Significant Changes In Samples Research Articles

The effect of synthesized Cu2O on the microbial corrosion inhibition of urban sewer systems

The microbial corrosion of reinforced concrete sewers was inhibited by synthesized cuprous oxide (Cu2O) nanoparticles. The antibacterial characteristics of Cu2O on Acidithiobacillus thiooxidans were investigated by temporal variation of pH, turbidity, and bacterial counting. Three reinforced concrete samples with different weight percentages of electrodeposited Cu2O (0.06 wt%, 0.055 wt %, 0.05 wt %) were used. The bacterial counting showed that the number of bacteria in samples with 0.06, 0.055, and 0.05 wt% of Cu2O was 4.82, 4.42, and 2.94 times lower than the blank sample (BS), respectively. After bacterial growth, the optical density measurement showed that the percentage of turbidity enhancement for samples with 0.06, 0.055, and 0.05 wt% of Cu2O were 108%, 118%, 165%, respectively, while it was 412% for the BS. Moreover, the pilot stage's pH monitoring revealed that the electrodeposited Cu2O lowered the concentration of hydronium between 7 to 81 times compared to the BS. Experiments indicated that slight changes in the amount of electrodeposited Cu2O lead to significant changes in samples' ability to hinder bacterial growth and microbial-induced corrosion.

Intestinal Virome in Patients With Alcoholic Hepatitis.

Alcoholic hepatitis (AH) is a severe manifestation of alcohol-associated liver disease (ALD) with high mortality. Although gut bacteria and fungi modulate disease severity, little is known about the effects of the viral microbiome (virome) in patients with ALD. We extracted virus-like particles from 89 patients with AH who were enrolled in a multicenter observational study, 36 with alcohol use disorder (AUD), and 17 persons without AUD (controls). Virus-like particles from fecal samples were fractionated using differential filtration techniques, and metagenomic sequencing was performed to characterize intestinal viromes. We observed an increased viral diversity in fecal samples from patients with ALD, with the most significant changes in samples from patients with AH. Escherichia-, Enterobacteria-, and Enterococcus phages were over-represented in fecal samples from patients with AH, along with significant increases in mammalian viruses such as Parvoviridae and Herpesviridae. Antibiotic treatment was associated with higher viral diversity. Specific viral taxa, such as Staphylococcus phages and Herpesviridae, were associated with increased disease severity, indicated by a higher median Model for End-Stage Liver Disease score, and associated with increased 90-day mortality. In conclusion, intestinal viral taxa are altered in fecal samples from patients with AH and associated with disease severity and mortality. Our study describes an intestinal virome signature associated with AH.

Effect of acidic and alkali shocks on expression of efaA gene in Enterococcus faecalis, isolated from root canal infection

Enterococcus faecalis is an important opportunistic infectious agent involving the oral cavity and endodontics. The aim of this study was to evaluate the expression ratio of efaA gene in biofilm producer E. faecalis before and after receiving acidic and alkali shocks. One hundred E. faecalis isolates were gathered from 170 infectious root canals. After analysis of biofilm formation by the Microtiterplate method, the presence of efaA gene was examined by PCR and its expression was evaluated by Real-time PCR, one before applying any stressed to isolates and another by applying acidic and alkali shock. Chi-square method was used for statistical analysis. Eighty-two percent of samples had efaA gene. Evaluation of biofilm formation, 49% of the isolates were strong biofilm producer, 42% moderate and 10 % of them had no biofilm. 59% overexpression of efaA gene was observed in biofilm producer isolates, while there were no significant changes in samples with acidic stress and decreased expression after alkali shock. Findings of the present study, indicates importance of efaA gene in biofilm formation and pathogenesis of E. faecalis. Acid had no effect of expression of this gene but alkali reduced expression of this gene in a significant level. These results indicate the importance of efaA and acidic conditions in biofilm production by E. faecalis.

Stability Analysis of Vascular Endothelial Growth Factor in Cerebrospinal Fluid

Vascular endothelial growth factor (VEGF) is a promising biological marker and prognostic indicator in many neurological diseases. Although VEGF concentrations in plasma and cerebrospinal fluid (CSF) are increasingly reported, CSF-VEGF stability pre- and during-assay procedures is seldom evaluated. In the current study, we investigated VEGF variability and stability in CSF related to sample preparation, storage, and routine experimental procedures. Results showed that contaminant cell breakdown or aggregation can occur gradually before sample processing. However, after the removal of contaminant cell components, CSF-VEGF levels did not show significant changes in samples incubated at room temperature for 5 h, thawed/refrozen for 6 cycles. Samples preserved at -80 °C for up to 7 years continued to show measurable levels. Since some cellular components such as platelets contain a large amount of releasable VEGF, we conclude that CSF samples should be processed as soon as possible to carefully remove all cellular components and prevent possible consequent release of VEGF into CSF. After centrifugation to remove cellular contents, VEGF in CSF was relatively stable during routine experimental procedures and storage.

