scholarly journals Electroporation can cause artefacts due to solubilization of cations from the electrode plates. Aluminum ions enhance conversion of inositol 1,3,4,5-tetrakisphosphate into inositol 1,4,5-trisphosphate in electroporated L1210 cells

1991 ◽  
Vol 277 (3) ◽  
pp. 883-885 ◽  
Author(s):  
J W Loomis-Husselbee ◽  
P J Cullen ◽  
R F Irvine ◽  
A P Dawson
Keyword(s):  
Experimental System ◽  
Experimental Medium ◽  
Assay Medium ◽  
L1210 Cells ◽  
Aluminum Ions ◽  
Inositol 1,4,5 Trisphosphate ◽  
The Difference ◽  
High Concentrations ◽  
As If ◽  
In Cells

1. In electroporated L1210 cells, Ins(1,3,4,5)P4 causes Ca2+ release, owing to its conversion into Ins(1,4,5)P3, but this does not happen in cells permeabilized by digitonin treatment [Cullen, Irvine, Drøbak & Dawson (1989) Biochem. J. 259, 931-933]. 2. If the assay medium is subjected to electroporation by using a commercially available electroporation apparatus and then the cells are added and permeabilized with digitonin, the cells behave as if they had been electroporated. 3. Electroporation causes the release of high concentrations of Al3+ into the experimental medium, and addition of these concentrations of Al3+ into the experimental medium mimics the effect of electroporation on the conversion of Ins(1,3,4,5)P4 into Ins(1,4,5)P3. 4. It is concluded that the difference between electroporated and digitonin-permeabilized L1210 cells in this experimental system can be attributed to dissolution of Al3+ from the electroporation cuvette. Al3+ contamination may thus be a serious problem when using this apparatus.

The metachor as a characteristic of the association of electrolytes in aqueous solutions

1984 ◽  
Vol 49 (5) ◽  
pp. 1061-1078 ◽  
Author(s):  
Jiří Čeleda ◽  
Stanislav Škramovský
Keyword(s):  
Aqueous Solutions ◽  
Apparent Volume ◽  
Solutions Of Electrolytes ◽  
Molal Volumes ◽  
The Difference ◽  
High Concentrations ◽  
Experimental Values ◽  
Suitable Characteristic ◽  
Association Of Ions ◽  
Very High

Based on the earlier paper introducing a concept of the apparent parachor of a solute in the solution, we have eliminated in the present work algebraically the effect which is introduced into this quantity by the additivity of the apparent molal volumes. The difference remaining from the apparent parachor after substracting the contribution corresponding to the apparent volume ( for which the present authors suggest the name metachor) was evaluated from the experimental values of the surface tension of aqueous solutions for a set of 1,1-, 1,2- and 2,1-valent electrolytes. This difference showed to be independent of concentration up to the very high values of the order of units mol dm-3 but it was directly proportional to the number of the free charges (with a proportionality factor 5 ± 1 cm3 mol-1 identical for all studied electrolytes). The metachor can be, for this reason, a suitable characteristic for detection of the association of ions and formation of complexes in the solutions of electrolytes, up to high concentrations where other methods are failing.

Buildings

2017 ◽  
Author(s):  
Peter Rez
Keyword(s):  
Heat Transfer ◽  
Heat Pump ◽  
Energy Efficient ◽  
Energy Use ◽  
Fossil Fuel ◽  
Local Climate ◽  
Heating And Cooling ◽  
The Difference ◽  
As If

Most of the energy used by buildings goes into heating and cooling. For small buildings, such as houses, heat transfer by conduction through the sides is as much as, if not greater than, the heat transfer from air exchanges with the outside. For large buildings, such as offices and factories, the greater volume-to-surface ratio means that air exchanges are more significant. Lights, people and equipment can make significant contributions. Since the energy used depends on the difference in temperature between the inside and the outside, local climate is the most important factor that determines energy use. If heating is required, it is usually more efficient to use a heat pump than to directly burn a fossil fuel. Using diffuse daylight is always more energy efficient than lighting up a room with artificial lights, although this will set a limit on the size of buildings.

