Animal-free heme production for artificial meat in Corynebacterium glutamicum via systems metabolic and membrane engineering.

Recently, heme has attracted much attention as a main ingredient that mimics meat flavor in artificial meat in the food industry. Here, we developed Corynebacterium glutamicum capable of high-yield production of heme with systems metabolic engineering and modification of membrane surface. The combination of two precursor pathways based on thermodynamic information increased carbon flux toward heme and porphyrin intermediate biosynthesis. The co-overexpression of genes involved in a noncanonical downstream pathway and the gene encoding the transcriptional regulator DtxR significantly enhanced heme production. The overexpression of the putative heme exporters, knockout of heme-binding proteins, modification of the cell wall by chemical treatment, and reduction of intermediate UP III substantially improved heme secretion. The fed-batch fermentation showed a maximum heme titer of 309.18 ± 16.43 mg l-1, including secreted heme of 242.95 ± 11.45 mg l-1, a yield on glucose of 0.61 mmol mol-1, and productivity of 6.44 mg l-1h-1, which are the highest values reported to date. These results demonstrate that engineered C. glutamicum can be an attractive cell factory for animal-free heme production.

Olfactory Stimulation Effect of Aldehydes, Nonanal, and Decanal on the Human Electroencephalographic Activity, According to Nostril Variation.

Fragrances play a pivotal role in humans' psychological and physiological functions through the olfactory system. Aldehydes are important organic compounds with a variety of fragrance notes. Particularly, nonanal (C9) and decanal (C10) aldehydes are important natural fragrant components used to enhance floral, as well as citrus notes in perfumery products. In general, each nostril of the human nose is tuned to smell certain odor molecules better than others due to slight turbinate swelling between the nostrils. Hence, the objective of the present investigation was aimed to evaluate the influence of binasal and uninasal inhalations of C9 and C10 aldehydes on human electroencephalographic (EEG) activity. Twenty healthy participants (10 males and 10 females) participated in this study. The EEG readings were recorded from 8 electrodes (QEEG-8 system) according to the International 10-20 System. The results revealed that C10 exposure exhibited significantly different EEG changes, during binasal and uninasal inhalations. In different brain regions, C10 odor markedly decreased the absolute alpha and absolute beta power spectra. In regards to C9 odor, significant changes of EEG power spectra were noticed only during binasal inhalation. In addition, C10 mainly produced changes at the left parietal site (P3) than other brain sites. In conclusion, the variations in EEG activities of C9 and C10 aldehydes might be owing to their characteristic fragrance quality, as well as the influence of nostril differences.

A Data-Driven Approach for the Diagnosis of Mechanical Systems Using Trained Subtracted Signal Spectrograms.

Toward the prognostic and health management of mechanical systems, we propose and validate a novel effective, data-driven fault diagnosis method. In this method, we develop a trained subtracted spectrogram, the so called critical information map (CIM), identifying the difference between the signal spectrograms of normal and abnormal status. We believe this diagnosis process may be implemented in an autonomous manner so that an engineer employs it without expert knowledge in signal processing or mechanical analyses. Firstly, the CIM method applies sequential and autonomous procedures of time-synchronization, time frequency conversion, and spectral subtraction on raw signal. Secondly, the subtracted spectrogram is then trained to be a CIM for a specific mechanical system failure by finding out the optimal parameters and abstracted information of the spectrogram. Finally, the status of a system health can be monitored accurately by comparing the CIM with an acquired signal map in an automated and timely manner. The effectiveness of the proposed method is successfully validated by employing a diagnosis problem of six-degree-of-freedom industrial robot, which is the diagnosis of a non-stationary system with a small amount of training datasets.

Ordinary kriging approach to predicting long-term particulate matter concentrations in seven major Korean cities.

OBJECTIVES: Cohort studies of associations between air pollution and health have used exposure prediction approaches to estimate individual-level concentrations. A common prediction method used in Korean cohort studies is ordinary kriging. In this study, performance of ordinary kriging models for long-term particulate matter less than or equal to 10 µm in diameter (PM10) concentrations in seven major Korean cities was investigated with a focus on spatial prediction ability. METHODS: We obtained hourly PM10 data for 2010 at 226 urban-ambient monitoring sites in South Korea and computed annual average PM10 concentrations at each site. Given the annual averages, we developed ordinary kriging prediction models for each of the seven major cities and for the entire country by using an exponential covariance reference model and a maximum likelihood estimation method. For model evaluation, cross-validation was performed and mean square error and R-squared (R(2)) statistics were computed. RESULTS: Mean annual average PM10 concentrations in the seven major cities ranged between 45.5 and 66.0 µg/m(3) (standard deviation=2.40 and 9.51 µg/m(3), respectively). Cross-validated R(2) values in Seoul and Busan were 0.31 and 0.23, respectively, whereas the other five cities had R(2) values of zero. The national model produced a higher crossvalidated R(2) (0.36) than those for the city-specific models. CONCLUSIONS: In general, the ordinary kriging models performed poorly for the seven major cities and the entire country of South Korea, but the model performance was better in the national model. To improve model performance, future studies should examine different prediction approaches that incorporate PM10 source characteristics.

Two Atypical Cases of Nodular Gastritis: A Poorly Differentiated Gastric Adenocarcinoma and a Pseudo-Low Grade Gastric MALT Lymphoma.

Nodular gastritis is a Helicobacter pylori-related gastritis with endoscopically proven gooseflesh skin-like nodularity in the gastric antrum. Although an association between nodular gastritis and gastric malignancies has been suggested, there is neither a treatment strategy nor a treatment guideline for this condition because of its relative rarity. We have recently experienced two cases of diffuse-type nodular gastritis invading both the antrum and corpus of the stomach with atypical findings that required specific treatments in two young females. The first patient was diagnosed with a suspicious low grade gastric mucosa associated lymphoid tissue (MALT) lymphoma lesion on a diffuse-type nodular gastritis, and was cured by H. pylori eradication. The second patient was diagnosed with a signet cell type gastric cancer on a diffuse-type nodular gastritis, and was cured by surgical resection. When considering the nature and significance of these gastric lesions, a link between nodular gastritis and gastric malignancy should be considered, especially in young women who have diffuse-type nodular gastritis involving both the antrum and corpus of the stomach.