scholarly journals The infection of human skin by schistosome cercariae: studies using Franz cells

Parasitology ◽  
2000 ◽  
Vol 121 (1) ◽  
pp. 49-54 ◽  
Author(s):  
A. BARTLETT ◽  
M. BROWN ◽  
C. MARRIOTT ◽  
P. J. WHITFIELD
Keyword(s):  
Human Skin ◽  
Cosmetic Surgery ◽  
Temporal Dynamics ◽  
Fluid Phase ◽  
Epidermal Surface ◽  
Franz Cells ◽  
Early Interaction ◽  
Physical And Chemical ◽  
First Time ◽  
Early Phases

Franz cells (2-chambered, air/fluid phase static diffusion devices, previously used for the study of drugs across viable human skin) are utilized for the first time to investigate the process of infection of human skin by Schistosoma mansoni cercariae. Skin obtained from cosmetic surgery sources was used in the Franz cells to describe the temporal dynamics of the early interaction of cercariae with skin. At 38 °C, about 50% of cercariae applied in water to the epidermal surface of the skin were irreversibly attached within 1 min and after 5 min about 85% were similarly irrecoverable. The technique also provides the means of following the early penetration path of cercariae by histological methods. Franz cell results on the dynamics of attachment/early penetration have been compared with those obtained using artificial skin equivalents and non-human mammalian skin models in the context of the physical and chemical differences between these systems and viable human skin. It is concluded that Franz cells provide a convenient system for directly investigating the early phases of S. mansoni cercariae interaction with human skin.

Effects of physical and chemical treatments upon biophysical properties and micro-relief of human skin

2008 ◽  
Vol 300 (5) ◽  
pp. 243-251 ◽  
Author(s):  
Nicolas Atrux-Tallau ◽  
Ngoc T. T. Huynh ◽  
Laurie Gardette ◽  
Cyril Pailler-Mattéi ◽  
Hassan Zahouani ◽  
...  
Keyword(s):  
Human Skin ◽  
Biophysical Properties ◽  
Chemical Treatments ◽  
Physical And Chemical

scholarly journals First record of Dero (Aulophorus) bimagnasetus Harman (Oligochaeta) from Brazil and habitat characteristics

2014 ◽  
Vol 74 (2) ◽  
pp. 483-488
Author(s):  
R. Campitelli-Ramos ◽  
JV. Lucca ◽  
LLD. Oliveira ◽  
MR. Marchese ◽  
O. Rocha
Keyword(s):  
Benthic Communities ◽  
First Record ◽  
Biological Data ◽  
Habitat Characteristics ◽  
Low Oxygen ◽  
Body Width ◽  
Ecological Information ◽  
Freshwater Biota ◽  
Physical And Chemical ◽  
First Time

Annelid worms represent a significant part of freshwater benthic communities worldwide and Oligochaeta is a particularly species-rich group. Dero (A) bimagnasetus (Naididae) previously found and described from a small marsh in Surinam in 1974, has now been found for the first time in Barra Lake, MG, Brazil. Due to the scarce biological data and absence of ecological information in the literature regarding this species we are presenting morphological information on the specimens obtained and the physical and chemical characteristics of the habitat they were found. This species occurred only in the littoral zone of Barra Lake, in muddy, low oxygen, low conductivity and low organic matter sediment. The four individuals collected ranged 3.17-4.15 mm total length; 0.25 - 0.26 mm body width and 0.16-0.21 mm3 total volume. Considering the present anthropic pressures on freshwater biota and fast biodiversity losses worldwide it is now recognized that attention must be paid to low abundance species and the urgency for preservation of their habitats.

scholarly journals The first report of ants (Formicidae: Hymenoptera) in salt marshes and salt pans in central parts of Iran

2019 ◽  
Vol 20 (9) ◽  
Author(s):  
MOHAMMAD REZA MOHSENI ◽  
SHAHROKH PASHAEI RAD
Keyword(s):  
Salt Marshes ◽  
Dominant Species ◽  
Salt Lake ◽  
Vegetation Density ◽  
Chemical Parameters ◽  
Salt Pans ◽  
Mountain Station ◽  
Physical And Chemical Parameters ◽  
Physical And Chemical ◽  
First Time

The present study was conducted in Salt marshes and Salt pans in central parts of Iran. 121 specimens of ants were collected by trapping and hand during spring, summer and autumn 2017 to 2019. Nine species belong to two subfamilies of Myrmicinae and Formicinae were identified. The vegetation, physical and chemical parameters of soil such as salinity, Ph, and other factors were investigated. Darband Shoor Mountain station with five species had the highest diversity and vegetation density and the lowest salinity of soil (72.14 ds/m) whereas Salt Lake station had only one species, with no vegetation and the highest salinity of soil (153.15 ds/m). Cataglyphis lividus (André, 1881) was the dominant species in all the stations except in Darband Shoor Mountain station. All the species were reported for the first time from salt marshes and salt pans in the central parts of Iran and were approved by Prof. Brian Taylor, in Royal Entomological Society of London, England.