Effect of One Year of Cryopreservation on the Activity of Lysosomal Hydrolases from EBV‐Transformed Lymphocytes

Background. The Epstein-Barr virus (EBV) was used as an agent of B lymphocyte proliferation for subsequent diagnosis of lysosomal storage disease. Due to the constant handling of long-preserved samples in our cell bank, we decided to observe the behavior and then compare cultured and frozen samples for at least one year's cryopreservation. Methods. Twenty-five samples from healthy individuals were used to assess the possible changes in activity of enzymes β-galactosidase, β-glucosidase, α-iduronidase, α-galactosidase, and α-glucosidase. Transmission electron microscopy was used to confirm cell transformation of B lymphocytes into EBV-infected cells, generating lymphoblastoid cell lines. Results. Transmission electron microscopy findings confirmed previous reports in the literature that is, significant and evident morphological changes in the nucleus occur after day 12 and the consequent cell transformation into EBV-infected cells. After thawing and subsequent treatment with the five enzymes utilized, we observed no significant changes in samples cryopreserved for more than one year, as compared to samples cultured for 12 days.

Metabolite profiling of fecal water extracts from human colorectal cancer

Colorectal cancer is the second leading cause of cancer death in developed countries. There is a need for better preventive strategies to improve the outcome of this disease. The increasing availability of high-throughput methodologies opens up new possibilities for screening new markers. The application of NMR metabolic profiling to fecal water extracts has interesting potential as a diagnostic tool for detecting colorectal cancer. We obtained NMR metabolic profiles of fecal water extracts from patients with colorectal cancer and healthy individuals, to characterize possible differences between them and to identify potential diagnostic markers. Our results show that metabolic profiling of fecal water extracts is a cheap, reproducible and effective method for detecting colorectal cancer markers and therefore complements other stool-screening methods. A low concentration of short-chain fatty acids, such as acetate and butyrate, previously associated with the development of colorectal cancer, appears to be the most effective marker. Concentrations of proline and cysteine, which are major components of most colonic epithelium mucus glycoproteins, also display significant changes in samples from colorectal cancer. Differentiation between fecal water extracts from controls and patients with colorectal cancer by NMR spectroscopy combined with chemometric techniques opens up new possibilities for developing new, efficient, high-throughput screening protocols.

Effects of the injection-molding temperatures and pyrolysis cycles on the butadiene phase of high-impact polystyrene

Recycling is a thermal process in which polymers are melted to produce new products. It is possible that these thermal processes could modify their mechanical and thermal properties. Polymer degradation can be characterized with thermogravimetric analysis and differential scanning calorimetry. Recycled materials tested with these methods have shown variations in some thermal properties, such as the glass-transition temperature and thermal degradation onset, but the sensitivity of these methods is not sufficient to investigate the changes in the characteristics of polymers when materials are exposed to moderate temperature conditions or several thermal cycles. To study these structural changes, a much more sensitive technique, such as pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS), is needed. Small variations in the structure can be determined by Py–GC/MS. Each pyrolysis product can be identified by its retention time and mass spectrum with the use of reference literature. In this work, we have studied structural changes in high-impact polystyrene as a function of the injection-molding temperature and pyrolysis cycles. The results do not show significant changes in samples processed at different temperatures with Py–GC/MS, but the values of the pyrolysis products differ as a function of the pyrolysis cycles. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

Effects of Oxygen Absorber and Temperature on ω3 Polyunsaturated Fatty Acids of Sardine Oil during Storage

ABSTRACTTo prevent loss of w3 polyunsaturated fatty acids over long‐term preservation, the effects of temperature and oxygen absorber on the fatty acids of sardine oil stored in air‐tight film were studied. The fatty acids of sardine oil and lipids in the diet of experimental animals rapidly decreased over 1 month at 22°C. The amounts in the diet decreased slowly at 2°C; however, no alterations in the oil samples were observed for 6 months. Also, the amounts did not change at ‐30°C. Significant changes in samples treated with oxygen absorber were not observed under all temperatures during 6 months storage (P > 0.05). These results indicate that treatment with an oxygen absorber and/or freezing can prevent ω3 polyunsaturated fatty acids of fish oil from decreasing during storage.