Rhetoric and argumentation: the unity of the field

2017 ◽  
Author(s):  
Michel Meyer
Keyword(s):  
The Other ◽  
Classic Problem ◽  
False Dilemma ◽  
The Difference ◽  
As If

Rhetoric has always been torn between the rhetoric of figures and the rhetoric of conflicts or arguments, as if rhetoric were exclusively one or the other. This is a false dilemma. Both types of rhetoric hinge on the same structure. A common formula is provided in Chapter 3 which unifies rhetoric stricto sensu and rhetoric as argumentation as two distinct but related strategies adopted according to the level of problematicity of the questions at stake, thereby giving unity to the field called “Rhetoric.” Highly problematic questions require arguments to justify their answers; non-divisive ones can be treated rhetorically through their answers as if they were self-evident. Another classic problem is how to understand the difference between logic and rhetoric. The difference between the two is due to the presence of questions explicitly answered in the premises in logic and only suggested (or remaining indeterminate) in rhetoric.

scholarly journals Ribonucleic acid stimulation of mammalian liver nuclear-envelope nucleoside triphosphatase. A possible enzymic marker for the nuclear envelope

1977 ◽  
Vol 162 (3) ◽  
pp. 671-679 ◽  
Author(s):  
P S Agutter ◽  
J R Harris ◽  
I Stevenson
Keyword(s):  
Nuclear Envelope ◽  
Specific Activity ◽  
Assay Medium ◽  
Exogenous Rna ◽  
Mammalian Liver ◽  
High Concentrations ◽  
Enzymic Marker ◽  
Stimulation Of ◽  
Nucleoside Triphosphatase

1. The specific activity of rat and pig liver nuclear-envelope nucleoside triphosphatase (EC 3.6.1.3) decreases when the system is depleted of RNA. The activity can be restored by adding high concentrations of yeast RNA to the assay medium. 2. Exogenous RNA also increases the activity of the enzyme in control envelopes (not RNA-depleted). The effect appears to be largely specific for poly(A) and poly(G); it is not stimulated by rRNA or tRNA preparations, ribonuclease-hydrolysed RNA, AMP, or double- or single-stranded DNA. 3. Inhibitors of the enzyme, in concentrations at which half-maximal inhibition of the enzyme is achieved, do not affect the percentage stimulation of the enzyme by yeast RNA. 4. The simulation is abolished by the inclusion of 150 mM-KCl or -NaCl in the assay medium, but not by increasing the assay pH to 8.5. 5. The results are discussed in the light of the possible role of the nucleoside triphosphatase in vivo in nucleo-cytoplasmic ribonucleoprotein translocation. 6. It is proposed that poly(G)-stimulated Mg2+-activated adenosine triphosphatase activity should be adopted as an enzymic marker for the nuclear envelope.

scholarly journals Thunderstorm outflows preceding epidemics of asthma during spring and summer

Thorax ◽  
2001 ◽  
Vol 56 (6) ◽  
pp. 468-471
Author(s):  
G B Marks ◽  
J R Colquhoun ◽  
S T Girgis ◽  
M Hjelmroos Koski ◽  
A B A Treloar ◽  
...  
Keyword(s):  
Pollen Grains ◽  
Ground Level ◽  
Fold Increase ◽  
Underlying Mechanism ◽  
Detailed Examination ◽  
Asthma Exacerbations ◽  
Eastern Australia ◽  
The Difference ◽  
High Concentrations ◽  
Thunderstorm Outflow

BACKGROUNDA study was undertaken to assess the importance of thunderstorms as a cause of epidemics of asthma exacerbations and to investigate the underlying mechanism.METHODSA case control study was performed in six towns in south eastern Australia. Epidemic case days (n = 48) and a random sample of control days (n = 191) were identified by reference to the difference between the observed and expected number of emergency department attendances for asthma. The occurrence of thunderstorms, their associated outflows and cold fronts were ascertained, blind to case status, for each of these days. In addition, the relation of hourly pollen counts to automatic weather station data was examined in detail for the period around one severe epidemic of asthma exacerbations. The main outcome measure was the number of epidemics of asthma exacerbations.RESULTSThunderstorm outflows were detected on 33% of epidemic days and only 3% of control days (odds ratio 15.0, 95% confidence interval 6.0 to 37.6). The association was strongest in late spring and summer. Detailed examination of one severe epidemic showed that its onset coincided with the arrival of the thunderstorm outflow and a 4–12 fold increase in the ambient concentration of grass pollen grains.CONCLUSIONSThese findings are consistent with the hypothesis that some epidemics of exacerbations of asthma are caused by high concentrations of allergenic particles produced by an outflow of colder air, associated with the downdraught from a thunderstorm, sweeping up pollen grains and particles and then concentrating them in a shallow band of air at ground level. This is a common cause of exacerbations of asthma during the pollen season.

