Osmotically induced volume changes in protoplasts isolated from Cucurbita ficifolia

1982 ◽  
Vol 60 (5) ◽  
pp. 730-736 ◽  
Author(s):  
M. T. Tyree ◽  
S. Salleo ◽  
M. A. LoGullo ◽  
G. F. Barclay ◽  
A. Salleo ◽  
...  
Keyword(s):  
High Capacity ◽  
Volume Changes ◽  
Bathing Medium ◽  
Large Coupling ◽  
Membrane Bound ◽  
Free Membrane ◽  
Transvacuolar Strands ◽  
Cucurbita Ficifolia ◽  
Solute Transporters ◽  
Stem Segments

Free membrane-bound protoplasts are formed when turgid stem segments are cross-sectioned into 2-mm-thick slices and placed in a nonplasmolysing solution of electrolyte or mannitol. The protoplasts range in diameter from less than 5 μm to a few more than 80 μm. The larger protoplasts contain a fuller complement of organelles than the small ones, and some large protoplasts form transvacuolar strands and restart cyclosis after 2 to 3 days. The protoplasts change diameter when they are exposed to fusicoccin or 2,4-dinitrophenol; from this we conclude that some of the solute transporters in the bounding membranes are still functioning. The pattern of swelling and shrinking of the protoplasts in response to the change in concentration and composition of the bathing medium leads us to believe that the membranes are very leaky to solutes causing a large coupling between solute and water flow. In addition high capacity net ion transport occurs at rates of up to 2 μosmol∙s−1∙m−2 causing shrinkage of the protoplasts in hypotonic KCl solution even though osmotic considerations force the prediction that the protoplasts will swell. Ion transporters working at the net rate of 0.5 μosmol∙s−1∙m−2 also appear to be responsible for swelling of protoplasts that previously shrank in hypertonic KCl or NaCl.

scholarly journals Polymer Binders: Characterization and Development toward Aqueous Electrode Fabrication for Sustainability

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 631
Author(s):  
Aleksander Cholewinski ◽  
Pengxiang Si ◽  
Marianna Uceda ◽  
Michael Pope ◽  
Boxin Zhao
Keyword(s):  
Energy Storage ◽  
Electrode Materials ◽  
Storage Systems ◽  
High Capacity ◽  
Energy Storage Systems ◽  
Volume Changes ◽  
Polymer Binders ◽  
Aqueous Conditions ◽  
Aqueous Binder ◽  
Electrode Processing

Binders play an important role in electrode processing for energy storage systems. While conventional binders often require hazardous and costly organic solvents, there has been increasing development toward greener and less expensive binders, with a focus on those that can be processed in aqueous conditions. Due to their functional groups, many of these aqueous binders offer further beneficial properties, such as higher adhesion to withstand the large volume changes of several high-capacity electrode materials. In this review, we first discuss the roles of binders in the construction of electrodes, particularly for energy storage systems, summarize typical binder characterization techniques, and then highlight the recent advances on aqueous binder systems, aiming to provide a stepping stone for the development of polymer binders with better sustainability and improved functionalities.

Two-dimensional SnS2@PANI nanoplates with high capacity and excellent stability for lithium-ion batteries

2015 ◽  
Vol 3 (7) ◽  
pp. 3659-3666 ◽  
Author(s):  
Gang Wang ◽  
Jun Peng ◽  
Lili Zhang ◽  
Jun Zhang ◽  
Bin Dai ◽  
...  
Keyword(s):  
Electron Transport ◽  
Lithium Ion Batteries ◽  
Electrode Materials ◽  
High Capacity ◽  
Lithium Ion ◽  
Two Dimensional ◽  
Volume Changes ◽  
Nanostructured Electrode ◽  
Charge Discharge ◽  
Excellent Stability

Nanostructured electrode materials have been extensively studied with the aim of enhancing lithium ion and electron transport and lowering the stress caused by their volume changes during the charge–discharge processes of electrodes in lithium-ion batteries.

