scholarly journals HISTOCHEMICAL INVESTIGATIONS OF A SILVER METHOD FOR AXONS

1959 ◽  
Vol 7 (2) ◽  
pp. 86-92 ◽  
Author(s):  
R. K. WINKELMANN ◽  
ROBERT W. SCHMIT
Keyword(s):  
Silver Oxide ◽  
Dark Field ◽  
Reducing Agent ◽  
Water Soluble ◽  
Silver Ion ◽  
General Distribution ◽  
Amine Groups ◽  
Solubility Studies ◽  
Sulfite Ion

Silver ion is not specific either in location or in action in the present silver method. Studies with radioactive silver, with the dark-field microscope, and with simple reducing solutions demonstrate a general distribution of silver ion in the impregnated tissue. Copper and mercury may be substituted for silver in the impregnating solution. A water-soluble aldehyde is necessary as a fixative. The substrate for staining appears to require the presence of protein-bound amine groups. The product-forming solution does not require the presence of a reducing agent. Sulfite ion is not necessary. All controllable sources of base that were utilized produced the histologic results. The product appears to be silver oxide in terms of the present solubility studies.

The structural basis for water exchange between the female cockroach (Blattella germanica) and her ootheca

2002 ◽  
Vol 205 (19) ◽  
pp. 2987-2996 ◽  
Author(s):  
Donald E. Mullins ◽  
K. June Mullins ◽  
Keith R. Tignor
Keyword(s):  
Water Balance ◽  
Water Exchange ◽  
Tritiated Water ◽  
Dark Field ◽  
Water Soluble ◽  
Structural Basis ◽  
Intimate Association ◽  
Low Humidity ◽  
Cockroach Blattella Germanica ◽  
Gravid Females

SUMMARY Female German cockroaches usually carry their oothecae until they hatch. The success of embryogenesis may be dependent on the water-balance relationship between females and their developing oothecae. Oothecae detached from females early in embryogenesis often fail to develop, especially in low-humidity environments. Experiments reported here using tritiated water have confirmed the transport of a significant amount of water to the ootheca from the female during embryogenesis; 18% of the tritiated water injected into gravid females was recovered in their oothecae after 24 h. We describe a structural basis of water absorption by the oothecae. An area located on the proximal end of the ootheca (adjacent to the `escutcheon-shaped vaginal imprint') contains small pores that penetrate the oothecal covering to access regions of the chorion lying beneath these pores. Experiments using microparabiotic chambers to examine transport of tritiated water and water-soluble materials across the escutcheon region of the oothecal covering, along with dark-field birefringent microscopy of the chorion, support the hypothesis that this chorionic network is capable of conducting water throughout the interior of the ootheca. Furthermore, the structural arrangement and intimate association of the female vestibulum with the oothecal pore field contained in the region of the escutcheon-shaped vaginal imprint appear to provide an efficient conduit to the chorion. The overall structural relationship might be a means for maintaining water balance between females and their oothecae during embryonic development. Evidence presented here supports observations that this species represents an important link in the transition from oviparity to ovoviviparity by internalization of cockroach oothecae.

Electrolytic Behavior Silver Microphases and Nanophases on the Graphite Electrode Surface

2016 ◽  
Vol 712 ◽  
pp. 117-122 ◽  
Author(s):  
Daria O. Perevezentseva ◽  
Eduard Gorchakov ◽  
Yulia A. Oskina
Keyword(s):  
Silver Nanoparticles ◽  
Silver Oxide ◽  
Graphite Electrode ◽  
Reducing Agent ◽  
Molar Ratio ◽  
Graphite Electrodes ◽  
Stepwise Mechanism ◽  
Voltage Curve ◽  
Current Voltage ◽  
Current Voltage Curve

