scholarly journals The Role of Concentration on Drop Formation and Breakup of Collagen, Fibrinogen, and Thrombin Solutions during Inkjet Bioprinting

Langmuir ◽  
2020 ◽  
Vol 36 (50) ◽  
pp. 15373-15385
Author(s):  
Hemanth Gudapati ◽  
Ibrahim T. Ozbolat
Keyword(s):  
Drop Formation

Dynamics of drop formation in granular suspensions: the role of volume fraction

2012 ◽  
Vol 14 (2) ◽  
pp. 169-174 ◽  
Author(s):  
T. Bertrand ◽  
C. Bonnoit ◽  
E. Clément ◽  
A. Lindner
Keyword(s):  
Volume Fraction ◽  
Drop Formation ◽  
Granular Suspensions

Phenotypic Changes of Hematopoietic Stem Cells and Stromal Cells by Aberrant Expression of GATA−2; Possible Role for the Development of Aplastic Anemia.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1289-1289
Author(s):  
Yoko Okitsu ◽  
Hideo Harigae ◽  
Shinichiro Takahashi ◽  
Naoko Minegishi ◽  
Norio Suzuki ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Bone Marrow ◽  
Cdna Array ◽  
Specific Gene ◽  
Drop Formation ◽  
Aberrant Expression ◽  
Hematopoietic Stem ◽  
Phenotypic Changes

Abstract (Introduction) Aplastic anemia (AA) is characterized by a fatty bone marrow and the reduced number of hematopoietic stem cell (HSC)s, resulting in peripheral pancytopenia. Several clinical studies have reported that the expression of transcription factor GATA−2 is significantly decreased in CD34 positive cells in AA, suggesting that downregulation of GATA−2 in HSCs may cause the reduction of number of HSCs in AA. Of note, GATA−2 has been shown to be essential for the maintenance of immaturity of preadipocytes as well as HSCs. If GATA−2 functions in the differentiation of stromal preadipocytes in bone marrow, GATA−2 may be involved in the formation of a fatty bone marrow in AA. In order to explore the role of GATA−2 for development of AA, phenotypic changes of HSCs and stromal preadipocytes by aberrant expression of GATA−2 were examined in this study. (Method) First, to analyze phenotypic changes of HSCs by decreased expression of GATA-2, lineage negative, sca-1 positive, c-kit positive (LSK) cells were sorted both from wild-type and GATA-2 haplodeficient mice (kindly provided Dr SH Orkin), and the gene expression profile was compared by cDNA array. The difference of expression level on cDNA array was confirmed by RQ-PCR. Next, in order to examine the role of GATA-2 in the differentiation of stromal preadipocytes, the GATA-2-GFP expression vector was transfected into TBR343, a mouse stromal preadipocyte cell line, and GFP positive cells were sorted. The differentiation capacity of these GATA-2 overexpressing TBR343 cells was compared to that of control cells. In addition, GATA-2 expression was suppressed by using siRNA in TBR343, and the phenotypic change was also examined. (Results) By comparing the gene expression profile, the expression levels of cyclin D1, D3, p21, E2F, c-Myc were found to be decreased in GATA-2 haplodeficient LSKs, suggesting GATA-2 down-regulation in HSCs may inhibit the cell cycle progression. When GATA-2 was overexpressed in TBR343, the oil drop formation and adipocyte-specific gene expression was significantly suppressed. Conversely, When GATA-2 was suppressed in TBR343 by siRNA, the oil drop formation and adipocyte-specific gene expression was significantly accelerated, suggesting that decrease of GATA-2 expression accelerates the differentiation of stromal preadipocytes. (Conclusion) These results suggest that suppression of GATA-2 in the bone marrow leads to an inactive cell cycle of HSCs and the accumulation of mature adipocytes, which may contribute to the expression of the representative features of AA, a fatty bone marrow and the reduced number of HSCs.