scholarly journals A Study of Zooplankton Community in Dukan Lake, Kurdistan Region-Iraq, with a New Record of Craspedacusta sowerbii Lankester (1880) Medusa (Cnidaria: Hydrozoa)

2017 ◽  
Vol 14 (4) ◽  
pp. 735-741 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Similarity Index ◽  
Chemical Properties ◽  
Zooplankton Community ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Alkaline Side ◽  
Physical And Chemical ◽  
First Time ◽  
Jaccard's Similarity Index ◽  
And Chemical Properties

A study of Zooplankton community has been carried out at four selected sites on Dukan Lake. Samples of water and zooplankton were collected monthly for the period from July 2015 to February 2016. Some physical and chemical properties of water were studied and the results showed that the air temperature were ranged from 0 to 36.16 °C, water temperature ranged from 2.83 to 34.66 °C, hydrogen ion concentration of studied sites were found to lie in alkaline side, it was ranged between 6.87 to 8.57, electrical conductivity ranged from 190.79 to 850.08 µs.cm­¹, turbidity ranged from 0.9-7.7 NTU, and dissolved oxygen from 3.3 to 6.8 mg.l-¹ while BOD5 were ranged from 0.53 to 34.66 mg.l-¹. Concerning to the zooplankton, 37 species were identified which belonged to Cladocera (48.38%), Copepod (43.28%), Rotifera (8.23%), Targigrada (0.08%) and Cnidaria (0.1%). The medusa of Craspedacusta sowerbii Lankester (1880) was recorded for the first time in Iraq. Regarding to zooplankton community, rotifer were ranged between 0 to 690.91 ind.m-3, Copepoda from 54.55 to 5927.27 ind.m-3 and Cladocera ranged from 18.18 to 6072.73 ind.m-3. According to Shanon-Weiner index, species diversity for zooplankton invertebrates was ranged from 0.325 to 1.091 bits/ind. Jaccard’s similarity index showed that the highest similarity was recorded between site (1) and site (4) with 40.74%.

Sla1p couples the yeast endocytic machinery to proteins regulating actin dynamics

2002 ◽  
Vol 115 (8) ◽  
pp. 1703-1715 ◽  
Author(s):  
Derek T. Warren ◽  
Paul D. Andrews ◽  
Campbell W. Gourlay ◽  
Kathryn R. Ayscough
Keyword(s):  
Immunofluorescence Microscopy ◽  
Fluid Phase ◽  
Actin Dynamics ◽  
Cell Cortex ◽  
Cortical Actin ◽  
Binding Studies ◽  
Endocytic Machinery ◽  
Single Complex ◽  
Actin Patch ◽  
First Time

Sla1p is a protein required for cortical actin patch structure and organisation in budding yeast. Here we use a combination of immunofluorescence microscopy and biochemical approaches to demonstrate interactions of Sla1p both with proteins regulating actin dynamics and with proteins required for endocytosis. Using Sla1p-binding studies we reveal association of Sla1p with two proteins known to be important for activation of the Arp2/3 complex in yeast, Abp1p and the yeast WASP homologue Las17p/Bee1p. A recent report of Sla1p association with Pan1p puts Sla1p in the currently unique position of being the only yeast protein known to interact with all three known Arp2/3-activating proteins in yeast. Localisation of Sla1p at the cell cortex is, however, dependent on the EH-domain-containing protein End3p, which is part of the yeast endocytic machinery. Using spectral variants of GFP on Sla1p(YFP) and on Abp1p (CFP) we show for the first time that these proteins can exist in discrete complexes at the cell cortex. However, the detection of a significant FRET signal means that these proteins also come close together in a single complex, and it is in this larger complex that we propose that Sla1p binding to Abp1p and Las17p/Bee1p is able to link actin dynamics to the endocytic machinery. Finally, we demonstrate marked defects in both fluid-phase and receptor-mediated endocytosis in cells that do not express SLA1, indicating that Sla1p is central to the requirement in yeast to couple endocytosis with the actin cytoskeleton.

Physical and chemical aspects of the development of overpressuring in sedimentary environments

Clay Minerals ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 425-437 ◽  
Author(s):  
P. L. Hall
Keyword(s):  
Fluid Pressure ◽  
Sediment Thickness ◽  
Volume Changes ◽  
Sedimentary Environments ◽  
Vertical Permeability ◽  
Burial Rate ◽  
Long Time ◽  
Physical And Chemical ◽  
First Time ◽  
Applied Stresses

AbstractFluid pressures in argillaceous sediments depend on, inter alia, mechanical stresses, temperature, diagenetic volume changes and permeability. However, the relative influence of the pressuring mechanisms depends critically upon the long time-scale compliance, C, of the overpressured layer.In sediments undergoing first-time burial and currently exposed to their historically maximum applied stresses, C can be relatively large. Here, fluid pressure increases are principally due to mechanical causes, and overpressuring will be associated with undercompaction. The tendency for undercompaction (compaction disequilibrium) depends on the sediment thickness, burial rate and vertical permeability. In other cases, when applied stresses have been reduced by uplift, or when impermeable hard caps or seals have been formed, C may be substantially smaller. Here pore pressures may be predominantly controlled by diagenetic and aquathermal processes, with mechanical (undercompaction) phenomena being relatively less significant.Three-dimensionally sealed overpressured zones may exhibit vertical fluid pressure discontinuities. Within a sealed aquifer, fluid pressures may rise to almost lithostatic values, relieved by episodic fracturing of the seal.

