184,014 research outputs found

    Development of hyper osmotic resistant CHO host cells

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    We have developed a cell culture platform for monoclonal antibody (IgG) production by Chinese Hamster Ovary (CHO) cells. The platform feed used the continuous feeding method. This platform can maintain high cell density and produce high antibody titer. However because operation of continuous feed is complex, contract manufacturing organization (CMO) that can perform continuous feed is limited. Therefore, we tried to change the feeding method from continuous feed to bolus feed. However the previous studies showed that the rapid changes of osmolality by bolus feed and the hyper osmolality repressed the cell culture growth and the final titer. In this study, we developed hyper osmotic resistant CHO-S host cell A (resistant to 450mOsm). To establish osmotic resistant CHO-S host cells, original CHO-S cells were passaged on a hyper osmotic basal media with repetition for about 100 days. We demonstrated that there were obviously differences in the cell growth under osmotic pressure of iso- (328 mOsm) and hyper- (450 mOsm) osmolality between the two host cells. Metabolic analysis of cell culture supernatant on CHO-S host cell A and CHO-S host cells with/ without osmotic stress performed. Compared to original CHO-S host cells, the osmotic resistant CHO-S host cell A has a greater capacity to generate osmolytes (sorbitol and erthritol) and decreased level of oxidized glutathione (GSSG), which suggests the osmotic resistant CHO-S host cells A handles osmotic stress better. Moreover, the characteristic of osmotic resistant on hyper osmotic resistant CHO-S host cell A was maintained even after 7 passages on a basal medium (330 mOsm). We will establish hyper osmotic resistant antibody production CHO cell line by using the CHO-S host cell A

    Genotype of CHO host cell line has higher impact on mAb production and quality than process strategy or cell culture medium

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    Chinese hamster ovary (CHO) cells comprise a variety of lineages, including CHO-DXB11, CHO-K1, CHO-DG44 and CHO-S. Despite the fact that CHO cell lines share a common ancestor, extensive mutagenesis and clonal selection have resulted in substantial genetic heterogeneity among them. Data from sequencing shows that different genes are lacking from individual CHO cell lines and that each cell line harbors a unique set of mutations that are relevant to the bioprocess. However, literature outlining how the observed genetic differences affect CHO cell performance during bioprocess operations remains scarce. In this study, we examined host cell-specific differences among three widely used CHO cell lines (CHO-K1, CHO-S and CHO-DG44) and recombinantly expressed the same monoclonal antibody (mAb) in an isogenic format in all cell lines by using bacterial artificial chromosomes (BACs) as transfer vector. Cell-specific growth, product formation and heavy and light chain mRNA levels were studied in batch, fed-batch and perfusion cultures. Furthermore, two different cell culture media were investigated. Product quality was studied through glycoprofiling, and the thermal denaturation was analyzed using differential scanning calorimetry (DSC). We found CHO cell line-specific preferences for mAb production or biomass synthesis that were determined by the host cell line rather than product-specific mRNA levels. Additionally, quality attributes of the expressed mAb were influenced by the host cell line and medium used

    Water and acetaldehyde in HH212: The first hot corino in Orion

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    Aims: Using the unprecedented combination of high resolution and sensitivity offered by ALMA, we aim to investigate whether and how hot corinos, circumstellar disks, and ejected gas are related in young solar-mass protostars. Methods: We observed CH3_3CHO and deuterated water (HDO) high-excitation (EuE_{\rm u} up to 335 K) lines towards the Sun-like protostar HH212--MM1. Results: For the first time, we have obtained images of CH3_3CHO and HDO emission in the inner ≃\simeq 100 AU of HH212. The multifrequency line analysis allows us to contrain the density (≥\geq 107^{7} cm−3^{-3}), temperature (≃\simeq 100 K), and CH3_3CHO abundance (≃\simeq 0.2--2 ×\times 10−9^{-9}) of the emitting region. The HDO profile is asymmetric at low velocities (≤\leq 2 km s−1^{-1} from VsysV_{\rm sys}). If the HDO line is optically thick, this points to an extremely small (∼\sim 20--40 AU) and dense (≥\ge 109^{9} cm−3^{-3}) emitting region. Conclusions: We report the first detection of a hot corino in Orion. The HDO asymmetric profile indicates a contribution of outflowing gas from the compact central region, possibly associated with a dense disk wind.Comment: Astronomy & Astrophysics Letter, in pres

