The Gene Pax4 Is an Essential Regulator of Pancreatic β-Cell Development

Beatriz Sosa-Pineda 한국분자세포생물학회 2004 Molecules and cells Vol.18 No.3

The Pax-gene family encodes a group of transcription factors characterized by the presence of a highly conserved DNA-binding motif, the paired domain. Pax proteins are key regulators of vertebrate organogenesis since they play major roles in embryonic pattern formation, cell proliferation and cell differentiation (Chi and Epstein, 2002; Dahl et al., 1997; Dohrman et al., 2000; Epstein et al., 1994). Indeed, mutations in Pax genes lead to profound defects in organisms as diverse as flies, mice and humans (Chi and Epstein, 2002; Dahl et al., 1997). To date, nine mammalian Pax genes are known and these are grouped into five different subclasses according to their structural similarities. One of these subclasses comprises two close homologues, Pax4 and Pax6, that contain a second DNA-binding domain: the homeodomain (Dahl et al., 1997; Dohrman et al., 2000). Previous studies showed that Pax4 is a crucial regulator of mammalian pancreas development since lack of its activity prevents the formation of mature pancreatic insulin-producing (beta) cells (Dohrman et al., 2000; Sosa-Pineda et al., 1997; Wang et al., 2004). Presently, it is not yet clear how Pax4 is specifically required for the development of beta cells. Nonetheless, evidence gathered from recent studies has begun to unravel important aspects of the molecular function of Pax4 in pancreatic endocrine cells. Here, I will try to summarize the results of different efforts aimed at understanding how Pax4 is required for both, beta cell development and beta cell function.

Level Set Advection of Free Fluid Surface Modified by Surface Tension

Pineda, Israel,Gwun, Oubong THE KOREAN INSTITUTE OF SMART MEDIA 2015 스마트미디어저널 Vol.4 No.2

Fluids appear in innumerable phenomena; therefore, it is interesting to reproduce those phenomena by computer graphics techniques. However, this process is not trivial. We work with a fluid simulation that uses Navier-Stokes equations to model the fluid, a semi-Lagrangian approach to solve it and the level set method to track the surface of the fluid. Modified versions of the Navier-Stokes equations for computer graphics allow us to create a wide diversity of effects. In this paper, we propose a technique that allows us to integrate a force inspired by surface tension into the model. We describe which information we need and how to modify the model with this new approach. We end up with a modified simulation that has additional effects that might be suitable for computer graphics purposes. The effects that we are able to recreate are small waves and droplet-like formations close to the surface of the fluid. This model preserves the overall behavior governed by the Navier-Stokes equations.

CO2 gas absorption by CH3OH based nanofluids in an annular contactor at low rotational speeds

Pineda, Israel Torres,Choi, Chang Kyoung,Kang, Yong Tae Elsevier 2014 INTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL Vol.23 No.-

<P>In this work, carbon dioxide (CO2) absorption experiments are performed in a custom designed vertical annular contactor (AC) at low rotational speeds. Methanol is used as solvent and Al2O3, SiO2 and TiO2 nanoparticles are combined with the methanol to produce nanofluids. The AC performance is compared to that of a modified version in which trays are added to enhance the CO2 absorption rate (T-AC). Experiments in co-current and counter-current flows are carried out. In addition, two-phase flow patterns in the AC and in the modified version are analyzed by using a high speed visualization system. The results show no effect on the absorption rate for pure methanol at Re-omega < 17,000. In the counter-current flow, however, nanofluids show a better performance in the AC with maximum enhancements of 4.6% for TiO2, 1.2% for Al2O3 and 1.1% for SiO2 compared to pure methanol. The addition of trays enhances the CO2 absorption rate up to 9%, 10%, 6% and 5% for pure methanol, Al2O3, SiO2, and TiO2, respectively for the counter-current flow. Likewise, the highest rotation effectiveness is found in the T-AC for Al(2)O(3)and TiO2 with 24.2% and 14.4%, respectively. (C) 2014 Elsevier Ltd. All rights reserved.</P>

Biotherapeutic Applications of Platelet-Rich Plasma in Regenerative Medicine

Pineda-Cortel Maria Ruth,Suarez Consuelo,Cabrera Jan-Tyrone,Daya Minerva,Bernardo-Bueno Mary Monica,Vergara Renz Cleve,Villavieja Adrian 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.6

BACKGROUND: Platelet-rich plasma (PRP), a blood-based product containing platelets and growth factors, is being utilized to treat numerous non-hemostatic disorders. Studies have explored the use of PRP to provide rapid repair, healing, and recovery from various injuries; some studies mentioned the effectiveness of PRP as compared with other forms of treatment like the use of hyaluronic acid. Commercially available PRP systems are available now, and each varies from one another depending on how it is prepared, thus causing variations in platelet concentration and growth factor content. These variations also implicated different therapeutic applications. METHODS: The paper reviews the various applications of PRP, including factors to consider before using PRP therapy, and provides an extensive list of PRP applications. RESULTS: The administration of PRP as a standalone treatment or as a co-therapy results in observed positive outcomes. However, there is a lack of standardization for PRP preparation, increasing the risks for heterogeneity and bias amongst results. CONCLUSION: The use of PRP is indeed an option for regenerative therapy, but more research is needed before it can fully be recommended as a primary treatment modality.

