101 research outputs found
A study of the photolysis of Porphyromonas gingivalis
No full textPorphyromonas gingivalis has been implicated in the development of periodontal diseases and the current treatments used are not entirely successful in eradicating periodontopathogens from the pocket. Photodynamic therapy has been successfully used in the treatment of a number of cancers and has been used in vitro to kill a variety of bacteria. Lethal photosensitisation of Por. gingivalis using toluidine blue O (TBO) with Helium/Neon (HeNe) laser light was compared to lethal photosensitisation using aluminium disulphonated phthalocyanine (AIPCS2) with gallium aluminium arsenide (GaAs) laser light. It was found that there were substantial reductions in viable counts using TBO/HeNe laser light and when using AIPcS2/GaAs laser light. Substantial kills were obtained when lethal photosensitisation was carried out under conditions most likely to be encountered in the periodontal pocket (presence of serum, increasing pH values, different Por. gingivalis strains and biofilm-grown bacteria). The involvement of singlet oxygen and hydroxyl radicals was investigated by carrying out lethal photosensitisation in the presence of the singlet oxygen enhancer, deuterium oxide. It was found that singlet oxygen and possibly hydroxyl radicals are involved in the killing of Por. gingivalis. Distribution studies using 3H-TBO showed that most of the 3H-TBO was bound to the outer membrane and SDS-PAGE analysis showed that there were alterations to the outer and plasma membrane proteins from cells sensitised with TBO and exposed to laser light. It was also found that there was DNA degradation as a result of lethal photosensitisation. The final part of the study involved conjugating antibody against surface components of Por. gingivalis with TBO and specifically to target Por gingivalis to light-induced killing when in the presence of commensal bacteria or host tissue. When sensitised with the antibody/TBO conjugate and exposed to laser light, there were no significant reductions in viable counts of Streptococcus sanguis or human gingival fibroblasts, whereas all of the Por. gingivalis present were killed. In conclusion, Por. gingivalis can be killed effectively (100%) when sensitised with 82 μM TBO at an energy dose of 4.4 J. Type II and possibly type I mechanisms are involved in the killing of Por gingivalis and the outer and plasma membrane proteins and DNA are adversely affected by lethal photosensitisation. Damage to oral commensal organisms and oral host tissue can be avoided by using laser light in combination with TBO conjugated to antibody against Por gingivalis surface components
Simultaneous Removal of Organic Matter and Nutrients from High Strength Organic Wastewater Using Sequencing Batch Reactor (SBR)
No full textIndustrial wastewater discharges often contain high levels of organic matter and nutrients, which can lead to eutrophication and constitute a serious hazard to receiving waters and aquatic life. The purpose of this study was to examine the efficacy of using a sequencing batch reactor (SBR) to treat high-strength organic wastewater for the removal of both chemical oxygen demand (COD) and nutrients (nitrogen and phosphorus). At a constant COD concentration of approximately 1000 mg/L, the effects of cycle time (3 and 9 h) and various C:N:P ratios (100:5:2, 100:5:1, 100:10:1, and 100:10:2) were investigated using four identical SBRs (R1, R2, R3, and R4). According to experimental data, a significant high removal, i.e., 90%, 98.5%, and 84.8%, was observed for COD, NH3-N, and PO43−-P, respectively, when C:N:P was 100:5:1, at a cycle time of 3 h. Additionally, when cycle time was increased to 9 h, the highest levels of COD removal (95.7%), NH3-N removal (99.6%), and PO43−-P removal (90.31%) were accomplished. Also, in order to comprehend the primary impacts and interactions among the various process variables, the data was statistically examined using analysis of variance (ANOVA) at a 95% confidence level, which revealed that the interaction of cycle time and C/N ratio, cycle time and C/P ratio is significant for COD and NH3-N removal. However, the same interaction was found to be insignificant for PO43−-P removal. Sludge volume index (SVI30 and SVI10) and sludge settleability were studied, and the best settling was found in R3 with SVI30 of 55 mL/g after 9 h. Further evidence that flocs were present in reactors came from an average ratio of SVI 30/SVI 10 = 0.70 after 9 h and 0.60 after 3 h
Possible Molecular Mediators Involved and Mechanistic Insight into Fibromyalgia and Associated Co-morbidities
