Irreversible Nature of Mesoscopic Aggregates in Lysozyme Solutions

Alcoa is undertaking rehabilitation in the jarrah (Eucalyptus marginata D.Don ex Sm.) forest of Western Australia, following bauxite mining. One of the methods used in the rehabilitation program is broadcasting seeds; however, about two-thirds of species require seed-dormancy-breaking treatments. Smoke overcomes dormancy and enhances the germination of many jarrah forest species. Smoke-application methods were investigated to find the best seed treatment for 64 jarrah forest species. The optimum duration of seed imbibition in aqueous smoke and dilution of the aqueous smoke product were also investigated. The method of smoke application was important. Smoke water enhanced the germination of 12% of species, whereas aerosol smoke enhanced the germination of 6% of species. Both Grevillea pilulifera (Lindl.) Druce and Velleia trinervis Labill. had germination enhanced by both smoke-application methods. Aerosol smoke inhibited the germination of Clematis pubescens Endl. and Hypocalymma angustifolium (Endl.) Schauer. A total of 78% of species did not exhibit significantly enhanced germination when smoke treated, including the two species inhibited by smoke treatment. Germination was equivalent following 1- and 12-h imbibition in the aqueous smoke extract. Dilutions of the aqueous extract Regen 2000 Smokemaster from 1 to 3% were optimal for the germination of Marianthus bicolor (Putt.) F.Muell and Stylidium amoenum R.Br., even after subsequent washing with water, demonstrating the irreversible nature of smoke treatments. For species that did not exhibit smoke-enhanced germination, other dormancy-breaking treatments may be required before a response to smoke is elicited. These results have application to a wide variety of natural managed lands, disturbed and designed landscapes.

Download Full-text

Molecular and cellular mechanisms of ultraviolet corneal crosslinking

POINT OF VIEW EAST – WEST ◽

10.25276/2410-1257-2021-4-48-54 ◽

2021 ◽

pp. 48-54

Author(s):

M.M. Bikbov ◽

◽

A.R. Khalimov ◽

Keyword(s):

Strength Properties ◽

Short Term ◽

Cellular Mechanisms ◽

Inflammatory Reactions ◽

Corneal Crosslinking ◽

Ultraviolet Exposure ◽

Uv Crosslinking ◽

Radical Processes ◽

Irreversible Nature ◽

Ultrastructural Transformation

In the presented mainly experimental work, the regularities and mechanisms of ultrastructural transformation and changes in corneal metabolism under ultraviolet exposure are established. High-quality saturation of the stroma with riboflavin is necessary to perform safe and effective UV crosslinking of the cornea, which can be achieved mainly due to a sufficient area of de-epithelization (at least 8-9 mm). It was found that UV crosslinking of the cornea with the use of developed riboflavin solutions (Dextralink, Ribolink and Khitolink) as photosensitizers increases its strength properties associated with changes in the structural state of collagen fibrils. It is proved that the riboflavin-UV effect on the optical shell of the eyeball is caused by a short-term local increase in free radical processes, a decrease in the overall antioxidant status, and the absence of necrotic and significant inflammatory reactions. It is shown that the lack of riboflavin in the stroma forms a cascade of pathomorphological events of an irreversible nature, leading to the loss of the native structure of the cornea. On the basis of the conducted studies, the necessity of a differentiated approach to the use of riboflavin-containing solutions during ultraviolet crosslinking of the cornea is justified. Key words: ultraviolet corneal crosslinking, molecular-cellular mechanisms, photosensitizers, riboflavin.

Download Full-text

Timing of Auctions of Real Options

Management Science ◽

10.1287/mnsc.2019.3374 ◽

2020 ◽

Vol 66 (9) ◽

pp. 3956-3976 ◽

Cited By ~ 4

Author(s):

Lin William Cong

Keyword(s):

Real Options ◽

Private Benefit ◽

Strike Price ◽

Partial Control ◽

Auction Design ◽

Bidding Strategies ◽

Information Rent ◽

Nature Of Time ◽

Irreversible Nature

This paper endogenizes auction timing and initiation in auctions of real options. Because bidders have information rent, a seller faces a “virtual strike price” higher than the actual exercise cost. The seller inefficiently delays the auction to encourage bidder participation and uses the irreversible nature of time to gain partial control over option exercises. The seller’s private benefit at option exercise may restore efficient auction timing, but option exercises are always inefficiently late. When the seller lacks commitment to auction timing, bidders always initiate in equilibrium, resulting in earlier option exercise and higher welfare than auctions proscribing bidder initiation. Overall, auction timing modifies the distribution of the bidder valuations and has important implications for bidding strategies, auction design, and real outcomes. This paper was accepted by Gustavo Manso, finance.

Download Full-text

Role of Vasomotion in Control of Retina Edema in Diabetic Retinopathy: Quantification of Fluid Transport Through Retinal Capillaries

ASME 2008 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2008-189507 ◽

2008 ◽

Author(s):

Liang Zhu ◽

Robert Flower

Keyword(s):

Diabetic Retinopathy ◽

Fluid Transport ◽

Vision Loss ◽

Early Screening ◽

Retinal Tissue ◽

Visual Damage ◽

Prevention Of Diabetes ◽

Irreversible Nature ◽

Retinal Capillaries

Diabetic retinopathy refers to diabetes-related complications in the retina, It is a progressive disease and its symptoms in the eyes can vary from non-vision threatening to vision loss, and it can lead to permanent damage to the neuronal retinal tissue. The irreversible nature of the damage suggests that prevention of diabetes by eliminating risk factors and early screening are the cornerstone of relevant treatment to stop or limit visual damage in those patients.