High capacity, power density and cycling stability of silicon Li-ion battery anodes with a few layer black phosphorus additive

2019 ◽  
Vol 3 (1) ◽  
pp. 245-250 ◽  
Author(s):  
Kingshuk Roy ◽  
Malik Wahid ◽  
Dhanya Puthusseri ◽  
Apurva Patrike ◽  
Subas Muduli ◽  
...  
Keyword(s):  
Power Density ◽  
Anode Material ◽  
High Capacity ◽  
Black Phosphorus ◽  
Cycling Stability ◽  
Li Ion Battery ◽  
Volume Changes ◽  
High Theoretical Capacity ◽  
Li Ion ◽  
Battery Anode

The exceptionally high theoretical capacity of silicon as a Li-ion battery anode material is hard to realize and stabilize in practice due to huge volume changes during lithiation/de-lithiation. With the use of black phosphorus additive we could achieve tremendous stability due to strain management.

Transport and hydrolysis of glucagon in the proximal nephron

1986 ◽  
Vol 251 (3) ◽  
pp. F460-F467 ◽  
Author(s):  
D. R. Peterson ◽  
E. A. Green ◽  
S. Oparil ◽  
J. T. Hjelle
Keyword(s):  
Proximal Tubule ◽  
Brush Border ◽  
High Capacity ◽  
Cell Fractionation ◽  
Bathing Medium ◽  
Proximal Tubule Cells ◽  
Large Peak ◽  
Hydrolysis Of ◽  
Contraluminal Membrane

Transport and hydrolysis of glucagon in the rabbit proximal nephron were studied. Iodinated glucagon (0.34 +/- 0.02 pg/nl, mean +/- SE) was microperfused (16.0 +/- 1.1 nl/min) in vitro through proximal straight nephron segments for 30 min. Radiolabeled material, primarily 125I-tyrosine, appeared in the bathing medium in a linear fashion as a function of time (0.406 pg glucagon X mm tubule length-1 X min-1). Hydrolysis of glucagon by proximal tubule homogenates was pH dependent, with a large peak of activity observed at pH 7.0-7.4 and a smaller one at pH 3.0. Analytical cell fractionation studies of proximal tubule cells revealed glucagon-hydrolyzing activity associated with the brush border and cytosol at pH 7.4. Less than 3% of activity was found associated with the contraluminal membrane. Substantial catabolism was observed at lysosomes on lowering the pH to 5.0. Incubation of glucagon directly in the presence of isolated renal cortical microvilli confirmed the presence of a high-capacity glucagon-degrading hydrolase. In addition to glucagon-hydrolyzing activity associated with the proximal nephron, noncortical activity was observed that was not accounted for by proximal tubule hydrolases. The data suggest several mechanisms for renal extraction of glucagon, including hydrolysis by enzymes at the brush border of the proximal tubule, prior to reabsorption of metabolites there. Conversely, enzymes associated with the contraluminal membrane of the proximal nephron probably contribute little to its hydrolysis. Nonproximal extracortical degradation of glucagon may account for its previously observed peritubular hydrolysis.

Uniform GeO2 dispersed in nitrogen-doped porous carbon core–shell architecture: an anode material for lithium ion batteries

2015 ◽  
Vol 3 (43) ◽  
pp. 21722-21732 ◽  
Author(s):  
Duc Tung Ngo ◽  
Hang T. T. Le ◽  
Ramchandra S. Kalubarme ◽  
Jae-Young Lee ◽  
Choong-Nyeon Park ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Anode Material ◽  
High Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Germanium Oxide ◽  
Volume Changes ◽  
Capacity Retention ◽  
Nitrogen Doped ◽  
Carbon Core

Germanium oxide (GeO2), which possesses great potential as a high-capacity anode material for lithium ion batteries, has suffered from its poor capacity retention and rate capability due to significant volume changes during lithiation and delithiation.

Observation of chemo-mechanical failure and influence of cut-off potentials in all-solid-state Li-S batteries

2019 ◽  
Author(s):  
Saneyuki Ohno ◽  
Georg Dewald ◽  
Raimund Koerver ◽  
Carolin Rosenbach ◽  
Paul Titscher ◽  
...  
Keyword(s):  
Solid State ◽  
High Capacity ◽  
Reversible Capacity ◽  
Mechanical Failure ◽  
Volume Changes ◽  
Long Term Stability ◽  
Solid State Batteries ◽  
S Model

