Phase Separation: From the Initial Nucleation Stage to the Final Ostwald Ripening Regime

1997 ◽  
Vol 481 ◽  
Author(s):  
Celeste Sagui ◽  
Dean Stinson O'Gorman ◽  
Martin Grant
Keyword(s):  
Phase Separation ◽  
Late Stage ◽  
Ostwald Ripening ◽  
Early Stage ◽  
Classical Problem ◽  
Nucleation And Growth ◽  
New Model ◽  
Nucleation Stage ◽  
Initial Nucleation

ABSTRACTIn this work we have re-examined the classical problem of nucleation and growth. A new model considers the correlations among droplets and naturally incorporates the crossover from the early-stage, nucleation dominated regime to the scaling, late-stage, coarsening regime within a single framework.

Distinctive phase separation dynamics of polymer blends: roles of Janus nanoparticles

2019 ◽  
Vol 21 (5) ◽  
pp. 2651-2658 ◽  
Author(s):  
Qing Li ◽  
Liquan Wang ◽  
Jiaping Lin ◽  
Liangshun Zhang
Keyword(s):  
Phase Separation ◽  
Polymer Blends ◽  
Spinodal Decomposition ◽  
Late Stage ◽  
Early Stage ◽  
Janus Nanoparticles

The present work demonstrates that Janus nanoparticles uniquely promote the phase separation of polymer blends at the early stage of spinodal decomposition, but impede it at the late stage.

Self-Organization of Surface Patterns during Clustering

1999 ◽  
Vol 570 ◽  
Author(s):  
Martin Zinke–Allmang ◽  
Oleksa Hul'ko ◽  
Sywert Brongersma ◽  
Graham Carlow
Keyword(s):  
Thin Film ◽  
Late Stage ◽  
Ostwald Ripening ◽  
Driving Forces ◽  
Early Stage ◽  
Partial Ordering ◽  
Self Organization ◽  
Surface Patterns ◽  
Novel Concept ◽  
Vertical Correlation

ABSTRACTOstwald ripening, early stage and late stage coalescence growth are well–characterized, fundamental late–stage processes in the phase separation of thin film deposits on surfaces. These processes have recently been studied in respect to ordering of the clustered phase. While late stage coalescence growth is associated with random positions of the growing clusters, partial ordering is observed for early stage coalescence and ripeningTo obtain even higher order of clustering, additional physical driving forces must be included in the process. Two examples are discussed, one utilizing vertical correlation of clusters in super-lattice growth of coherent Stranski–Krastanov structures (coalescence based structures) and a novel concept based on preferential secondary clustering based on ripening morphologies.

scholarly journals Making the Grade during Pandemic: Early-stage and Late-stage Provisional Institutions

2021 ◽  
pp. 073112142110286
Author(s):  
Alexander B. Kinney ◽  
Nicholas J. Rowland
Keyword(s):  
Late Stage ◽  
Early Stage ◽  
State University ◽  
Institutional Work ◽  
Traditional Grading ◽  
Grading Policy ◽  
Temporary Solution ◽  
Rural State ◽  
Empirical Implications ◽  
Common Understanding

This is an article that draws on the institutional work literature about provisional institutions. To date, nearly every U.S. sector has been impacted by COVID-19. To sustain their core missions, highly institutionalized organizations such as universities have had to rethink foundational structures and policies. Using a historical ethnographic approach to investigate records from faculty senate deliberations at “Rural State University” (RSU), the authors examine the implementation of a temporary grading policy to supplement traditional, qualitative grades spring 2020 during the outbreak. The authors find that RSU implemented a temporary, supplemental grading policy as a provisional institution to momentarily supersede traditional grading as a means to—as soon as possible—return to it. This finding contrasts with the common understanding that provisional institutions operate primarily as a temporary solution to a social problem that leads to more stable and enduring, ostensibly nonprovisional institutions. The temporary grading policy, the authors argue, constitutes a “late-stage” provisional institution and, with this new lens, subsequently characterize the more commonplace understanding of provisional institutions as “early-stage.” This contribution has theoretical implications for studies of institutions and empirical implications for research on shared governance and disruption in higher education.

