Inhibitory Effect of Gamma-Irradiated Chitosan on the Growth of Denitrifiers

In order to find an environmentally benign substitute to hazardous inhibitory agents, the inhibitory effect of γ-irradiated chitosans against a mixed culture of denitrifying bacteria was experimentally evaluated. Unlike other studies using pure aerobic cultures, the observed effect was not a complete inhibition but a transient inhibition reflected by prolonged lag phases and reduced growth rates. Raw chitosan under acid conditions (pH 6.3) exerted the strongest inhibition followed by the 100 kGy and 500 kGy irradiated chitosans, respectively. Therefore, because the molecular weight of chitosan decreases with the degree of γ-irradiation, the inhibitory properties of chitosan due to its high molecular weight were more relevant than the inhibitory properties gained due to the modification of the surface charge and/or chemical structure by γ-irradiation. High dosage of γ-irradiated appeared to increase the growth of mixed denitrifying bacteria in acid pH media. However, in neutral pH media, high dosage of γ-irradiation appeared to enhance the inhibitory effect of chitosan

Physiological and Pathological Mitochondrial Clearance Is Related to Pectoralis Major Muscle Pathogenesis in Broilers With Wooden Breast Syndrome

Wooden breast syndrome (WB) constitutes an emerging myopathy in the pectoralis major muscle (PM) of broiler chickens, characterized by myofiber hypertrophy and degeneration along with severe fibrosis. WB pathogenesis has been considered to involve hypoxia induced by rapid growth of the PM. In this study, we focused on mitochondrial morphology and dynamics in the myofibers, as these organelles are sensitive to damage by hypoxia, and examined the effects on WB pathogenesis. Specifically, the PMs of a flock of 35 broilers at 50 days of age were evaluated. First, the severity of disease in each bird was determined by measuring histopathological indices including the fibrotic area (FA) in the muscle and circularity of myofibers (CM). These values were 29.4 ± 9.6% and 0.70 ± 0.042, respectively, showing variety among the flock. Myofiber vacuolization was observed in all birds including numerous small- or large-rimmed vacuoles, with the former consisting of ultrastructurally autophagosome-like vacuoles engulfing degenerated mitochondria. The large-rimmed vacuoles frequently occurred in the PMs with more severe FA and CM, indicating a relationship between altered autophagy/mitophagy and WB severity. Next, the expression levels of hypoxia-adaptive and mitochondrial dynamics-related genes were analyzed, and their correlations with the histopathological indices were examined. The histopathological indices were negatively correlated with the expression of vascular endothelial growth factor A (VEGFA), indicating that less angiogenesis owing to weakened hypoxia-inducible factor signaling induces more severe WB pathology. In addition, the observed negative correlation with mitochondrial dynamics-related genes implied that WB pathology deteriorates concomitant with reduced mitochondrial dynamics. Furthermore, the expression of mitochondrial dynamics-related genes showed strong positive correlation with that of VEGFA and autophagy-/mitophagy-related genes. These results revealed that the PMs of broilers possess the mechanism of physiological clearance of mitochondria damaged by the hypoxia resulting from the continuous mitochondrial dynamics and autophagy/mitophagy accompanying rapid PM growth. In turn, the altered mitochondrial clearance induced by chronic hypoxia and the accumulation of damaged mitochondria likely underly the severe pathological features of WB.ArticleFrontiers in Pharmacology.11:579(2020)journal articl

Bioethanol Production via Syngas Fermentation of Clostridium Ljungdahlii in a Hollow Fiber Membrane Supported Bioreactor