No full text
Effects of nanoplastics and compound pollutants containing nanoplastics on plants, microorganisms and rhizosphere systems: A review
No full textNanoplastics (NPs) are the most widespread and least detectable type of plastic pollutant due to their extremely small particle size. The root system of plants has become an important pathway for NPs to enter the food chain from the natural environment. By combining with heavy metals or organic pollutants, NPs can exhibit greater biological toxicity compared to single pollutants. Although many studies have focused on the phytotoxicity and microbial toxicity of NPs separately, to the best of our knowledge, no review summarizes the toxicity of NPs from the perspective of the plant rhizosphere system with a combination of pollutants. By summarizing samples from 2015 to 2025, this review highlights that NPs can affect photosynthesis, gene transcription, and enzyme activity in both plants and microorganisms. NPs with large particle size can also disrupt the chemical balance of the rhizosphere environment and intensify competition for nutrients between plants and microorganisms, ultimately affecting the geochemical cycle. NPs of different particle sizes and concentrations can poison various biological structures, from surface layers to genetic material. In compound pollutants, where NPs combine with other contaminants, they can further disrupt elemental cycles in plants, reduce microbial community diversity, and increase the accumulation of other pollutants in the rhizosphere system compared to single pollutants. These findings provide new insights into the biotoxicity of NPs and the degradation of compound pollutants containing NPs. In addition, combined with the research results of this review, some research prospects on the relationship between NPs and rhizosphere systems are given
Preparing and presenting effective abstracts and posters in psychiatry.
No full textPresenting an abstract and a poster gives scientists from all fields, including psychiatry, an important opportunity to introduce their research to others. Researchers and mental health professionals at all levels of career development can use several media resources to assist them with the technical aspects of preparing an abstract or a poster. This article will focus on major principles associated with preparing and presenting an abstract and a poster at a scientific meeting. A literature search using NIH PubMed was conducted to identify peer and nonpeer-reviewed articles that provide methods for effective abstract and poster presentation for the period of 1966 to June 2014. First, the author reviews the purpose and relative importance of abstracts and posters in academic settings. Next, the author describes the qualities of an effective abstract and poster and common pitfalls that may occur. Finally, the author presents a systematic approach to preparing and presenting an abstract and a poster in a scientific setting. Several sources consistently suggest that readability, organization, and succinctness are qualities that make an effective and successful abstract and poster. Mental health professionals in all stages of their career development may benefit from following these guidelines in presenting their scientific work
Tailoring the Substitution Pattern on 1,3,5-Triazine for Targeting Cyclooxygenase-2: Discovery and Structure–Activity Relationship of Triazine–4-Aminophenylmorpholin-3-one Hybrids that Reverse Algesia and Inflammation in Swiss Albino Mice
No full textHere,
we report analgesic and anti-inflammatory activity of a series
of compounds obtained by appending 4-aminophenylmorpholin-3-one and
acyclic, cyclic, or heterocyclic moieties on 1,3,5-triazine. The structures
of compounds 4b and 6b are optimized for
the best inhibition of COX-2 with IC50 values of 0.06 and
0.08 μM, respectively, and selectivity over COX-1 of 166 and
>125, respectively. At the dose of 5 mg kg–1,
these
compounds significantly reduced acetic acid induced writhings, and
their ED50 values were found to be 2.2 and 1.9 mg kg–1, respectively. Besides the cell-based and animal-based
experiments showing the modes of action of these compounds targeting
COX-2, the interaction behavior of 4b with COX-2 was
also characterized, with physicochemical experiments including ITC,
NMR, UV–vis, and molecular-modeling studies. Characteristically,
these compounds interact with R120, Y355, and W385, the residues responsible
for holding the substrate and mediating the process of electron transfer
during the metabolic phase of the enzyme
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