Health Insurance Status as a Predictor of Mode of Colon Cancer Detection but Not Stage at Diagnosis: Implications for Early Detection

2021 ◽  
pp. 003335492199917
Author(s):  
Lindsey A. Jones ◽  
Katherine C. Brewer ◽  
Leslie R. Carnahan ◽  
Jennifer A. Parsons ◽  
Blase N. Polite ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Health Insurance ◽  
Early Detection ◽  
Late Stage ◽  
Early Stage ◽  
Insurance Status ◽  
Stage At Diagnosis ◽  
Health Insurance Status ◽  
Percentage Point Increase ◽  
Point Increase

Objective For colon cancer patients, one goal of health insurance is to improve access to screening that leads to early detection, early-stage diagnosis, and polyp removal, all of which results in easier treatment and better outcomes. We examined associations among health insurance status, mode of detection (screen detection vs symptomatic presentation), and stage at diagnosis (early vs late) in a diverse sample of patients recently diagnosed with colon cancer from the Chicago metropolitan area. Methods Data came from the Colon Cancer Patterns of Care in Chicago study of racial and socioeconomic disparities in colon cancer screening, diagnosis, and care. We collected data from the medical records of non-Hispanic Black and non-Hispanic White patients aged ≥50 and diagnosed with colon cancer from October 2010 through January 2014 (N = 348). We used logistic regression with marginal standardization to model associations between health insurance status and study outcomes. Results After adjusting for age, race, sex, and socioeconomic status, being continuously insured 5 years before diagnosis and through diagnosis was associated with a 20 (95% CI, 8-33) percentage-point increase in prevalence of screen detection. Screen detection in turn was associated with a 15 (95% CI, 3-27) percentage-point increase in early-stage diagnosis; however, nearly half (47%; n = 54) of the 114 screen-detected patients were still diagnosed at late stage (stage 3 or 4). Health insurance status was not associated with earlier stage at diagnosis. Conclusions For health insurance to effectively shift stage at diagnosis, stronger associations are needed between health insurance and screening-related detection; between screening-related detection and early stage at diagnosis; or both. Findings also highlight the need to better understand factors contributing to late-stage colon cancer diagnosis despite screen detection.

scholarly journals EU FP7 research funding for an orphan drug (Orfadin®) and vaccine (Hep C) development: a success and a failure?

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
L. Schmidt ◽  
O. Sehic ◽  
C. Wild
Keyword(s):  
Hepatitis C ◽  
Late Stage ◽  
Research Funding ◽  
Early Stage ◽  
Basic Research ◽  
Pharmaceutical Products ◽  
Clinical Development ◽  
Clinical Indication ◽  
Market Authorisation ◽  
Risk Capital

Abstract Background We considered the extent of the contribution of publicly funded research to the late-stage clinical development of pharmaceuticals and medicinal products, based on the European Commission (EC) FP7 research funding programme. Using two EC FP7-HEALTH case study examples—representing two types of outcomes—we then estimated wider public and charitable research funding contributions. Methods Using the publicly available database of FP7-HEALTH funded projects, we identified awards relating to late-stage clinical development according to the systematic application of inclusion and exclusion criteria, classified them according to product type and clinical indication, and calculated total EC funding amounts. We then identified two case studies representing extreme outcomes: failure to proceed with the product (hepatitis C vaccine) and successful market authorisation (Orfadin® for alkaptonuria). Total public and philanthropic research funding contributions to these products were then estimated using publicly available information on funding. Results 12.3% (120/977) of all EC FP7-HEALTH awards related to the funding of late-stage clinical research, totalling € 686,871,399. Pharmaceutical products and vaccines together accounted for 84% of these late-stage clinical development research awards and 70% of its funding. The hepatitis C vaccine received total European Community (FP7 and its predecessor, EC Framework VI) funding of €13,183,813; total public and charitable research funding for this product development was estimated at € 77,060,102. The industry sponsor does not consider further development of this product viable; this now represents public risk investment. FP7 funding for the late-stage development of Orfadin® for alkaptonuria was so important that the trials it funded formed the basis for market authorisation, but it is not clear whether the price of the treatment (over €20,000 per patient per year) adequately reflects the substantial public funding contribution. Conclusions Public and charitable research funding plays an essential role, not just in early stage basic research, but also in the late-stage clinical development of products prior to market authorisation. In addition, it provides risk capital for failed products. Within this context, we consider further discussions about a public return on investment and its reflection in pricing policies and decisions justified.

scholarly journals Context-Specific Efficacy of Apalutamide Therapy in Preclinical Models of Pten-Deficient Prostate Cancer

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 3975
Author(s):  
Marco A. De Velasco ◽  
Yurie Kura ◽  
Naomi Ando ◽  
Noriko Sako ◽  
Eri Banno ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Antitumor Activity ◽  
Cancer Cells ◽  
Late Stage ◽  
Early Stage ◽  
Castration Resistant Prostate Cancer ◽  
Akt Inhibitor ◽  
Molecular Features ◽  
Context Specific