Ethanol production via syngas fermentation obtained from lignocellulose gasification provides a method to completely utilize all the carbon content from lignocellulosic feedstock. A low mass transfer rate of less soluble gas CO and H2 to liquid has been considered as the major bottleneck of the overall process; thus, microporous membrane was proposed as a gas diffuser to improve gas-to-liquid mass transfer. In this study, a liquid batch of syngas fermentation employing Clostridium ljungdahlii with continuous gas supply was carried out with the configuration of a bioreactor connected to the microporous hydrophobic polypropylene hollow fiber membrane (HFM) as a gas diffuser. Liquid recirculation between the fermentation vessel and membrane module was applied to enhance the gas-liquid contact as well as cell-recycle. Fermentation performance with and without HFM was compared and evaluated by cell growth, CO utilization, ethanol yield, and productivity. A higher ethanol yield, 0.22 mol/mol, was achieved by the system of HFM-supported bioreactor with higher ethanol titter of 1.09 g/L and ethanol to acetate molar ratio of 1.43 mol/mol. The obtained result indicates HMF-supported bioreactor is the best fermentation system compared to STR without the membrane

C-arm Cone-beam CT-guided Needle Biopsies through the Erector Spinal Muscle for Posterior Thoracic Pulmonary Lesions

This study investigated retrospectively the diagnostic yield and complication rate of transthoracic needle biopsies for posterior thoracic pulmonary lesions using C-arm cone-beam computed tomography （CBCT）. The risk factors for pulmonary hemorrhage were evaluated. Our study included 113 patients with 113 posterior pulmonary lesions （mean longest diameter: 30.6mm, and mean depth: 4.7mm） through the erector spinal muscles using a 19/20-gauge coaxial system. The diagnostic performances of procedures for malignant lesions and the incidence of complications after biopsies were also assessed. The patient-related and procedure-related variables were investigated. Risk factors for pulmonary hemorrhage were analyzed with a multivariate logistic regression analysis. Findings revealed 99 malignant, 13 benign, and one intermediate lesion. Sensitivity, specificity, and diagnostic accuracy rates were 100％ （99/99）, 92.3％ （12/13）, and 99.1％ （111/112）, respectively. Air embolization, hemothorax, hemoptysis, pneumothorax, and pulmonary hemorrhage, occurred in 0, 2, 12, 48, and 70 procedures. The averaged spinous process-pleura depth and the traversed lung parenchyma depth achieved by the introducer needles were 54.2mm and 27.4mm, respectively. The needle position at the pleural puncture site within the intercostal space was in middle （31％） and inferior （69％） areas. The incidence of pulmonary hemorrhage was significantly higher in smaller lesions （p＝0.001）. Manual evacuation was performed in five procedures for patients with pneumothorax. The chest tube placement （trocar＞8 Fr） was performed in two procedures in patients with hemothorax and pneumothorax. In conclusion, the biopsy method with a posterior intercostal approach for posterior thoracic pulmonary lesions yielded high diagnostic accuracy and few major complications

X-ray Spectra from Neon-like Tungdten Ions in the Interaction with Electrons

X-ray spectra from highly charged tungsten ions have been observed in the interaction with an electron beam at energies ranging from 14 to 1.5 keV by using an electron beam ion trap (EBIT). In this energy range, resonant x-ray transitions at around 9 keV predominantly take place through dielectronic recombination processes. The measured spectra were compared with the theoretical calculation with the Hebrew University Lawrence Livermore Atomic Code (HULLAC)

Evaluation of dose delivery accuracy of Gamma Knife by polymer gel dosimetry

The BANG ™ polymer gel dosimeter was used to evaluate 3D absorbed dose distributions in tissue delivered with Gamma Knife stereotactic radiosurgery systems. We compared dose distributions calculated with Leksell GammaPlan (LGP) treatment-planning software with dose distributions measured with the polymer gel dosimeter for single-shot irradiations. Head-sized spherical glass vessels filled with the polymer gel were irradiated with Gamma Knife. The phantoms were scanned with a 1.0T MRI scanner. The Hahn spin-echo sequence with two echoes was used for the MRI scans. Calibration relations between the spin-spin relaxation rate and the absorbed dose were obtained by using small cylindrical vials, which were filled with the polymer gel from the same batch as for the spherical phantom. We made voxel-by-voxel comparisons of measured and calculated dose distributions for 31 × 31 × 31 dose matrix elements. With the 3D dose data we calculated the tumor control probability (TCP) and normal tissue complication probability (NTCP) for a simple model. For the maximum dose of 100 Gy, the mean and one standard deviation of differences between the measured and the calculated doses were th