Zobrazení zdroje stránky Grahammills1843

Changes in the operational taxonomic units revealed that the top abundant ureC genes were mostly consistent between gDNA and cDNA, and most differences occurred in the ureC genes with lower abundances. These results revealed distinct ureolytic bacteria community profiles based on gDNA and cDNA. The dominant ureolytic bacteria had high transcriptional activity, and the differential were mainly distributed in the genus of low abundance.The aim of disinfection is to reduce the number of microorganisms on surfaces which is a challenge due to biofilms. In the present study, six quinolone resistant Escherichia coli (QREC) strains with three different biofilm matrix compositions were included to assess the log10 colony forming units (CFU) reduction effect of three disinfectants at various exposure times on biofilm of different ages and morphotypes. Biofilm was formed on stainless steel coupons for two and five days before transferred to tubes with Virocid 0, 25%, VirkonS 1%, and TP990 1% and left for various exposure times. The biofilms were scraped off and serial dilutions were spread on blood agar plates where colony forming units (CFU) were counted. A mean log10 CFU reduction ≥4 was seen on two-day-old biofilm with VirkonS and Virocid (30 min) but not on five-day old biofilm. TP990 did not display sufficient effect under the conditions tested. The bactericidal effect was inferior to that reported on planktonic bacteria. The findings of this study should be considered when establishing both disinfectant routines and standard susceptibility tests, which further should accommodate E. coli biofilms and not only Pseudomonas as is the case today.We synthesized manganese ferrite (MnFe2O4) nanoparticles of different sizes by varying pH during chemical co-precipitation procedure and modified their surfaces with polysaccharide chitosan (CS) to investigate characteristics of hyperthermia and magnetic resonance imaging (MRI). Structural features were analyzed by X-ray diffraction (XRD), high-resolution transmission electron microscopy (TEM), selected area diffraction (SAED) patterns, and Mössbauer spectroscopy to confirm the formation of superparamagnetic MnFe2O4 nanoparticles with a size range of 5-15 nm for pH of 9-12. The hydrodynamic sizes of nanoparticles were less than 250 nm with a polydispersity index of 0.3, whereas the zeta potentials were higher than 30 mV to ensure electrostatic repulsion for stable colloidal suspension. MRI properties at 7T demonstrated that transverse relaxation (T2) doubled as the size of CS-coated MnFe2O4 nanoparticles tripled in vitro. However, longitudinal relaxation (T1) was strongest for the smallest CS-coated MnFe2O4 nanoparticles, as revealed by in vivo positive contrast MRI angiography. Cytotoxicity assay on HeLa cells showed CS-coated MnFe2O4 nanoparticles is viable regardless of ambient pH, whereas hyperthermia studies revealed that both the maximum temperature and specific loss power obtained by alternating magnetic field exposure depended on nanoparticle size and concentration. Overall, these results reveal the exciting potential of CS-coated MnFe2O4 nanoparticles in MRI and hyperthermia studies for biomedical research.Survivors of the 2003 SARS epidemic were found to have higher rates of adverse mental conditions. This study aimed to assess cognitive function in women delivering during the COVID-19 pandemic, as compared to women who delivered before the COVID-19 pandemic. A cohort study was performed during the immediate postpartum period of women delivering singletons at term. Cognitive function was assessed using an objective neurocognitive test (Symbol Digit Modalities Test SDMT90, SDMT4) and a subjective self-estimation questionnaire (Attention Function Index AFI). The exposed group was recruited during the COVID-19 outbreak in Israel (May 2020), whereas the comparison group consisted of women delivering at the same medical center before the COVID-19 pandemic (2016-2017). Multivariable regression models were constructed to control potential confounders. There were 79 parturients recruited during the COVID-19 pandemic and compared with 123 women who delivered before the COVID-19 pandemic. Women delivering during the COVID-19 pandemic scored lower in the subjective AFI test compared to the unexposed group (70.0 ± 15.4 vs. 75.1 ± 14.7, p = 0.018). However, no significant difference was found in the objective SDMT tests scores. These results remained similar in the multivariable regression models when controlling for maternal age, ethnicity and time from admission to assessment, for AFI, SDMT90 and SDMT4 scores (p = 0.014; p = 0.734; p = 0.786; respectively). While no significant difference was found in objective tests, our findings propose that the exposure to the COVID-19 pandemic is independently associated with a significant decrease in subjective maternal cognitive function during the immediate postpartum period.The aim of this work is to simulate the fragmentation of bullets impacted through granular media, in this case, sand. In order to validate the simulation, a group of experiments were conducted with the sand contained in two different box prototypes. The walls of the first box were constructed with fiberglass and the second with plywood. The prototypes were subjected to the impact force of bullets fired 15 m away from the box. After the shots, X-ray photographs were taken to observe the penetration depth. Transient numerical analyses were conducted to simulate these physical phenomena by using the smooth particle hydrodynamics (SPH) module of ANSYS® 2019 AUTODYN software. Advantageously, this module considers the granular media as a group of uniform particles capable of transferring kinetic energy during the elastic collision component of an impact. The