Budsabong Kuntalue

Ultrastructure of adhesive device in fly in families calliphoridae, muscidae and sarcophagidae, and their implication as mechanical carriers of pathogens.

The ultrastructure of adhesive device or the pulvilli, pad-like structure between the tarsal claws of the legs, is presented in the blowfly (Calliphoridae), housefly and relatives (Muscidae), and flesh fly (Sarcophagidae) through scanning electron microscopy. The blowfly species were Chrysomya chani, Chrysomya nigripes, Chrysomya pinguis, and Chrysomya villeneuvi; while those of the housefly and relatives were Musca domestica and Hydrotaea chalcogaster, respectively. Fresh fly species included Boettcherisca peregrina and Liosarcophaga dux. Numerous tenent setae were observed on the ventral side of the pulvilli. Two features of the tip of the tenent setae were found as a spatula-like (in C. chani, C. pinguis, C. nigripes, M. domestica, H. chalcogaster, B. peregrina, and L. dux) and spoon-like tip (in C. villeneuvi). Transmission electron microscopy of the tenent setae in M. domestica revealed the electron-lucent centrally located, suggesting an adhesive substance. These results provided anatomical information that allow us to not only understand the successful attachment of flies to smooth surfaces but also clarify their role as a mechanical carrier of microorganisms.

Surface ultrastructure of Chrysomya rufifacies (Macquart) larvae (Diptera: Calliphoridae).

Abstract The surface ultrastructure of all larval instars of Chrysomya rufifacies (Macquart) is described by means of scanning electron microscopy (SEM). Morphological changes were greatest from the first to the second instar, but less from the second to the third instar. Most of these changes involved the structure of the anterior spiracle, posterior spiracle, integument of the body, and mouthhooks. Modification of the mouthhooks, especially in the third instar, are helpful in explaining the ferocious feeding ability of the older maggots. The common name of “hairy-maggot” for C. rufifacies is only appropriate for the second and third instars because of their elongated tubercles along the body, whereas this name is not descriptive of the first instar that lack tubercles.

Morphology of the puparia of the housefly, Musca domestica (Diptera: Muscidae) and blowfly, Chrysomya megacephala (Diptera: Calliphoridae)

Examination of the puparia of the housefly, Musca domestica L. and blowfly Chrysomya megacephala (F.), through scanning electron microscopy (SEM), revealed many differences in the profile of their morphology. Special attention was focused on puparial characteristics used to differentiate between the two fly species studied, and between other forensically important flies. Results of this study indicate that the housefly puparia are almost evenly rounded at both ends and the anterior spiracle bears six papillae. A pair of pupal respiratory horns is found laterally before the posterior boundary of the first abdominal segment, bearing numerous papillae that have a longitudinal opening along the oval convex base. The peritreme of each posterior spiracle forms a crude forward or reverse D-shape, encircling three sinuous slits. The blowfly pupariums anterior spiracle contains 8–12 papillae. The pupal respiratory horns protrude slightly and in some specimens a group of ~38 globules on the bubble-like membrane may be observed. Each of the posterior spiracles is more or less an oval- shaped peritreme, encircling three straight spiracular slits. The anatomical features presented herein allow for the differentiation of puparia of the two fly species studied and could prove useful in future forensic entomological assessments.

Fine Structure of the Eggshell of the Blow Fly, Lucilia cuprina

Abstract The fine structure of the eggshell of blow fly, Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae), was examined using scanning and transmission electron microscopy. Eggs, 1.09±0.07 mm in length and 0.25±0.05 mm in width, bore a relatively wide plastron that extending along almost the entire length. The polygonal pattern of chorionic sculpture was indistinct. The ultrathin section indicated a multi-layered eggshell having an exochorion, outer endochorion, pillars, an inner endochorion, innermost chorionic layer, and a wax layer. This study provides new information about the fine morphology of blow flies eggs. A key to differentiate the eggs of forensically important flies in Thailand is given.

Fine structure of the alimentary canal of the larval blow fly Chrysomya megacephala (Diptera: Calliphoridae)

Morphology of the alimentary canal of the mature third instar larva of the blow fly, Chrysomya megacephala (F.), was examined using light, scanning, and transmission electron microscopy. Salivary structures consist of a single median deferent duct that bifurcates into efferent ducts connected to paired, tubular salivary glands comprised of closely packed conical-shaped epithelial cells with large nuclei. The crop occurs as a large, swollen diverticulum of the digestive tube and is lined internally with convoluted cuticle (epicuticle and endocuticle). The esophagus is a simple, straight tube internally lined with cuticle and externally encompassed by muscle fibers. The cardia is a bulb-like structure composed of anterior foregut tissue and posterior midgut tissue from which the peritrophic membrane (PM) is produced. The midgut begins within the cardia which is flanked posteriorly by four tubular gastric caeca that are lined internally with four to five layers of cuboidal epithelial cells bearing microvilli. Midgut tissue is lined with simple cuboidal epithelium whose cells are filled with numerous secretory granules and possessed long microvilli facing the lumen. A peritrophic membrane is contained within the midgut lumen. The larval hindgut consists of the pylorus, Malpighian tubules, ileum, colon, rectum, and anus, posteriorly. The pylorus is characterized by a single layer of epithelial cells encircled by a muscular layer and the presence of PM within the lumen. Malpighian tubules each diverge into two tubular structures totalling four long tubules of long chained cuboidal cells bearing microvilli internally. The wall of the ileum is comprised primarily of a monolayer of cuboidal epithelial cells with large oval nuclei and more intense muscular fibers surrounding the periphery. A cuticular layer surrounds the lumen containing the PM. This inner cuticle consists of a thin epicuticle that is electron-dense; whereas, the endocuticle is much thicker but less electron-dense. Myo-epithelial cells are dense in the anal region, where the PM persists.