Significant improvements with apalutamide, a nonsteroidal antiandrogen used to treat patients suffering from advanced prostate cancer (PCa), have prompted evaluation for additional indications and therapeutic development with other agents; however, persistent androgen receptor (AR) signaling remains problematic. We used autochthonous mouse models of Pten-deficient PCa to examine the context-specific antitumor activity of apalutamide and profile its molecular responses. Overall, apalutamide showed potent antitumor activity in both early-stage and late-stage models of castration-naïve prostate cancer (CNPC). Molecular profiling by Western blot and immunohistochemistry associated persistent surviving cancer cells with upregulated AKT signaling. While apalutamide was ineffective in an early-stage model of castration-resistant prostate cancer (CRPC), it tended to prolong survival in late-stage CRPC. Molecular features associated with surviving cancer cells in CRPC included upregulated aberrant-AR, and phosphorylated S6 and proline-rich Akt substrate of 40 kDa (PRAS40). Strong synergy was observed with the pan-AKT inhibitor GSK690693 and apalutamide in vitro against the CNPC- and CRPC-derived cell lines and tended to improve the antitumor responses in CNPC but not CRPC in vivo. Upregulation of signal transducer and activator of transcription 3 (STAT3) and proviral insertion in murine-1 (PIM-1) were associated with combined apalutamide/GSK690693. Our findings show that apalutamide can attenuate Pten-deficient PCa in a context-specific manner and provides data that can be used to further study and, possibly, develop additional combinations with apalutamide.

scholarly journals Lung Cancer Inequalities in Stage of Diagnosis in Ontario, Canada

2021 ◽  
Vol 28 (3) ◽  
pp. 1946-1956
Author(s):  
Aisha K. Lofters ◽  
Evgenia Gatov ◽  
Hong Lu ◽  
Nancy N. Baxter ◽  
Sara J. T. Guilcher ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Relative Risk ◽  
Late Stage ◽  
Early Stage ◽  
Small Cell ◽  
Cancer Type ◽  
Adjusted Relative Risk ◽  
Late Stage Diagnosis ◽  
Adjusted Model

Lung cancer is the most common cancer and cause of cancer death in Canada, with approximately 50% of cases diagnosed at stage IV. Sociodemographic inequalities in lung cancer diagnosis have been documented, but it is not known if inequalities exist with respect to immigration status. We used multiple linked health-administrative databases to create a cohort of Ontarians 40–105 years of age who were diagnosed with an incident lung cancer between 1 April 2012 and 31 March 2017. We used modified Poisson regression with robust standard errors to examine the risk of diagnosis at late vs. early stage among immigrants compared to long-term residents. The fully adjusted model included age, sex, neighborhood-area income quintile, number of Aggregated Diagnosis Group (ADG) comorbidities, cancer type, number of prior primary care visits, and continuity of care. Approximately 62% of 38,788 people with an incident lung cancer from 2012 to 2017 were diagnosed at a late stage. Immigrants to the province were no more likely to have a late-stage diagnosis than long-term residents (63.5% vs. 62.0%, relative risk (RR): 1.01 (95% confidence interval (CI): 0.99–1.04), adjusted relative risk (ARR): 1.02 (95% CI: 0.99–1.05)). However, in fully adjusted models, people with more comorbidities were less likely to have a late-stage diagnosis (adjusted relative risk (ARR): 0.82 (95% CI: 0.80–0.84) for those with 10+ vs. 0–5 ADGs). Compared to adenocarcinoma, small cell carcinoma was more likely to be diagnosed at a late stage (ARR: 1.29; 95% CI: 1.27–1.31), and squamous cell (ARR: 0.89; 95% CI: 0.87–0.91) and other lung cancers (ARR: 0.93; 95% CI: 0.91–0.94) were more likely to be diagnosed at an early stage. Men were also slightly more likely to have late-stage diagnosis in the fully adjusted model (ARR: 1.08; 95% CI: 1.05–1.08). Lung cancer in Ontario is a high-fatality cancer that is frequently diagnosed at a late stage. Having fewer comorbidities and being diagnosed with small cell carcinoma was associated with a late-stage diagnosis. The former group may have less health system contact, and the latter group has the lung cancer type most closely associated with smoking. As lung cancer screening programs start to be implemented across Canada, targeted outreach to men and to smokers, increasing awareness about screening, and connecting every Canadian with primary care should be system priorities.

Inverse Ostwald Ripening and Self-Organization of Nanoclusters due to Ion Irradiation

2000 ◽  
Vol 647 ◽  
Author(s):  
K.-H. Heinig ◽  
B. Schmidt ◽  
M. Strobel ◽  
H. Bernas
Keyword(s):  
Phase Separation ◽  
Ion Implantation ◽  
Ostwald Ripening ◽  
Ion Irradiation ◽  
Experimental Studies ◽  
Self Organization ◽  
Mathematical Treatment ◽  
Thermodynamical Equilibrium ◽  
Unusual Behavior ◽  
Thermally Activated