Friction Behavior of CMP Slurries Based on Novel Organic Particles

2005 ◽  
Author(s):  
Yuzhuo Li ◽  
Ning Wang
Keyword(s):  
Removal Rate ◽  
Dielectric Materials ◽  
Friction Behavior ◽  
Abrasive Particles ◽  
Added Benefit ◽  
Increasing Demand ◽  
Organic Particles ◽  
Physical And Chemical ◽  
The Impact ◽  
First Time

With the integration of copper as interconnect and low k materials as dielectric, the CMP community is facing an ever increasing demand on reducing defectivity without scarifying production throughput. One such strategy is to significantly lower the polishing pressure to below 1 psi. Such a move has placed tremendous challenges to the tool manufactures, consumable suppliers (especially the slurry vendors), and end-users. It is a challenge to remain the high throughput (MRR and selectivity) at low down force without using harsh abrasives. For the first time, we recently report the use of novel hydrophilic organic particles for metal CMP. Unlike conventional abrasive particles such silica or alumina, these unique particles are designed to specifically interact with the metal surface to be polished and significantly modify the rheological behavior of the slurry. The obvious advantage of using such particles is the reduction of defects during CMP. The consequence of using such particles is also its ability to provide unsurpassed high selectivity in removal rate for copper over barrier and dielectric materials due to their weak interaction with these particles. The added benefit for slurry that uses such particles is to allow CMP process conducted at a lower down force without compromising the throughput. In this talk, some basic physical and chemical characteristics of the particles and slurry will be first presented. The friction beavior of these new slurries in relation to conventional slurries on blanket wafers will be discussed. The impact of particle hydrophobicity on the friction behviors of the slurries will be explored.

scholarly journals Composition of Essential Oils from Leaves and Flowers of Stachys Germanica Subsp. Salviifolia (Ten.) Gams (Labiatae) and Related Secretory Structures

2009 ◽  
Vol 4 (6) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Claudia Giuliani ◽  
Roberto Maria Pellegrino ◽  
Bruno Tirillini ◽  
Laura Maleci Bini
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Glandular Trichomes ◽  
Secretory Structures ◽  
Epidermal Surface ◽  
Germacrene D ◽  
Different Types ◽  
Leaf Oil ◽  
Leaf Essential Oil ◽  
First Time

The essential oils from both leaves (L) and flowers (F) of Stachys germanica subsp. salviifolia (Ten.) Gams (Labiatae/Lamiaceae) from Italy were analyzed by GC-MS for the first time. The distribution, morphology and histochemistry of the different types of glandular trichomes present on the epidermal surface were also determined. Twenty-nine constituents, representing 89.4% of the total leaf oil, and forty-one compounds, forming 97.8% of the total flower oil, were identified. Germacrene D (39.4%), phytol (10.2%), β-bourbonene (3.5%) and β-ylangene (3.3%) were recognized as the main constituents of the leaf essential oil, while limonene (24.1%), β-pinene (18.7%), germacrene D (12.8%) and ( E)-nerolidol (6.6%) were the main compounds of the flower essential oil.

Effect of silver nanoparticles on human primary keratinocytes

2013 ◽  
Vol 394 (1) ◽  
pp. 113-123 ◽  
Author(s):  
Radoslaw Szmyd ◽  
Anna Grazyna Goralczyk ◽  
Lukasz Skalniak ◽  
Agnieszka Cierniak ◽  
Barbara Lipert ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Chemical Properties ◽  
Wound Dressings ◽  
Epidermal Keratinocytes ◽  
Primary Keratinocytes ◽  
Human Epidermal Keratinocytes ◽  
Normal Human ◽  
Physical And Chemical ◽  
First Time ◽  
Human Primary Keratinocytes

Abstract Silver nanoparticles (AgNPs) have many biological applications in biomedicine, biotechnology and other life sciences. Depending on the size, shape and the type of carrier, AgNPs demonstrate different physical and chemical properties. AgNPs have strong antimicrobial, antiviral and antifungal activity, thus they are used extensively in a range of medical settings, particularly in wound dressings but also in cosmetics. This study was undertaken to examine the potential toxic effects of 15 nm polyvinylpyrrolidone-coated AgNPs on primary normal human epidermal keratinocytes (NHEK). Cells were treated with different concentrations of AgNPs and then cell viability, metabolic activity and other biological and biochemical aspects of keratinocytes functioning were studied. We observed that AgNPs decrease keratinocyte viability, metabolism and also proliferatory and migratory potential of these cells. Moreover, longer exposure resulted in activation of caspase 3/7 and DNA damage. Our studies show for the first time, that AgNPs may present possible danger for primary keratinocytes, concerning activation of genotoxic and cytotoxic processes depending on the concentration.

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