scholarly journals The role of concentration on drop formation and breakup of collagen, fibrinogen, and thrombin solutions during inkjet bioprinting

2020 ◽  
Author(s):  
Hemanth Gudapati ◽  
Ibrahim T. Ozbolat
Keyword(s):  
Inertial Force ◽  
Viscous Force ◽  
Protein Solutions ◽  
Drop Formation ◽  
Minimum Diameter ◽  
Subvisible Particles ◽  
Potential Flows ◽  
Drop On Demand ◽  
Initial Onset

AbstractThe influence of protein concentration on drop formation and breakup of aqueous solutions of fibrous proteins collagen, fibrinogen, and globular protein thrombin in different concentration regimes is investigated during drop-on-demand (DOD) inkjet bioprinting. The capillary-driven thinning and breakup of dilute (c/c* < 1, where c is the concentration and c* is the overlap concentration) collagen, fibrinogen, and thrombin solutions is predominantly resisted by inertial force on the initial onset of necking. The minimum diameter (Dfmin(t)) of the necked fluid up to the critical pinch-off time (tc) scales with time as Dfmin(t) ∼ (tc − t)2/3, a characteristic of potential flows. Although the capillary-driven thinning and breakup of semidilute unentangled collagen (1 ≤ c/c* ≤ 4) and fibrinogen (1 ≤ c/c* ≤ 1.3) solutions is predominantly resisted by inertial force on the initial onset of necking, the breakup of droplets is delayed beyond tc, where the minimum diameter of the necked fluid decreases exponentially with time because of the resistance of elastic force. The resistance of viscous force to the necking of both the dilute and semidilute untangled protein solutions is negligible. Aggregates or subvisible particles (between 1 and 100 μm) constantly disrupt the formation of droplets for the semidilute unentangled protein solutions, even when their inverse Ohnesorge number (Z) is within the printability range of 4 ≤ Z ≤ 14. Although aggregates are present in the dilute protein solutions, they do not disrupt the formation of droplets.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor

Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre
Keyword(s):  
Diagnosis And Management

The power of norms to sway fused group members

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam
Keyword(s):  
Evolutionary Anthropology ◽  
Normative Systems ◽  
Violent Extremism ◽  
Identity Fusion ◽  
Group Members

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

The role of affect in feelings of obligation

2020 ◽  
Vol 43 ◽  
Author(s):  
Stefen Beeler-Duden ◽  
Meltem Yucel ◽  
Amrisha Vaish
Keyword(s):  
Positive Emotions ◽  
The Creation ◽  
Sense Of Obligation

Abstract Tomasello offers a compelling account of the emergence of humans’ sense of obligation. We suggest that more needs to be said about the role of affect in the creation of obligations. We also argue that positive emotions such as gratitude evolved to encourage individuals to fulfill cooperative obligations without the negative quality that Tomasello proposes is inherent in obligations.

Refining our understanding of the “elephant in the room”

2020 ◽  
Vol 43 ◽  
Author(s):  
Andrew Whiten
Keyword(s):  
Social Cognition ◽  
Cultural Evolution ◽  
Cognitive Abilities ◽  
Critical Factors ◽  
Technological Culture

Abstract The authors do the field of cultural evolution a service by exploring the role of non-social cognition in human cumulative technological culture, truly neglected in comparison with socio-cognitive abilities frequently assumed to be the primary drivers. Some specifics of their delineation of the critical factors are problematic, however. I highlight recent chimpanzee–human comparative findings that should help refine such analyses.

Choosing a Markov blanket

2020 ◽  
Vol 43 ◽  
Author(s):  
Thomas Parr
Keyword(s):  
Markov Blanket ◽  
Target Article ◽  
The Relationship

Abstract This commentary focuses upon the relationship between two themes in the target article: the ways in which a Markov blanket may be defined and the role of precision and salience in mediating the interactions between what is internal and external to a system. These each rest upon the different perspectives we might take while “choosing” a Markov blanket.

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