Use of scanning electron microscopy and energy dispersive X-ray for urine analysis: A preliminary investigation

Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) are powerful tools to study the ultrastructure of numerous specimens and to determine their elemental composition, respectively. However, results have not yet been reported on their application to urine samples in routine clinical laboratory practice. Herein we investigate urine sediment by using SEM and EDX to detect and identify different urine components. A total of 206 urine samples from patients with and without urinary tract infections were analyzed using SEM and EDX. Microorganisms, crystals, epithelial cells, leukocytes, and erythrocytes were targeted in urine sediment samples. The identification of urine components was based on their morphology, size, contrast, and elemental composition. SEM-analysis allowed us to identify and classify microorganisms in urine sediments into the categories of gram-negative bacilli, cluster cocci, chain cocci, gram-negative bacilli, gram-positive bacilli, and yeasts. In addition, various types of epithelial cells such as renal, transitional, and squamous epithelial cells were found. Furthermore, leukocytes and erythrocytes were well identified, with the detection of various morphological forms of erythrocytes, such as dysmorphic and isomorphic erythrocytes. Using SEM-EDX analysis, calcium oxalate was the most frequently-identified crystal (92.0%), with prominent peaks of C, O, and Ca elements, followed by struvite (6%), with peaks of Mg, P, O, and N. These preliminary data suggest that the two complementary SEM-EDX analyses can be used to detect and identify microorganisms and crystals in urine samples. Further studies are still needed to apply SEM-EDX to urine sediment analysis. SEM-EDX analyses provided comparative results with the routine results, with accurate identification, high resolution and deep focus compared to the routine urinalysis SEM-analysis allowed us to identify and classify microorganisms in urine sediments into the categories of gram-negative bacilli, cluster cocci, chain cocci, gram-negative bacilli, gram-positive bacilli and yeasts. SEM-EDX analysis enabled the accurate identification of crystals based on both morphology and elemental composition.

Comparative evaluation of remineralizing potential of commercially available agents MI paste, Remin pro, and Clinpro using Scanning Electron Microscope and Energy Dispersive X-ray: An in vitro study

Background:

According to recent approaches, the prevention of initial dental caries is achieved using certain noninvasive methods. One such method is the topical application of remineralizing agents. Various remineralizing products are commercially available, but their efficacy is uncertain.

Aim:

The aim of the study was to evaluate the remineralizing potential of MI, Reminpro, and Clinpro using scanning electron microscope (SEM) and energy dispersive X-ray (EDX).

Methodology:

Forty extracted human premolars were collected. The samples were decoronated and the crown portion was coated with nail varnish leaving behind a 3 mm × 3 mm window on the labial surface. The samples were soaked in demineralizing solution for 4 days to create an artificial lesion, followed by SEM-EDX analysis. The samples were then randomly divided into 4 groups Control, MI, Remin Pro, and Clinpro with ten samples each. The remineralizing agents were applied according to the group and subjected to pH cycling for 21 days which was followed by SEM-EDX analysis. Data obtained were statistically analyzed using SPSS IBM version 23 (ANOVA, post hoc-Tukey, and Paired-t-test).

Results:

Ca and P were increased after remineralization in all groups. Between groups, the increase was more for ReminPro, followed by Clinpro and MI.

Conclusion:

In this study, the remineralizing potential of Remin Pro was effectively more, followed by Clinpro and MI.

Aerobic granular sludge for simultaneous accumulation of mineral phosphorus and removal of nitrogen via nitrite in wastewater

Lab-scale experiments were conducted to investigate the aerobic granular sludge process for simultaneous phosphorus (P) accumulation by chemical precipitation and biological nitrogen removal via nitrite. The P-rich granules were successfully incubated in a sequencing batch reactor, in which simultaneous nitrification-denitrification occurred via nitrite. The average diameter of the P-rich granules was 2.47 mm and the P content in granules was much higher than that in other granular systems with enhanced biological phosphorus removal process. Filamentous bacteria (genus Thiothrix) in the granules and the long sludge retention time (30 d) of the granular system played a crucial role in accumulation of precipitated phosphate. X-ray diffraction analysis, scanning electron microscopy coupled with energy dispersive X-ray and the experimental design using response surface methodology confirmed that the main mineral patterns in P-rich granules were Ca-Mg phosphate and whitlockite.

Structural properties of silver doped hydroxyapatite and their biocompatibility

The aim of this study was to obtain a novel hydroxyapatite-based material with high biocompatibility. The structural properties of the samples were well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). The X-ray diffraction studies revealed the characteristic peaks of hydroxyapatite in each sample. Other phases or impurities were not observed. The scanning electron microscopy observations suggest that the doping components have no influence on the surface morphology of the samples, which reveals a homogeneous aspect of the synthesized particles for all samples. The presence of calcium (Ca), phosphor (P), oxygen (O) and silver (Ag) in the Ag:HAp is confirmed by energy dispersive X-ray (EDAX) and X-ray Photoelectron Spectroscopy analyses. Nanocrystalline silver doped HAp stimulated viability and potentiated the activation of murine macrophages.