scholarly journals Nrf2 Signaling Pathway in Chemoprotection and Doxorubicin Resistance: Potential Application in Drug Discovery

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 349
Author(s):  
Sepideh Mirzaei ◽  
Ali Zarrabi ◽  
Farid Hashemi ◽  
Amirhossein Zabolian ◽  
Hossein Saleki ◽  
...  
Keyword(s):  
Cancer Therapy ◽  
Adverse Effects ◽  
Cancer Progression ◽  
Related Factor ◽  
Pharmacological Agents ◽  
Nrf2 Signaling Pathway ◽  
High Concentrations ◽  
Genetic Interventions ◽  
Underlying Mechanisms ◽  
In Cells

Doxorubicin (DOX) is extensively applied in cancer therapy due to its efficacy in suppressing cancer progression and inducing apoptosis. After its discovery, this chemotherapeutic agent has been frequently used for cancer therapy, leading to chemoresistance. Due to dose-dependent toxicity, high concentrations of DOX cannot be administered to cancer patients. Therefore, experiments have been directed towards revealing underlying mechanisms responsible for DOX resistance and ameliorating its adverse effects. Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling is activated to increase levels of reactive oxygen species (ROS) in cells to protect them against oxidative stress. It has been reported that Nrf2 activation is associated with drug resistance. In cells exposed to DOX, stimulation of Nrf2 signaling protects cells against cell death. Various upstream mediators regulate Nrf2 in DOX resistance. Strategies, both pharmacological and genetic interventions, have been applied for reversing DOX resistance. However, Nrf2 induction is of importance for alleviating side effects of DOX. Pharmacological agents with naturally occurring compounds as the most common have been used for inducing Nrf2 signaling in DOX amelioration. Furthermore, signaling networks in which Nrf2 is a key player for protection against DOX adverse effects have been revealed and are discussed in the current review.

Sodium current function in adult and aged canine atrial cells

2006 ◽  
Vol 291 (2) ◽  
pp. H756-H761 ◽  
Author(s):  
Shigeo Baba ◽  
Wen Dun ◽  
Masanori Hirose ◽  
Penelope A. Boyden
Keyword(s):  
Normal Sinus Rhythm ◽  
Sodium Current ◽  
Cell Voltage ◽  
Current Function ◽  
Structural Remodeling ◽  
Channel Protein ◽  
Normal Sinus ◽  
Atrial Cells ◽  
The Difference ◽  
In Cells

The incidence of atrial fibrillation increases with age, but it is unknown whether there are changes in the intrinsic function of Na+ currents in cells of the aged atria. Thus, we studied right (RA) and left (LA) atrial cells from two groups of dogs, adult and aged (>8 yr), to determine the change in Na+ currents with age. In this study all dogs were in normal sinus rhythm. Whole cell voltage clamp techniques were used to compare the Na+ currents in the two cell groups. Immunocytochemical studies were completed for the Na+ channel protein Nav1.5 to determine whether there was structural remodeling of this protein with age. In cells from aged animals, we found that Na+ currents are similar to those we measured in adult atria. However, Na+ current ( INa) density of the aged atria differed depending on the atrial chamber with LA cell currents being larger than RA cell currents. Thus with age, the difference in INa density between atrial chambers remains. INa kinetic differences between aged and adult cells included a significant acceleration into the inactivated state and an enhanced use-dependent decrease in peak current in aged RA cells. Finally, there is no structural remodeling of the cardiac Na+ channel protein Nav1.5 in the aged atrial cell. In conclusion, with age there is no change in INa density, but there are subtle kinetic differences contributing to slight enhancement of use dependence. There is no structural remodeling of the fast Na+ current protein with age.

scholarly journals An attempt at clarifying Maximus the Confesor’s remarks on (the fate of) sexual difference in Ambiguum 41