The stepwise mechanism of electrooxidation and reduction of silver nanophases and microphases is proposed on the graphite electrodes surface in alkaline medium. The electrochemical splitting of silver nanophases peak is observed on the anodic branch of the cyclic current-voltage curve. There is the shoulder at E = 0.2 V on the he anodic branch of cyclic current-voltage curve. The appearance of additional cathodic wave at E = -0.08 V is observed on the cathodic branch of the cyclic current-voltage curve that is caused by the reduction of silver nanoparticles. The additional cathode maximum is represented at 0.3 V on the cathodic branch of the cylic current-voltage curves of only silver nanophases. This effect is associated the catalytic process of decomposition of hydrogen peroxide on silver nanoparticles surface. The offset of the cathodic maxima of current-voltage curves of silver nanophases obtained with an excess of a reducing agent are observed to more negative potentials. There is a significant decrease of the all currents maxima compared to silver nanophases obtained with an equal molar ratio of reactants. These results may be connected with the formation of silver oxide monolayers in the different oxidation in the presence of large amounts a reducing agent. The excess of the reducing agent required for the preparation of silver nanoparticles leads to decrease of the cathodic maximum of silver nanoparticles

INORGANIC SOIL PHOSPHORUS FRACTIONS OF SOME ONTARIO SOILS AS STUDIED USING ISOTOPIC EXCHANGE AND SOLUBILITY CRITERIA

1962 ◽  
Vol 42 (1) ◽  
pp. 150-156 ◽  
Author(s):  
A. F. MacKenzie
Keyword(s):  
Soil Solution ◽  
Isotopic Exchange ◽  
Soil Phosphorus ◽  
Low Ph ◽  
Water Soluble ◽  
Ph Values ◽  
Measurable Amount ◽  
P Fraction ◽  
Solubility Studies ◽  
Inorganic Phosphates

The water soluble and inorganic phosphates associated with aluminum (Al-P), iron (Fe-P) and calcium (Ca-P) were studied in eight Ontario soils. Isotopic exchange studies indicated that in most of the soils the Al-P fraction was in equilibrium with the water soluble phosphorus. Exceptions were thought to be a result of high or low pH values. Solubility studies in 0.01M CaCl2 indicated that the Al-P fraction supplied most of the phosphorus to the soil solution. In one soil the Fe-P fraction may have supplied a measurable amount of phosphorus to the soil solution also.

Gram scale synthesis of specialized pro-resolving mediator 17( S )-HDHA using lipoxygenase enhanced by water-soluble reducing agent TCEP

2016 ◽  
Vol 26 (2) ◽  
pp. 343-345 ◽  
Author(s):  
Toshimasa Itoh ◽  
Tomoko Saito ◽  
Yoshinori Yamamoto ◽  
Hiroaki Ishida ◽  
Keiko Yamamoto
Keyword(s):  
Reducing Agent ◽  
Water Soluble

Two new water-soluble derivatives of 1,3,5-triaza-7-phosphaadamantane (PTA): Synthesis, characterization, X-ray analysis and solubility studies of 3,7-diformyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane and 1-pyridylmethyl-3,5-diaza-1-azonia-7-phosphatricyclo[3.3.1.1]decane bromide

Polyhedron ◽  
2007 ◽  
Vol 26 (15) ◽  
pp. 4093-4100 ◽  
Author(s):  
Donald Alan Krogstad ◽  
Gordon S. Ellis ◽  
Andrew K. Gunderson ◽  
Alyssa J. Hammrich ◽  
Joseph W. Rudolf ◽  
...  
Keyword(s):  
Water Soluble ◽  
X Ray ◽  
Solubility Studies ◽  
Derivatives Of

scholarly journals Improvements of synergetic aerosol retrieval for ENVISAT

2008 ◽  
Vol 8 (24) ◽  
pp. 7651-7672 ◽  
Author(s):  
T. Holzer-Popp ◽  
M. Schroedter-Homscheidt ◽  
H. Breitkreuz ◽  
D. Martynenko ◽  
L. Klüser
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Surface Brightness ◽  
Dark Field ◽  
Water Soluble ◽  
Aerosol Composition ◽  
Aerosol Retrieval ◽  
First Case ◽  
Satellite Platform ◽  
Version 2.0