Hydrothermal synthesis and characterization of Bi 2 MoO 6 nanoplates and their photocatalytic activities

The pH effect of the precursor solutions on the phase, morphologies, and photocatalytic activity of Bi2MoO6 synthesized by a hydrothermal reaction at 180°C for 20 h was investigated. X-ray powder diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectrometry, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) revealed the presence of pure orthorhombic well-crystallized γ-Bi2MoO6 nanoplates, including the symmetric (A1g) and asymmetric (A2u) stretching vibrations of the MoO6 octahedrons involving the motion of apical oxygen atoms. The photocatalytic activity of Bi2MoO6 nanoplates at the pH 6 determined via the decomposition of rhodamine-B (RhB) organic dye was the highest at 98.66% decolorization under Xe light irradiation.

Hydrothermal Synthesis, Characterization, and Optical Properties of Ce Doped Bi2MoO6 Nanoplates

Undoped and Ce doped Bi2MoO6 samples were synthesized by hydrothermal reaction at 180°C for 20 h. Phase, morphology, atomic vibration, and optical properties were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and UV-visible spectroscopy. In this research, the products were orthorhombic Bi2MoO6 nanoplates with the growth direction along the [0b0], including the asymmetric and symmetric stretching and bending modes of Bi–O and Mo–O. Undoped and Ce doped Bi2MoO6 samples show a strong absorption in the UV region.

Ultrasonic-assisted synthesis, characterization, and optical properties of Sb doped ZnO and their photocatalytic activities

Sb doped ZnO nanostructures were synthesized by an ultrasonic-assistedmethod. Effect of Sb dopant on the structure, morphology, and composition of as-synthesized Sb doped ZnO nanostructures was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and transmission electron microscopy (TEM). All samples were identified to wurtzite hexagonal ZnO structure. UV-visible spectra of the as-synthesized 3% Sb doped ZnO sample exhibit broad absorption bands at around 343 nm which is blue shift of 373 nm of pure ZnO. The photocatalytic activity was tested by decolorization of methylene blue (MB) solution under UV light. After 300 min irradiation, the degradation efficiencies were 56, 90, and 95% for ZnO, 1% Sb doped ZnO, and 3% Sb doped ZnO, respectively. The 3% Sb doped ZnO shows the highest photocatalytic activity than any other samples.

Ovarian ultrastructure and development of the blow fly, Chrysomya megacephala (Diptera: Calliphoridae).

Chrysomya megacephala (F.) (Diptera: Calliphoridae) is a medically important blow fly species in many parts of the world. In this study, we examined the ovary of C. megacephala at the ultrastructural level using light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Dissection of the ovaries revealed eight stages of ovarian development, thus providing a means of estimation of the age of females based on this organ. In the initial stage I (day 0-2), freshly-emerged flies up to three days old each display piriform germaria while the follicles are not yet well differentiated. In stage II (day 3), each follicle is nearly spherical and sepa- rating from the germarium. During stage III (day 4), each follicle is now easily distinguished from the germarium and is only connected by a thin interfollicular stalk. The nurse cells are completely surrounded by the cuboidal epithelial follicular cells. In stage IV (day 5-6), each folli- cle is spherical and considerably enlarged; whereas, the nurse cells within are more differentiated into individual round inclusions and grouped in the follicle chamber. Stage V (day 7) marks appearance of the visible oocyte at the posterior pole of the follicle. During stage VI (day 8), each follicle displays oocyte expansion anteriorly to occupyfrom one-third to one-half of the total length. In stage VII (day 9) the oo- cyte characteristically fills the posterior two-thirds of the total length of the follicle and in the final stage VIII (day 10), each follicle is com- pletely filled by an oocyte and nurse cells have disappeared. The micropyle and narrow, elongate median area are clearly seen in this final stage. SEM images reveal that the ovary is covered by an ovarian envelope, which is tough and thickened in 3-day-old adult ovarioles; whereas, it becomes thin and fragile in 9-day-old adult ovarioles. TEM analysis of ovarioles of 3-day-old adult flies shows that cuboidal follic- ular cells containing large nuclei with visible fibrils of muscle simply encircle the large compartments of nurse cells; whereas, ovarioles of 7- day-old adult flies displayed a more completely developed enclosure for the developing oocyte. This was observed by the presence of the outermost follicular cell layer with underlying eggshell, vitelline envelope, trabecular layer, and layer of granular material that surrounded the innermost oocyte.

Effect of lead salts on phase, morphologies and photoluminescence of nanocrystalline PbMoO4 and PbWO4 synthesized by microwave radiation

Abstract PbMoO4 and PbWO4 were successfully synthesized by microwave radiation using different lead salts (acetate, chloride, nitrate and sulfate) and Na2MO4 (M = Mo, W) in propylene glycol. The products were characterized by X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM, TEM), Fourier transform infrared (FT-IR), Raman spectroscopy and photoluminescence (PL) spectroscopy. In this research, morphologies, crystallization and photoluminescence of the products were influenced by the kinetics of anions, including the detection of M–O (M = Mo, W) stretching modes in the (MO4)2− tetrahedrons. Photoluminescence of PbMoO4 synthesized from Pb(NO3)2 and of PbWO4 synthesized from PbCl2 showed the strongest blue emission due to the electronic diffusion in tetrahedrons at room temperature.