    The effect of a carbohydrate mouth rinse on performance of the yo-yo intermittent recovery level 1 test with female university level hockey players

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    It has been suggested that carbohydrate mouth rinse (CHO-MR) effects short duration, high intensity exercise by activation of sensory receptors on the tongue (Carter et al., 2004: Medicine and Science in Sports and Exercise, 36, 2107–2111). Research has predominately focused on the effects of CHO-MR on the performance of cycling and running time trials (Painelli et al., 2010: Nutritional Journal, 9, 1-4). Limited research has been conducted on the effectiveness of a CHO-MR on intermittent high-intensity field-based sports performance. The aim of this study was to analyse the effects of a CHO mouth rinse on performance of the Yo-yo Intermittent Recovery Level 1 Test (IR1T) with female University standard hockey players. Following ethical approval, twelve members (mean age 20 ± 0.98 years, stature 167 ± 7.09 cm, and body mass 64.7 ± 4.96 kg) of the University of Lincoln’s female 1st team volunteered for the study. The study used a single-blind counter-balanced design with repeated measures on two treatment conditions: 1) a CHO-MR, and 2) a placebo mouth rinse (PL-MR). Participants were instructed to maintain a normal diet and fasted for 12hr prior to testing. After a familiarisation test, twelve participants completed the IR1T twice, one week apart; rinsing with either a CHO-MR or PL-MR. Administration occurred before (20min prior) the IR1T and during the 10s active recovery periods, at intervals (IV) which corresponded to five level increments in speed (IV1-13.5km/h, IV2-14km/h, IV3-14.5km/h, IV4-15km/h, IV5-15km/h). At these points, rate of perceived exertion (RPE) was recorded using the traditional Borg scale. Total distance (m) achieved was recorded as the performance measure. A dependent t-test did not detect any performance improvement (P = >0.05) between CHO-MR (1060 ± 273m) and PL-MR (1127 ± 402m) trials. Multiple dependent t-tests revealed that at the first IV (SL 12.1), RPE scores were significantly different (P = 0.006) between CHO-MR (10.9 ± 0.79) and PL-MR (11.4 ± 1.08) trials. No differences were detected between CHO-MR and PL-MR trials during the rest of the protocol (IV2-5, all P = >0.05). A CHO-MR had no effect on IR1T test performance with female university level hockey players compared to a PL-MR. The participants did not experience any differences in the feeling of exertion between the two conditions as the IR1T progressed. Further research needs to illuminate any possible performance effects from CHO-MR with intermittent high intensity activity, revealing any plausible physiological mechanisms of action

    Heavy Baryons and electromagnetic decays

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    In this talk I review the theory of electromagnetic decays of the ground state baryon multiplets with oneheavy quark, calculated using Heavy Hadron Chiral Perturbation Theory. The M1 and E2 amplitudes for (S^{*}-> S gamma), (S^{*} -> T gamma) and (S -> T gamma)are separately analyzed. All M1 transitions are calculated up to O(1/\Lambda_\chi^2). The E2 amplitudes contribute at the same order for (S^{*}-> S gamma), while for (S^{*} -> T gamma) they first appear at O(1/(m_Q \Lambda_\chi^2))and for (S -> T gamma) are completely negligible. Once the loop contributions is considered, relations among different decay amplitudes are derived. Furthermore, one can obtain an absolute prediction for the widths of Xi^{0'(*)}_c-> Xi^{0}_c gamma and Xi^{-'(*)}_b-> Xi^{-}_b gamma.Comment: Talk presented at 4^{th} International Conference Hyperons, Charm and Beauty Hadrons Conference, Valencia June 200