<p>Owing to a remarkably high theoretical energy density, the lithium-sulfur (Li-S) battery has attracted significant attention as a candidate for next-generation batteries. While employing solid electrolytes can provide a new avenue for high capacity Li-S cells, all-solid-state batteries have unique failure mechanisms such as chemo-mechanical failure due to the volume changes of active materials. In this study, we investigate all-solid-state Li-S model cells with differently processed cathode composites and elucidate a typical failure mechanism stemming from irreversible Li<sub>2</sub>S formation in the cathode composites. Reducing the particle size is key to minimizing the influence of volume changes and a capacity of over 1000 mAh g<sub>sulfur</sub><sup>-1</sup>is achieved by ball-milling of the cathode composites. In addition, the long-term stability of the ball-milled cathode is investigated by varying upper and lower cut-off potentials for cycling, which results in unveiling the significantly detrimental role of the lower cut-off potential. Preventing a deep-discharge leads to a reversible capacity of 800 mAh g<sub>sulfur</sub><sup>-1</sup>over 50 cycles in the optimized cell. This work highlights the importance of mitigating chemo-mechanical failure using microstructural engineering as well as the influence of the cut-off potentials in all-solid-state Li-S batteries. </p>

Observation of chemo-mechanical failure and influence of cut-off potentials in all-solid-state Li-S batteries

2019 ◽  
Author(s):  
Saneyuki Ohno ◽  
Georg Dewald ◽  
Raimund Koerver ◽  
Carolin Rosenbach ◽  
Paul Titscher ◽  
...  
Keyword(s):  
Solid State ◽  
High Capacity ◽  
Reversible Capacity ◽  
Mechanical Failure ◽  
Volume Changes ◽  
Long Term Stability ◽  
Solid State Batteries ◽  
S Model

<p>Owing to a remarkably high theoretical energy density, the lithium-sulfur (Li-S) battery has attracted significant attention as a candidate for next-generation batteries. While employing solid electrolytes can provide a new avenue for high capacity Li-S cells, all-solid-state batteries have unique failure mechanisms such as chemo-mechanical failure due to the volume changes of active materials. In this study, we investigate all-solid-state Li-S model cells with differently processed cathode composites and elucidate a typical failure mechanism stemming from irreversible Li<sub>2</sub>S formation in the cathode composites. Reducing the particle size is key to minimizing the influence of volume changes and a capacity of over 1000 mAh g<sub>sulfur</sub><sup>-1</sup>is achieved by ball-milling of the cathode composites. In addition, the long-term stability of the ball-milled cathode is investigated by varying upper and lower cut-off potentials for cycling, which results in unveiling the significantly detrimental role of the lower cut-off potential. Preventing a deep-discharge leads to a reversible capacity of 800 mAh g<sub>sulfur</sub><sup>-1</sup>over 50 cycles in the optimized cell. This work highlights the importance of mitigating chemo-mechanical failure using microstructural engineering as well as the influence of the cut-off potentials in all-solid-state Li-S batteries. </p>

scholarly journals The Regulation of Stomatal Aperture in Tobacco Leaf Epidermal Strips II. The Effect of Ouabain

1970 ◽  
Vol 23 (4) ◽  
pp. 981 ◽  
Author(s):  
DA Thomas
Keyword(s):  
Transport System ◽  
Stomatal Opening ◽  
Stomatal Aperture ◽  
Excitable Cells ◽  
Bathing Medium ◽  
Transport Atpase ◽  
Low Concentrations ◽  
Membrane Bound ◽  
The Times ◽  
K Transport

The K+-dependent, light-stimulated opening of stomata on tobacco and V icia faba epidermal strips was found to be rapidly reduced by low concentrations of ouabain. On removing ouabain stomatal aperture rapidly increased. This suggests that the influx of K+ into the guard cells is associated with a membrane�bound transport ATPase. Experiments with 10-5M p.chloromercuribenzoate (PCMB) and ouabain indicate that the considered transport ATPase is not markedly affected by PCMB. The stomatal opening obtained in the presence of Na+ alone is also decreased on the addition of ouabain, though ouabain does not prevent the longer-term stomatal opening which occurs in the dark in the presence of N a + alone. In the light, recovery of stomatal opening on the removal of ouabain from the bathing medium only occurred in the presence of K+. It is considered that an ATPase�linked K+ transport system could give the rapid rate of influx that would be necessary to bring about stomatal opening in the times observed. The presence of an ATPase transport system would give an evolutionary link between the stomatal control mechanism and that associated with the function of other excitable cells such as nerve and muscle.

Sign in / Sign up

Export Citation Format

Share Document