Abstract. The synergetic aerosol retrieval method SYNAER (Holzer-Popp et al., 2002a) has been extended to the use of ENVISAT measurements. It exploits the complementary information of a radiometer and a spectrometer onboard one satellite platform to extract aerosol optical depth (AOD) and speciation (as a choice from a representative set of pre-defined mixtures of water-soluble, soot, mineral dust, and sea salt components). SYNAER consists of two retrieval steps. In the first step the radiometer is used for accurate cloud screening, and subsequently to quantify the aerosol optical depth (AOD) at 550 nm and spectral surface brightness through a dark field technique for different pre-defined aerosol mixtures. In the second step the spectrometer is applied to choose the most plausible aerosol mixture through a least square fit of the measured spectrum with simulated spectra using the mixture-dependent values of AOD and surface brightness retrieved in the first step. This method was developed and a first case study evaluation against few (15) multi-spectral ground-based AERONET sun photometer observations was conducted with a sensor pair (ATSR-2 and GOME) onboard ERS-2. Due to instrumental limitations the coverage of SYNAER/ERS-2 is very sparse. Therefore, SYNAER was transferred to similar sensors AATSR and SCIAMACHY onboard ENVISAT. While transferring to the new sensor pair significant improvements in the methodology were made based on a thorough evaluation of the methodology: (1) an update of the aerosol model, (2) improved cloud detection in the tropics and sub tropics, and (3) an enhanced dark field albedo characterization. This paper describes these improvements in detail and assesses their combined impact on the results. After a brief assessment of atmospheric noise impact on comparisons of pixel and station measurements a validation against ground-based measurements establishes error bars for the SYNAER/ENVISAT method version 2.0. A theoretical analysis of the information content with regard to aerosol composition (second retrieval step) is presented to quantify the potential and limitations of this new capability provided by the SYNAER method. Building on this analysis, first seasonal and monthly composition results calculated by applying SYNAER version 2.0 to AATSR and SCIAMACHY are shown to demonstrate the potential of the approach. An inter-comparison to earlier results of SYNAER version 1.0 is made for both the validation and the example datasets.

Novel Water-Soluble Organosilane Compounds as a Radical Reducing Agent in Aqueous Media

1997 ◽  
Vol 70 (10) ◽  
pp. 2519-2523 ◽  
Author(s):  
Osamu Yamazaki ◽  
Hideo Togo ◽  
Genki Nogami ◽  
Masataka Yokoyama
Keyword(s):  
Aqueous Media ◽  
Reducing Agent ◽  
Water Soluble

Bi[3,5-dimethyl-5-(hydroxymethyl)-2-oxomorpholin-3-yl] (DHM-3 dimer). A water-soluble, one-electron reducing agent

1987 ◽  
Vol 52 (14) ◽  
pp. 3073-3081 ◽  
Author(s):  
Giorgio Gaudiano ◽  
Tad H. Koch
Keyword(s):  
Reducing Agent ◽  
Water Soluble

Reactions of Chloramines with Ag(0) and Ag(I) States

1972 ◽  
Vol 50 (8) ◽  
pp. 1167-1180 ◽  
Author(s):  
O. E. Edwards ◽  
D. Vocelle ◽  
J. W. ApSimon
Keyword(s):  
Silver Oxide ◽  
Silver Ions ◽  
Silver Ion ◽  
Short Chain ◽  
Ferrous Ion ◽  
Metallic Silver ◽  
Nitrenium Ions ◽  
Homolytic Decomposition ◽  
Nitrogen Radicals ◽  
Silver Metal

Reactions of N-chloroazacyclooctane and N-chloroazacyclononane are described which give good yields of bicyclic amines. These are: (a) short chain homolytic reactions involving neutral nitrogen radicals initiated by ferrous ion or metallic silver; (b) apparent homogeneous reactions involving silver ion and bases; (c) reactions using silver oxide suspension which also require added bases.Both rate and product composition for (b) and (c) are sensitive to oxygen indicating that they are homolytic processes, probably initiated by traces of silver metal. No evidence for involvement of discrete nitrenium ions was found. However, reaction of N-chloroisoquinuclidine with silver ions has the character of a heterolytic process, giving products completely distinct from those from its homolytic decomposition. The addition of neutral piperidino radicals to styrene is described.

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