AbstractUnder ion irradiation collisional mixing competes with phase separation if the irradiated solid consists of immiscible components. If a component is a chemical compound, there is another competition between the collisional forced chemical dissociation of the compound and its thermally activated re-formation. Especially at interfaces between immiscible components, irradiation processes far from thermodynamical equilibrium may lead to new phenomena. If the formation of nanoclusters (NCs) occurs during ion implantation, the phase separation caused by ion implantation induced supersaturation can be superimposed by phenomena caused by collisional mixing. In this contribution it will be studied how collisional mixing during high-fluence ion implantation affects NC synthesis and how ion irradiation through a layer of NCs modifies their size and size distribution. Inverse Ostwald ripening of NCs will be predicted theoretically and by kinetic lattice Monte-Carlo simulations. The mathematical treatment of the competition between irradiation-induced detachment of atoms from clusters and their thermally activated diffusion leads to a Gibbs-Thomson relation with modified parameters. The predictions have been confirmed by experimental studies of the evolution of Au NCs in SiO2 irradiated by MeV ions. The unusual behavior results from an effective negative capillary length, which will be shown to be the reason for inverse Ostwald ripening. Another new phenomenon to be addressed is self-organization of NCs in a d-layer parallel to the Si/SiO2 interface. Such d-layers were found when the damage level at the interface was of the order of 1-3 dpa. It will be discussed that the origin of the d-layer of NCs can be assigned to two different mechanisms: (i) The negative interface energy due to collisional mixing gives rise to the formation of tiny clusters of substrate material in front of the interface, which promotes heteronucleation of the implanted impurities. (ii) Collisional mixing in the SiO2produces diffusing oxygen, which may be consumed by the Si/SiO2 interface. A thin layer parallel to the interface becomes denuded of diffusing oxygen, which results in a strong pile up of Si excess. This Si excess promotes heteronucleation too. Independent of the dominating mechanism of self-organization of a d-layer of NCs, its location in SiO2 close to the SiO2/Si interface makes it interesting for non-volatile memory application.

Phase separation in undercooled molten Pd80Si20: Part I

1999 ◽  
Vol 14 (9) ◽  
pp. 3653-3662 ◽  
Author(s):  
K. L. Lee ◽  
H. W. Kui
Keyword(s):  
Growth Rate ◽  
Phase Separation ◽  
Crystal Growth ◽  
Grain Refinement ◽  
Crystallization Temperature ◽  
Sharp Decrease ◽  
Nucleation And Growth ◽  
Crystal Growth Rate ◽  
Large Undercooling ◽  
Kinetic Crystallization

Three different kinds of morphology are found in undercooled Pd80Si20, and they dominate at different undercooling regimens ΔT, defined as ΔT = T1 – Tk, where T1 is the liquidus of Pd80Si20 and Tk is the kinetic crystallization temperature. In the small undercooling regimen, i.e., for ΔT ≤ 190 K, the microstructures are typically dendritic precipitation with a eutecticlike background. In the intermediate undercooling regimen, i.e., for 190 ≤ ΔT ≤ 220 K, spherical morphologies, which arise from nucleation and growth, are identified. In addition, Pd particles are found throughout an entire undercooled specimen. In the large undercooling regimen, i.e., for ΔT ≥ 220 K, a connected structure composed of two subnetworks is found. A sharp decrease in the dimension of the microstructures occurs from the intermediate to the large undercooling regimen. Although the crystalline phases in the intermediate and the large undercooling regimens are the same, the crystal growth rate is too slow to bring about the occurrence of grain refinement. Combining the morphologies observed in the three undercooling regimens and their crystallization behaviors, we conclude that phase separation takes place in undercooled molten Pd80Si20.

Absence of Glaciation in Illinois during Marine Isotope Stages 3 through 5

1996 ◽  
Vol 46 (1) ◽  
pp. 19-26 ◽  
Author(s):  
B. Brandon Curry ◽  
Milan J. Pavich
Keyword(s):  
Oxygen Isotope ◽  
Late Stage ◽  
Lake Michigan ◽  
Early Stage ◽  
Ice Sheet ◽  
Laurentide Ice Sheet ◽  
Argillic Horizon ◽  
Late Wisconsinan ◽  
Lake Michigan Lobe

A10Be inventory and14C ages of material from a core from northernmost Illinois support previous interpretations that this area was ice free from ca. 155,000 to 25,000 yr ago. During much of this period, from about 155,000 to 55,000 yr ago, 10Be accumulated in the argillic horizon of the Sangamon Geosol. Wisconsinan loess, containing inherited 10Be, was deposited above the Sangamon Geosol from ca. 55,000 to 25,000 yr ago and was subsequently buried by late Wisconsinan till deposited by the Lake Michigan Lobe of the Laurentide Ice Sheet. The Sangamonian interglacial stage has been correlated narrowly to marine oxygen isotope substage 5e; our data indicate instead that the Sangamon Geosol developed during late stage 6, all of stages 5 and 4, and early stage 3.

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