Download Full-text

ON THE STRUCTURE OF SUPERCRITICAL PHASE TRANSITION

Modern Physics Letters A ◽

10.1142/s0217732390001207 ◽

1990 ◽

Vol 05 (14) ◽

pp. 1081-1087 ◽

Cited By ~ 1

Author(s):

YUMI S. HIRATA ◽

HISAKAZU MINAKATA

Keyword(s):

Phase Transition ◽

Statistical Mechanics ◽

Order Phase Transition ◽

False Vacuum ◽

Close Analogy ◽

First Order ◽

First Order Phase Transition ◽

Supercritical Phase ◽

First Order Phase ◽

Irreversible Nature

A novel physical picture is presented for the normal-to-supercritical "phase" transition in QED around a large-Z nucleus. The process is described as the decay of the false vacuum in close analogy to the first-order phase transition in statistical mechanics. The irreversible nature of the transition is pointed out and the physical implications of this picture are discussed.

Download Full-text

Formation of a -bicyclo[3.3.0]Octane by tandem anionic cyclization: evidence for the highly stereoselective irreversible nature of 5-hexen-1-yllithium cyclizations

Tetrahedron Letters ◽

10.1016/s0040-4039(00)98011-0 ◽

1990 ◽

Vol 31 (42) ◽

pp. 5993-5996 ◽

Cited By ~ 20

Author(s):

William F. Bailey ◽

Atmaram D. Khanolkar

Keyword(s):

Irreversible Nature

Download Full-text

Cohesive Model in Prediction of Multi-Axial Fatigue

Volume 12: Processing and Engineering Applications of Novel Materials ◽

10.1115/imece2010-40353 ◽

2010 ◽

Author(s):

Deepak K. Jha ◽

Anuradha Banerjee

Keyword(s):

Stress State ◽

Cohesive Zone Model ◽

State Dependence ◽

Life Assessment ◽

Zone Model ◽

State Dependent ◽

Response To Stress ◽

Frame Work ◽

Stress States ◽

Irreversible Nature

A fatigue failure model for life assessment of a structure that incorporates the stress-state dependence and irreversible nature of fatigue damage is presented. In the frame work of cohesive zone model, a stress state dependent traction separation law for plane strain is taken to represent an undamaged ferritic steel. The evolution of damage has two additional fatigue parameters: a stress and a length parameter. Initially a parametric study is done to show that the model is able to reproduce a typical uniaxial fatigue response to stress based cyclic load, that of a stress-life curve and reduction in life due to positive mean stress. The effect of the cohesive fatigue parameters on the characteristics of the stress-life curve is then established. The model is further applied for a range of sinusoidally varying in-phase stress states which are characterised by a fixed bi-axiality ratio. The initiation and growth of damage is shown to be more rapid for higher bi-axiality. Except for stress amplitudes in which the lower bi-axiality case has conditions close to monotonic failure, the effect of bi-axiality is shown to be detrimental to the life expectancy of the material as observed in available experimental literature.

Download Full-text

Cellular senescence impairs the reversibility of pulmonary arterial hypertension

Science Translational Medicine ◽

10.1126/scitranslmed.aaw4974 ◽

2020 ◽

Vol 12 (554) ◽

pp. eaaw4974 ◽

Cited By ~ 2

Author(s):

Diederik E. van der Feen ◽

Guido P. L. Bossers ◽

Quint A. J. Hagdorn ◽

Jan-Renier Moonen ◽

Kondababu Kurakula ◽

...

Keyword(s):

Endothelial Cells ◽

Pulmonary Arterial Hypertension ◽

Arterial Hypertension ◽

Structural Changes ◽

Human Situation ◽

Vascular Phenotype ◽

Pulmonary Arterial ◽

End Stage ◽

Irreversible Nature

Pulmonary arterial hypertension (PAH) in congenital cardiac shunts can be reversed by hemodynamic unloading (HU) through shunt closure. However, this reversibility potential is lost beyond a certain point in time. The reason why PAH becomes irreversible is unknown. In this study, we used MCT+shunt-induced PAH in rats to identify a dichotomous reversibility response to HU, similar to the human situation. We compared vascular profiles of reversible and irreversible PAH using RNA sequencing. Cumulatively, we report that loss of reversibility is associated with a switch from a proliferative to a senescent vascular phenotype and confirmed markers of senescence in human PAH-CHD tissue. In vitro, we showed that human pulmonary endothelial cells of patients with PAH are more vulnerable to senescence than controls in response to shear stress and confirmed that the senolytic ABT263 induces apoptosis in senescent, but not in normal, endothelial cells. To support the concept that vascular cell senescence is causal to the irreversible nature of end-stage PAH, we targeted senescence using ABT263 and induced reversal of the hemodynamic and structural changes associated with severe PAH refractory to HU. The factors that drive the transition from a reversible to irreversible pulmonary vascular phenotype could also explain the irreversible nature of other PAH etiologies and provide new leads for pharmacological reversal of end-stage PAH.

Download Full-text