experimental results demonstrated a reduction in the maximum bullet kinetic energy of 2750 J to 100 J in 0.8 ms. The numerical results compared with the X-ray photographs showed similar results demonstrating the capability of sand to dissipate kinetic energy and the fragmentation of the bullet caused at the moment of impact.Avenanthramides are a group of phenolic alkaloids that have been shown to have anti-inflammatory, anti-oxidant, anti-atherogenic, and vasodilation effects. The aim of the present study was to investigate the neuroprotective effect of avenanthramide-c (Avn-c) in focal brain ischemia and reperfusion injury using middle cerebral artery occlusion (MCAo) model with mice. Male C57BL/6 mice were divided into 4 groups sham, control (MCAo), Avn-c, and Avn-c + LY294002 (phosphoinositide 3-kinase inhibitor) group. They were subjected to 60 min MCAo followed by reperfusion. Brain infarct volume and neurological deficit scores were measured after 24 h of reperfusion. We evaluated the blood brain barrier (BBB) integrity (ZO-1, VE-cadherin and occludin) and apoptosis (Bax, Bcl2, caspase3, Cytochrome C, and poly ADP ribose polymerase(PARP)-1). We also measured GSK3β for evaluation of the downstream mechanism of Akt. We examined the effect of the Avn-c in the phosphoinositide 3-kinase pathway. Avn-c reduced neurological score and infarction size. Avn-c inhibited the MCAo-induced disruption of tight junction proteins. Avn-c decreased apoptotic protein expression (Bax, Cytochrome C, and cleaved PARP-1) and increased anti-apoptotic protein expression (Bcl2) after MCAo. Akt and GSK3β were decreased in MCAo group and were restored in Avn-c group. This effect of Avn-c was abolished by PI3K inhibitor. In summary, Avn-c showed neuroprotective effects through PI3K-Akt-GSK3β signaling pathway.Ecological concerns have recently led to the increasing trend to upgrade carbon contained in waste streams into valuable chemicals. One of these components is acetate. Its microbial upgrading is possible in various species, with Escherichia coli being the best-studied. Several chemicals derived from acetate have already been successfully produced in E. coli on a laboratory scale, including acetone, itaconic acid, mevalonate, and tyrosine. As acetate is a carbon source with a low energy content compared to glucose or glycerol, energy- and redox-balancing plays an important role in acetate-based growth and production. In addition to the energetic challenges, acetate has an inhibitory effect on microorganisms, reducing growth rates, and limiting product concentrations. Moreover, extensive metabolic engineering is necessary to obtain a broad range of acetate-based products. In this review, we illustrate some of the necessary energetic considerations to establish robust production processes by presenting calculations of maximum theoretical product and carbon yields. Moreover, different strategies to deal with energetic and metabolic challenges are presented. Finally, we summarize ways to alleviate acetate toxicity and give an overview of process engineering measures that enable sustainable acetate-based production of value-added chemicals.Glioblastomas (GBs) are malignant brain tumours with poor prognosis even after aggressive therapy. Programmed cell death-1 (PD-1) immune checkpoint blockade is a promising strategy in many types of cancer, but its therapeutic effects in GB remain low and associated with immune infiltration. Previous work suggests that oscillations of magnetic resonance spectroscopic imaging (MRSI)-based response pattern with chemotherapy could act as a biomarker of efficient immune system attack onto GBs. The presence of such oscillations with other monotherapies such as anti-PD-1 would reinforce its monitoring potential. Here, we confirm that the oscillatory behaviour of the response biomarker is also detected in mice treated with anti PD-1 immunotherapy both in combination with temozolomide and as monotherapy. This indicates that the spectral pattern changes observed during therapy response are shared by different therapeutic strategies, provided the host immune system is elicited and able to productively attack tumour cells. Moreover, the participation of the immune system in response is also supported by the rate of cured animals observed with different therapeutic strategies (in the range of 50-100% depending on the treatment), which also held long-term immune memory against tumour cells re-challenge. Taken together, our findings open the way for a translational use of the MRSI-based biomarker in patient-tailored GB therapy, including immunotherapy, for which reliable non-invasive biomarkers are still missing.The mechanism of natural-hazard-triggered technological (Na-tech) cascading disasters is complex, and the extent to which their damage is aggravated by various secondary events is difficult to quantify. This study selected a large oil depot and constructed a full-scale three-dimensional scene model based on the surrounding geographical environment. The discrete element method (DEM), finite element method (FEM) and finite volume method (FVM) were employed to conduct numerical simulations of the process and consequences of the following Na-tech disasters heavy-rainfall-induced landslide → blocks impacting an oil transportation pipeline and breaking it → oil leaking, spreading and resulting in a vapor cloud explosion. According to the results, the maximum impact of the 1 m3 of sliding mass formed in the landslide on the pipeline was over 7 MN (meganewton), and the pipeline fractured completely when it was loaded with a contact force of only 1.44 MN. The numerical simulation methods revealed the mechanism of Na-tech cascading disasters in a large oil depot and quantified the consequences of each event in the cascading disasters.