Medium Lots Research Articles

Development of a versatile high-temperature short-time (HTST) pasteurization device for small-scale processing of cell culture medium formulations.

The compatibility of CHO cell culture medium formulations with all stages of the bioprocess must be evaluated through small-scale studies prior to scale-up for commercial manufacturing operations. Here, we describe the development of a bespoke small-scale device for assessing the compatibility of culture media with a widely implemented upstream viral clearance strategy, high-temperature short-time (HTST) treatment. The thermal stability of undefined medium formulations supplemented with soy hydrolysates was evaluated upon variations in critical HTST processing parameters, namely, holding times and temperatures. Prolonged holding times of 43s at temperatures of 110°C did not adversely impact medium quality while significant degradation was observed upon treatment at elevated temperatures (200°C) for shorter time periods (11s). The performance of the device was benchmarked against a commercially available mini-pilot HTST system upon treatment of identical formulations on both platforms. Processed medium samples were analyzed by untargeted LC-MS/MS for compositional profiling followed by chemometric evaluation, which confirmed the observed degradation effects caused by elevated holding temperatures but revealed comparable performance of our developed device with the commercial mini-pilot setup. The developed device can assist medium optimization activities by reducing volume requirements relative to commercially available mini-pilot instrumentation and by facilitating fast throughput evaluation of heat-induced effects on multiple medium lots.

Replicates, Read Numbers, and Other Important Experimental Design Considerations for Microbial RNA-seq Identified Using Bacillus thuringiensis Datasets.

RNA-seq is being used increasingly for gene expression studies and it is revolutionizing the fields of genomics and transcriptomics. However, the field of RNA-seq analysis is still evolving. Therefore, we specifically designed this study to contain large numbers of reads and four biological replicates per condition so we could alter these parameters and assess their impact on differential expression results. Bacillus thuringiensis strains ATCC10792 and CT43 were grown in two Luria broth medium lots on four dates and transcriptomics data were generated using one lane of sequence output from an Illumina HiSeq2000 instrument for each of the 32 samples, which were then analyzed using DESeq2. Genome coverages across samples ranged from 87 to 465X with medium lots and culture dates identified as major variation sources. Significantly differentially expressed genes (5% FDR, two-fold change) were detected for cultures grown using different medium lots and between different dates. The highly differentially expressed iron acquisition and metabolism genes, were a likely consequence of differing amounts of iron in the two media lots. Indeed, in this study RNA-seq was a tool for predictive biology since we hypothesized and confirmed the two LB medium lots had different iron contents (~two-fold difference). This study shows that the noise in data can be controlled and minimized with appropriate experimental design and by having the appropriate number of replicates and reads for the system being studied. We outline parameters for an efficient and cost effective microbial transcriptomics study.

Influência da cera de carnaúba no comportamento reológico de misturas usadas na moldagem por injeção em baixa pressão

A moldagem por injeção em baixa pressão (MIBP) tem algumas vantagens sobre outros métodos de conformação de peças cerâmicas com formas complexas. Dentre as vantagens estão os menores custos na produção de lotes pequenos e médios e o menor desgaste de moldes e equipamento. Neste trabalho, foi estudado o efeito de um dos aditivos orgânicos usados na MIBP, a cera de carnaúba, no comportamento reológico da mistura (feedstock). O pó cerâmico utilizado foi uma alumina, com tamanho de partícula em torno de 0,4 μm. Com adições de 5% e 10% em peso de cera de carnaúba no veículo orgânico a viscosidade diminui significativamente, sendo bem mais acentuada com 10%, enquanto que, acima deste valor (15%), a viscosidade diminui, mas esta redução é menos pronunciada. Em contrapartida, em feedstocks sem a cera de carnaúba (0%), a viscosidade é tão elevada que praticamente inviabiliza a injeção em baixas pressões.

Effect of mid-storage corrective treatments on different vigour lots of soybean seed

Soybean (Glycine max) seeds are poor storers, mid storage corrective hydration and dehydration treatments viz., common bleach, catharanthus leaf powder, Trigonella powder, chilli powder, sand moist conditioning and sand moist conditioning soaking and drying were given to high, medium and low vigour seed lots of soybean. The performance of soybean seed was measured in terms of germination per cent and field emergence. Sand moist conditioning soaking and drying was most effective in enhancing germination and field emergence per cent irrespective of different vigour lots of soybean seed. The effect is more prominent in medium and low vigour lots.