    Similar effects on cognitive performance during high- and low-carbohydrate obesity treatment

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    OBJECTIVE: Low-carbohydrate (L-CHO) diets are often used for weight loss but their effects on cognitive function are not well understood. The present study compared the effects of a L-CHO and high-carbohydrate (H-CHO) weight-loss diet on cognitive function adults. DESIGN: Participants were randomized to either a L-CHO (n=22) or H-CHO (n=25) weight-loss diet. Cognitive function was evaluated by four computerized cognitive tasks (Stroop Task, Continuous Performance Task, Word Recall and Wisconsin Card Sorting Task) presented in random order before and at 1, 4, 12 and 24 weeks after the initiation of the L-CHO or H-CHO diet. PARTICIPANTS: Forty-seven adults (25 males) with a mean±s.d. age of 47.4±8.7 years and body mass index of 35.3±3.4 kg m(−2). RESULTS: There were no significant differences in weight loss between groups at any time point. There were significant improvements on color Stroop task accuracy over time in both diet groups (P<0.05), but there were no differences in performance between groups on this or any other cognitive task at any time period. CONCLUSION: These findings suggest that weight loss has neither a positive nor a negative effect on cognitive function and that L-CHO and H-CHO weight-loss diets have similar effects on cognitive performance

    BRST symmetry of SU(2) Yang-Mills theory in Cho--Faddeev--Niemi decomposition

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    We determine the nilpotent BRST and anti-BRST transformations for the Cho--Faddeev-Niemi variables for the SU(2) Yang-Mills theory based on the new interpretation given in the previous paper of the Cho--Faddeev-Niemi decomposition. This gives a firm ground for performing the BRST quantization of the Yang--Mills theory written in terms of the Cho--Faddeev-Niemi variables. We propose also a modified version of the new Maximal Abelian gauge which could play an important role in the reduction to the original Yang-Mills theory.Comment: 11 pages, no figure; Introduction improved, 3 references adde

    The effect of 1,3-butanediol and carbohydrate supplementation on running performance

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    Objectives: Ingested ketogenic agents offer the potential to enhance endurance performance via the provision of an alternative exogenous, metabolically efficient, glycogen-sparing fuel (i.e. ketone bodies). This study aimed to assess the impact of combined carbohydrate and 1,3-butanediol (CHO-BD) supplementation on endurance performance, blood beta-hydroxybutyrate (βHB) concentration and glycolytic activity, in comparison to carbohydrate supplementation alone (CHO). Design: Eleven male runners (age 38 ± 12 years, mass 67.3 ± 6.5 kg, height 174.5 ± 5.0 cm, V̇O2peak 64.2 ± 5.0 ml·kg-1·min-1) performed two experimental trials in a randomised crossover design. Methods: Each trial consisted of 60 min of submaximal running, followed by a 5 km running time-trial (TT), and was performed following the ingestion of an energy matched ~650 ml drink (CHO-BD or CHO). Results: There was no difference in TT completion time between the trials (CHO: 1265 ± 93, CHO-BD: 1261 ± 96 s; p=0.723). However, blood βHB concentration in the CHO-BD trial was at least double that of the CHO trial at all time points following supplementation (p<0.05). While blood lactate concentration was lower in the CHO-BD versus CHO trial after 30 min submaximal exercise (CHO-BD: 1.46 ± 0.67 mmol·L-1, CHO: 1.77 ± 0.46 mmol·L-1, p=0.040), it was similar at other time points. Blood glucose concentrations were higher post-TT in the CHO-BD trial (CHO-BD: 5.83 ± 1.02 mmol·L-1, CHO: 5.26 ± 0.95 mmol·L-1, p=0.015). Conclusions: An energy matched CHO-BD supplementation drink raised βHB concentration and acutely lowered blood lactate concentration, without enhancing 5km TT running performance
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