabilize them under the high vacuum conditions of high-resolution SEM. These often produce unwanted artifacts. We have previously reported that the polymerization of natural surface substances on organisms by the electron beam of the SEM setup or by plasma irradiation causes a nano-scale layer to form-called a "NanoSuit"-that can act as a barrier and keep organisms alive and hydrated in a field-emission SEM system. In the study reported herein, we examined the suitability of the NanoSuit method for elemental analyses of biological specimens by EDS. We compared experimental results for living Drosophila larvae and Aloe arborescens specimens prepared by the NanoSuit method and by conventional fixation. The NanoSuit method allowed accurate detection of the elemental compositions at high resolution. By contrast, specimens prepared by the conventional fixation method displayed additional EDS signals corresponding to the elements in the chemicals involved in the fixation process. Our results demonstrate that the NanoSuit method is useful for studying hydrous samples via EDS and SEM, particularly in biological sciences.


Drosophila melanogaster/metabolism , Elements , Larva/metabolism , Microscopy, Electron, Scanning/methods , Nanotechnology/methods , Polymers/chemistry , Spectrometry, X-Ray Emission/methods , Animals , Drosophila melanogaster/ultrastructure , Larva/ultrastructure , Vacuum
4.
PLoS One ; 15(5): e0232992, 2020.
Article En | MEDLINE | ID: mdl-32392263

Although scanning electron microscopy (SEM) can generate high-resolution images of nanosized objects, it requires a high vacuum to do so, which precludes direct observations of living organisms and often produces unwanted structural changes. It has previously been reported that a simple surface modification gives rise to a nanoscale layer, termed the "NanoSuit", which can keep small animals alive under the high vacuum required for field-emission scanning electron microscopy (FE-SEM). We have previously applied this technique to plants, and successfully observed healthy petals in a fully hydrated state using SEM. The flower petals protected with the NanoSuit appeared intact, although we still lack a fundamental understanding of the images of other plants observed using FE-SEM. This report presents and evaluates a rich set of images, acquired using the NanoSuit, for a taxonomically diverse set of plant species. This dataset of images allows the surface features of various plants to be analyzed and thus provides a further complementary morphological profile. Image data can be accessed and viewed through Figshare (https://doi.org/10.6084/m9.figshare.c.4446026.v1).


Microscopy, Electron, Scanning/methods , Nanostructures , Plants/ultrastructure , Animals , Flowers/ultrastructure , Microscopy, Electron, Scanning/instrumentation , Microscopy, Electron, Transmission/methods , Nanotechnology , Surface Properties , Vacuum
6.
Intern Med ; 57(14): 2001-2006, 2018 Jul 15.
Article En | MEDLINE | ID: mdl-29491286

The initial symptoms of Crohn's disease (CD) sometimes present as extraintestinal lesions, which can be a diagnostic challenge for physicians. Painful legs, known as "gastrocnemius myalgia syndrome", are rare complications that often precede abdominal manifestations. We herein report the case of a 38-year-old man who presented with bilateral leg myalgia lasting for 4 months. Magnetic resonance imaging showed abnormal intensity, and a muscle biopsy revealed inflammatory cell infiltration. Abdominal symptoms appeared three months after the myalgia onset, and the diagnosis of CD was confirmed later by endoscopic and radiological findings. To our knowledge, this is the first description of gastrocnemius myalgia syndrome in Japan.


Analgesics/therapeutic use , Crohn Disease/complications , Muscle, Skeletal/drug effects , Muscle, Skeletal/physiopathology , Myalgia/drug therapy , Myalgia/physiopathology , Adult , Humans , Japan , Male , Muscle, Skeletal/diagnostic imaging , Myalgia/diagnostic imaging , Myalgia/etiology , Treatment Outcome
7.
Sci Rep ; 8(1): 1685, 2018 01 26.
Article En | MEDLINE | ID: mdl-29374227

Land plants have evolved on dry land and developed surface barriers to protect themselves from environmental stresses. We have previously reported that polymerization of a natural extracellular substance (ECS) on the outer surface of animals by electron beam or plasma irradiation, can give rise to a nano-scale layer, termed the "NanoSuit", which can keep small animals alive under the high vacuum of a scanning electron microscope (SEM). In the present research, we have focused on plants, using petals of cherry blossoms, as experimental specimens and examined their behavior under high vacuum conditions. Experiments on healthy living petals have demonstrated that without any pre-treatment, the overall morphology of specimens is well preserved and intact after imaging in an SEM, suggesting that natural substances on the petal surface behave like animal ECS and form a NanoSuit following irradiation with an electron beam. Furthermore, we have shown that the surface material can be extracted with chloroform and polymerized into a free-standing membrane by plasma irradiation. From our results, we conclude that surface materials, which have the ability to prevent water loss under natural conditions, increase the barrier ability and can protect plants under high vacuum conditions.


Beta Particles , Flowers/physiology , Flowers/radiation effects , Vacuum , Animals , Flowers/chemistry , Microscopy, Electron, Scanning , Phytochemicals/isolation & purification , Polymerization , Surface Properties , Survival Analysis
8.
R Soc Open Sci ; 4(3): 160887, 2017 Mar.
Article En | MEDLINE | ID: mdl-28405375

Although field-emission scanning electron microscopy (FE-SEM) has proven very useful in biomedical research, the high vacuum required (10-3 to 10-7 Pa) precludes direct observations of living cells and tissues at high resolution and often produces unwanted structural changes. We have previously described a method that allows the investigator to keep a variety of insect larvae alive in the high vacuum environment of the electron microscope by encasing the organisms in a thin, vacuum-proof suit, the 'NanoSuit®'. However, it was impossible to protect wet tissues freshly excised from intact organisms or cultured cells. Here we describe an improved 'NanoSuit' technique to overcome this limitation. We protected the specimens with a surface shield enhancer (SSE) solution that consists of glycerine and electrolytes and found that the fine structure of the SSE-treated specimens is superior to that of conventionally prepared specimens. The SSE-based NanoSuit affords a much stronger barrier to gas and/or liquid loss than the previous NanoSuit did and, since it allows more detailed images, it could significantly help to elucidate the 'real' organization of cells and their functions.

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