Phenotyping the quality of complex medium components by simple online-monitored shake flask experiments.

BackgroundMedia containing yeast extracts and other complex raw materials are widely used for the cultivation of microorganisms. However, variations in the specific nutrient composition can occur, due to differences in the complex raw material ingredients and in the production of these components. These lot-to-lot variations can affect growth rate, product yield and product quality in laboratory investigations and biopharmaceutical production processes. In the FDA’s Process Analytical Technology (PAT) initiative, the control and assessment of the quality of critical raw materials is one key aspect to maintain product quality and consistency. In this study, the Respiration Activity Monitoring System (RAMOS) was used to evaluate the impact of different yeast extracts and commercial complex auto-induction medium lots on metabolic activity and product yield of four recombinant Escherichia coli variants encoding different enzymes.ResultsUnder non-induced conditions, the oxygen transfer rate (OTR) of E. coli was not affected by a variation of the supplemented yeast extract lot. The comparison of E. coli cultivations under induced conditions exhibited tremendous differences in OTR profiles and volumetric activity for all investigated yeast extract lots of different suppliers as well as lots of the same supplier independent of the E. coli variant. Cultivation in the commercial auto-induction medium lots revealed the same reproducible variations. In cultivations with parallel offline analysis, the highest volumetric activity was found at different cultivation times. Only by online monitoring of the cultures, a distinct cultivation phase (e.g. glycerol depletion) could be detected and chosen for comparable and reproducible offline analysis of the yield of functional product.ConclusionsThis work proves that cultivations conducted in complex media may be prone to significant variation in final product quality and quantity if the quality of the raw material for medium preparation is not thoroughly checked. In this study, the RAMOS technique enabled a reliable and reproducible screening and phenotyping of complex raw material lots by online measurement of the respiration activity. Consequently, complex raw material lots can efficiently be assessed if the distinct effects on culture behavior and final product quality and quantity are visualized.Electronic supplementary materialThe online version of this article (doi:10.1186/s12934-014-0149-5) contains supplementary material, which is available to authorized users.

서울도심부 도시한옥주거지의 입지와 특성

This study was aimed at analyzing the location and the characteristics of the Urban hanok tissues that were formed in the downtown since 1920s. Focusing on the relationship between roads and lots, the developing process and the typological characteristics are examined. Through dividing the large and medium lots of the aristocratic families and on the hilly area near the Seoul City Wall, various shapes of urban hanok tissue were evolved. The urban hanok tissues developed before 1936 locate on the downtown sites, while those developed after 1936 locate on the hilly sites. The location of the tissues were identified in the upper area of Jong-no street. The former is composed of small size lots divided into average area <TEX>$104.4m^2$</TEX> with the narrow alleys of about 2.0m width, while the latter is composed of medium size lots divided into average area <TEX>$131.54m^2$</TEX> with the alleys of about 4.0m width. Moreover the structures of the tissues were evolved based on the developing period and the site condition. Moreover the structures of the tissues were evolved based on the developing period and the site condition. The typological characteristics were defined as the four patterns categorized with the bilateral concepts of alley's form and of alley's spacial feature.

Telepresence in Industrial Applications: Implementation Issues for Assembly Tasks

In contrast to automated production, human intelligence is deemed necessary for successful execution of assembly tasks that are difficult or expensive to automate in small and medium lots. However, human ability is hindered in some cases by physical barriers such as miniaturization or in contrast, very heavy components. Telepresence technology can be considered a solution for performing a wide variety of assembly tasks where human intelligence and haptic sense are needed. This work highlights several issues involved in deploying industrial telepresence systems to manipulate and assemble microparts as well as heavy objects. Two sets of experiments are conducted to investigate telepresence related aspects in an industrial setting. The first experiment evaluates the usefulness of haptic feedback for a human operator in a standard pick-and-place task. Three operation modes were considered: visual feedback, force feedback, and force assistance (realized as vibration). In the second experiment, two different guidance strategies for the teleoperator were tested. The comparison between a position and a velocity scheme in terms of task completion time and subjective preferences is presented.

