Schistosoma mansoni: tail loss in relation to permeability changes during cercaria–schistosomulum transformation

Parasitology ◽  
1975 ◽  
Vol 71 (1) ◽  
pp. 9-18 ◽  
Author(s):  
R. E. Howells ◽  
S. E. Gerken ◽  
F. J. Pinto-Ramalho ◽  
U. Kawazoe ◽  
G. Gazzinelli ◽  
...  
Keyword(s):  
Amino Acids ◽  
Methylene Blue ◽  
Schistosoma Mansoni ◽  
Body Region ◽  
Experimental Conditions ◽  
General Body ◽  
Tail Loss ◽  
Permeability Changes ◽  
Extensive Lesion ◽  
Scanning Electron

The hind-body region of Schistosoma mansoni cercariae observed in the scanning electron microscope demonstrates various stages of contraction which may be compared with those of living larvae which are secreting the acetabular gland contents.No evidence for an extensive lesion was found in cercarial bodies which had shed their tails under experimental conditions. Experiments on the permeability of the larvae to sodium fluoride, methylene blue and amino acids demonstrated that tail loss significantly affects the permeability of the bodies although the effect is greater immediately after decaudation than at later times. Subsequent increases in permeability may be correlated with a change in the general body surface.

Delayed tail loss during the invasion of mouse skin by cercariae of Schistosoma japonicum

Parasitology ◽  
2011 ◽  
Vol 139 (2) ◽  
pp. 244-247 ◽  
Author(s):  
TING WANG ◽  
ZHENG-MING FANG ◽  
JIA-HUI LEI ◽  
FEI GUAN ◽  
WEN-QI LIU ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Schistosoma Japonicum ◽  
Human Skin ◽  
Mouse Skin ◽  
Density Range ◽  
Experimental Conditions ◽  
Density Dependent ◽  
Tail Loss ◽  
Traditional Assumption

SUMMARYA traditional assumption is that schistosome cercariae lose their tails at the onset of penetration. It has, however, recently been demonstrated that, for Schistosoma mansoni, cercarial tails were not invariably being shed as penetration took place and a high proportion of tails entered human skin under experimental conditions. This phenomenon was termed delayed tail loss (DTL). In this paper, we report that DTL also happens with S. japonicum cercariae during penetration of mouse skin. It occurred at all cercarial densities tested, from as few as 10 cercariae/2·25 cm2 of mouse skin up to 200 cercariae. Furthermore, it was demonstrated that there was a density-dependent increase in DTL as cercarial densities increased. No such density-dependent enhancement was shown for percentage attachment over the same cercarial density range.

Photocatalytic Degradation of Methylene Blue over Co-Ag3VO4 under Visible Light Irradiation

2011 ◽  
Vol 335-336 ◽  
pp. 1385-1390 ◽  
Author(s):  
Shuo Wiei Zhao ◽  
Hui Xu ◽  
Hua Ming Li ◽  
Yuan Guo Xu
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Absorption Edge ◽  
Diffuse Reflectance Spectroscopy ◽  
Dye Degradation ◽  
Light Irradiation ◽  
Experimental Conditions ◽  
X Ray

In order to improve the photocatalytic activity, Co was successfully loaded into Ag3VO4 by using impregnation process. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS) and diffuse reflectance spectroscopy (DRS). The XRD and SEM–EDS analyses revealed that Co ion was dispersed on Ag3VO4. The DRS results indicated that the absorption edge of the Co–Ag3VO4 catalyst shifted to longer wavelength. The enhanced photocatalytic activity of Co–Ag3VO4 for Methylene Blue(MB) dye degradation under visible light irradiation was due to its wider absorption edge and higher separation rate of photo-generated electron and holes. In the experimental conditions, it is demonstrated that the MB was effectively degraded by more than 95% within 40 min when the Co–Ag3VO4 catalyst was calcined at 300°C with 1 wt.% Co content.

Synthesis of Visible-Light Responsive CdS/ZnO Nanocomposite Photocatalysts via Simple Precipitation Method

2014 ◽  
Vol 608 ◽  
pp. 224-229 ◽  
Author(s):  
Potjanaporn Chaengchawi ◽  
Karn Serivalsatit ◽  
Pornapa Sujaridworakun
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Photocatalytic Performance ◽  
Precipitation Method ◽  
Cds Nanoparticles ◽  
Methylene Blue Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Blue Solution ◽  
Scanning Electron

A visible-light responsive CdS/ZnO nanocomposite photocatalyst was successfully synthesized by precipitation of CdS nanoparticles, using Cd (NO3)2 and Na2S as starting materials, on ZnO nanoparticles and then calcined at 400°C for 2 hours. The effects of the mole ratio of CdS and ZnO in the composites on their phase, morphology, and surface area were investigated by X-ray Diffraction (XRD), scanning electron microscope (SEM), Brunauer Emmett Teller method (BET), respectively. The photocatalytic degradation of methylene blue solution in the presence of composite products under visible-light irradiation was investigated. The results showed that the mole ratio of CdS and ZnO played a significant role on photocatalytic performance. The highest photocatalytic activity was obtained from the CdS/ZnO nanocomposite with mole ratio of 1:4, which is higher than that of pure CdS and pure ZnO.

