Production of recombinant human dipeptidyl peptidase IV from SF9 cells in microbial fermenters

The human dipeptidyl peptidase IV (hDPPIV/CD26) is expressed as an immune response in some cancer cells as well as intestine and incretin metabolism, and deficiency of the enzyme leads to metabolic disorders. In the present study, recombinant hDPPIV/CD26 genes were expressed in baculovirus–insect cell systems in a 5-L stirred-tank fermenter. Because of the shear sensitivity of the insect cell line, production from insect cells should be performed in new-generation type bioreactors, which are commonly more expensive than microbial fermenters. To optimize the process, hydrodynamic parameters and oxygen consumption of Sf9 cells at 1.5 L and 3 L were monitored, and a certain amount of serum was added to the production medium to decrease shear and stabilize the growth of insect cells that normally do not need serum addition. In this study, dimensionless numbers and some hydrodynamic parameters were calculated in 1.5 L, and predictions were made for 3 L fermenter volumes. Agitation rates of 60 rpm were determined to protect insect cells against damaging shear stress. Regarding the agitation rate, oxygen mass transfer coefficient (k L a) was 0.0129 min –1 for 1.5 L and was kept constant for 3 L (0.0133 min –1 ). The maximum enzyme activity from microbial fermenters was 2.37-fold higher than activity from T-flask in our previous work. The infection efficiency of transfected cells was 78%–81% in the 1.5-L and 3-L fermenters. © TÜBİTAK

Chlorinated and brominated polycyclic aromatic hydrocarbons in ambient air: seasonal variation, profiles, potential sources, and size distribution

Chlorinated and brominated polycyclic aromatic hydrocarbons (ClPAHs and BrPAHs, respectively) are a new derivative group of PAHs. These halogenated PAHs (Halo-PAHs) have been reported to be carcinogenic and are considered emerging persistent organic pollutants. Gaining a clear understanding of the distribution and behavior of these ubiquitous organic pollutants is essential for the control and mitigation of their emission into the environment. However, research into the characteristics of Halo-PAHs in the atmosphere has been somewhat limited. This review paper thus aims to provide an overview of the seasonal patterns, profiles, potential sources, and particle-size distributions of atmospheric ClPAHs and BrPAHs with 3-5 rings. Most previous studies have focused on particulate Halo-PAHs and reported that their levels are higher during the cold season than during the warm season, with this seasonal variation more apparent for ClPAHs than for BrPAHs. In terms of their phase distribution, ClPAHs and BrPAHs share a similar trend, with their gaseous concentrations highest in summer and lowest in winter and their particulate concentrations exhibiting the opposite trend. Halo-PAH profiles have been shown to differ between sampling locations, possibly reflecting differences in the potential sources present at these sites, e.g., coal burning, traffic emissions, and industrial activity. The majority of Halo-PAHs tend to accumulate as ultrafine particles with an aerodynamic diameter of less than 1.0 mu m. Overall, a detailed understanding of the characteristics of Halo-PAHs in the atmosphere has yet to be achieved; hence, further research on atmospheric Halo-PAHs is necessary

Spectroscopic Study of 41,45Sc Nuclei Through (d,n) Reactions on 40,44Ca at 25 MeV

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Study of the Proton Single-Particle Strengths in 19F and Proton Shell Closure of 18O through the 18O(d, n)19F Reaction

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Single-Proton Strengths in 19F Through the (d, n) Reaction at 25 MeV

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Gamow-Teller Transition in the (p,n) Reaction on 42Ca and 44Ca

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A Study of Single Proton States for the 21, 23Na Nuclei through (d,n) Reactions at 25 MeV

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Novel Synthesis of Cellulose-Based Diblock Copolymer of Poly(hydroxyethyl methacrylate) by Mechanochemical Reaction

The mechanical fracture of polymer produces polymeric free radical chain-ends, by which liner block copolymers have been synthesized. A diblock copolymer of microcrystalline cellulose (MCC) and poly 2-hydroxyethyl methacrylate (pHEMA) was produced by the mechanochemical polymerization under vacuum and room temperature. The fraction of pHEMA in MCC-blockpHEMA produced by the mechanochemical polymerization increased up to 21 mol% with increasing fracture time (∼6 h). Then, the tacticities of HEMA sequences in MCC-block-pHEMA varied according to the reaction time. In the process of mechanochemical polymerization, cellulose could play the role of a radical polymerization initiator capable of controlling stereoregularity

15N(p, n)15O Reaction at 35 MeV

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Proton Single-Particle States in 209Bi via the 208Pb(d, n)209Bi Reaction

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