2021 ◽  
Vol 32 (2) ◽  
pp. 194-203
Author(s):  
Sotiris Mitralexis
Keyword(s):  
Sexual Difference ◽  
Human Person ◽  
Close Reading ◽  
Church Fathers ◽  
Male And Female ◽  
The Subject ◽  
The Difference ◽  
Maximus The Confessor ◽  
As If

Maximus the Confessor?s Ambiguum 41 contains some rather atypical observations concerning the distinction of sexes in the human person. There is a certain ambiguity as to whether the distinction of the sexes was intended by God and is ?by nature? (as found in Genesis and asserted by most Church Fathers) or a product of the Fall. Namely, Christ is described three times as ?shaking out of nature the distinctive characteristics of male and female?, ?driving out of nature the difference and division of male and female? and ?removing the difference between male and female?. Different readings of those passages engender important implications that can be drawn out from the Confessor?s thought, both eschatological implications and otherwise. The subject has been picked up by Cameron Partridge, Doru Costache and Karolina Kochanczyk-Boninska, among others, but is by no means settled, as they draw quite different conclusions. The noteworthy and far-reaching implications of Maximus? theological stance and problems are not the object of this paper. In a 2017 paper I attempted to demonstrate what Maximus exactly says in these peculiar and oft-commented passages through a close reading, in order to avoid a two-edged Maximian misunderstanding: to either draw overly radical implications from those passages, projecting decidedly non-Maximian visions on the historical Maximus, or none at all, as if those passages represented standard Patristic positions. Here, I am revisiting this argument, given that the interest in what the Confessor has to say on the subject seems to be increasing.

scholarly journals The Effect of Aloe Vera Extract to Extensive Lesion and Expression of Transforming Growth Factor (TGF-β) on Alkaline Chemical Trauma Cornea Model

2018 ◽  
Vol 1 (2) ◽  
pp. 1-17
Author(s):  
Fahcreza ◽  
Elsa Iskandar ◽  
Rachmat Hidayat ◽  
Petty Purwanita ◽  
Anang Tribowo ◽  
...  
Keyword(s):  
Wound Healing ◽  
Growth Factor ◽  
Wistar Rats ◽  
Aloe Vera ◽  
Control Group ◽  
Treatment Groups ◽  
White Rats ◽  
Significant Difference ◽  
The Difference ◽  
In Cells

Abstract Background: Chemical trauma to the cornea is an emergency condition of the eye that requires early diagnosis and good treatment. Alkaline have ability to saponify fatty acids in cells and cell membranes which can make penetration into the stroma and destroy proteoglycans and collagen in cells. Aloe vera (AV) contains several active substances that are reported to have anti-inflammatory, immunomodulatory, and wound healing effects. AV has been reported to accelerate the healing process of corneal epithelial defects by increasing fibroblast proliferation, collagen production and growth factor production. This study aims to determine the difference between the effect of aloe vera extract with a concentration of 10%, 20%, 40% and BSS on the healing of extensive corneal lesions in white wistar rats alkaline trauma models. Method: This study was an experimental study with a pre and posttest only with control group design in vivo approach to 30 Wistar white rats which were divided into 5 treatment groups for 3 days. Comparative analysis of effectiveness using the ANNOVA test or the Kruskal Wallis test and continued by the post hoc test. Results: Based on the one way ANOVA test there was a statistically significant difference in effectiveness between the five treatment groups on the percentage of corneal wound healing area and TGF-β expression with an assessment of p = 0,000 each. The administration of alloevera (AV) concentration of 20% had a significant difference in percentage of healing of corneal lesions and TGF-β expression compared with other treatment groups with p = 0,000 each. Large differences in the area of corneal lesions in the 40% AV group were -0.45 in the BBS group, 0.146 in the 10% AV group, 0.493 in the 20% AV group. The difference in the AV group 10% was 0.30 in the BBS group, -064 in the AV group 20%, and -0.14 in the AV group 40%. However, TGFβ expression in the normal control group that did not receive treatment was 54.94 (53.21-56-12). TGFβ levels in the BSS group were 10.44, the 10% aloe vera group was 25.43, 47.99 for the 20% aloe vera group and 37.95 for the 40% aloe vera group. Conclusion: There is a difference between the effect of aloe vera extract with concentrations of 10%, 20%, 40% and BSS on the extensive healing of corneal lesions in white wistar rats with alkaline chemical trauma models.

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