Toward standards in practices and techniques on ootaxonomy in the Pieridae (Lepidoptera: Papilionoidea)

Zootaxa ◽  
2021 ◽  
Vol 4985 (3) ◽  
Author(s):  
SANDRA NIEVES-URIBE ◽  
JORGE LLORENTE-BOUSQUETS ◽  
ADRIÁN FLORES-GALLARDO
Keyword(s):  
Methylene Blue ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Graphic Representation ◽  
Blue Staining ◽  
Detailed Data ◽  
Staining Techniques ◽  
General Aspects ◽  
Scanning Electron

We present a proposal on the standards used on ootaxonomy practices and techniques in the butterfly family Pieridae Duponchel (Lepidoptera: Papilionoidea) in five stages: 1) getting the specimens, 2) integration into a collection, 3) dissections to recover the exochorion, 4) elaboration of images of it, and 5) the preparation of its description with the necessary diagrams and tabulations. Also, we present the detailed techniques applied in observation and graphic representation, based on the methylene blue staining techniques and those required for the use with the scanning electron microscope (SEM). We compare the result of the standardized techniques with those from macro photography, drawings, and photographs with SEM—all of them found in books with descriptions and images of eggs of the Pieridae. We present a glossary and general aspects of the exochorion in the Pieridae as an Appendix to this article. Standardized techniques show more accurate and extensive character retrieval for systematics. For the scale in which they work, these techniques recovered more information than those present from oviposited eggs, where the exochorionic base is not seen. Also, the descriptions contain detailed data on more structures—which are comparable to each other—than are absent in the references mentioned. We present the recovered characters with the techniques found in the literature as three synthetically supplementary materials.

scholarly journals Plant growth and solute accumulation and distribution in two sorghum genotypes, under NaCl stress

2001 ◽  
Vol 13 (3) ◽  
pp. 270-284 ◽  
Author(s):  
CLAUDIVAN FEITOSA DE LACERDA ◽  
JOSÉ CAMBRAIA ◽  
MARCO ANTONIO OLIVA CANO ◽  
HUGO ALBERTO RUIZ
Keyword(s):  
Amino Acids ◽  
Root System ◽  
Nacl Stress ◽  
Soluble Carbohydrates ◽  
Saline Stress ◽  
Organic Solutes ◽  
Experimental Conditions ◽  
Absolute Increase ◽  
Sorghum Genotypes ◽  
Sensitive Genotype

Seedlings of two sorghum (Sorghum bicolor (L.) Moench) genotypes with differential tolerance to salinity were exposed to 0 and 100 mM NaCl, gradually added in increments of 25 mM every 12 hours, in nutrient solution. Seven days after starting the salt treatment the growth of the shoot and root system and the inorganic and organic solutes contents were determined. Salinity reduced the dry matter yield and length of the shoot and root system in both sorghum genotypes, specially in the sensitive one. In general, it was observed an increase in Na+ and Cl- transfer to the shoot, in Na+ and Cl- accumulation and in the Na+/Cl- ratio but a decrease in the K+ and Ca2+ transfer to shoot and in the K+ and Ca2+ contents in the shoot, always with higher intensity in sensitive genotype. Apparently, the tolerance to high saline concentrations in sorghum seems to be related to the genotype ability to avoid accumulation of harmful levels of Na+ and Cl- and, or to maintain adequate levels of K+ and Ca2+, specially in the shoot. The soluble carbohydrates and amino acids constituted together over 98% of the total organic solutes and showed the greatest absolute increase in concentration during saline stress. Probably, the soluble carbohydrates were the most important organic solutes to contribute to the osmotic adjustment in the leaves and the amino acids in the roots. Under saline stress there was an expressive increase in proline contents, specially in the oldest leaves of sensitive genotype. The proline contents, however, even under salt stress, did not reach the levels of other organic solutes. Contrary to the general acceptance, proline does not seem to have an important role in the mechanism of salt tolerance, at least for these genotypes and under the experimental conditions applied here.

The Photoluminescence Spectra Research of SiC Thin Film under Different Sputtering Powers

2019 ◽  
Vol 295 ◽  
pp. 93-97
Author(s):  
Chang Zhao ◽  
Man Zhao ◽  
Su Ye Lv ◽  
Qing Jun Liu ◽  
Guang Jian Xing
Keyword(s):  
Thin Film ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Crystal Morphology ◽  
Growth Conditions ◽  
Photoluminescence Spectra ◽  
Experimental Conditions ◽  
Grain Sizes ◽  
Power Inputs ◽  
Scanning Electron

This study prepared an SiC thin film by using the ratio frequency magnetron sputtering method, investigated the effects of different sputtering powers on the SiC material and analysed the changes in crystal morphology and photoluminescence characteristics caused by changes in the growth conditions used. It was considered that there was 6H-SiC crystal morphologies in the SiC thin film under the experimental conditions prevailing in this study. The SiC morphologies with small grain sizes intermingled and therefore formed anSiC thin film. The analyses of the photoluminescence spectra and Scanning Electron Microscope indicated that the SiC thin film materials with preferable crystal compositions could be prepared under appropriate power inputs.

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