Globalization, Women and Work : The Philippine Experience

Rosalinda Pineda Ofreneo 숙명여자대학교 아세아여성문제연구소 1998 Asian Women Vol.7 No.-

CO₂ absorption enhancement by nanoabsorbents in Taylor-Couette absorber

Torres Pineda, I.,Kang, Y.T. Pergamon Press ; Elsevier Science Ltd 2016 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.100 No.-

CO<SUB>2</SUB> gas is physically absorbed in liquid methanol in bubbly Taylor-Couette absorber. The experiments are performed in the turbulent regime with rotational Reynolds numbers ranging from 1.9x10<SUP>4</SUP> to 19.2x10<SUP>4</SUP>. The volumetric mass transfer coefficients are obtained for the counter-current operation. Methanol is utilized as the base absorbent. In addition, with the purpose of enhancing CO<SUB>2</SUB> absorption performance, Al<SUB>2</SUB>O<SUB>3</SUB> nanoparticles are combined with methanol to produce the absorbent. The results show an increase in the volumetric mass transfer coefficient that reaches a maximum value at 4x10<SUP>4</SUP> rotational Reynolds number for both pure methanol and the nanoabsorbents, after which the absorption rate declines almost linearly with the rotational speed. The reasons for the reduction in the absorption performance are discussed. The maximum enhancement in the volumetric mass transfer coefficient is estimated at 20% for 4x10<SUP>4</SUP> rotational Reynolds number and up to 27% for methanol and Al<SUB>2</SUB>O<SUB>3</SUB> nanoparticles at a concentration of 0.1vol%.

Mass transfer analysis for CO₂ bubble absorption in methanol/Al₂O₃ nanoabsorbents

Torres Pineda, Israel,Kim, Dongmin,Kang, Yong Tae Elsevier 2017 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.114 No.-

<P><B>Abstract</B></P> <P>In this paper computational fluid dynamics (CFD) analysis is carried out to investigate CO<SUB>2</SUB> bubble absorption characteristics in methanol/Al₂O<SUB>3</SUB> nanoabsorbents. Bubble size, rising velocity and mass transfer rate are compared to the previous experimental results for validation. It is found that the distance traveled for each CO<SUB>2</SUB> bubble increases as the concentration of Al<SUB>2</SUB>O<SUB>3</SUB> increases, which, in consequence, increases the residence time between liquid and gas phases resulting in higher interfacial mass transfer rates. For the case of a bubble rising in the gap between walls, the wall shear stress has a major effect on the bubble diameter and rising velocity which in consequence affects the mass transfer coefficient. It is concluded that the mass transfer coefficient enhances by about 40% by adding Al₂O<SUB>3</SUB> nanoparticles (0.01vol%) compared with pure methanol absorbent from the experimental and simulation results. It is also concluded that the use of nanoparticles has a higher impact on mass transfer rate than it does on mass transfer amount, which depends on the residence time and travel distance of CO<SUB>2</SUB> bubbles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Mass transfer analysis is carried out for CO<SUB>2</SUB> bubble absorption in nanoabsorbents. </LI> <LI> CO<SUB>2</SUB> absorption enhancement by nanoabsorbents is evaluated. </LI> <LI> Mass transfer coefficient enhances by about 40% by adding Al₂O<SUB>3</SUB> nanoparticles (0.01vol%). </LI> <LI> The use of nanoparticles has a higher impact on mass transfer rate than it does on mass transfer amount. </LI> </UL> </P>

The future is Accessible : Accelerating Inclusive Digital Transformation into Post-Pandemic Cities

Victor Santiago Pineda 국토교통부, 국토교통과학기술진흥원 2021 스마트시티 탑 아젠다(Smart City Top Agenda) Vol.1 No.E

The Edible Mushroom Pleurotus djamor Produces Metabolites with Lethal Activity Against the Parasitic Nematode Haemonchus contortus

Jesus Antonio Pineda-Alegrıa,Jose Ernesto Sa´nchez-Vazquez,Manases Gonzalez-Cortazar,Alejandro Zamilpa,Marıa Eugenia Lopez-Arellano,Edgar Josue Cuevas-Padilla,Pedro Mendoza-de-Gives,Liliana Aguilar-Ma 한국식품영양과학회 2017 Journal of medicinal food Vol.20 No.12

Pleurotus djamor is an edible mushroom that has medicinal properties. This study aimed to assess the in vitro activity of P. djamor extracts and fractions against Haemonchus contortus eggs and exsheathed infective larvae (L3). Crude hydroalcoholic extracts were obtained by maceration and fractions were obtained through chromatography. Metabolite identity was determined using gas chromatography/mass spectrometry (GC-MS) analysis. The results showed that P. djamor extracts had no significant activity against eggs at the concentrations used. However, the extract showed 98.7% and 77% larval mortality 72 h postconfrontation at 320 and at 160 mg/mL, respectively. The chromatography analysis resulted in 23 fractions that were eventually grouped into three fractions (E1, E2, and E3). These fractions showed the following egg hatching inhibition percentages: E1 = 100, E2 = 38.7, and E3 = 5.5 at 10 mg/mL concentration 72 h postexposure. Likewise, larval mortality percentages after this period were 90.6, 100, and 0.44 at 40 mg/mL (P < .05), respectively. The GC-MS showed five major compounds in E1 fraction, including four fatty acids: (i) pentadecanoic, (ii) hexadecanoic, (iii) octadecadienoic, (iv) octadecanoic acid, and one terpene identified as β-sitosterol. We concluded that the edible mushroom P. djamor possesses nematicidal metabolites, which could be used as an alternative anthelmintic treatment.

CO2 Absorption in Methanol-based AI2O3 and SiO2 Nanofluids

( Israel Torres Pineda ),( Jae Won Lee ),( Yong Tae Kang ) 한국액체미립화학회 2011 한국액체미립화학회 학술강연회 논문집 Vol.2011 No.-