Comparison of the Plating Efficiencies and Shelf Lives of Three Different Commercial Buffered Charcoal Yeast Extract Media Supplemented with α-Ketoglutaric Acid

The plating efficiencies and shelf lives of locally made buffered charcoal yeast extract medium supplemented with alpha-ketoglutaric acid (BCYEalpha) were compared to those of media made by BD, Hardy, and Remel. Lung homogenates from guinea pigs infected with Legionella pneumophila were plated monthly onto different medium lots. All media performed equally well and had shelf lives of at least 12 months.

Optimization of cutting parameters in micro end milling operations in dry cutting condition using genetic algorithms

Micro end milling with fine grained carbide end mills is an economical way to machine small and medium lots of micro components. Considering the sensitivity of the slender end mills which are very costly compared to conventional end mills, it is imperative that the machining parameters are chosen appropriately so as to ensure maximum tool life and minimum possible production cost without violating any of the imposed constraints. Unlike in conventional end milling operations the tool life in micro end milling operations increases with axial depth of cut till it equals the tool diameter and this makes it even difficult to ascertain the appropriate depth of cut to machine a specific component. In this paper the influence of depth of cut on tool life is illustrated and depth of cut is also considered as one of the decision variables in the optimization problem. More over in this paper Genetic Algorithms (GA) based on natural laws of evolution is used to optimize the cutting parameters. Finally a test case is presented to give a clear picture of the application of the optimization algorithm.

Development of gemifloxacin in vitro susceptibility test methods for gonococci including quality control guidelines

Gemifloxacin (formerly SB-265805 or LB20304a) is a new fluoronapthyridone with documented activity against Gram-positive and -negative organisms. The activity of gemifloxacin was tested against 150 Neisseria gonorrhoeae strains, using reference agar dilution, standardized disk diffusion, and Etest (AB BIODISK, Solna, Sweden) methods. Gemifloxacin was very potent against ciprofloxacin (CIPRO)-susceptible strains (MIC 90, 0.008 μg/ml) but was significantly less active against the CIPRO-resistant gonococci (MIC 90, 0.12 μg/ml). Etest and reference agar dilution MIC results showed excellent correlation ( r = 0.96), and 98.7% MICs were within ± one log 2 dilution. Agar dilution MICs were also compared to zone diameters obtained using gemifloxacin 5-μg disks; and complete intermethod categorical agreement (100%) was achieved applying breakpoints proposed as follows: ≤0.25 μg/ml (zone, ≥ 25 mm) for susceptible and ≥1 μg/ml (zone, ≤21 mm) for resistant. Gemifloxacin MIC and disk diffusion test quality control (QC) ranges were established for N. gonorrhoeae ATCC 49226. Data were collected from ≥ seven laboratories, three GC agar medium lots for both agar MICs and disk methods, and two lots each of the 5- and 10-μg disks. The proposed MIC QC range was 0.002 to 0.016 μg/ml and the calculated mm zone ranges (median ± 0.5× average mm range) for both disks were similar, but contained only 88.1 to 91.9% of participant results. To achieve the acceptable ≥ 95% of all study results within range, a 43 to 54 mm limits (5-μg disks) were necessary. The excellent broad-spectrum activity and a low reported adverse effects profile of gemifloxacin shows a potential for treatment of fluoroquinolone-resistant gonorrhea.

Determination of MIC Quality Control Ranges for ABT-733, a Novel Ketolide Antimicrobial Agent

Determination of MIC Quality Control Ranges for ABT-733, a Novel Ketolide Antimicrobial Agent

Computer Aided Planning of Flexible, Modular Assembly Cells

Assembly automation in form of robotized assembly cells is one of the most important application areas of robotics today and in the future. The flexibility of these cells offers possibilities to automatize assembling of small and medium lots. Planning of assembly cells will be done manually in most cases by means of some computer facilities. The paper presents first results for totally computer aided planning. The creation of an integrated database model, the planning process and knowledge will be discussed. The assembly operations, their sequencing, list of selecting components, assembly time and price of flexible cells are the goals of the proposed planning system.